G. Grant | University of Aberdeen (original) (raw)

Papers by G. Grant

Research paper thumbnail of 80 Uptake and inter-organ distribution of dietary polyamines in the rat

Biochemical Society Transactions, 1998

Research paper thumbnail of Expression of fimbrial lectins on the surface of Salmonella

Biochemical Society Transactions, 1999

Research paper thumbnail of Intestinal and pancreatic responses to dietary soyabean ( Glycine max ) proteins

Biochemical Society Transactions, 1988

Research paper thumbnail of Polyamine metabolism during pancreas enlargement induced by dietary soya-bean proteins

Biochemical Society Transactions, 1989

Research paper thumbnail of Changes in composition and polyamine content in the gastrointestinal tract due to pathogenic infection

Biochemical Society transactions, 1996

Research paper thumbnail of Uptake and bioavailability of dietary polyamines

Biochemical Society transactions, 1996

Research paper thumbnail of Survival and distribution of cell-free SEF 21 of Salmonella enterica serovar Enteritidis in the stomach and various compartments of the rat gastrointestinal tract in vivo

Journal of Medical Microbiology

Rats were dosed for 6 days with purified SEF 21 fimbriae of Salmonella enterica serovar Enteritid... more Rats were dosed for 6 days with purified SEF 21 fimbriae of Salmonella enterica serovar Enteritidis 10360. The levels of fimbriae in gut contents associated with tissues and in the faeces were quantified by direct non-competitive ELISA. SEF 21 was distributed throughout the gut. The majority was found in the large intestine where it was primarily in the luminal contents. In contrast, a high proportion of SEF 21 detected in the ileum, the main site of salmonella colonisation and invasion, was tissue-bound. Thus, purified SEF 21 survived intestinal passage and associated with the stomach and gastrointestinal tract in a pattern similar to that found with whole Salmonella cells.

Research paper thumbnail of Nutritional utilization by rats of chickpea (Cicer arietinum) meal and its isolated globulin proteins is poorer than that of defatted soybean or lactalbumin

The Journal of nutrition, 1998

The effects on performance, digestibility, N utilization and plasma amino acid concentrations of ... more The effects on performance, digestibility, N utilization and plasma amino acid concentrations of dietary chickpea (Cicer arietinum, var. Kabuli) seed meal, globulin proteins or buffer-insoluble residue [starch + non-starch polysaccharides (NSP) + lignin] were studied in growing rats. Chickpea meal, defatted soybean meal, chickpea globulins and lactalbumin were each incorporated into diets as the sole source of dietary protein (100 g/kg). In addition, chickpea insoluble residue was included in a control diet in the same proportion found in the chickpea meal. Rats were killed while under halothane anesthesia after 10 d of consuming the diets, and ileal contents were washed out and freeze-dried for digestibility measurements. Weight gains and gain:feed ratios of rats fed chickpea diets for 10 d did not differ from those of rats fed defatted soybean but were significantly lower than those of rats given the control (lactalbumin) diet. However, ileal and fecal N digestibilities and N rete...

Research paper thumbnail of Kidney bean lectin-induced Escherichia coli overgrowth in the small intestine is blocked by GNA, a mannose-specific lectin

Journal of Applied Bacteriology, 1993

Research paper thumbnail of Direct anthelmintic and immunostimulatory effects of oral dosing semi-purified phytohaemagglutinin lectin in sheep infected with Teladorsagia circumcincta and Trichostrongylus colubriformis

Veterinary Parasitology, 2012

Lectins are plant secondary compounds that can have anthelmintic properties in vitro. In particul... more Lectins are plant secondary compounds that can have anthelmintic properties in vitro. In particular, the phytohaemagglutinin lectin extracted from Phaseolus vulgaris has been shown to inhibit the feeding of Trichostrongylus colubriformis and Teladorsagia circumcincta L1 larvae. However, little is known about the potential anthelmintic properties of this lectin in vivo and its suitability to control gastrointestinal parasite infections in lambs. In a 2 × 2 study, lambs were either orally dosed, or not, with 2.3mg semi-purified PHA lectin per kg live weight (LW) per day, whilst concurrently infected, or not, with 1000 T. circumcincta and 1000 T. colubriformis L3 infective larvae per day for 42 days. There were no adverse clinical effects observed with this dose of PHA lectin. Although worm burdens were similar, animals dosed with PHA lectin had reduced concentration of nematode eggs in the faeces compared with their non-lectin dosed counterparts (P=0.026), suggesting that there may be a direct effect of PHA lectin on parasite fecundity. Irrespective of infection, PHA lectin had immune-stimulatory properties with increased eosinophillia in both abomasal and small intestine tissue sections taken at slaughter on day 42 (P<0.02 for both) and a tendency for decreased ability of Teladorsagia larvae to penetrate abomasal tissue explants (P=0.06). Compared with infection alone, concurrent PHA lectin dosing and infection further increased the number of eosinophils (P<0.01), PAS-positive (mucin-producing cells) (P=0.03) and tended to increase the number of T helper cells (P=0.06). No interactions were observed for cell populations in small intestine tissue sections. These results suggest PHA lectin could have two possible modes of action against T. circumcincta and T. colubriformis, a direct anthelmintic effect on nematode fecundity and an indirect effect through enhancing local immune responses in the host.

