Stephen Gbedema - Academia.edu (original) (raw)

Papers by Stephen Gbedema

Recent studies have provided relevant scientific support for the use of C. membranaceus root in t... more Recent studies have provided relevant scientific support for the use of C. membranaceus root in the treatment of prostate cancers. In the current study, we formulated both liquid and solid oral dosage forms from the ethanol extract of C. membranaceus root and investigated their physicochemical properties, release effects and suitability in comparison with the currently used aqueous decoctions and directly powdered plant material, in order to determine the most appropriate and suitable dosage form that will maximize the benefits of therapy with this species. The prepared solution from the ethanol extract had characteristics similar to the aqueous decoction, but unlike the later, it maintained its specifications and stability throughout the period of study. However, the use of large volumes, convenience and suitability for long term use, will limit their application. The assessed properties of the prepared tablets and capsules met all the specifications required for good quality and they can be used in simple and convenient doses of one tablet or capsule, three times a day, in place of unstable decoctions and large volume solutions. The in vitro release profile of the capsules was however, better (98.8±1.3 % after 45 minutes) and significantly higher (P<0.01) than that of the tablets (85.2±1.6 %), and with the protection of the extract from light and masking of unwanted color and taste as added advantages, the oral capsules should be the preferred choice of solid dosage form for C. membranaceus. The capsules of the direct plant material had active content (2.8±1.4 mg) and in vitro cumulative release after 45 minutes (42.0±2.6 %) lower and significantly different (P<0.01) from those of the tablets and capsules prepared with the extract. The results strongly support the assertions that the formulation of suitable and appropriate herbal remedies from plant extracts may be more desirable, advantageous and therapeutically more beneficial than incorporating the direct plant materials, and that the oral capsule of C. membranaceus root extract will ensure compliance and maximize therapeutic outcomes.

Background and purpose: Different Proteus species may vary with the type of infections they cause... more Background and purpose: Different Proteus species may vary with the type of infections they cause in both the community and hospital environments. However, in many laboratories in developing countries, differentiation of the genus Proteus into species is not generally done during bacteriological diagnosis due to high cost and special skills involved. This study aimed at determining the prevalence of different Proteus species in KATH, their antibiotic resistance pattern and how they relate to patients' demographic data. Method: This is a prospective study involving the analyses of clinical samples for Proteus species and determining their antimicrobial susceptibility pattern. Results: Two hundred Proteus species were isolated from 2361 clinical specimens obtained from patients suspected of bacterial infection, giving 8.4 % prevalence of Proteus infections. Wound isolates were the highest (64.5 %) followed by ear swab. Three Proteus species; P. mirabilis, P. vulgaris and P. penneri were recovered from the samples. P. mirabilis was the commonest species (61.5 %), and hence the causative species of a majority of Proteus infections followed by P. vulgaris (30.5 %), and P. penneri (8 %). There was no significant difference between the out-patient and in-patient cases, just as there were no preferences for gender or age of the patients. All the species were resistant to chloramphenicol, ampicillin and co-trimoxazole. About 72.9 % of the isolates produced βlactamase and 88.5 % were resistant to more than 2 antibiotics. P. penneri was the most resistant among the recovered species. Conclusion: The three Proteus species recovered in KATH were all resistant to ampicillin, tetracycline, chloramphenicol and co-trimoxazole. These drugs are no longer useful in empirical treatment of Proteus infections at KATH. This study has also provided information for use in generating national data on the prevalence of antimicrobial resistant pathogens in Ghana. enterobacteriaceae and perhaps salmonellae since indiscriminate ingestion of antibiotics provides selective pressure, leading to a higher prevalence of resistant bacteria which is very common in developing countries like Ghana. Not only are these species potential causes of infections but also potential reservoirs of resistance genes that could be transferred to other bacterial pathogens. The high levels of β-lactamase production and multi-drug resistance of the isolates are indications of an increase in the resistance menace reported by earlier studies in Ghana.

Journal of Pharmacognosy and Phytotherapy

The antimicrobial activity of the methanolic root extract and compounds isolated from Croton memb... more The antimicrobial activity of the methanolic root extract and compounds isolated from Croton membranaceus against the bacteria; Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and fungi; Aspergillus niger and Candida albicans, using the agar diffusion and broth dilution techniques was studied in order to establish its possible usefulness in the treatment of measles. The methanolic extract showed a significant (p < 0.01) antibacterial and antifungal activity against the test organisms used with minimum inhibitory concentrations (MICs) ranging from 0.53 -1.43 mg/ml. Out of the six compounds tested (crotomembranafuran, gomojoside H, julocrotine, -sitosterol, -sitosterol-3-D-glucoside, and DL-threitol), gomojoside H, showed significant antibacterial activity against; S. aureus, B. subtilis and P. aeruginosa (MICs < 10 g/ml). The other compounds exhibited no significant antimicrobial activity (MICs > 200 g/ml). The activities of gomojoside H we...

