Search

Premna tomentosa (L. Verbanacae) is a widely used medicinal plant. Our earlier studies show that the extract of P. tomentosa leaves prevents acetaminophen-induced hepatotoxicity owing to its antioxidant property. In the present study, we have investigated the immunomodulatory effects of P. tomentosa extract against Chromium (VI) induced immunosuppression in splenic lymphocytes. Chromium (Cr) addition at a concentration of 5 microg showed an increase in cytotoxicity, apoptosis and reactive oxygen species (ROS) and a decrease in lymphocyte proliferation and antioxidant levels, whereas pre-treatment of the cells with P. tomentosa extract (at 500 microg concentration) resulted in decreased cytotoxicity and ROS levels. Further, the drug treatment also maintained antioxidant levels and restored lymphocyte proliferation similar to that of control cells. The results indicated that the leaf extract of P. tomentosa has cytoprotective and immunomodulatory activities.

The present study reports the anti-oxidant activity of alcoholic extracts of leaf and fruit of seabuckthorn (SBT) on nitric oxide (NO) induced cytotoxicity in J-774 macrophages. Sodium nitroprusside (SNP), which generates NO at the concentration of 500 microg/ml, induced cytotoxicity as revealed by decreased neutral red uptake by macrophages. The cytotoxicity of SNP was attributed to enhanced reactive oxygen species (ROS) production, which in turn resulted in decrease in anti-oxidant levels. Alcoholic leaf and fruit extracts of SBT at the concentration of 500 microg/ml were found to have a significant cytoprotective effect against SNP-induced oxidative stress. These extracts inhibited SNP-induced cytotoxicity, free radical production and maintained the anti-oxidant status identical to that of control cells. The alcoholic fruit extract of SBT was found to have significantly higher anti-oxidant activity than leaf extract against SNP-induced cytotoxicity in murine macrophages.