Phytochemical screening, antimicrobial and antioxidant activity from Sonneratia caseolaris leaves extract

Abstract

This work deals with the screening of phytochemical compounds, and the analysis of the antimicrobial and antioxidant activity of Sonneratia caseolaris leaves from Maros Regency, South Sulawesi Province, Indonesia. The phytochemical compounds were extracted separately using n-hexane, ethyl acetate, 70% and 96% ethanol. The antimicrobial activity was assessed by measuring the clear zone in the agar diffusion method. The phytochemical screening detected the presence of alkaloids, tannins, saponins, phenolics and flavonoids extracted by four different solvents, n-hexane, ethyl acetate, 70% ethanol and 96% ethanol. The ANOVA results showed that n-hexane and 70% ethanol extract had significant antimicrobial activity (P<0.05) against E. coli, S. aureus and C. albicans, while ethyl acetate extract had no significant (P>0.05) antimicrobial activity against these three microbes. The antioxidant activity was determined using the DPPH radical scavenging assay, and the total phenolic content was determined using the Folin-Ciocalteu method. The highest radical scavenging activity of 80.21% was found in 96% ethanol extract, and the lowest antioxidant activity of 16.71% was found in ethyl acetate extract. The total phenolic content is expressed as mg of gallic acid equivalent (GAE) per gram of the extract, with the highest phenolic content, 74.77 mg GAE/g, found in the 70% ethanol extract. Meanwhile, n-hexane extract had the lowest total phenolic content of 4.67 mg GAE/g. These findings showed that S. caseolaris leaves extracts have antimicrobial and antioxidant activities, thus suggesting their potential as natural antimicrobials or antioxidants in the medicinal and food processing industries.