As part of our ongoing study to screen local herbs for their possible usefulness in chemotherapy ... more As part of our ongoing study to screen local herbs for their possible usefulness in chemotherapy of infectious diseases, we assessed extracts from sixteen herbs for their antimicrobial properties and their influence on the activity of tetracycline. The minimum inhibito-ry concentrations (MIC) of tetracycline against Staph. aureus, B. subtilis, P. aeruginosa, E. coli and S. typhi were determined alone and in the presence of sub-inhibitory concentrations of the extracts by the Kirby–Bauer agar diffusion method of antibacterial assay. Twelve of the extracts potentiated the antibacterial activity of tetracycline against at least one of the test bacteria. Extracts of B. arun-dinacea, B. pilosa, C. membranaceus, E. guineensis, H. sabdariffa, J. curcas root, M. oppositifolius, M. lucida and S. campanulata significantly (p<0.05) reduced the MIC of tetracycline against Staph aureus. J. curcas root extract did not exhibit any antimicrobial activity against Staph. ureus, B. subtilis and P. ...

Journal of ethnopharmacology, 2015

Plasmodium falciparum drug resistance is a major public health challenge in sub-Sahara Africa. Ma... more Plasmodium falciparum drug resistance is a major public health challenge in sub-Sahara Africa. Many people are now resorting to the use of herbs in managing malaria due to the increasing treatment failures with the conventional drugs. In this study the ethanolic extract of Polyalthia longifolia (Sonn) Thw. var. pendula, a variety fondly used in folklore medicine in Ghana was investigated for potential antimalarial drug development. The ethanolic extract of P. longifolia (Sonn) Thw. var. pendula stem bark was screened against the multidrug resistant, K1 strain of P. falciparum by the parasite lactate dehydrogenase (pLDH) assay and a good antiplasmodial activity (IC50 22.04± 4.23µg/ml) was observed which led to further chromatographic analysis in search for actives. Bioassay guided fractionation of the extract yielded; three clerodane diterpenes [16-hydroxycleroda-3,13-dien-16,15-olide (1), 16-oxocleroda-3,13E-dien-15-oic acid (2) and 3,16-dihydroxycleroda-4(18),13(14)Z-dien-15,16-oli...

As part of our ongoing study to screen local herbs for their possible usefulness as anti-infectiv... more As part of our ongoing study to screen local herbs for their possible usefulness as anti-infectives, we assessed extracts from 16 medicinal plants for their antibacterial properties and their influence on the activity of amoxicillin. The minimum inhibitory concentrations (MIC) of amoxicillin against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi were determined alone and in the presence of sub-inhibitory concentrations of the extracts by the Kirby-Bauer agar diffusion method of antibacterial assay. Eleven out of 18 extracts exhibited antibacterial activity with MIC values below 20 mg/ml against at least one of the test bacteria employed. Amoxicillin activity against Staph. aureus was significantly (p<0.05) enhanced by the presence of subinhibitory concentrations of 5 extracts (Mallotus oppositifolius, Bidens pilosa, Morinda lucida, Croton membranaceus and Jatropha curcas). B. subtilis also became significantly susceptible to amoxicillin in the presence of 10 μg/ml extracts of B. pilosa, Hibiscus sabdariffa, M. oppositifolius, Momordica charantia, Anoclesta nobilis, Cryptolepis sanguinolenta and Moringa oleifera. Spathodia campanulata, M. lucida, M. oleifera and J. curcas leaf extracts also significantly reduced the MIC of amoxicillin against E. coli while S. typhi susceptibility was enhanced by the presence of A. nobilis, M. charantia and J. curcas extracts. We hereby report that sub-inhibitory concentrations of some plant extracts can enhance amoxicillin activity and these plants may provide lead compounds that may serve as cheap alternative adjuvants to clavulanic acid in amoxicillin formulations for the treatment of resistant opportunistic bacterial infections usually encountered among HIV/AIDS patients.

