INVESTIGATION OF THE ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF PSIDIUM GUAJAVA L. LEAVES EXTRACT
Main Article Content
Abstract
Objectives: To investigate preliminary phytochemical constituents, determine total phenolic and flavonoid contents, and evaluate the antioxidant and antimicrobial activities of guava leaf ethanol extract.
Subjects and methods: The extract was prepared using 70% ethanol-assisted ultrasonic extraction. Phytochemical constituents were screened qualitatively. Total phenolic and flavonoid contents were determined by Folin-Ciocalteu and AlCl₃ methods, respectively. Antioxidant activity was evaluated by DPPH, ABTS+ and NO assays; antimicrobial activity was assessed by agar well diffusion.
Results: The extraction yield was 17.82%. The extract contained flavonoids, tannins, terpenoids, alkaloids, saponins, and other phytochemical groups. Total flavonoid and phenolic contents were 409.09 ± 8.46 mgQE/g and 295.34 ± 17.25 mgGA/g dry material, respectively. IC₅₀ values for DPPH, ABTS+ and NO assays were 31.87 ± 4.57, 37.42 ± 6.43, and 539.72 ± 5.87 µg/mL, respectively. The extract inhibited MRSA, MSSA, E.coli, P.vulgaris, and C.albicans, with the strongest activity against MRSA.
Conclusions: Guava leaf ethanol extract is rich in polyphenols and flavonoids and exhibits notable antioxidant and antimicrobial activities.
Article Details
Keywords
Psidium guajava, guava leaves, ethanol extract, antioxidant activity, antimicrobial activity.
References
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