Research paper thumbnail of In vitro screening of plant lectins and tropical plant extracts for anthelmintic properties

Veterinary Parasitology, 2012

Lectins are plant secondary metabolites (PSM) found in many forages and which may confer anthelmi... more Lectins are plant secondary metabolites (PSM) found in many forages and which may confer anthelmintic properties to gastrointestinal parasites through disrupting the development of parasitic larvae throughout its life cycle. In experiment 1, the ability of the plant lectins jacalin (JAC), concanavalin A (Con A), phytohemagglutinin E2L2 (PHA-E2L2), phytohemagglutinin L4 (PHA-L4), phytohemagglutinin E3L (PHA-E3L), kidney bean albumin (KBA), Robinia pseudoacacia agglutinin (RPA), Maackia amurensis lectin (MAA), Maclura pomifera agglutinin (MAA), Dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA) and Galanthus nivalis agglutinin (GNA) to disrupt the feeding of the first stage larvae (L(1)) of the sheep gastro-intestinal nematodes (GIN) Teladorsagia circumcincta, Haemonchus contortus and Trichostrongylus colubriformis was investigated using a larval feeding inhibition test (LFIT). Only PHA-E3L, WGA and Con A had a potent effect on disrupting larval feeding of all of the three species of GIN investigated. The lectin concentration required to inhibit feeding in 50% of L(1) (IC50) was 7.3±1.2, 8.3±1.4 and 4.3±1.7 μg/ml for PHA-E3L; 59.1±32.4, 58.7±11.9 and 8.1±7.0 μg/ml for Con A and 78.9±11.2, 69.4±8.1 and 28.0±14.1 μg/ml for WGA for T. circumcincta, H. contortus and T. colubriformis larvae, respectively (P=0.006). The addition of the lectin inhibitors fetuin, glucose/mannose or N-acetylglucosamine for PHA-E3L, Con A and WGA, respectively, caused an increase in the proportion of larvae that had fed at all concentrations for PHA-E3L only. In experiment 2, the effect of extracts from the tropical plants Azadiractha indica, Trichanthera gigantea, Morus alba, Gliricidia sepium and Leucaena leucocephala on the feeding behaviour of H. contortus L(1,) was examined. A. indica, T. gigantea and M. alba failed to inhibit 50% of larvae from feeding at concentrations up to 10mg plant extract per ml. In contrast, both G. sepium and L. leucocephala demonstrated a dose-dependent effect on larval feeding with respective IC50 estimates (mean±s.e.) of 0.015 mg/ml ±0.001 and 3.465 mg/ml ±0.144, effects which were partly reversed by the inclusion of either the tannin inhibitor polyethylene glycol or the lectin inhibitor Fetuin. These studies demonstrate that plant lectins can have an inhibitory effect on the feeding behaviour of first stage larvae of ovine GIN in vitro. Moreover they also provide novel evidence that lectins may contribute to the anthelmintic properties of some tropical forage plant extracts, such as G. sepium and L. leucocephala.

Research paper thumbnail of A survey of the nutritional and haemagglutination properties of legume seeds generally available in the UK

British Journal of Nutrition, 1983

Eighty-five samples from fifteen different legume seed lines generally available in the UK were e... more Eighty-five samples from fifteen different legume seed lines generally available in the UK were examined by measurements of their net protein utilization by rats and by haemagglutination tests with erythrocytes from a number of different animal species. From these results the seeds were classified into four broad groups. Group a seeds from most varieties of kidney (Phaseolus vulgaris), runner (Phaseolus coccineus) and tepary (Phaseolus acutifolius) beans showed high reactivity with all cell types and were also highly toxic. Group b, which contained seeds from lima or butter beans (Phaseolus lunatus) and winged bean (Psophocarpus tetragonolobus), agglutinated only human and pronase-treated rat erythrocytes. These seeds did not support proper growth of the rats although the animals survived the 10 d experimental period. Group c consisted of seeds from lentils (Lens culinaris), peas (Pisum sativum), chick-peas (Cicer arietinum), blackeyed peas (Vigna sinensis), pigeon peas (Cajanus cajan), mung beans (Phaseolus aureus), field or broad beans (Vicia faba) and aduki beans (Phaseolus angularis). These generally had low reactivity with all cells and were non-toxic. Group d, represented by soya (Glycine max) and pinto (Phaseolus vulgaris) beans, generally had low reactivity with all cells but caused growth depression at certain dietary concentrations. This growth depression was probably mainly due to antinutritional factors other than lectins. Lectins from group a seeds showed many structural and immunological similarities. However the subunit composition of the lectin from the tepary bean samples was different from that of the other bean lectins in this or any other groups.

