Ameliorative effect of water spinach, Ipomea aquatica (Convolvulaceae), against experimentally induced arsenic...

Ipomea aquatica (Convolvulaceae) is traditionally used against Arsenic (As) poisoning in folk medicines in India. The present study was designed to explore the therapeutic role of aqueous extract of I. aquatica (AEIA) against As-intoxication.

AEIA was chemically standardized by spectroscopic and chromatographic analysis. The cytoprotective role of AEIA was measured on isolated murine hepatocytes. The effect on redox status were measured after incubating the hepatocytes with NaAsO2 (10 μM) + AEIA (400 μg/ml). The protective effect of AEIA (400 μg/ml) in expressions of apoptotic proteins were estimated in vitro. The protective role of AEIA was measured by in vivo assay in mice. Haematological, biochemical, As bioaccumulation and histological parameters were evaluated to ensure the protective role of AEIA (100 mg/kg) against NaAsO2 (10 mg/kg) intoxication.

Phytochemical analysis revealed presence of substantial quantities of phenolics, flavonoids, saponins and ascorbic acid in AEIA. Incubation of murine hepatocytes with AEIA (0-400 μg/ml) + NaAsO2 (10 μM) exerted a concentration dependent cytoprotective effect. Incubation of murine hepatocytes with NaAsO2 (10 μM, ~ IC50) induced apoptosis via augmenting oxidative stress. NaAsO2 treated hepatocytes exhibited significantly (p < 0.01) enhanced levels of ROS production, lipid peroxidation and protein carbonylation with concomitant depletion of antioxidant enzymes (p < 0.05-0.01) and GSH (p < 0.01) levels. However, AEIA (400 μg/ml) + NaAsO2 (10 μM) could significantly (p < 0.05-0.01) reinstate the aforementioned parameters to near-normal status. Besides, AEIA (400 μg/ml) could significantly counteract (p <0.05-0.01) ROS mediated alteration in the expressions of apoptotic proteins viz. Bcl-2, BAD, Cyt C, Apaf 1, caspases, Fas and Bid. In in vivo bioassay, NaAsO2 (10 mg/kg) treatment in mice caused significantly (p < 0.05-0.01) elevated As bioaccumulation, ATP levels, DNA fragmentations and oxidative stress in the liver, kidney, heart, brain and testes along with alteration in cytoarchitecture of these organs. In addition, the serum biochemical and haematological parameters were significantly (p < 0.05-0.01) altered in the NaAsO2-treated animals. However, concurrent administration of AEIA (100 mg/ml) could significantly reinstate the NaAsO2-induced pathogenesis.

Presence of substantial quantities of dietary antioxidants within AEIA would be responsible for overall protective effect.