Bioactive Potential of Ethanol Extracts of Avocado Leaves: Review of Antioxidant and Antibacterial Activities

Abstract

Changing lifestyles and increasing bacterial resistance pose a serious challenge to global health. Free radicals and bacterial infections are major contributors to degenerative and infectious diseases. Avocado (Persea americana Mill.) leaves contain bioactive compounds such as flavonoids, tannins, and polyphenols that may provide such benefits. This study is a literature review with a qualitative descriptive approach that aims to evaluate the antioxidant and antibacterial activities of the ethanol extract of avocado leaves. Data were obtained from 396 articles from searches on Google Scholar, PubMed, PLOS One, and Science Direct databases, then selected based on inclusion and exclusion criteria until 12 eligible articles were obtained. The review results showed that the antioxidant activity of avocado leaf ethanol extract varied based on the extraction method, type and concentration of solvent, and extraction time, with the best IC₅₀ value of 9.24 μg/mL (very strong category). Antibacterial activity showed the ability to inhibit the growth of Gram-positive and Gram-negative bacteria with inhibition zones reaching the strong category, especially against Escherichia coli, Staphylococcus aureus, Lactobacillus acidophilus, Streptococcus mutans, and Pseudomonas aeruginosa. It can be concluded that the ethanol extract of avocado leaves has strong potential as an antioxidant and antibacterial agent. However, the current evidence is mainly based on in vitro studies, so further in vivo and clinical research is needed to validate these findings.