Assessment of Phenolic and Flavonoid Contents, Antioxidant Properties, and Antimicrobial Activities of Stocksia Brahuica Benth

Introduction: Stocksia brahuica Benth. (Sapindaceae) is an invaluable shrubby plant distributed in Iran, Afghanistan, and Balochistan region of Pakistan. In this study, the total phenolic and flavonoid contents and the antioxidant and antimicrobial properties of leaf, fruit, and seed extracts of S. brahuica were screened. Methods: Plant materials were collected in September 2021 from Zahedan, southeast of Iran. The total phenolic and flavonoid contents and total antioxidant capacity were assessed spectrophotometrically using Folin-Ciocalteu, aluminum chloride colorimetric, and DPPH free radical scavenging methods, respectively. The effectiveness of crude hydroethanolic extracts of the leaf, fruit, and seed of Stocksia brahuica were also assayed against four gram-negative (Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and Escherichia coli) and two gram-positive bacteria (Staphylococcus epidermidis and Streptococcus pyogenes) as well as two fungi (Aspergillus fumigatus and Candida albicans). Results: The total phenolic and flavonoid contents were observed to vary from 136.7 to 263.5 mg gallic acid equivalents/g and 26.6 to 104.8 mg quercetin equivalents/g of powdered dry weight. The highest amounts of phenolic and flavonoid content were detected in leaves. Good antioxidant activities were observed with leaves followed by fruits and seeds. Based on our antimicrobial experiments, some plant organs were successful in blocking the growth of tested pathogenic strains. Conclusion: As a result, natural products derived from this plant can make a significant contribution to the development of the nutritional and pharmaceutical industries.