Atul Upadhyay - Academia.edu (original) (raw)

Papers by Atul Upadhyay

European Journal of Medicinal Plants, 2013

To determine the antioxidant, antiglycation and antibacterial activity of two selected plants fou... more To determine the antioxidant, antiglycation and antibacterial activity of two selected plants found wild in Pakistan (Ziziphus oxyphylla and Cedrela serrata). Study Design: In vitro assessment of antioxidant assays, phenolic and flavonoid content, protein-glycation inhibition and antibacterial study. Place and Duration of Study: ; antibacterial). Methodology: In vitro laboratory experimental tests; preparation of plant extracts, antioxidant assays (ABTS .+ , PMS-NADH radicals), total phenol, total flavonoid; protein glycation (fluorescence); susceptibility tests (zones of inhibition). Results: The bark of C. serrata contained the highest amount of total phenol (0.35 ± 0.04 mg GAE/g extract) and exhibited significantly superior ABTS .+ and PMS superoxide radical scavenging activity with IC 50 values of 0.043 ± 0.001 mg/ml and 0.18 ± 0.01 mg/ml, respectively (P=0.05). Similarly, the protein-glycation assay revealed that the bark of C. serrata had the best inhibitory property with a low IC 50 value of 0.61 ± 0.02 mg/ml

Phytotherapy research : PTR, Jan 10, 2016

Nymphoides indica (L.) Kuntze (Menyanthaceae) is traditionally used in the Indian subcontinent. H... more Nymphoides indica (L.) Kuntze (Menyanthaceae) is traditionally used in the Indian subcontinent. However, scientific data reporting its constituents are poor. This study aimed at evaluating its phytochemical constituents and various biological activities. Phytochemical investigations of the extracts and fractions resulted in the isolation of 5 lipophilic compounds, i.e. azelaic (nonanedioic) acid (1) and 4-methyl-heptanedioic acid (3), hexadecanoic (2) and stearic acid (5) and the fatty alcohol hexadecanol (4); 3 seco-iridoids, i.e. 7-epiexaltoside (6), 6″,7″-dihydro-7-epiexaltoside (7) and menthiafolin (8); 3 flavonoids, i.e. 3,7-di-O-methylquercetin-4'-O-β-glucoside (9), 3-O-methylquercetin-7-O-β-glucoside (10) and 3,7-di-O-methylquercetin (11); scopoletin (12) and ferulic acid (13); and the monoterpenoids foliamenthoic acid (14) and 6,7-dihydrofoliamenthoic acid methyl ester (15). Compounds 1-5 showed moderate antimicrobial activities, whereas compound 9 presented mild antipro...

Antioxidants, 2016

Ziziphus oxyphylla and Cedrela Serrata plants have a folkloric use in Pakistan for treatments of ... more Ziziphus oxyphylla and Cedrela Serrata plants have a folkloric use in Pakistan for treatments of different ailments, i.e., Jaundice, Hepatitis, Diabetes, and antimicrobial. Until now, none of the research studies have reported any phytochemical work on leaves of these two plants. This study aimed to isolate and perform phytochemical analysis in order to search for the constituent having the active role in treatment of the aforementioned ailments. A bioassay-guided fractionation and isolation procedure was used to isolate the concerned phytochemicals present in leaf extracts of Z. oxyphylla and C. serrata. The process involved the hyphenated techniques, i.e., Flash Chromatography, Semi-Preparative HPLC/DAD, UPLC/MS, and NMR in order to isolate and elucidate the structure of the phytochemicals. Seven compounds (1-7) were isolated and identified as flavonoids, more in particular glycosides of quercetin and kaempferol. They showed DPPH scavenging activity, compound 3 (isoquercitrin) being the most active one with an IC50 of 10.8 µg/mL (positive control quercetin; IC50 3.6 µg/mL). The superoxide-radical scavenging and total antioxidant (ABTS) assays indicated IC50 values ranging from 200 to 910 µg/mL and 170 to 320 µg/mL, respectively (positive control quercetin: 374 and 180 µg/mL, respectively). Furthermore, these compounds had low IC50 values for inhibition of protein glycation (AGEs inhibition), ranging from 530 to 818 µg/mL, comparable to aminoguanidine (510 µg/mL) used as a positive control. This study resulted in the identification of seven flavonoid glycosides for the first time from the leaves of Z. oxyphylla and C. serrata with antioxidative and antiglycating activities.

