University of Madras

About: University of Madras is a education organization based out in Chennai, Tamil Nadu, India. It is known for research contribution in the topics: Ring (chemistry) & Lipid peroxidation. The organization has 8496 authors who have published 11369 publications receiving 211152 citations. The organization is also known as: Madras University & University of Chennai.

Chromium (VI)-induced oxidative stress and apoptosis is reduced by garlic and its derivative S-allylcysteine through the activation of Nrf2 in the hepatocytes of Wistar rats.

Abstract: Chromium (VI) compounds are genotoxic and carcinogenic in a variety of experimental systems. Garlic and its derivatives possess antioxidant properties to scavenge the toxic radicals. The mechanism by which garlic induces the antioxidant and phase II enzymes during oxidative stress-induced apoptosis is not known. This study aims to evaluate the protective role of aqueous garlic extract (AGE; 200 mg kg(-1) b.w.) and S-allylcysteine (SAC; 100 mg kg(-1) b.w.) on potassium dichromate-induced apoptosis and oxidative stress in the hepatocytes of Wistar rats. Activities of liver marker enzymes such as aspartate transaminase, alanine transaminase and lactate dehydrogenase were found to be increased in the serum of chromium-induced group, whereas administration of garlic extract and SAC restored the enzymes to near normal status. The activities of enzymic antioxidants (superoxide dismutase, catalase, glutathione peroxidase), non-enzymic antioxidants (vitamin C and vitamin E) and the levels of reduced glutathione were found to be decreased, while an increase in lipid peroxidation (LPO) and reactive oxygen species were observed in the liver tissues of chromium-induced group. Administration of AGE and SAC reversed the status of these parameters substantially. Histological and transmission electron microscopic studies support our findings. Confocal microscopic analysis using annexin-V showed the involvement of apoptosis. Further, the expression of a novel transcription factor, nuclear factor-E2 related factor 2 (Nrf2) was investigated using Immunofluorescence and Western blotting. The results show the promising role of Nrf2-mediated antioxidant defense of AGE and SAC against chromium toxicity.

An in vitro cytotoxicity study of 5-fluorouracil encapsulated chitosan/gold nanocomposites towards MCF-7 cells

Abstract: Chitosan/gold nanocomposite was synthesized using the chemical reduction method. The XRD pattern shows the semi-crystalline nature of chitosan and the face centered cubic structure of gold. The binding of gold to chitosan was confirmed using XPS and FTIR. The presence of gold in its metallic state is evident from XPS. The prepared nanocomposite was used as a drug delivery carrier for 5-fluorouracil. The encapsulation efficiency of 5-FU and the drug loading efficiency were found to be 96% and 41% respectively. A dialysis membrane was used to study the release of 5-fluorouracil from chitosan/gold nanocomposite. The amount of drug released in vitro was analyzed using the UV-vis characterization of PBS solution. 5-fluorouracil encapsulated nanocomposite was characterized using HRTEM with SAED, HRSEM with elemental mapping, XRD and FTIR analysis. The presence of fluorine, observed from the elemental mapping, confirms the loading of the drug into the nanocomposite. Cytotoxicity analysis was performed for the MCF-7 and VERO cell lines, which shows the effectiveness of the sample towards the destruction of MCF-7 and its non-toxicity towards VERO. 50% cell viability for the MCF-7 cells was obtained at a sample concentration of 31.2 μg ml−1. The non-toxicity of the system towards VERO cells at the concentration wherein IC50 is obtained for MCF-7 and the adherence of the maximum portion of the release profile to zero order kinetics, which means a constant release of the drug from the delivery vehicle, are the highlights of this system.