Abstract

Indra Sen Singh66230* and Sidney Muzyamba66232

Medicinal plants have been used in Zambia as folk medicine from time immemorial. Ethnopharmacological studies have indicated that various parts of Paropsia brazzeana have been used to treat various ailments such as Venereal Diseases (VD), gastrointestinal complications, malaria, hernia, and toothaches while also possessing antibacterial, antispasmodic, antiamoebic activity and aphrodisiac potential. In the present study, we report the qualitative phytochemical screening, Gas Chromatography Mass Spectrometry (GC-MS) phytochemical profiling, Global Natural Product Social (GNPS) and (METLIN) Gen 2 Database assisted molecular mining, total phenolic content, total flavonoid content, in vitro antioxidant activity of crude root bark extract, and molecular docking analysis of selected phytochemicals of Paropsia brazzeana. Qualitative phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, carbohydrates, tannins, terpenoids, and steroids. Phytochemical profiling revealed the presence of therapeutic compounds such as d-allose, vanillic acid, 2,5-diphenyloxazole, linoelaidic acid, beta-sitosterol, and many other molecules. Total phenol content was estimated to be 403.7165 ± 6.4771 mg GAE/kg, while total flavonoid content was found to be 587.15 ± 2.4768 mg QE/kg. The root bark extract of P. brazzeana showed strong antioxidative potential with IC₅₀ value of 42.37 mg/l, while for ascorbic acid (standard), IC₅₀ was 23.19 mg/l. Furthermore, the identified compounds could potentially have anti-cancer, anti-diabetic, anti-obesity, anti-fungal, anti-bacterial, anti-inflammatory properties while also having the ability to ease cramps, and thus it can be used as a potential nutraceutical. Molecular docking analysis and its results indicated that beta-sitosterol outperformed the anti-inflammatory drug, ibuprofen when bound to the Cyclooxygenase 2 (COX2) enzyme. With a binding energy of -11.43 kcal/mole and an inhibition constant of 4.18 nM, beta-sitosterol exhibited stronger binding affinity, outperforming Ibuprofen, which displayed a binding energy of -6.88 kcal/mole and an inhibition constant of 9.10 µM. Consequently, beta-sitosterol emerges as a promising candidate for further investigations in anti-inflammatory drug development. The findings of this study are promising for advancing future drug development initiatives.