Journal of Functional Foods

ABSTRACT

Alpinia (Alpinia zerumbet), leucaena (Leucaena leucocephala) and pineapple (Ananus comosus) are p... more Alpinia (Alpinia zerumbet), leucaena (Leucaena leucocephala) and pineapple (Ananus comosus) are popular plants found in Okinawa. Alpinia has been traditionally important and economic in Okinawa since various secondary metabolites of this plant are used in many industries. The plant contains a pyrone derivative, 5,6-dehydrokawain (DK), which has antioxidant and antibacterial properties. DK is structurally similar to a fungal metabolite, hispidin, and considerably of pathological importance. The compound was metabolized in the microsomes of rabbit liver containing CYP2C9 to produce hispidin. Leucaena with high annual yield oand rich palatable protein in foliage could be used as source of animal feed. The plant contains a toxic metabolite, mimosine, which is a non-protein amino acid. The ingestion of leucaena results in alopecia, growth retardation, cataracts and infertility in animals. However, mimosine is converted to 3-hydroxy-4(1H)-pyridone (DHP) by HCl in stomach. In addition, mim...

Planta Medica

The end-products of a complex series of non-enzymatic reactions involving glycation of proteins a... more The end-products of a complex series of non-enzymatic reactions involving glycation of proteins are the AGEs. Elevated levels of AGEs are associated with diabetic complications (nephropathy, retinopathy, cataract), atherosclerosis, neurological disorders and the normal ageing process. In this study DL-kawain (1), methysticin (2) and dihydromethysticin (3), all belonging to the group of kavalactones, were identified as AGEs inhibitors. With IC50 values of 0.87 ± 0.02 mM and 0.90 ± 0.03 mM for 1 and 2, respectively, the compounds inhibited the in vitro protein glycation significantly better than aminoguanidine (IC50= 4.62 ± 0.23 mM; p= 0.01). Compound 3 showed lower inhibitory activities (IC50= 11.28 ± 0.87 mM). Furthermore, compounds 1 and 2 inhibited the formation of fructosamine, which is an intermediate in the process of AGEs formation. Moreover, 1 and aminoguanidine prevented AGEs formation by chelating Cu2+ and Fe3+. However, these compounds showed less entrapment of the reactiv...

Planta Medica, 2014

ABSTRACT Nymphoides indica (L.) Kuntze (Menyanthaceae) is traditionally used in many ethnomedicin... more ABSTRACT Nymphoides indica (L.) Kuntze (Menyanthaceae) is traditionally used in many ethnomedicinal formulations in Asia [1]; however, scientific data reporting its constituents are poor. N. indica leaves were macerated with methanol 90% and subsequently extracted using various solvents. After successful extraction, each fraction was evaluated for various claimed bioactivities such as antibacterial, antifungal, cytotoxic, antioxidant and antiglycation activity. The microorganism used included S. aureus, E. coli, C. albicans, M. canis and MRC-5 cells. The methanol 90% fraction showed notable cytotoxic properties (IC50 38.9 µg/mL). Antifungal and antibacterial activities were observed for the methanol 90% (IC50 32 µg/mL) and n-hexane (IC50 19.15 µg/mL) fractions respectively. The ethyl acetate fraction was found to present the highest antioxidant activity (IC50 147 µg/mL) followed by methanol 90% (IC50 211 µg/mL) and chloroform (IC50 380 µg/mL) fractions. The n-butanol fraction had the highest (IC50 32 µg/mL) anti-glycation (Advanced Glycation Endproducts, AGEs) activity, followed by the chloroform (IC50 64 µg/mL), ethyl acetate (IC50 69 µg/mL) and methanol 90% (IC50 86 µg/mL) fractions. All extracts were further fractionated using repeated flash chromatography and analysed using TLC and HPLC-DAD. For the isolation of major compounds, a semi preparative HPLC(RP)-DAD-MS system was used. Subsequently NMR and mass spectra were recorded to elucidate the structure of the isolated compounds. Isolated compounds included flavonoids (1 – 4), seco-cyclopentane glucosides (5 – 7), caumerine (8), phenolic acids (9) and monoterpenes (10 – 11).

Planta Medica, 2013

ABSTRACT The end-products of a complex series of non-enzymatic reactions involving glycation of p... more ABSTRACT The end-products of a complex series of non-enzymatic reactions involving glycation of proteins are the AGEs. Elevated levels of AGEs are associated with diabetic complications (nephropathy, retinopathy, cataract), atherosclerosis, neurological disorders and the normal ageing process. In this study DL-kawain (1), methysticin (2) and dihydromethysticin (3), all belonging to the group of kavalactones, were identified as AGEs inhibitors. With IC50 values of 0.87 ± 0.02 mM and 0.90 ± 0.03 mM for 1 and 2, respectively, the compounds inhibited the in vitro protein glycation significantly better than aminoguanidine (IC50= 4.62 ± 0.23 mM; p= 0.01). Compound 3 showed lower inhibitory activities (IC50= 11.28 ± 0.87 mM). Furthermore, compounds 1 and 2 inhibited the formation of fructosamine, which is an intermediate in the process of AGEs formation. Moreover, 1 and aminoguanidine prevented AGEs formation by chelating Cu2+ and Fe3+. However, these compounds showed less entrapment of the reactive carbonyl species (RCS), glyoxal and methylglyoxal, compared to aminoguanidine. These data indicate that kavalactones prevent early and advanced glycation, partly through metal chelation, and partly through the entrapment of RCS.