Research paper thumbnail of Lipid accumulation in obese Zucker rats is reduced by inclusion of raw kidney bean (Phaseolus vulgaris) in the diet

British Journal of Nutrition, 1998

The effects of inclusion of different levels of raw kidney bean (Phaseolus vulgaris) of high lect... more The effects of inclusion of different levels of raw kidney bean (Phaseolus vulgaris) of high lectin content (27 g/kg meal) in a high-quality (lactalbumin) control diet were tested in nutritional trials on the growth and metabolism of obese Zucker (fafa) rats and their lean littermates in comparison with pair-fed controls. All diets contained 100 g total protein/kg and either 50 g lipids/kg (low fat) or 150 g lipids/kg (moderate fat). The growth of both obese and lean rats on bean diets was retarded by the daily bean intake in a dose-dependent manner. However, most of this was because bean-fed rats contained less body fat than the controls after 10 d. Thus, after feeding low-fat diets containing up to 130 g kidney bean/kg (lectin intake < or = 0.2 g/kg body weight (BW) per d) in both 10 d and 70 d trials, the bodies of obese rats contained less fat but not protein than their pair-fed controls. Moreover, by increasing the lipid content of the diet to 150 g/kg, the level of bean inclusion could be increased to 280 g/kg (lectin intake > or = 0.4 g/kg BW per d) without loss of body protein and skeletal muscle. Although these rats contained more body fat than those which were fed on low-fat diets, their weight reduction could be accounted for exclusively by reduced lipid content. In contrast, significant body protein loss occurred when the same diet of high lectin content was fed to lean littermates. Plasma insulin levels were significantly depressed in the obese Zucker rats on bean diets but the pancreas was not significantly enlarged nor its insulin content changed in 10 d trials. However, significant pancreatic growth occurred on long-term (70 d) bean feeding compared with pair-fed controls. The results suggest that, in addition to animal nutrition, it may also be possible to use the bean lectin as a dietary adjunct or therapeutic agent to stimulate gut function and ameliorate obesity if a safe and effective dose-range can be established for human subjects.

Research paper thumbnail of The effect of phytohaemagglutinin at different dietary concentrations on the growth, body composition and plasma insulin of the rat

British Journal of Nutrition, 1996

Research paper thumbnail of Mineral excretion of rats fed on diets containing faba beans (Vicia faba L.) or faba bean fractions

British Journal of Nutrition, 1992

The effects on faecal mineral excretion of two commercial varieties (local cultivar and Troy cult... more The effects on faecal mineral excretion of two commercial varieties (local cultivar and Troy cultivar) of raw faba beans (Vicia faba L., minor) meal (VFM) and its fractions have been studied in growing rats. Diets contained local-VFM (dark seed coat) and Troy-VFM (light seed coat) at 474-500 g/kg diet, hull (VFH) from both varieties at 65 g/kg diet, and the insoluble cotyledon residue (VFCR) obtained from the Troy variety at 237 g/kg diet. Rats were pair-fed on diets which had been supplemented with amino acids to target requirements and contained similar amounts of zinc, manganese, iron and copper. With VFM diets the apparent absorption of Zn and Mn was significantly reduced. On the other hand, with hulls the apparent absorption of Fe was reduced while that of Cu slightly increased. As the amounts of calcium, phosphorus and magnesium in VFM and VFH diets were higher than in the controls, the increased intake resulted in a significant increase in both the apparent absorption and the faecal excretion of these minerals. The inclusion of VFCR in the diet had no significant effect on the mineral content of faeces. The relatively low concentrations of phytate in the bean seeds of 7.8 and 6.7 g/kg for the local and Troy cultivars respectively, could not adequately account for the increased mineral excretion. The results suggest that other seed constituents, possibly the soluble non-starch polysaccharides, may be involved in the elevated loss of Zn and Mn in rats fed on diets containing faba bean for extended periods, while some insoluble structural hull components may interfere with the absorption of Fe from the gut.

