Antioxidant and free radical scavenging activities of Viola odorata in the search of potential inhibitor of tobaccos free radicals

Evaluation of antioxidant activities and essential/toxicmetal levels and their health risk assessment in citrus fruits from Pakistan

Fruits are important components of human diet, and their contamination by environmental pollutants is an emerging challenge nowadays. The present study is based on the measurement of selected essential and toxic trace metals including Na, K, Ca, Mg, Fe, Zn, Cu, Mn, Cr, Co, Sr, Li, Ni, Pb, and Cd in commercially available citrus fruits from Pakistan. The samples were digested in HNO₃ and HCLO₄ mixture, and the metal contents were quantified by flame atomic absorption spectrometry. Highest concentration was found for Ca (609.0-3596 mg/kg), followed by relatively higher levels of K (277.6-682.1 mg/kg), Mg (53.65-123.4 mg/kg), Na (1.173-52.14 mg/kg), and Fe (0.236-10.57 mg/kg), while Li, Ni, and Cd showed the lowest contributions in most of the samples. In addition, antioxidant activities such as DPPH radical scavenging assay, hydroxyl radical scavenging activity, ferrous chelating activity, ferric reducing antioxidant power assay, and phosphomolybdenum assay were also evaluated in the fruit samples. Considerably higher antioxidant activities were shown by grapefruit, mandarin, sweet lime, and tangerine. Most of the antioxidant assays were significantly correlated with Na, Mg, Fe, Mn, and Cu levels in the fruits. Human health risk was evaluated in terms of health risk index (HRI), target hazard quotient (THQ), and target cancer risk (TCR) which revealed insignificant health risks; thus, the consumption of these fruits can be considered as safe for human diet.

Modulatory effects of Viola odorata flower and leaf extracts upon oxidative stress-related damage in an experimental model of ethanol-induced hepatotoxicity

Ethanol is the most widely abused drug in the world and its long-term use induces oxidative stress in the liver tissue. The aim of this study was to evaluate protective effect of Viola odorata against ethanol-induced hepatotoxicity in Wistar rat. Animals were divided into 9 groups as follows: control (normal saline), ethanol (10 mg/kg, intraperitoneally), ethanol with 3 doses (125, 250, and 500 mg/kg) of ethyl acetate flower and leaf extracts, and positive control (vitamin E 80 mg/kg). Animals were gavaged 30 min before ethanol injection for 28 days. Then, animals were killed and the livers were separated. Oxidative stress parameters, including reactive oxygen species, lipid peroxidation, and protein carbonyl as well as glutathione content, were evaluated. Also, histopathological examination was performed and assessment of blood alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total antioxidant capacity were evaluated. Ethanol significantly increased oxidative stress markers in liver. Interestingly, administration of both extracts significantly decreased oxidative stress markers in liver tissue and biochemical parameters in the plasma. In addition, abnormal pathological features were improved after treatment with flower and leaf extracts. These results suggested that V. odorata can be considered a candidate for improving conditions due to ethanol-induced tissue oxidative damage because of its antioxidant activity.