Both advanced glycation endproducts (AGEs) and advanced lipoxidation endproducts (ALEs) are impli... more Both advanced glycation endproducts (AGEs) and advanced lipoxidation endproducts (ALEs) are implicated in many age-related chronic diseases and in protein ageing. In this study kawain, methysticin and dihydromethysticin, all belonging to the group of kavalactones, were identified as AGEs inhibitors. With IC50 values of 43.5 ± 1.2 M and 45.0 ± 1.3 M for kawain and methysticin, respectively, the compounds inhibited the in vitro protein glycation significantly better than aminoguanidine (IC50 = 231.0 ± 11.5 M; p = 0.01), an established reference compound. Kawain and methysticin also inhibited the formation of dicarbonyl compounds, which are intermediates in the process of AGEs formation. Similarly, kawain and aminoguanidine prevented the formation of thiobarbituric reactive substances (TBARs) in both low density lipoprotein (LDL) and linoleic acid oxidation. Moreover, kawain and aminoguanidine prevented AGEs formation by chelating Fe3+ and Cu2+ two-three times better than aminoguanidine. Furthermore, kawain increased the mean life span of Caenorhabditis elegans exposed to high glucose. With glycation inhibiting, lipid peroxidation inhibiting, metal chelating properties, and lifespan extending ability, kavalactones show a high potential as AGEs and ALEs inhibitors.

Advanced glycation end products (AGEs) have been implicated in many age-related chronic diseases ... more Advanced glycation end products (AGEs) have been implicated in many age-related chronic diseases and the search for AGEs has intensified. In the present study, eight Okinawan edible or medicinal plants were screened for the antiglycation activity. A polymethoxylated flavonoid, 5-O-demethyl nobiletin (DN), was isolated from the chloroform fraction of Citrus depressa Hayata (Rutaceae) and was identified for the first time as an AGEs inhibitor. DN prevented protein glycation significantly better than aminoguanidine (AG) with the respective IC50 values of 64.2 and 484.3 M (p = 0.01). Further studies revealed that DN prevented AGEs formation predominantly by inhibiting fructosamine adduct formation while only partly by preventing dicarbonyl generation. Together, these results suggest that further exploration on the identification of AGEs inhibitors from Okinawan plants and in-depth investigations on the AGEs inhibitions by polymethoxylated flavonoids are required.

The present study describes the chemical composition and neuraminidase (NA) enzyme inhibition and... more The present study describes the chemical composition and neuraminidase (NA) enzyme inhibition and anti-atherogenic properties of the essential oils (EO) of two varieties of Alpinia zerumbet (alpinia) leaves. A total of forty eight compounds were identi• ed using GC-MS studies, which showed that tairin variety contained more compounds than shima variety. The EO inhibited NA in a dosedependent manner with IC 50 values of 41.5 ± 2.7 and 62.3 ± 3.1 •g/ml for tairin and shima varieties, respectively. Furthermore, the kinetic studies of NA inhibitions revealed that tairin EO exhibited slow, time-dependent and mixed type of inhibitions. It seems that the minor components of tairin EO have better inhibitory properties. In order to assess the anti-atherogenic activities of EO, and low density lipoprotein (LDL) oxidation were investigated. The results also showed that tairin EO had better activities against and 133 ± 3 •g/ml), than shima EO (IC 50 = 465 ± 12, and 195 ± 5 •g/ml). Finally, the acute toxicity analysis using Caenorhabditis elegans showed that LC 50 values were more than 2500 •g/ml. These • ndings suggest that tairin EO could be a possible candidate for further investigations in search for bioactive compounds against neuraminidase.

Waste utilization in fruits and vegetable processing industries is one of the important and chall... more Waste utilization in fruits and vegetable processing industries is one of the important and challengeable jobs around the world. It is anticipated that the discarded fruits as well as its waste materials could be utilized for further industrial purposes viz. fermentation, extraction of bioactive components, extraction of functional ingredients etc. Researchers have focused on the utilization of pineapple waste primarily for extraction of bromelain enzyme and secondarily as low-cost raw material for the production of ethanol, phenolic anti-oxidants, organic acids, biogas and fiber production. Pertinent scientific and technological implications would produce better and more profitable markets for pineapple wastes. This review is the collection of previous reports along with our ongoing work on utilization of pineapple wastes.

