Antioxidant and antimicrobial activities of Salsola imbricata methanolic extract and its phytochemical characterization.

Abstract

Methanolic extract from Salsola imbricata was investigated for its phytochemical content, antioxidant, and antimicrobial properties against phytopathogenic fungi and bacteria. Phytochemical analysis revealed the presence of saponin, tannins, and alkaloids with 1.25%, 18.8 mg catechin/g of extract, and 9.12%, respectively. Total flavonoid content was 20.8 mg quercetin equivalent/g while total phenolic content was 202 mg gallic acid equivalent/g. Antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay resulted in an IC₅₀ value of 48.61 µg/mL, while the phosphomolybdenum method yielded a value of 215.43 mg ascorbic acid equivalent/g of extract. The highest phenolic acids detected in the extract were gallic acid (712.97 µg/g), syringic acid (742.7 µg/g), and caffeic acid (474.70 µg/g) according to high-performance liquid chromatography analysis. Palmitic acid (28.38%) dominated the fatty acids identified by gas chromatography-mass spectrometry, while stigmasterol (8.34%) was the most abundant steroid. At a concentration of 3 mg/mL, the extract showed strong antibacterial activity against Pectobacterium carotovorum (10.50 mm), Ralstonia solanacearum (9.93 mm), and Pectobacterium atrosepticum (8.37 mm). Additionally, the extract significantly suppressed fungal growth of Rhizoctonia solani (38.22%) and Fusarium oxysporum (33.56%) but showed lower activity toward Botrytis cinerea (13.33%) at 5 mg/mL. In conclusion, S. imbricata extract exhibited promising antioxidant and antimicrobial properties, making it a potential candidate for further exploration in agricultural applications.