Research paper thumbnail of Nutritional response of growing rats to faba beans (Vicia faba L., minor) and faba bean fractions

British Journal of Nutrition, 1991

The effects of raw faba bean (Vicia faba L., minor) meal (VFM) and its fractions on the growth an... more The effects of raw faba bean (Vicia faba L., minor) meal (VFM) and its fractions on the growth and nitrogen utilization of rats have been determined in two experiments. Two commercial varieties of VFM were tested, local VFM (409-439 g/kg diet) and Troy VFM (439 g/kg diet). The bean fractions tested were V. faba lectin-depleted protein (VFDP), V. faba lectin (VFL) and V. faba cotyledon residue (VFCR). All diets were supplemented with amino acids to target requirements. Body-weight, body N and lipid contents of rats fed on VFM were reduced significantly in comparison with control rats fed on lactalbumin. This was due, in part, to the lower digestibility of the protein, lipid and dry matter (DM) of VFM diets. As a result, net protein utilization (NPU) and biological value (BV) of faba bean proteins were less than expected. Urine and urea-N outputs of the VFM-fed rats were also elevated in both experiments. Increasing the energy content of local VFM diets led to significantly higher dry body-weight, body N and lipid contents, with the result that the NPU and BV values of the protein also increased. However, the NPU values for VFM-fed rats were still significantly lower than those for the controls in both experiments. In contrast, true N, lipid and DM digestibilities in rats given local VFM were not significantly affected by the difference in the energy content of the diets. The replacement of two-thirds of the lactalbumin in the diet with VFDP (65 g/kg) reduced dry body-weight, N and lipid contents, NPU and BV compared with the control rats, even though N, lipid and DM digestibilities were not significantly different. The nutritional performance of rats fed on lactalbumin-based diets containing 7 g VFL/kg was similar to that of the controls. Similarly, the inclusion of the cotyledon residue (237 g VFCR/kg diet) had no appreciable effect on any of the variables studied. As VFL and VFCR had no antinutritional effects in these rats, it appears that the low nutritional value of VFM for rats (NPU 0.66) results not only from the low digestibility of the bean proteins, but also from disturbances in N metabolism.

Research paper thumbnail of Consumption of diets containing raw soya beans (Glycine max), kidney beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata) or lupin seeds (Lupinus angustifolius) by rats for up to 700 days: effect on body composition and organ weights

British Journal of Nutrition, 1995

Feeding trials have been done with rats to assess the effects of long-term (700 d) consumption of... more Feeding trials have been done with rats to assess the effects of long-term (700 d) consumption of diets based on raw cowpeas (Vigna unguiculata; moderate Bowman-Birk inhibitor content, low lectin content), lupin seeds (Lupinus angustifolius; low lectin and protease inhibitor content) or soya beans (Glycine max; high Kunitz inhibitor content, moderate Bowman-Birk inhibitor content, moderate lectin content) or diets containing low levels of raw kidney bean (Phaseolus vulgaris; high lectin content, low Bowman-Birk inhibitor content) on body weight and composition and organ weights. All the legume-based diets reduced feed conversion efficiency and growth rates during the initial 250 d. However, after 250 d the weight gains by rats given legume-based diets were similar to those of controls given the same daily feed intake. Long-term consumption of diets containing low levels of kidney bean significantly altered body composition of rats. The levels of lipid in the body were significantly reduced. As a result, carcasses of these rats contained a higher proportion of muscle/protein than did controls. Small-intestine relative weight was increased by short- and long-term consumption of the kidney-bean-based diet. However, the increase in relative pancreatic weight observed at 30 d did not persist long term. None of the other legume-based diets caused any significant changes in body composition. However, long-term exposure to a soya-bean- or cowpea-based diet induced an extensive increase in the relative and absolute weights of the pancreas and caused an increase in the incidence of macroscopic pancreatic nodules and possibly pancreatic neoplasia. Long-term consumption of the cowpea-, kidney-bean-, lupin-seed- or soya-bean-based diets by rats resulted in a significant increase in the relative weight of the caecum and colon.

Research paper thumbnail of The importance of dietary polyamines in cell regeneration and growth

British Journal of Nutrition, 1995

Research paper thumbnail of Antinutritive effects of wheat-germ agglutinin and other N-acetylglucosamine-specific lectins

British Journal of Nutrition, 1993

Research paper thumbnail of Dietary Soya Beans and Kidney Beans Stimulate Secretion of Cholecystokinin and Pancreatic Digestive Enzymes in 400-Day-Old Hooded-Lister Rats But Only Soya Beans Induce Growth of the Pancreas

Pancreas, 2000

The effects of age on cholecystokinin (CCK) release, pancreatic enzyme secretion, and growth of t... more The effects of age on cholecystokinin (CCK) release, pancreatic enzyme secretion, and growth of the pancreas mediated by dietary kidney beans or soya beans were evaluated in trials with 30-, 90-, 250-, and 400-day-old rats. Soya beans increased blood CCK and caused hypersecretion of digestive enzymes and rapid pancreatic growth in all rats. Kidney beans also elevated circulating CCK and stimulated enzyme secretion. However, with 90-, 250-, and 400-day-old rats, the secretory responses were attenuated. Furthermore, kidney beans did not induce pancreatic growth in 250- and 400-day-old rats.