African Journal of Traditional Complementary and Alternative Medicines, Mar 5, 2014

Background: Clausena anisata belongs to the family Rutaceae, a shrub widely used in West Africa f... more Background: Clausena anisata belongs to the family Rutaceae, a shrub widely used in West Africa for the treatment of bacterial and fungal infections of the skin including boils, ringworm and eczema. The study was designed to evaluate the antimicrobial activity and phytochemical screening of ethanol leaf extract of C. anisata (CLE). Method: Antimicrobial activity of CLE was investigated using agar well diffusion and micro-dilution methods against four Gram-positive bacteria (Bacillus substilis NCTC 10073, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Bacillus thuringiensis ATCC 13838) and two Gram-negative bacteria (Pseudomonas aeruginosa ATCC 4853, Proteus vulgaris ATCC 4175) and a clinical isolate of Candida albicans. Results: CLE was active against all test organisms with minimum inhibitory concentration (MIC), range of 0.5 to 7.0 mg/mL against Gram-positive bacteria, 2.5 to 1.0 mg/mL against Gram-negative bacteria and 5.5mg/mL against C. albicans. The MICs of the methanol fraction of CLE were 0.6 mg to 5.0/mL and 1.0 to 3.0 mg/mL for Gram-positive and Gram-negative bacteria respectively. Chloroform fraction had MIC of 3.0 to 7.5 mg/mL and 2.0 to 6.5 mg/mL for Gram-positive and Gram-negative bacteria, respectively and petroleum ether fraction had 4.5 to 8.0 mg/mL for Gram-positive and Gram-negative bacteria. The CLE exhibited static action against all test organisms within a range of 0.5 to 22.0 mg/mL. Phytochemical screening of C. anisata revealed the presence of tannins, flavonoids, steroids, saponins, glycosides and alkaloids. HPLC finger-printing of the CLE and its fractions were determined. Conclusion: These results may justify the medicinal uses of C. anisata for the treatment of microbial infections.

Background: Parasitic helminth infection is one of the major risk factors underlying the high rat... more Background: Parasitic helminth infection is one of the major risk factors underlying the high rates of anaemia and malnutrition in many third world countries due to the poor socio-economic and environmental conditions of the people and these play a very significant role in their transmission. Method: 2000 stool specimens collected between May and October 2008 at the Komfo Anokye Teaching Hospital in Ghana were screened using the Kato-Katz and formol-ether concentration methods for the presence of intestinal helminthes. Prior to sample collection, histories of any antihelmentic drug usage in the last three months preceding this study were collected. Hookworm positive stool specimens were further cultured by the modified Harada-Mori test-tube technique for the identification of the hookworm filariform larvae. Results: Hookworm (Necator americanus) was the most prevalent helminth parasite (2.9%) found in the study. Other parasitic helminthes detected were Dicrocoelium dendriticum (2.1%...

International Journal of Pharmacy and Pharmaceutical Sciences

The stem wood and twigs of Garcinia kola are extensively used in Ghana and other West African cou... more The stem wood and twigs of Garcinia kola are extensively used in Ghana and other West African countries as “chew‐sticks” for personal oral hygiene and the decoction of various parts is used to treat infections and other diseases. In this study we investigated the in vitro antimicrobial properties of a methanolic extract of G. kola stem wood and its toothpaste formulation against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Bacillus subtilis, Staphylococcus aureus, α‐haemolytic Streptococcus pneumoniae, Streptococcus pyogenes and Candida albicans by the standard agar diffusion and broth dilution methods. The cytotoxic activity of the extract against a normal human cell lines (SVK‐14) and three human cancer cell lines (DLD‐1, MCF‐7 and M14) was also assessed by the standard MTT Colorimetric method. All the micro‐organisms were significantly susceptible (p<0.01) to the extract (MIC range 0.25 ‐ 2.0 mg/ml) and the toothpaste (zones of growth‐inh...

Staphylococcus aureus continues to offer challenges to medical science in the area of resistance ... more Staphylococcus aureus continues to offer challenges to medical science in the area of resistance to chemotherapeutic agents leading to treatment failures using common antibiotics. In this study, S. aureus isolated from patients from three hospitals in Kumasi, Ghana were tested for their sensitivity to some reference antibiotics using the Kirby-Bauer agar disc diffusion method. A total of 109 S. aureus isolates were obtained from wound and nose swabs of 300 patients. S. aureus was isolated from 44% female and 56.0% male patients. Majority of the S. aureus isolates were identified in patients aged between 20 and 29 years, while those within the age group of 60 to 69 years recorded the least number of S. aureus isolates. Vancomycin had the highest susceptibility of 74.1% followed by ceftriaxone with 67.6%, erythromycin with 49.0%, ampicillin with 47.0% and gentamicin with 44.4%. Out of the 109 S. aureus isolated from the three hospitals, 32.1% exhibited multiple drug resistance.

