Santinath Ghosh

Antimicrobial activity of Sesbania grandiflora flower polyphenol extracts on some pathogenic bacteria and growth stimulatory effect on the probiotic organism Lactobacillus acidophilus.

Polyphenolic extracts (PE) of edible flower of Sesbania grandiflora were tested to evaluate its antimicrobial effect against some common pathogenic bacteria and growth promoting property against probiotic organism Lactobacillus acidophilus. The antimicrobial activity of S. grandiflora flower PE against selected pathogens was evaluated using both in vitro and in situ methods. In vitro studies suggested that PE has inhibitory effect against Staphylococcus aureus, Shigella flexneri 2a, Salmonella Typhi, Escherichia coli and Vibrio cholerae. The gram-positive organism S. aureus was the most sensitive organism to PE and minimum inhibitory concentration (MIC) was found to be 0.013 mg/mL where as the MIC of PE against V. cholerae was the highest (0.25 mg/mL). On the other hand PE showed growth promoting effect on the common probiotic bacterium L. acidophilus. The major finding was that S. grandiflora PE induced a significant biomass increase of L. acidophilus grown in liquid culture media. PE showed reduction of S. aureus growth in food (fish) during storage at 10°C. High performance liquid chromatography analysis showed that rutin, a major flavonoid of the PE diminished in the culture medium MRS broth with the growth of L. acidophilus.

Lutein content and in vitro antioxidant activity of different cultivars of Indian marigold flower (Tagetes patula L.) extracts.

Three different cultivars of marigold flowers ( Tagetes patula L.) (marigold orange, marigold yellow, and marigold red) were analyzed for the lutein ester contents, and the in vitro antioxidative activities of the flower extracts were compared. The total antioxidant capacity, reducing power, hydroxyl, DPPH, and ABTS(*+) radical scavenging activities, iron chelation capacity, and inhibition of lipid peroxidation in a linoleic acid emulsion system were measured. Iron-mediated Fenton reaction was carried out to evaluate the protective effect of leutin against DNA damage. The marigold orange (MGO) variety contains the maximum amount of lutein. It also had the highest DPPH radical scavenging activity and ABTS radical scavenging activity, with an EC(50) value of 0.344 mg/mL. It was also the most effective against lipid peroxidation and hydroxyl radical scavenging activities. The MGO extract has the maximum reducing power. Hepatic cell damage in iron-mediated Fenton reaction caused by free radicals was reduced by the marigold extracts. Marigold flowers of Indian variety can be effectively utilized to produce lutein ester, which can be used as a food supplement or as an accessible source of natural antioxidants.

Influence of polyphenolic extracts from Enydra fluctuans on oxidative stress induced by acephate in rats

Acephate, an organophosphorus pesticide, has been proved to play an important role in tissue damage by inducing oxidative stress through the release of free radicals. The aim of this study was to evaluate the protective effect of the plant phenolic compounds present in Enydra fluctuans against acephate toxicity based on lipid peroxidation and antioxidant enzymes profile in rats. An oral dose of acephate at 30 mg/kg of body weight has been given against the extracts containing 20mg of polyphenolic compounds (expressed as gallic acid equivalents)/kg body weight for 14 days. The results showed that under the influence of the pesticides, there was significant decrease in the activities of the antioxidant enzymes SOD, Catalase and Glutathione peroxidase (GPx) and an increase in the non-enzymatic Glutathione, with respect to the normal and the plant extract gavaged groups. Also that there was an increase in the plasma and erythrocyte membrane lipid peroxidation levels in the pesticide treated group compared to the normal or the group treated with the plant extract. The present study thus gives an insight into the ill-effects of this organophosphate and the protective role of plant polyphenols in minimizing those effects.

Comparative study of hypocholesterolemic and hypolipidemic effects of conjugated linolenic acid isomers against induced biochemical perturbations and aberration in erythrocyte membrane fluidity

Aim of studyThe purpose of the study was to evaluate hypolipidemic and hypocholesterolemic activities of conjugated linolenic acid (CLnA) isomers, present in bitter gourd and snake gourd seed, in terms of amelioration of plasma lipid profile, lipoprotein oxidation and erythrocyte membrane fluidity after oral administration.MethodsMale albino rats were divided into six groups. Group 1 was control, and others were induced with oxidative stress by oral gavage of sodium arsenite (Sa). Group 2 was kept as treated control, and groups 3–6 were further treated with different oral doses of seed oils to maintaining definite concentration of CLnA isomers (0.5 and 1.0% of total lipid for each CLnA isomer).ResultsCLnA isomers normalized cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride contents in plasma and body weight of experimental rats and decreased cholesterol synthesis by reducing hepatic HMG-CoA reductase activity. Administration of Sa caused alteration in erythrocyte membrane fluidity due to increase in cholesterol and decrease in phospholipid content. Tissue cholesterol and lipid contents were also increased by Sa administration. These altered parameters were reversed by experimental oil administration. Protective effect of CLnA isomers on erythrocyte morphology was observed by atomic force microscopy (AFM). Fatty acid composition of erythrocyte membrane showed decrease in polyunsaturated fatty acid (PUFA) and increase in arachidonic acid content after Sa administration, which was normalized with the treatment of these oils. Supplementation of CLnA isomers restored erythrocyte membrane (EM) lipid peroxidation and lipoprotein oxidation.ConclusionCLnA isomers, present in vegetable oils, showed potent hypolipidemic and hypocholesterolemic activities against biochemical perturbations.

