Mahua Ghosh

Surface-modified sulfur nanoparticles: an effective antifungal agent against Aspergillus niger and Fusarium oxysporum

Surface-modified sulfur nanoparticles (SNPs) of two different sizes were prepared via a modified liquid-phase precipitation method, using sodium polysulfide and ammonium polysulfide as starting material and polyethylene glycol-400 (PEG-400) as the surface stabilizing agent. Surface topology, size distribution, surface modification of SNPs with PEG-400, quantitative analysis for the presence of sulfur in nanoformulations, and thermal stability of SNPs were determined by atomic force microscopy (AFM), dynamic light scattering (DLS) plus high-resolution transmission electron microscopy (HR-TEM), fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, and thermogravimetric analysis (TGA), respectively. A simultaneous study with micron-sized sulfur (S0) and SNPs was carried out to evaluate their fungicidal efficacy against Aspergillus niger and Fusarium oxysporum in terms of radial growth, sporulation, ultrastructural modifications, and phospholipid content of the fungal strains using a modified poisoned food technique, spore-germination slide bioassay, environmental scanning electron microscopy (ESEM), and spectrometry. SNPs expressed promising inhibitory effect on fungal growth and sporulation and also significantly reduced phospholipid content.

Studies on comparative efficacy of α-linolenic acid and α-eleostearic acid on prevention of organic mercury-induced oxidative stress in kidney and liver of rat.

The present study was undertaken to evaluate the effect of α-linolenic acid and α-eleostearic acid, two isomers of linolenic acid, against oxidative stress induced by organic mercury in kidney and liver cells of rat. Male albino rats were divided into six groups. Groups 1, 2 were normal control and methyl mercury chloride (MeHgCl) treated (5 mg/kg BW/day) control, respectively. Groups 3, 4, 5 and 6 were orally treated with different doses of two fatty acids (0.5% and 1.0% of total lipid given for each isomer) along with MeHgCl (5 mg/kg BW). Results showed that activity of antioxidant enzymes viz. catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH) in liver and kidney decreased significantly due to oxidative stress generated by MeHg. Administration of the linolenic acid isomers almost restored all the altered parameters and also reduced lipid peroxidation and leakage of trans-aminase enzymes from liver to blood due to liver injury when administrated in higher doses. Histopathology of liver and kidney cells showed that administration of α-linolenic acid significantly reduced the damage generated by MeHg. Thus, α-linolenic acid and α-eleostearic acid could serve as cost-effective and natural phytochemical preparation to protect against the adverse effects caused by organic mercury in human.

Role of Ferulic Acid in the Amelioration of Ionizing Radiation Induced Inflammation: A Murine Model

Ionizing radiation is responsible for oxidative stress by generating reactive oxygen species (ROS), which alters the cellular redox potential. This change activates several redox sensitive enzymes which are crucial in activating signaling pathways at molecular level and can lead to oxidative stress induced inflammation. Therefore, the present study was intended to assess the anti-inflammatory role of ferulic acid (FA), a plant flavonoid, against radiation-induced oxidative stress with a novel mechanistic viewpoint. FA was administered (50 mg/kg body wt) to Swiss albino mice for five consecutive days prior to exposing them to a single dose of 10 Gy 60Co γ-irradiation. The dose of FA was optimized from the survival experiment and 50 mg/kg body wt dose showed optimum effect. FA significantly ameliorated the radiation induced inflammatory response such as phosphorylation of IKKα/β and IκBα and consequent nuclear translocation of nuclear factor kappa B (NF-κB). FA also prevented the increase of cycloxygenase-2 (Cox-2) protein, inducible nitric oxide synthase-2 (iNOS-2) gene expression, lipid peroxidation in liver and the increase of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in serum. It was observed that exposure to radiation results in decreased activity of superoxide dismutase (SOD), catalase (CAT) and the pool of reduced glutathione (GSH) content. However, FA treatment prior to irradiation increased the activities of the same endogenous antioxidants. Thus, pretreatment with FA offers protection against gamma radiation induced inflammation.

Comparative study of antioxidant activity of α-eleostearic acid and punicic acid against oxidative stress generated by sodium arsenite

The present study was undertaken to evaluate the antioxidant efficacy of alpha-eleostearic acid and punicic acid, two isomers of conjugated linolenic acid, in terms of normalization of altered biochemical parameters of oxidative stress following sodium arsenite treatment in rats. Animals were divided into four groups. The first group used as control. While, group 2, 3 and 4 were orally treated with alpha-eleostearic acid (0.5% of total lipid given) plus sodium arsenite (Sa; 10mg/kgBW), punicic acid (0.5% of total lipid given) plus sodium arsenite (Sa; 10mg/kg BW) and sodium arsenite (Sa; 10mg/kg BW), respectively. Results showed that activities of antioxidant enzymes decreased significantly due to oxidative stress generated by sodium arsenite. Lipid peroxidation also increased due to sodium arsenite administration. alpha-Eleostearic acid and punicic acid acted as antioxidant and caused mostly all the altered parameters restored to normal level. Results also showed that antioxidant activity of alpha-eleostearic acid was more predominant than that of punicic acid.

