Chemomodulatory Potential of Bartogenic Acid Against DMBA/Croton Oil Induced Two-Step Skin Carcinogenesis in Mice.

Barringtonia racemosa fruits are believed to be useful in cancer treatment in Ayurveda, the Indian system of medicine. In present study, bartogenic acid (BA), a triterpenoid constituent of Barringtonia fruits was evaluated for its cytotoxicity property using the human skin carcinoma cell line (SCC-13) and human peripheral blood mononuclear cells (PBMC). The chemopreventive efficacy of BA was evaluated against the DMBA/Croton oil-induced skin carcinogenesis in mice.BA was orally administered at the doses of 1, 2 or 4 mg/kg/day or applied topically every day for 12 weeks following DMBA application. The in vitro data from cell lines revealed that BA induces cytotoxicity against the SCC-13 cells (IC50=7.5 µM). It was found 4.05 times more selective to exert cytotoxicity against SCC-13 as compared to the PBMC (IC50=30.4 µM). The in vivo datacollected from mice model of DMBA/Croton oil-induced skin carcinogenesis revealed that BA administered orally or applied topically, both reduced the precancerous skin lesions andthe incidence of tumor bearing. The oral doses of BA (2 and 4 mg/kg) and topical treatment significantly reduced the incidence and number of skin papillomas. At these doses, BA also increased the activities of catalase and superoxide dismutase and induced an increase in glutathionecontent and inhibited lipid peroxidation in the skin. These findings reveal the chemopreventive efficacy of BA and also demonstrate that it contributes to the cytotoxic and antioxidative effects of Barringtonia racemosa fruits. The study also validates the traditional claims of Barringtonia fruits and provides a scientific basis of its chemopreventive property.

Ameliorative potential of aliskiren in experimental colitis in mice.

In the present study, we investigated the ameliorative potential of aliskiren in dextran sulfate sodium (DSS) induced colitis in mice. Aliskiren (3 and 10mg/kg, i.p.) was administered for 10 days from the day of DSS administration. The severity of colitis in mice was assessed using body weight loss, colon and spleen weight, hematological parameters, food intake, stool consistency, rectal bleeding and colon shortening. Colonic malondialdehyde (MDA), myeloperoxidase (MPO) and renin mRNA levels were also estimated. Furthermore, TNF-α and IL-6 in plasma and colon were analyzed. The results showed that aliskiren (10mg/kg, i.p.) significantly improved the severity of colitis by, decrease in weight loss, improvement in food intake and stool consistency, decrease in rectal bleeding, decrease in relative colon and spleen weight and improvement in colonic shortening. Aliskiren (10mg/kg, i.p.) improved blood hemoglobin, red blood cells (RBC) and hematocrit. Colonic malondialdehyde (MDA), MPO and histolopathological score were significantly diminished by aliskiren (10mg/kg, i.p.). Furthermore, aliskiren (10mg/kg, i.p.) significantly diminished the elevated levels of TNF-α, IL-6 and renin mRNA in inflammed colon. These results indicate involvement of renin in colitis and inhibition of renin by aliskiren ameliorates colitis.

Anti-nociceptive and anti-allodynic activity of aliskiren in various pain models.

In the present study, we have investigated the anti-nociceptive and anti-allodynic activity of the renin inhibitor, aliskiren, in various pain models. The anti-nociceptive activity of aliskiren was investigated in chemically-induced pain, orofacial pain and centrally mediated pain models. Anti-allodynic activity was evaluated in post-operative and neuropathic pain models. The levels of TNF-α and IL-6 were measured in homogenates of hind paw as markers of inflammation in formalin injected mice. Intraperitoneal administration of aliskiren (1-50mg/kg) showed anti-nociceptive activity in the writhing test, formalin hind paw test, capsaicin induced pain, and orofacial pain tests in ICR mice in a dose dependent manner. Aliskiren (50mg/kg, i.p.) reduced levels of TNF-α and IL-6 in hind paw homogenates of formalin-injected mice. Aliskiren (50mg/kg, i.p.) did not show any analgesic activity in hot-plate and tail-flick tests, indicating the absence of centrally mediated anti-nociceptive effects. On the other hand, intra-plantar administration of aliskiren (0.1, 0.5 and 1mg) showed analgesic activity in rat formalin tests, indicating a locally mediated effect. Aliskiren (30-100mg/kg, i.p.) showed anti-allodynic activity in post-operative pain and chronic constriction injury-induced neuropathic pain in Sprague Dawley rats. This data suggests that aliskiren may have the potential to be used as an anti-nociceptive and anti-allodynic agent.