Research paper thumbnail of 80 Uptake and inter-organ distribution of dietary polyamines in the rat

Biochemical Society Transactions, 1998

Research paper thumbnail of Expression of fimbrial lectins on the surface of Salmonella

Biochemical Society Transactions, 1999

Research paper thumbnail of Intestinal and pancreatic responses to dietary soyabean ( Glycine max ) proteins

Biochemical Society Transactions, 1988

Research paper thumbnail of Polyamine metabolism during pancreas enlargement induced by dietary soya-bean proteins

Biochemical Society Transactions, 1989

Research paper thumbnail of Changes in composition and polyamine content in the gastrointestinal tract due to pathogenic infection

Biochemical Society transactions, 1996

Research paper thumbnail of Uptake and bioavailability of dietary polyamines

Biochemical Society transactions, 1996

Research paper thumbnail of Survival and distribution of cell-free SEF 21 of Salmonella enterica serovar Enteritidis in the stomach and various compartments of the rat gastrointestinal tract in vivo

Journal of Medical Microbiology

Rats were dosed for 6 days with purified SEF 21 fimbriae of Salmonella enterica serovar Enteritid... more Rats were dosed for 6 days with purified SEF 21 fimbriae of Salmonella enterica serovar Enteritidis 10360. The levels of fimbriae in gut contents associated with tissues and in the faeces were quantified by direct non-competitive ELISA. SEF 21 was distributed throughout the gut. The majority was found in the large intestine where it was primarily in the luminal contents. In contrast, a high proportion of SEF 21 detected in the ileum, the main site of salmonella colonisation and invasion, was tissue-bound. Thus, purified SEF 21 survived intestinal passage and associated with the stomach and gastrointestinal tract in a pattern similar to that found with whole Salmonella cells.

Research paper thumbnail of Nutritional utilization by rats of chickpea (Cicer arietinum) meal and its isolated globulin proteins is poorer than that of defatted soybean or lactalbumin

The Journal of nutrition, 1998

The effects on performance, digestibility, N utilization and plasma amino acid concentrations of ... more The effects on performance, digestibility, N utilization and plasma amino acid concentrations of dietary chickpea (Cicer arietinum, var. Kabuli) seed meal, globulin proteins or buffer-insoluble residue [starch + non-starch polysaccharides (NSP) + lignin] were studied in growing rats. Chickpea meal, defatted soybean meal, chickpea globulins and lactalbumin were each incorporated into diets as the sole source of dietary protein (100 g/kg). In addition, chickpea insoluble residue was included in a control diet in the same proportion found in the chickpea meal. Rats were killed while under halothane anesthesia after 10 d of consuming the diets, and ileal contents were washed out and freeze-dried for digestibility measurements. Weight gains and gain:feed ratios of rats fed chickpea diets for 10 d did not differ from those of rats fed defatted soybean but were significantly lower than those of rats given the control (lactalbumin) diet. However, ileal and fecal N digestibilities and N rete...

Research paper thumbnail of Kidney bean lectin-induced Escherichia coli overgrowth in the small intestine is blocked by GNA, a mannose-specific lectin

Journal of Applied Bacteriology, 1993

Research paper thumbnail of Direct anthelmintic and immunostimulatory effects of oral dosing semi-purified phytohaemagglutinin lectin in sheep infected with Teladorsagia circumcincta and Trichostrongylus colubriformis

Veterinary Parasitology, 2012

Lectins are plant secondary compounds that can have anthelmintic properties in vitro. In particul... more Lectins are plant secondary compounds that can have anthelmintic properties in vitro. In particular, the phytohaemagglutinin lectin extracted from Phaseolus vulgaris has been shown to inhibit the feeding of Trichostrongylus colubriformis and Teladorsagia circumcincta L1 larvae. However, little is known about the potential anthelmintic properties of this lectin in vivo and its suitability to control gastrointestinal parasite infections in lambs. In a 2 × 2 study, lambs were either orally dosed, or not, with 2.3mg semi-purified PHA lectin per kg live weight (LW) per day, whilst concurrently infected, or not, with 1000 T. circumcincta and 1000 T. colubriformis L3 infective larvae per day for 42 days. There were no adverse clinical effects observed with this dose of PHA lectin. Although worm burdens were similar, animals dosed with PHA lectin had reduced concentration of nematode eggs in the faeces compared with their non-lectin dosed counterparts (P=0.026), suggesting that there may be a direct effect of PHA lectin on parasite fecundity. Irrespective of infection, PHA lectin had immune-stimulatory properties with increased eosinophillia in both abomasal and small intestine tissue sections taken at slaughter on day 42 (P<0.02 for both) and a tendency for decreased ability of Teladorsagia larvae to penetrate abomasal tissue explants (P=0.06). Compared with infection alone, concurrent PHA lectin dosing and infection further increased the number of eosinophils (P<0.01), PAS-positive (mucin-producing cells) (P=0.03) and tended to increase the number of T helper cells (P=0.06). No interactions were observed for cell populations in small intestine tissue sections. These results suggest PHA lectin could have two possible modes of action against T. circumcincta and T. colubriformis, a direct anthelmintic effect on nematode fecundity and an indirect effect through enhancing local immune responses in the host.

