Preliminary evaluation of In vitro and In vivo antioxidative and antitumor activities of flavonoid extract of Tabernaemontana divaricata leaves in Ehrlich's lymphoma and Dalton's lymphoma ascites model

Aims: In the present study, the flavonoid fraction of Tabernaemontana divaricata flavonoid fraction(TdFf) leaves was investigated for its in vitro and in vivo antioxidative and antitumor activity. Subjects and Methods: The flavonoid fraction of ethyl acetate extract was assessed for their in vitro antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), superoxide radicals, ferric reducing antioxidant power (FRAP), hydrogen peroxide, hydroxyl radicals and nitric oxide and in vivo antioxidative activity by enzymic and nonenzymic antioxidants in the liver of intraperitoneally implanted Ehrlich's lymphoma (EAC) and Dalton's lymphoma ascites (DLAs) model. The in vitro cytotoxicity was assessed using trypan blue exclusion assay and in vivo antitumor activity was assessed by screening the ILS, serum liver marker enzymes and histopathology of the liver. Statistical Analysis Used: The data were expressed as the mean +/- standard deviation of the means, and statistical analysis was carried out employing one-way and two-way analysis of variance using Web Agri Stat Package 2.0. Results: The dose-dependent percentage scavenging of ABTS, DPPH, FRAP, OH, superoxide radical, and nonradical NO and H2O2 by TdFf indicated their antioxidative potential. Incubation of EAC/DLA tumor cells with TdFf showed a concentration-dependent cytotoxic effect, and the extract killed 50% of EAC/DLA tumor cells at a concentration of 80 mu g of TdFf. Coadministration of TdFf with EAC/DLA-induced mice showed a significant increase in the liver enzymic and nonenzymic antioxidants and significant decrease in the serum liver marker enzymes to prove the in vivo antioxidative and antitumor activity of TdFf. It was also confirmed by the histopathology of the liver. Conclusions: It may be concluded that the flavonoid fractions of Td possess considerable antioxidative and antitumorigenic activity against the tested DLA/EAC in both in vitro and in vivo system.