AimTo evaluate the protective effect of phyllanthin and hypophyllanthin of standardized aqueous extract of Phyllanthus amarus in acetic acid induced colitis model of inflammatory bowel disease in Wistar rats. MethodsRats were rendered colitic by a colonic instillation of 2 ml (4%) acetic acid solution. Rats were pretreated orally for 7 days before induction of colitis with P. amarus (50, 100 and 200 mg/kg) or vehicle (1 ml of distilled water). Colonic inflammation was evaluated by disease activity index, gross morphologic damage, histological injury and different biochemical markers of colonic inflammation such as superoxide dismutase (SOD), reduced glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NO) and tumor necrosis factor-α (TNF-α) were performed in colonic contents from colitic rats. DNA damage, a marker of apoptosis was also assessed in colonic contents. ResultsThe results show that P. amarus (100 and 200 mg/kg) exerted a preventive anti-inflammatory, antioxidant and anti-apoptotic effect in this model of rat colitis, as evidenced by a significant increase in SOD and GSH content as well as reduction of MPO activity, by a decrease of MDA and reduction in NO as well as TNF-α production which is unregulated as a consequence of the inflammatory status. It also significantly decreased the extent of DNA fragmentation. ConclusionIn conclusion, it is strongly suggested that the potent anti-inflammatory and anti-apoptotic effects of P. amarus in rats with acetic acid induced colitis are mediated via the neutrophil infiltration inhibition, inhibition of pro-inflammatory mediator production and reducing DNA damage due to the presence of phyllanthin and hypophyllanthin phytoconstituents which offers a promising means for the treatment of diseases characterized by inflammation of the gastrointestinal tract.