Research paper thumbnail of In vitro screening of plant lectins and tropical plant extracts for anthelmintic properties

Veterinary Parasitology, 2012

Lectins are plant secondary metabolites (PSM) found in many forages and which may confer anthelmi... more Lectins are plant secondary metabolites (PSM) found in many forages and which may confer anthelmintic properties to gastrointestinal parasites through disrupting the development of parasitic larvae throughout its life cycle. In experiment 1, the ability of the plant lectins jacalin (JAC), concanavalin A (Con A), phytohemagglutinin E2L2 (PHA-E2L2), phytohemagglutinin L4 (PHA-L4), phytohemagglutinin E3L (PHA-E3L), kidney bean albumin (KBA), Robinia pseudoacacia agglutinin (RPA), Maackia amurensis lectin (MAA), Maclura pomifera agglutinin (MAA), Dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA) and Galanthus nivalis agglutinin (GNA) to disrupt the feeding of the first stage larvae (L(1)) of the sheep gastro-intestinal nematodes (GIN) Teladorsagia circumcincta, Haemonchus contortus and Trichostrongylus colubriformis was investigated using a larval feeding inhibition test (LFIT). Only PHA-E3L, WGA and Con A had a potent effect on disrupting larval feeding of all of the three species of GIN investigated. The lectin concentration required to inhibit feeding in 50% of L(1) (IC50) was 7.3±1.2, 8.3±1.4 and 4.3±1.7 μg/ml for PHA-E3L; 59.1±32.4, 58.7±11.9 and 8.1±7.0 μg/ml for Con A and 78.9±11.2, 69.4±8.1 and 28.0±14.1 μg/ml for WGA for T. circumcincta, H. contortus and T. colubriformis larvae, respectively (P=0.006). The addition of the lectin inhibitors fetuin, glucose/mannose or N-acetylglucosamine for PHA-E3L, Con A and WGA, respectively, caused an increase in the proportion of larvae that had fed at all concentrations for PHA-E3L only. In experiment 2, the effect of extracts from the tropical plants Azadiractha indica, Trichanthera gigantea, Morus alba, Gliricidia sepium and Leucaena leucocephala on the feeding behaviour of H. contortus L(1,) was examined. A. indica, T. gigantea and M. alba failed to inhibit 50% of larvae from feeding at concentrations up to 10mg plant extract per ml. In contrast, both G. sepium and L. leucocephala demonstrated a dose-dependent effect on larval feeding with respective IC50 estimates (mean±s.e.) of 0.015 mg/ml ±0.001 and 3.465 mg/ml ±0.144, effects which were partly reversed by the inclusion of either the tannin inhibitor polyethylene glycol or the lectin inhibitor Fetuin. These studies demonstrate that plant lectins can have an inhibitory effect on the feeding behaviour of first stage larvae of ovine GIN in vitro. Moreover they also provide novel evidence that lectins may contribute to the anthelmintic properties of some tropical forage plant extracts, such as G. sepium and L. leucocephala.

Research paper thumbnail of A survey of the nutritional and haemagglutination properties of legume seeds generally available in the UK

British Journal of Nutrition, 1983

Eighty-five samples from fifteen different legume seed lines generally available in the UK were e... more Eighty-five samples from fifteen different legume seed lines generally available in the UK were examined by measurements of their net protein utilization by rats and by haemagglutination tests with erythrocytes from a number of different animal species. From these results the seeds were classified into four broad groups. Group a seeds from most varieties of kidney (Phaseolus vulgaris), runner (Phaseolus coccineus) and tepary (Phaseolus acutifolius) beans showed high reactivity with all cell types and were also highly toxic. Group b, which contained seeds from lima or butter beans (Phaseolus lunatus) and winged bean (Psophocarpus tetragonolobus), agglutinated only human and pronase-treated rat erythrocytes. These seeds did not support proper growth of the rats although the animals survived the 10 d experimental period. Group c consisted of seeds from lentils (Lens culinaris), peas (Pisum sativum), chick-peas (Cicer arietinum), blackeyed peas (Vigna sinensis), pigeon peas (Cajanus cajan), mung beans (Phaseolus aureus), field or broad beans (Vicia faba) and aduki beans (Phaseolus angularis). These generally had low reactivity with all cells and were non-toxic. Group d, represented by soya (Glycine max) and pinto (Phaseolus vulgaris) beans, generally had low reactivity with all cells but caused growth depression at certain dietary concentrations. This growth depression was probably mainly due to antinutritional factors other than lectins. Lectins from group a seeds showed many structural and immunological similarities. However the subunit composition of the lectin from the tepary bean samples was different from that of the other bean lectins in this or any other groups.

