Iridoid glycoside from the leaves of Clerodendrum volubile beauv. shows potent antioxidant activity against oxidative stress in rat brain and hepatic tissues.

OBJECTIVE

This study aims at reporting the isolation, structure elucidation, and antioxidant potentials of ajugoside from C. volubile leaves in sodium nitroprusside (SNP)-induced oxidative stressed rat brain and hepatic tissues.

METHODS

An iridoid monoterpene, ajugoside was isolated from the n-butanol fraction of C. volubile and evaluated for its antioxidant protective potential on brain and liver tissues of male Wister rats in an ex vivo model. Two molar concentrations (6.4 × 10(-4) M and 1.28 × 10(-3) M) of the metabolite and SNP were incubated with the tissues homogenate at 37°C for 2 hr prior to the test and assayed for catalase, superoxide dismutase (SOD) activities, and lipid peroxidation. α tocopherol (6.4 × 10(-4) M) was used as standard.

RESULTS

Both molar concentrations exhibited high catalase activity in the tissues. However, 6.4 × 10(-4) M ajugoside exhibited a very high SOD activity (liver: 96.45 and brain: 96.30%) and inhibition of lipid peroxidation (liver: 88.11 and brain: 93.27%) compared to the standard. 1.28 × 10(-3) M ajugoside also exhibited good activities but lower than that of the standard and 6.4 × 10(-4) M ajugoside.

CONCLUSIONS

Ajugoside showed potent antioxidant activities as evidenced by the synergistic high activities of SOD and catalase as well as inhibition of lipid peroxidation in the studied tissues.