Antioxidant effect of vegetable oils containing conjugated linolenic acid isomers against induced tissue lipid peroxidation and inflammation in rat model

The purpose of the present study was to examine the antioxidant activity of two typical oils obtained from two vegetables, bitter gourd seed and snake gourd seed, containing two different isomers of conjugated linolenic acid (CLnA) against oxidative stress induced by sodium arsenite in relation to tissue lipid peroxidation and inflammation. Male albino rats were taken as subject and divided into six groups: Group 1 was control and Group 2 was treated with sodium arsenite (Sa; 10mg/Kg BW); Groups 3-6 were orally treated with different doses of seed oils maintaining definite concentration of CLnA isomers (0.5% and 1.0% of total lipid for each CLnA isomer) along with sodium arsenite. There was significant increase in lipid peroxidation, pro-oxidant enzyme activity and decrease in antioxidant enzyme activity in brain due to Sa administration. Decrease in total protein content was also observed in plasma, liver and brain of Sa treated group. Significant decrease in phospholipid content and increase in total lipid content and cholesterol content were observed in arsenite treated group. There was significant increase in relative organ weight of liver due to Sa administration. Fatty acid profile of liver and brain lipid shows significant (P<0.05) reduction in most of the polyunsaturated fatty acids and increase in arachidonic acid (20:4n-6) (75.23%) due to inflammation after arsenite treatment. Administration of experimental oils made almost complete restoration of those altered parameters. Overall, these two oils were effective in protecting tissue lipid profiles which were altered due to oxidative stress.

Ameliorative role of conjugated linolenic acid isomers against oxidative DNA damage induced by sodium arsenite in rat model.

The present study was undertaken to evaluate the ameliorative role of α-eleostearic acid and punicic acid, isomers of conjugated linolenic (CLnA) acid, against oxidative stress induced DNA damage. Male albino rats were divided into six groups. Group 1 and 2 were normal control and sodium arsenite treated (Sa; 10 mg/kg BW) control respectively. Group 3-6 were orally treated with different doses of two fatty acids (0.5% and 1.0% of total lipid given for each isomer) along with sodium arsenite (Sa; 10 mg/kg BW). Comet assay of blood leukocytes showed that administration of CLnA reduced DNA damage significantly (P<0.05) which was determined by tail DNA percent and olive tail moment. Results showed that activity of antioxidant enzymes viz. catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) in plasma, liver and erythrocyte lysate decreased and activity of nitric oxide synthase in plasma and liver increased significantly due to oxidative stress generated by sodium arsenite. Administration of CLnA isomers restored all the altered parameters and also reduced lipid peroxidation and leakage of transaminase enzymes from liver to blood due to liver injury. α-Eleostearic acid was more efficient antioxidant than punicic acid against oxidative DNA damage.

Synergistic effect of conjugated linolenic acid isomers against induced oxidative stress, inflammation and erythrocyte membrane disintegrity in rat model

BACKGROUND α-Eleostearic acid and punicic acid, two typical conjugated linolenic acid (CLnA) isomers present in bitter gourd and snake gourd oil respectively, exhibit contrasting cis-trans configuration which made them biologically important. METHODS Rats were divided into six groups. Group 1 was control and group 2 was treated control. Rats in the groups 3 and 4 were treated with mixture of α-eleostearic acid and punicic acid (1:1) (0.5% and 1.0% respectively) while rats in the groups 5 and 6 were treated with 0.5% of α-eleostearic acid and 0.5% of punicic acid respectively along with sodium arsenite by oral gavage once per day. RESULTS Results showed that increase in nitric oxide synthase (NOS) activity, inflammatory markers expression, platelet aggregation, lipid peroxidation, protein oxidation, DNA damage and altered expression of liver X receptor-α (LXR-α) after arsenite treatment were restored with the supplementation of oils containing CLnA isomers. Altered activities of different antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and ferric reducing ability of plasma (FRAP) also restored after oil supplementation. Altered morphology and fluidity of erythrocyte membrane studied by atomic force and scanning electron microscopy, after stress induction were significantly improved due to amelioration in cholesterol/phospholipid ratio and fatty acid profile of membrane. Oils treatment also improved morphology of liver and fatty acid composition of hepatic lipid. CONCLUSIONS Overall two isomers showed synergistic antioxidant and anti-inflammatory effect against induced perturbations and membrane disintegrity. GENERAL SIGNIFICANCE Synergistic antioxidant and anti-inflammatory role of these CLnA isomers were established by this study.

