Evaluation of Phenolic Compounds, Flavonoids, Antioxidant, and Antimicrobial Potential in Psidium guajava L. Fruit and Leaf Extracts

Psidium guajava L., commonly known as guava, is a tropical plant renowned for its nutritional and medicinal properties.This study aimed to evaluate the total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, and antibacterial properties of methanolic extracts from guava fruits and leaves.The TPC and TFC were determined using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively.Antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays.Antibacterial activity was tested against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis using the agar well diffusion method.Results revealed that guava leaf extracts exhibited significantly higher TPC and TFC compared to fruit extracts.Both extracts demonstrated potent antioxidant activity, with leaf extracts showing superior free radical scavenging and reducing power.Additionally, guava leaf extracts exhibited broad-spectrum antibacterial activity, particularly against Gram-positive bacteria.These findings highlight the potential of Psidium guajava L. as a natural source of antioxidants and antimicrobial agents, with leaves being a more potent source than fruits.The study underscores the importance of guava as a functional food and its potential applications in pharmaceuticals and nutraceuticals.