Rute Elaine Pires de Carvalho Filha*, Sabrina Cruz Ferreira Cerqueira
UNEF University Center, Pharmacy Program – Undergraduate Students, Feira de Santana, Bahia, Brazil
*Address for Corresponding Author
Rute Elaine Pires de Carvalho Filha
UNEF University Center, Pharmacy Program – Undergraduate Students, Feira de Santana, Bahia, Brazil
Abstract
Introduction: Bacterial resistance has intensified due to the abusive use of antibiotics and inadequate disposal, making common infections increasingly difficult to treat. The scarcity of new antimicrobials reinforces the search for natural alternatives capable of acting as therapeutic adjuvants. Melaleuca alternifolia and Aloe vera stand out for their complex phytochemical composition and bioactive compounds with antimicrobial potential and a low risk of inducing resistance. Objective: To evaluate, through a literature review, the antimicrobial potential of Melaleuca alternifolia and Aloe vera extracts, comparing their efficacy, safety, and clinical applicability with conventional antibiotics. Methodology: This is an exploratory-descriptive bibliographic study with a qualitative approach. The search was conducted in SciELO, PubMed, and ScienceDirect using DeCS descriptors related to antimicrobials, phytochemical compounds, and the species Melaleuca alternifolia and Aloe vera. Studies published between 2015 and 2025, available in full and aligned with the theme, were included. After screening by title, abstract, and full text, the data were organized into six thematic axes corresponding to the specific objectives. Results and Discussion: The essential oil of Melaleuca alternifolia demonstrated strong antimicrobial activity, particularly due to terpinen-4-ol and its synergistic effect with antibiotics such as amikacin, meropenem, and oxacillin, in addition to a low tendency to induce resistance. It was also effective against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans. Aloe vera exhibited relevant antimicrobial activity, especially at higher concentrations, with compounds such as aloe-emodin and acemannan acting in biofilm inhibition and controlling both Gram-positive and Gram-negative pathogens. However, its efficacy was, in many studies, lower than that of standard antibiotics. Regarding safety, both plant extracts showed favorable toxicological profiles when used in standardized formulations, although Aloe vera anthraquinones and high concentrations of Tea Tree Oil may pose specific risks. Conclusion: Extracts of Melaleuca alternifolia and Aloe vera present significant therapeutic potential as alternatives or adjuvants in the management of resistant bacterial infections, due to their diversity of secondary metabolites and low propensity to induce resistance. However, their efficacy varies according to concentration, pharmaceutical form, and target pathogen. Chemical and pharmaceutical standardization, as well as further clinical and toxicological studies, are essential to ensure the safe and effective application of these formulations in antimicrobial therapy.
Keywords: Melaleuca alternifolia; Aloe vera; Antimicrobial activity.