Research paper thumbnail of Lipid accumulation in obese Zucker rats is reduced by inclusion of raw kidney bean (Phaseolus vulgaris) in the diet

British Journal of Nutrition, 1998

The effects of inclusion of different levels of raw kidney bean (Phaseolus vulgaris) of high lect... more The effects of inclusion of different levels of raw kidney bean (Phaseolus vulgaris) of high lectin content (27 g/kg meal) in a high-quality (lactalbumin) control diet were tested in nutritional trials on the growth and metabolism of obese Zucker (fafa) rats and their lean littermates in comparison with pair-fed controls. All diets contained 100 g total protein/kg and either 50 g lipids/kg (low fat) or 150 g lipids/kg (moderate fat). The growth of both obese and lean rats on bean diets was retarded by the daily bean intake in a dose-dependent manner. However, most of this was because bean-fed rats contained less body fat than the controls after 10 d. Thus, after feeding low-fat diets containing up to 130 g kidney bean/kg (lectin intake < or = 0.2 g/kg body weight (BW) per d) in both 10 d and 70 d trials, the bodies of obese rats contained less fat but not protein than their pair-fed controls. Moreover, by increasing the lipid content of the diet to 150 g/kg, the level of bean inclusion could be increased to 280 g/kg (lectin intake > or = 0.4 g/kg BW per d) without loss of body protein and skeletal muscle. Although these rats contained more body fat than those which were fed on low-fat diets, their weight reduction could be accounted for exclusively by reduced lipid content. In contrast, significant body protein loss occurred when the same diet of high lectin content was fed to lean littermates. Plasma insulin levels were significantly depressed in the obese Zucker rats on bean diets but the pancreas was not significantly enlarged nor its insulin content changed in 10 d trials. However, significant pancreatic growth occurred on long-term (70 d) bean feeding compared with pair-fed controls. The results suggest that, in addition to animal nutrition, it may also be possible to use the bean lectin as a dietary adjunct or therapeutic agent to stimulate gut function and ameliorate obesity if a safe and effective dose-range can be established for human subjects.

Research paper thumbnail of The effect of phytohaemagglutinin at different dietary concentrations on the growth, body composition and plasma insulin of the rat

British Journal of Nutrition, 1996

Research paper thumbnail of Mineral excretion of rats fed on diets containing faba beans (Vicia faba L.) or faba bean fractions

British Journal of Nutrition, 1992

The effects on faecal mineral excretion of two commercial varieties (local cultivar and Troy cult... more The effects on faecal mineral excretion of two commercial varieties (local cultivar and Troy cultivar) of raw faba beans (Vicia faba L., minor) meal (VFM) and its fractions have been studied in growing rats. Diets contained local-VFM (dark seed coat) and Troy-VFM (light seed coat) at 474-500 g/kg diet, hull (VFH) from both varieties at 65 g/kg diet, and the insoluble cotyledon residue (VFCR) obtained from the Troy variety at 237 g/kg diet. Rats were pair-fed on diets which had been supplemented with amino acids to target requirements and contained similar amounts of zinc, manganese, iron and copper. With VFM diets the apparent absorption of Zn and Mn was significantly reduced. On the other hand, with hulls the apparent absorption of Fe was reduced while that of Cu slightly increased. As the amounts of calcium, phosphorus and magnesium in VFM and VFH diets were higher than in the controls, the increased intake resulted in a significant increase in both the apparent absorption and the faecal excretion of these minerals. The inclusion of VFCR in the diet had no significant effect on the mineral content of faeces. The relatively low concentrations of phytate in the bean seeds of 7.8 and 6.7 g/kg for the local and Troy cultivars respectively, could not adequately account for the increased mineral excretion. The results suggest that other seed constituents, possibly the soluble non-starch polysaccharides, may be involved in the elevated loss of Zn and Mn in rats fed on diets containing faba bean for extended periods, while some insoluble structural hull components may interfere with the absorption of Fe from the gut.

