Protective effects of bark extract against D-galactose induced cognitive impairment and oxidative stress in mice.

(Buch.-Ham. ex D.Don) Vickery is a native species of India. Different parts of the plant are used for the medicinal purpose by the tribal peoples of south-eastern part of India. However, the biological properties of have not been studied well. The extracts obtained from the bark of were evaluated to determine their protective effect on cognitive impairment and oxidative stress in mice induced by D-galactose using the standard protocol. Different dosages of extract (100, 200, and 300 mg/kg, p.o.) were administered to mice, which were previously treated for six weeks with D-galactose (100 mg/kg s.c.). The D-galactose-induced mice showed significantly impaired cognitive behavior, i.e., oxidative defense, compared to the sham group. Six weeks of treatment with extract (100, 200 and 300 mg/kg, p.o.) considerably improved the cognitive behavior and oxidative impairment of mice compared to the control alone (D-galactose). For the phytochemical investigation, the bark of was successively extracted with dichloromethane and methanol. The chemical constituents of were isolated by multiple column chromatography and characterized by different spectral analyses. ()-Coclaurine (), an alkaloid, was isolated along with two other compounds from the extract; three more compounds were also isolated from the extract of the bark of . All the compounds were isolated for the first time from the bark of , and their structures were established by detailed spectral studies. The structure of compound was also investigated and confirmed by X-ray diffraction and DFT studies. This study highlights the protective effect of bark extract against D-galactose-induced biochemically dysfunction in mice. ()-Coclaurine () was isolated as one of the major components of bark from extract; this compound could be further evaluated for the development of new potential drug candidates.