Natarajan Gopalan

Pelargonidin Modulates Keap1/Nrf2 Pathway Gene Expression and Ameliorates Citrinin-Induced Oxidative Stress in HepG2 Cells

Pelargonidin chloride (PC) is one of the major anthocyanin found in berries, radish and other natural foods. Many natural chemopreventive compounds have been shown to be potent inducers of phase II detoxification genes and its up-regulation is important for oxidative stress related disorders. In the present study, we investigated the effect of PC in ameliorating citrinin (CTN) induced cytotoxicity and oxidative stress. The cytotoxicity of CTN was evaluated by treating HepG2 (Human hepatocellular carcinoma) cells with CTN (0–150 μM) in a dose dependent manner for 24 h, and the IC50 was determined to be 96.16 μM. CTN increased lactate dehydrogenase leakage (59%), elevated reactive oxygen species (2.5-fold), depolarized mitochondrial membrane potential as confirmed by JC-1 monomers and arrested cell cycle at G2/M phase. Further, apoptotic and necrotic analysis revealed significant changes followed by DNA damage. To overcome these toxicological effects, PC was pretreated for 2 h followed by CTN exposure for 24 h. Pretreatment with PC resulted in significant increase in cell viability (84.5%), restored membrane integrity, reactive oxygen species level were maintained and cell cycle phases were normal. PC significantly up-regulated the activity of detoxification enzymes: heme oxygenase 1 (HO-1), glutathione transferase, glutathione peroxidase, superoxide dismutase and quinone reductase. Nrf2 translocation into the nucleus was also observed by immunocytochemistry analysis. These data demonstrate the protective effect of PC against CTN-induced oxidative stress in HepG2 cells and up-regulated the activity of detoxification enzyme levels through Keap1/Nrf2 signaling pathway.

Chemical composition, antioxidant potential, macromolecule damage and neuroprotective activity of Convolvulus pluricaulis

Herbal medicines are known to mitigate radical induced cell damage. Hence identification and scientific validation of herbal medicines contribute to better use in Ayurvedic/Unani research. In the present study, we investigated antioxidant and anti-apoptotic properties of Convolvulus pluricaulis (C. pluricaulis). C. pluricaulis exhibited antioxidant potential evident by free radical scavenging activities. C. pluricaulis pretreatment inhibited H2O2 induced macromolecule damage such as plasmid DNA damage and AAPH induced oxidation of bovine serum albumin and lipid peroxidation of rat hepatic tissues. Further to identify the neuroprotective properties of C. pluricaulis, SHSY5Y cells were treated with H2O2 with or without pretreatment of C. pluricaulis. The C. pluricaulis pretreatment at 50 μg/ml dose exhibited 50% cell survival against 100 μM H2O2 challenge for 24 h and it also decreased the lactate dehydrogenase leakage. Further C. pluricaulis pretreatment restored and regulated the antioxidant and apoptosis markers such as SOD, CAT, p53, and caspase-3 and inhibited, reactive oxygen species generation and depolarization of the mitochondrial membrane. C. pluricaulis possess a high content of flavonoids and polyphenols and GC-MS and FTIR analysis showed a wide variety of compounds which may contribute to the observed effects.

Growth inhibition and morphological alteration of Fusarium sporotrichioides by Mentha piperita essential oil

Objective: The aim of this study is to determine the phytochemical composition, antifungal activity of Mentha piperita essential oil (MPE) against Fusarium sporotrichioides. Methods: The phytochemical composition was conducted by gas chromatography mass spectrometry (GC MS) analysis and mycelia growth inhibition was determined by minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), the morphological characterization was observed by scanning electron microscopy. Finally, the membrane permeability was determined by the release of extracellular constituents, pH, and total lipid content. Result: In GC MS analysis, 22 metabolites were identified such as menthol, l menthone, pulegone, piperitone, caryophyllene, menthol acetate, etc. The antifungal activity against targeted pathogen, with MIC and MFC 500 μg/mL and 1000 μg/mL, respectively. The MPE altered the morphology of F. sporotrichoides hyphae with the loss of cytoplasm content and contorted the mycelia. The increasing concentration of MPE showed increase in membrane permeability of F. sporotrichoides as evidenced by the release of extracellular constituents and pH with the disruption of cell membrane indicating decrease in lipid content of F. sporotrichoides. Conclusion: The observed results showed that MPE exhibited promising new antifungal agent against Fusarium sporotrichioides.