Evaluation of antibacterial, antioxidant, and anti-inflammatory properties of GC/MS characterized methanol leaf extract of Terminalia superba (Combretaceae, Engl. & Diels)

Abstract

Terminalia superba is a well-known medicinal plant used in folk medicine for the management of various diseases and swelling. Validation of its efficacy in standardized scientific models is lacking. This gap needs to be filled as a way of enhancing modern drug discovery. The aim is to evaluate the antibacterial, antioxidant, and anti-inflammatory properties of T. superba in known and established models. Also, to establish and possibly correlate the established activity with the phytochemicals identified using GC/MS and qualitative methods. The result showed a dose-dependent percentage inhibition of DPPH, HO•, and Fe3+ reducing activity. The antibacterial activity showed dose-dependent significant (p < 0.05) inhibition against all the organisms used. The anti-inflammatory activity of METS was confirmed in the carrageenan model with significant (p < 0.05) inhibition of paw volume when compared to control while significantly decreasing (p < 0.05) weight of xylene-induced ear. For instance, after 6 h, there was  a reduction of 42%, 33%, and 22% for diclofenac, 200 mg, and 100 mg, respectively, as against 4% in control. The significant (p < 0.05) increase in MDA was attenuated by the treatment with METS dose dependently. Phytochemical assay and GC/MS characterization showed that alkaloids, saponins, phenols, quinone, tannins, coumarins, proteins, flavonoids, and amino acids were dominant with fatty acids accounting for 53%. Others are esters (23%), organic compounds (12%), alkanes (9%), and carboxylic acids (3%). T. superba possesses antioxidant, antibacterial, and anti-inflammatory properties which are believed to arise from the secondary metabolites observed in the GC–MS characterization.