The beneficial effects of the phytochemical compounds in fruits and vegetables have been extrapol... more The beneficial effects of the phytochemical compounds in fruits and vegetables have been extrapolated mainly from in vitro studies or short-term dietary supplementation studies. Recent approaches using animal models of Caenorhabditis elegans are becoming quite popular, and in this regard the effects of Alpinia zerumbet leaf extract (ALP) on C. elegans lifespan were investigated under both normal and stress conditions. ALP significantly increased, mean lifespan by 22.6%, better than the positive control, resveratrol. Furthermore, both under thermal and oxidative stressed conditions, ALP increased the survival rate significantly better than quercetin. Further studies indicated that the significant longevity-extending effects of ALP on C. elegans can be attributed to its in vitro free-radical scavenging effects and its upregulation of stress-resistance proteins, including superoxide dismutase 3 (SOD-3) and heat-shock protein (HSP-16.2). These results suggest that phytochemical compounds in A. zerumbet have beneficial effects on the lifespan of C. elegans, and that they can be used as a source of dietary supplements for aging and age-related diseases.

Oxidation of low-density lipoprotein (LDL) is the principal risk factor for the development of at... more Oxidation of low-density lipoprotein (LDL) is the principal risk factor for the development of atherosclerosis. In this study, we used several methods to investigate the ability of the acetone extract from rhizomes, stems, leaves, flowers, pericarps and seeds of Alpinia zerumbet to inhibit atherosclerosis in vitro. The seed extract had the strongest activity against tyrosinase, pancreatic lipase (PL), 15-lipoxygenase (15-LO) and LDL oxidation activities (IC 50 = 2.30 ± 0.02, 5.00 ± 0.07, 1.29 ± 0.07 and 15.40 ± 0.86 g/mL, respectively), amongst all different parts. It also had similar effects to the positive controls. Most of the extracts showed partial agonistic properties towards estrogenic activity. Cholest-4-ene-3,6-dione, a steroid present only in the seed extract seems to be the compound responsible for these activities. The results showed that cholest-4-ene-3,6-dione had similar ability to curcumin and quercetin against PL and LDL oxidation (IC 50 = 19.50 ± 1.17 and 16.12 ± 1.43 g/mL, respectively). Furthermore, cholest-4-ene-3,6-dione (IC 50 = 34.21 ± 1.31 g/mL) had higher inhibition against 15-LO than quercetin (IC 50 = 54.79 ± 1.12 g/mL).

Methanol extract and sub-fractions of Smilax sebeana rhizomes and roots were analyzed to evaluate... more Methanol extract and sub-fractions of Smilax sebeana rhizomes and roots were analyzed to evaluate the compounds involved in antioxidant activity. In all separated fractions of the different polarity solvents, ethyl acetate fraction showed the highest antioxidant activity and total phenolic content. This fraction was subjected to the sephadex LH-20 column and preparative HPLC for purification. Six phenolic compounds, chlorogenic acid (1), 4-formylphenol (2), epicatechin , cinchonain IIa (4), Ia (5) and Ib were isolated and identified by spectroscopic analyses and further evaluated their potential antioxidant activities by DPPH and superoxide radical scavenging assays. Compared with synthetic antioxidant Trolox, except 4-formylphenol, the other isolated five compounds exhibited excellent antioxidant activities. This is the first report on the chemical constituents of S. sebeana which potentially involved in antioxidant activity. The results suggest that the ethyl acetate extract of S. sebeana might be used as a readily accessible source of natural antioxidant.

Pineapple stem has been extensively used for bromelain extraction; however, almost no attention h... more Pineapple stem has been extensively used for bromelain extraction; however, almost no attention has been given to the waste obtained during bromelain manufacturing. In this regard, antioxidant, antimicrobial, and inhibitions against 15-lipoxygenase and advanced glycation end product formations by pineapple stem waste (PSW) obtained during bromelain manufacturing process were studied. The PSW had moderate bioactivities in all the performed assays. It also showed a considerable inhibition against fungal growth, probably due to high amounts of the benzoic acid present in the sample. These results indicate that PSW could be utilized as an economic source of preventive or therapeutic agent in disease and in different functional food industries.

Advanced glycation end products (AGEs) are major factors responsible for the complication of diab... more Advanced glycation end products (AGEs) are major factors responsible for the complication of diabetes.