Chemical composition and biological activities of Momordica charantia leaves: a review

Abstract Momordica charantia is a climbing plant popularly known as melon-de-São-Caetano, erva-de-São-Vicente, fruit-de-snake, melonzinho and gourd-de-São-Caetano. Its traditional use in folk medicine, associated with a wide range of therapeutic effects—such as antioxidant, anthelmintic, anti-inflammatory, antifungal, gastroprotective, hepatoprotective and antihyperglycemic activities—has aroused scientific interest and motivated the performance of pharmacological analyses to investigate and prove such properties. Thus, the objective of the present study was to carry out a systematic review (SR) composed of studies to analyze the chemical composition and biological activities of M. charantia leaves. The systematic review followed the PRISMA protocol, with searches in the Lilacs, PubMed and SciElo databases, using descriptors related to M. charantia leaves. Original non-clinical articles, published between 2000 and March 2020, that evaluated the chemical composition and biological effects of the plant were considered. Initially, 542 publications were identified, resulting in 479 after removal of duplicates. After screening and exclusion based on specific criteria, 131 articles were fully evaluated, with 42 included in the final analysis. Brazil, Japan, and China accounted for the largest number of publications. Despite this, 92% of the studies demonstrated adequate statistical treatment and information on doses and routes of administration, while 54% mentioned submission to the animal ethics committee. Hypotheses and objectives were clearly described in 69% of the studies. Randomization and blinding were indicated as essential to reduce bias in nonclinical studies. The systematic review confirmed the significant pharmacological potential of M. charantia leaves, driven by triterpenoids, flavonoids, saponins, and tannins. Their activities point to promising clinical applications in three areas: combating resistant infections (antimicrobial effect), controlling metabolic diseases (antihyperglycemic potential), and acting as a chemopreventive agent (antitumor and antioxidant actions). The low reported toxicity supports their pharmaceutical viability. However, the analysis highlighted a critical need for rigorous methodological standardization in non-clinical studies (adherence to ethics, blinding, randomization) to reduce bias and guarantee data reliability. Comprehensive phytochemical, pharmacological, and toxicological studies are thus indispensable. Targeted investment in research and standardization is vital to transform this proven medicinal potential into a globally validated and safe therapeutic product.