Research paper thumbnail of Nutritional response of growing rats to faba beans (Vicia faba L., minor) and faba bean fractions

British Journal of Nutrition, 1991

The effects of raw faba bean (Vicia faba L., minor) meal (VFM) and its fractions on the growth an... more The effects of raw faba bean (Vicia faba L., minor) meal (VFM) and its fractions on the growth and nitrogen utilization of rats have been determined in two experiments. Two commercial varieties of VFM were tested, local VFM (409-439 g/kg diet) and Troy VFM (439 g/kg diet). The bean fractions tested were V. faba lectin-depleted protein (VFDP), V. faba lectin (VFL) and V. faba cotyledon residue (VFCR). All diets were supplemented with amino acids to target requirements. Body-weight, body N and lipid contents of rats fed on VFM were reduced significantly in comparison with control rats fed on lactalbumin. This was due, in part, to the lower digestibility of the protein, lipid and dry matter (DM) of VFM diets. As a result, net protein utilization (NPU) and biological value (BV) of faba bean proteins were less than expected. Urine and urea-N outputs of the VFM-fed rats were also elevated in both experiments. Increasing the energy content of local VFM diets led to significantly higher dry body-weight, body N and lipid contents, with the result that the NPU and BV values of the protein also increased. However, the NPU values for VFM-fed rats were still significantly lower than those for the controls in both experiments. In contrast, true N, lipid and DM digestibilities in rats given local VFM were not significantly affected by the difference in the energy content of the diets. The replacement of two-thirds of the lactalbumin in the diet with VFDP (65 g/kg) reduced dry body-weight, N and lipid contents, NPU and BV compared with the control rats, even though N, lipid and DM digestibilities were not significantly different. The nutritional performance of rats fed on lactalbumin-based diets containing 7 g VFL/kg was similar to that of the controls. Similarly, the inclusion of the cotyledon residue (237 g VFCR/kg diet) had no appreciable effect on any of the variables studied. As VFL and VFCR had no antinutritional effects in these rats, it appears that the low nutritional value of VFM for rats (NPU 0.66) results not only from the low digestibility of the bean proteins, but also from disturbances in N metabolism.

Research paper thumbnail of Consumption of diets containing raw soya beans (Glycine max), kidney beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata) or lupin seeds (Lupinus angustifolius) by rats for up to 700 days: effect on body composition and organ weights

British Journal of Nutrition, 1995

Feeding trials have been done with rats to assess the effects of long-term (700 d) consumption of... more Feeding trials have been done with rats to assess the effects of long-term (700 d) consumption of diets based on raw cowpeas (Vigna unguiculata; moderate Bowman-Birk inhibitor content, low lectin content), lupin seeds (Lupinus angustifolius; low lectin and protease inhibitor content) or soya beans (Glycine max; high Kunitz inhibitor content, moderate Bowman-Birk inhibitor content, moderate lectin content) or diets containing low levels of raw kidney bean (Phaseolus vulgaris; high lectin content, low Bowman-Birk inhibitor content) on body weight and composition and organ weights. All the legume-based diets reduced feed conversion efficiency and growth rates during the initial 250 d. However, after 250 d the weight gains by rats given legume-based diets were similar to those of controls given the same daily feed intake. Long-term consumption of diets containing low levels of kidney bean significantly altered body composition of rats. The levels of lipid in the body were significantly reduced. As a result, carcasses of these rats contained a higher proportion of muscle/protein than did controls. Small-intestine relative weight was increased by short- and long-term consumption of the kidney-bean-based diet. However, the increase in relative pancreatic weight observed at 30 d did not persist long term. None of the other legume-based diets caused any significant changes in body composition. However, long-term exposure to a soya-bean- or cowpea-based diet induced an extensive increase in the relative and absolute weights of the pancreas and caused an increase in the incidence of macroscopic pancreatic nodules and possibly pancreatic neoplasia. Long-term consumption of the cowpea-, kidney-bean-, lupin-seed- or soya-bean-based diets by rats resulted in a significant increase in the relative weight of the caecum and colon.

Research paper thumbnail of The importance of dietary polyamines in cell regeneration and growth

British Journal of Nutrition, 1995

Research paper thumbnail of Antinutritive effects of wheat-germ agglutinin and other N-acetylglucosamine-specific lectins

British Journal of Nutrition, 1993

Research paper thumbnail of Dietary Soya Beans and Kidney Beans Stimulate Secretion of Cholecystokinin and Pancreatic Digestive Enzymes in 400-Day-Old Hooded-Lister Rats But Only Soya Beans Induce Growth of the Pancreas

Pancreas, 2000

The effects of age on cholecystokinin (CCK) release, pancreatic enzyme secretion, and growth of t... more The effects of age on cholecystokinin (CCK) release, pancreatic enzyme secretion, and growth of the pancreas mediated by dietary kidney beans or soya beans were evaluated in trials with 30-, 90-, 250-, and 400-day-old rats. Soya beans increased blood CCK and caused hypersecretion of digestive enzymes and rapid pancreatic growth in all rats. Kidney beans also elevated circulating CCK and stimulated enzyme secretion. However, with 90-, 250-, and 400-day-old rats, the secretory responses were attenuated. Furthermore, kidney beans did not induce pancreatic growth in 250- and 400-day-old rats.