African journal of traditional, complementary, and alternative medicines : AJTCAM / African Networks on Ethnomedicines, 2008

Xylopia aethiopica is a medicinal plant of great repute in West Africa which produces a variety o... more Xylopia aethiopica is a medicinal plant of great repute in West Africa which produces a variety of complex chemical compounds. The fresh and dried fruits, leaf, stem bark and root bark essential oils showed various degrees of activity against the gram positive bacteria, Bacillus subtilis and Staphylococcus aureus, the gram negative bacteria Pseudomonas aeruginosa and the yeast-like fungus Candida albicans, using the cup plate method. However, none of the oils showed activity against Escherichia coli.

African journal of traditional, complementary, and alternative medicines : AJTCAM / African Networks on Ethnomedicines, 2014

HIV/AIDS is a pandemic retarding economic growth and destroying human capital globally. This stud... more HIV/AIDS is a pandemic retarding economic growth and destroying human capital globally. This study therefore investigated the perceived efficacy of Betula alba (BA) and Sutherlandia frutescens (SF) decoctions used in the management of HIV/AIDS in Ghana. A study on the records of HIV/AIDS patients attending Habibi Herbal Clinic, Kumasi, Ghana, was conducted to obtain information on the initial viral load presented during their maiden visit and results after treatment with the herbal decoctions. The decoctions were assessed for immunostimulatory property in cyclophosphamide-induced immunosuppressed ICR mice. Total white blood cell count, as well as lymphocyte and neutrophil counts were determined and their effects compared with Levamisole. The decoctions were also screened for antimicrobial activity by the micro dilution method. The two herbal decoctions used significantly reduced (P ≤ 0.001) the patients' viral loads (47.42 ± 17.28 % to 13.69 ± 12.42 %; n=16). BA (1, 2, and 4 mg/...

ISRN Microbiology, 2012

Nosocomial infections are infections acquired by a patient as a result of treatment in a hospital... more Nosocomial infections are infections acquired by a patient as a result of treatment in a hospital or healthcare service providing center and symptoms occurs within a short period of hospitalization. The study was to determine the antibiotic resistance patterns of Escherichia coli isolated from Kumasi-South, Tafo and Suntreso Hospitals, Kumasi, Ghana. Total of 600 swabs samples from the hospitals were collected between January and June, 2010. The isolates were identified using morphological and biochemical means. A total of 97 E. coli isolates were obtained from the hospitals. Beds in hospital wards had the highest number of E. coli strains (53.6%), followed by floors (20.6%) while drainages had the least isolates (3.1%). Majority of the E. coli isolates (90.7%) exhibited resistance to ampicillin while 6.2 and 3.1% showed intermediate and sensitive respectively. Co-trimoxazole, 78.4% of the isolates were resistant while 9.3 and 12.4% exhibited intermediate and sensitive responses respectively. E. coli isolates (28.6 to 46.4%) were resistant to gentamicin, ciprofloxacin and ceftriaxone while 14.4 to 47.4% gave intermediate responses. Most isolates (80.4%) exhibited multi-drug resistance. There is a need to observe proper personal hygiene, use of effective disinfectants and proper disposal of contaminated/pathogenic materials in these hospitals to control nosocomial infections.

International Journal of Health Research, 2010

We carried out a parasitological survey of Schistosoma haematobium infection among the residents ... more We carried out a parasitological survey of Schistosoma haematobium infection among the residents of Lowveld Siphofaneni, Swaziland, an area which is devoid of sanitation. Subjects with positive infection were confirmed by the detection of S. haematobium ova in their urine. The intensity of the infection was estimated by calculating the total number of S. haematobium ova present in 10 ml urine specimen (geometric mean intensity; GMI). Overall, the prevalence of S. haematobium infection was 6.1% (18/295) with a GMI of 20.7 (95% CI = 9.1~32.2). Female (10.5%, 16/153) had significantly higher prevalence than that in male (1.4%, 2/142) (ORs = 8.2, 95% CI = 1.8-36.2, P < 0.01); conversely, male had higher GMI (60.0) than that (17.3) in female. The age group of <5 yrs (15.3%, 9/59) had significantly higher prevalence than that in age group of >19 yrs (2.6%, 3/115) (ORs = 0.2, 95% CI =0.04-0.57, P < 0.01). The highest GMI of 27.9 (95% CI = 7.6~48.2) was also seen in age group of <5 yrs.