Phytochemical Analysis of Selected Medicinal Plants Used in Management of Anxiety and Depressive Disorders in Goma City, Democratic Republic of the Congo

Background: Latex of Euphorbia abyssinica (J. F. Gmel) (EA) and leaves of Cleome gynandra L.(CG), Conyza symatrensis (Retz) E. Walker (CS) and Emilia coccinea (Sims) G. Don (EC) are medicinal plant materials (MPMs) commonly used in treatment of mental illnesses (MIs) in folk medicine of Goma city, in Democratic Republic of the Congo (DRC). However, there is still limited information on phytochemical contents of these MPMs. Objective: To screen phytochemicals of the commonly used MPMs and to determine total contents of those with reported anxiolytic and anti-depressive activities. Methods: Phytochemical analysis involving both qualitative and quantitative aspects was carried out in Goma city in DRC and at Makerere University in Uganda from February to June 2022. Medicinal plant materials were extracted by methanol 90%, diethyl ether and water for eight hours replicated three times. Various qualitative tests were used in phytochemicals screening using Throth, Dragendroff, Borntrager, Salkowski, Nitric Acid, Ferric Chloride, Translucent Spot, for detecting saponins, alkaloids, carbohydrates, phytosterols, amino-acid, phenols and fatty acid respectively. Total contents of phenols, flavonoids, alkaloids and phytosteroids were determined using Folin Ciocalteau, aluminium chloride, bromocresol green-complex assay, Liberman-Burchard methods respectively. Results: Various phytochemicals were detected in investigated medicinal plants (MPs), among which terpenoids, phytosterols, steroids, phenols, amino-acids, tannins and saponins were the commonest. Among those with reported anxiolytic and anti-depressive activities, the highest concentration of alkaloids, phenols, flavonoids and phytosteroids were found in EA ether and aqueous extracts, as well as in CS aqueous extract. Conclusion: Findings proved that selected MPs contain potential phytochemicals with anxiolytic and anti-depressive activities.