Phytochemical and Pharmacological Investigation of Hydroalcoholic Leaf Extracts of Hamelia patens Jacq. and Ixora coccinea Linn. for Antidepressant Activity in Experimental Animal Models

Abstract

Depression is a common and debilitating neuropsychiatric disorder characterized by persistent sadness, loss of interest, behavioral changes, and disturbances in emotional and cognitive functions. Although several synthetic antidepressant drugs are available for the management of depression, their therapeutic limitations and adverse effects have stimulated the search for safer and effective plant-based alternatives. The present study was designed to investigate the phytochemical profile and antidepressant potential of hydroalcoholic leaf extracts of Hamelia patens Jacq. and Ixora coccinea Linn. using experimental animal models. The leaves of Hamelia patens and Ixora coccinea were collected, authenticated, shade-dried, powdered, and subjected to extraction using a hydroalcoholic solvent system. The prepared extracts were evaluated for preliminary phytochemical constituents, including alkaloids, flavonoids, phenolic compounds, tannins, saponins, glycosides, terpenoids, steroids, and other secondary metabolites. The antidepressant activity of the extracts was evaluated in suitable experimental animal models, particularly the Forced Swim Test (FST) and Tail Suspension Test (TST). An Open Field Test (OFT) was additionally employed to assess locomotor activity and to differentiate antidepressant-like effects from nonspecific motor stimulation. A standard antidepressant drug was used as the positive control. The hydroalcoholic leaf extracts demonstrated the presence of several biologically important phytoconstituents, particularly flavonoids, phenolic compounds, alkaloids, tannins, saponins, and terpenoids. Treatment with the extracts produced a dose-dependent reduction in immobility time in the FST and TST compared with the control group, indicating significant antidepressant-like activity. The extracts did not produce marked alterations in locomotor activity in the OFT, suggesting that the observed reduction in immobility was not primarily attributable to nonspecific hyperactivity. The observed activity may be associated with the synergistic action of flavonoids, phenolics, alkaloids, and other bioactive constituents present in the leaves. The findings of the study suggest that hydroalcoholic leaf extracts of Hamelia patens and Ixora coccinea possess promising antidepressant-like activity in experimental animal models. These medicinal plants may serve as potential sources of bioactive phytoconstituents for the development of novel herbal therapeutic agents for depression. Further studies involving isolation and characterization of active constituents, mechanistic investigations, neurochemical evaluation, and molecular studies are warranted to establish their precise antidepressant mechanism of action.