Hypolipidemic effect of mustard oil enriched with medium chain fatty acid and polyunsaturated fatty acid

OBJECTIVE The hypolipidemic effect of two structured lipids prepared from mustard oil was studied: one was medium chain fatty acid (MCFA) rich mustard oil and the other was polyunsaturated fatty acid (PUFA) rich mustard oil. METHODS Thirty-six rats were involved in the study with six rats in each group. Three groups were normal, whereas the others were hypercholesterolemic. Hypolipidemic effects were investigated in both plasma and tissues. RESULTS Both structured lipids with similar content of functional fatty acids (about 19%) were fed (20% of diet weight) to normal and hypercholesterolemic male albino rats. After 28 d of feeding, the fat and protein digestibility increased by administration of the two structured lipids in comparison with the control group fed with normal mustard oil. In both normal and hypercholesterolemic condition plasma cholesterol, non-high-density lipoprotein, and triacylglycerols were reduced by feeding the rats with experimental oils, but the reduction was in lesser amount in rats fed with MCFA-rich mustard oil than in rats fed with PUFA-rich mustard oil and same findings were also seen in hypercholesterolemia. However the HDL levels increased with the administration of both experimental oils. CONCLUSION Mustard oil can be enriched with MCFA and n-3 PUFA and these modified lipids exhibited hypocholesterolemic and hypolipidemic effects in rats when compared to unmodified mustard oil.

Investigation of antimicrobial physiology of orthorhombic and monoclinic nanoallotropes of sulfur at the interface of transcriptome and metabolome

Nanosized elemental sulfur (ES) is already reported to exert superior antimicrobial efficacy than micron-sized ES, which encourages their use in drugs and therapeutics. The aim of the present study is to explore the possible route and mode of antimicrobial action of orthorhombic (α-SNPs) and monoclinic (β-SNPs) allotropes of sulfur, respectively, at their nano-dimensions. The antimicrobial efficacy of α- and β-SNPs was determined against both the conventionally ES-resistant and ES-susceptible fungi and bacteria. Both the SNPs inhibited the microbial growth, irrespective of their resistance profile to ES and caused significant deformities on the microbial cell surfaces. However, the extent of antimicrobial efficacy was found to be optimum for α-SNPs, which can be attributed to their size, shape, and surface modification. Subsequent transcript profiling, metabolite profiling, and enzymatic analyses revealed that α- and β-SNPs impaired a cluster of mitochondrial enzymes involved in cellular respiration and oxidative phosphorylation. ES and SNPs stress were found to elicit the NADPH-dependent glutathione reductase mediated ES-detoxification response in fungi and caused them to undertake the glyoxylate shunt in favor of energy conservation. A simultaneous study was also undertaken to assess the biocompatible or bio-adverse properties of SNPs in terms of their cytotoxic and genotoxic effects against the human derived lung fibroblast cell line (MRC-5). The present study hence explores the antimicrobial physiology of two novel functional materials and demonstrates their compatibility as a future putative antimicrobial drug.

Integrity of erythrocytes of hypercholesterolemic and normocholesterolemic rats during ingestion of different structured lipids

PurposeTo assess the effect of medium-chain fatty acid (MCFA)-rich mustard oil and polyunsaturated fatty acid (PUFA)-rich mustard oil on erythrocyte membrane composition and osmotic fragility in normal and hypercholesterolemic rats.MethodMembrane composition was analyzed using standard kits. Osmotic fragility was determined using method described by Dacie and Lewis. Fatty acid composition of membrane was analyzed using gas chromatographic methods. Membrane shape analysis was performed using scanning electron microscope.ResultsOsmotic fragility data suggested that the erythrocyte membrane of hypercholesterolemic rats were relatively more fragile than that of the normal rat’s membrane, which could be reversed with the addition of MCFA- and PUFA-rich oil in the diet. The increased plasma cholesterol in hypercholesterolemic rats could also be lowered by the experimental oils. There was also marked changes in the fatty acid composition of the plasma and erythrocyte membrane phospholipids. Polyunsaturated fatty acids decreased in the plasma of the hypercholesterolemic subjects were increased with the treatment of the experimental oils. Shape changes of the membrane holes were observed in the hypercholesterolemic condition, which was brought to normal shape with the administration of the experimental oils.ConclusionIn conclusion, rat erythrocytes appear to be deformed and became more fragile in cholesterol-rich blood. This deformity and fragility was partially reversed by experimental oils by virtue of their ability to lower the extent of hypercholesterolemia.