Plocama is a flowering plant genus belonging to Rubiaceae family. The natural products are soxlated from the dried powder of Plocama root with various solvents like n-Hexane, Ethyl acetate, Chloroform, Water and Ethanol. Phytochemical screening revealed that Alkaloids are present in chloroform extract where as Anthocyanins are present in ethanol extract. Terpenoids, Flavonoids, Alkaloids and Phenolic compounds are present in water extract.
In the present study, Plocama pendula root water extract (PPRWE) (400 mg/kg) produced significant antidepressant effect in Forced swim test & Tail Suspension Test. Ecliptin alkaloid & Culumbin, a flavonoid present in PPRWE may be facilitating monoaminergic transmission there by producing antidepressant effects.
In this work, it was demonstrated that the administration of different doses of the water extract of Plocama pendula root in mice was able to induce antidepressant effects. On the basis of the clinical association of depressive episodes and stressful life events, many of the animal models for the evaluation of antidepressant drug activity assess stress‐precipitated behaviors. Results of this study showed that the administration of the PPRWE produced a diminution of immobility time of mice exposed to the both forced swimming and tail suspension tests.
Harmaline alkaloids present in Plocama pendula act as reversible monoamine oxidase inhibitors and in common with other beta carboline binds to 5‐Hydroxy Tryptamine receptors. Inhibition of this enzyme causes a reduction in metabolism and subsequent increase in the concentration of biogenic amines. The flavonoid components of PPRWE might be interacting with adrenergic and serotonergic systems in mediating the antidepressant effects of PPRWE. However, the precise mechanisms by which the extract produced antidepressant‐like effect are not completely understood. Further studies would be necessary to evaluate the contribution of active chemical constituents for the observed antidepressant activity.