Phytochemical analysis, antioxidant, antimicrobial, and toxicity studies of Schima wallichii growing in Nepal

Abstract

ABSTRACT The present study focuses on qualitative and quantitative phytochemical and biological analysis in bark and leaf extracts of Schima wallichii growing in Gulmi, Nepal. TPC and TFC were measured using the Folin-Ciocalteu reagent and the aluminum chloride colorimetric method, respectively. The DPPH assay was used for antioxidant activity, and antimicrobial activity was studied with the agar-well diffusion method. The presence of polyphenols, flavonoids, quinones, coumarins, saponins, terpenoids, and tannins was detected by qualitative phytochemical analysis. Total phenolic content in an aqueous leaf extract and methanol bark extract ranged from 199 ± 5 to 219 ± 8 mg GAE/g. Similarly, the flavonoid content found between 6.0 ± 1.7 in bark to 33 ± 2 mg QE/g in leaf extract. The antioxidant activity of IC50 36 ± 3, 39 ± 1, 52 ± 3, and 73 ± 4 µg/mL for methanolic bark extract, methanolic leaf, aqueous bark, and aqueous leaf extracts, respectively. The bark methanol extract showed the most antibacterial activity with ZOI of 10.0 ± 0.3, 8.0 ± 0.3, 14 ± 0, and 11 ± 1 mm against Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis, and Escherichia coli, respectively. Plant extracts were found to be nontoxic to mildly toxic to the brine shrimp nauplii. The plant is found to be rich in phenolics, and flavonoids showing significant antioxidant and antibacterial activities, and is nontoxic against brine shrimp nauplii. The plant imparts a health-promoting effect that needs to be explored in pharmaceutical research.