In vitro Antioxidant Activity of Different Cultivars of Banana Flower (Musa paradicicus L.) Extracts Available in India

Six different cultivars of banana flowers (Musa paradicicus) (Kathali, Bichi, Shingapuri, Kacha, Champa, and Kalabou) were analyzed for the content of polyphenol expressed as gallic acid equivalent and flavonoid expressed as quercetein equivalent, and the in vitro total antioxidative activities of the flower extracts were compared with standard and expressed as trolox equivalent. The reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•(+)) scavenging activities, inhibition of lipid peroxidation in a linoleic acid emulsion system, and liposome peroxidation system were measured and compared with respective standard antioxidants. Iron-mediated Fenton reaction was carried out to evaluate the protective effect of the extract of banana flower (Kacha cultivar) against H(2)O(2)-induced DNA damage. The Kacha variety contains the maximum amount of polyphenol (11.94 ± 0.03 mg of gallic acid equivalent/g of dry weight) and flavonoid (0.174 ± 0.001 g of quercetin equivalent/g of polyphenol). It also has the highest total antioxidant capacity, DPPH radical scavenging activity, and ABTS•(+) radical scavenging activity with a least EC(50) value of 0.051 mg/mL. Hepatic cell damage in iron-mediated Fenton reaction caused by free radicals is reduced by the banana flower extract. On the basis of the results obtained, the banana flowers are found to be a potential source of natural antioxidants. This is the first report on the antioxidant properties of the extracts from banana flowers. The study suggests that the flowers of M. paradicicus that are found in India and consumed as vegetable can provide valuable functional ingredients that help in the prevention of oxidative stress.

Comparative evaluation of essential fatty acid composition of mothers' milk of some urban and suburban regions of West Bengal, India

This study investigated the fatty acid composition of lipid present in breast milk of mothers residing in urban and suburban regions of West Bengal with special emphasis on n-6 and n-3 polyunsaturated fatty acids, which played a crucial role in the growth and development of neonates. Milk samples collected from 135 mothers of middle income group (average monthly income around ‘Rs 10,000/-’) were analysed by gas liquid chromatography after extraction and transmethylation to determine fatty acid composition. Information about the dietary intake of individual mothers was obtained through food frequency questionnaire. The fractions of n-6 and n-3 polyunsaturated fatty acids available in milk of urban mothers were 13.59 ± 0.94 and 3.65 ± 0.49, respectively, and in suburban mothers 12.74 ± 0.89 and 4.36 ± 0.39, respectively. The green leafy vegetables, fishes and vegetable oils were the major sources of essential fatty acids in the diet of the experimental groups of Bengali mothers. This study revealed a relationship between the alimentary habits of mothers and the concentration of essential fatty acids in breast milk of Bengali mothers.

Oxalis corniculata (Oxalidaceae) Leaf Extract Exerts In Vitro Antimicrobial and In Vivo Anticolonizing Activities Against Shigella dysenteriae 1 (NT4907) and Shigella flexneri 2a (2457T) in Induced Diarrhea in Suckling Mice

In this study, the extract of a green leafy vegetable Oxalis corniculata (Oxalidaceae) was evaluated for its in vitro antibacterial and in vivo anti colonizing effect against common intestinal pathogenic bacteria. Methanolic extract (80%) of Oxalis corniculata (Oxalidaceae) leaf contained a polyphenol content of 910 mg gallic acid equivalent per gram of dry weight and the yield was 8%. The flavonoid content was 2.353 g quercetin equivalent per 100 g of the extract. In vitro studies indicated that the extract inhibited numerous pathogenic bacteria like Staphylococcus aureus (ATCC 25922), Escherichia coli (ATCC 25923), Shigella dysenteriae 1 (NT4907), Shigella flexneri 2a (2457T), Shigella boydii 4 (BCH612), and Shigella sonnie phase I (IDH00968). The minimum inhibitory concentration (MIC) against E. coli (ATCC 25923) was minimal (0.08 mg/mL), whereas MIC against S. flexneri 2a (2457T) was higher (0.13 mg/mL). A suckling mouse model was developed which involved challenging the mice intragastrically with S. flexneri 2a (2457T) and S. dysenteriae 1 (NT4907) to study the anticolonization activity. It was revealed that the extract was more potent against S. dysenteriae 1 (NT4907) as compared to S. flexneri 2a (2457T). It was also found that simultaneous administration of extract along with bacterial inoculums promoted good anticolonization activity. Significant activity was observed even when treated after 3 h of bacterial inoculation.