A Phytochemical Profiling and in vitro Antimicrobial Evaluation of Methanolic Extract and Fractions of Dicranopteris linearis Leaves

Introduction: Dicranopteris linearis, locally known as resam, has been recognized for its potential health benefits, primarily due to its rich phytochemical content. Traditionally used for medicinal purposes, the leaves are known to possess antioxidant and antimicrobial properties. This study aimed to screen the phytochemical composition and evaluate the antimicrobial activity of the methanolic extract of D. linearis leaves, with potential applications in the medicinal industry. Materials and Methods: The dried and ground leaves of D. linearis were macerated in 100% methanol to extract the phytochemicals. The extract was subjected to qualitative phytochemical profiling. Total Phenolic Content (TPC) was determined by the Folin-Ciocalteu method and Total Flavonoid Content (TFC) was measured using the AlCl? method. The methanol extract was fractionated by Vacuum Liquid Chromatography (VLC) with ethyl acetate (100%), ethyl acetate: methanol (5:5) and methanol (100%). Antimicrobial activity of the crude extract and fractions was assessed against Escherichia coli and Staphylococcus aureus using the disc diffusion assay and broth microdilution techniques. Results: Phytochemical profiling of the methanol extract revealed the presence of phenolic compounds, flavonoids, tannins, and saponins. The TPC and TFC assays showed that the methanolic extract contained 225.43 ± 4.16 mg GAE/g of phenolic compounds and 50.20 ± 4.78 mg QE/g of flavonoids. Fractionation of methanol extract was afforded three fractions, F1, F2 and F3. Antimicrobial testing demonstrated that the extract exhibited stronger activity against S. aureus (MIC = 1.563 mg/mL) compared to E. coli (MIC > 50 mg/mL). For the fraction, F1 exhibited both microbes with promising activity. Conclusions: The methanolic extract from D. linearis leaves contain bioactive phytochemicals with significant antioxidant and antimicrobial properties. These findings suggest that D. linearis may serve as a valuable source for the development of natural antimicrobial agents in the pharmaceutical industry.