Natural extracts as a promising solution for gram-positive antibiotic resistance: A comprehensive review

Abstract

Background: Antibiotic resistance is currently one of the biggest problems in public health. Infectious diseasesare the second human death cause, and the emergence of antimicrobial-resistant bacteria increases mortalityand morbidity rates. There is a growing clinical need for the development of new antibiotics. In this line, WHOissued an alert about 12 bacteria with an urgent need to develop new antibiotics. Aims: This review aims toanalyze the current knowledge of their antibacterial activity against the gram-positive pathogens listed by WHOand their extraction techniques. Methods: We systematically reviewed the literature in PubMed, searchingpublications describing the use of natural extracts as antibiotics over bacteria. The exclusion criteria consisted oflimiting papers on natural extracts tested over the bacteria culture related to eleven selected bacteria, accordingto an alert issued by WHO in 2017, and seven plant extracts. Results: All the gram-positive bacteria present inthe WHO alert have been treated, with different degrees of advance, with some of the plant extracts and plantbasedcompounds reviewed. Currently, they are in the preclinical stage. Edible herbs are more often used, aswell as artemisia and wine byproducts. Discussion: Natural products based on plants have shown to be efficientin inhibiting bacterial growth, even in antibiotic-resistant strains. The classical extraction methods are still in useand have been improved with the available technology to improve efficiency and yield. Conclusions: Ongoingevidence shows that plant extracts and plant-based compounds are effective as antibacterial, with minimal effectson the host cell, a promising antibiotic source. Furthermore, they are sustainable, environmentally friendly, andrenewable