Variação sazonal do óleo essencial, características microscópicas e potencial alelopatico de Momordica charantia L. (Cucurbitaceae)

Abstract

Brazil harbors the greatest plant biodiversity on the planet, which highlights the importance of studies focused on the chemical, ecological, and functional characterization of plant species with biological potential. In this context, Momordica charantia L. (Cucurbitaceae), popularly known as bitter melon, stands out due to its widespread use in traditional medicine and the presence of secondary metabolites with ecological and pharmacological relevance. The present study aimed to evaluate the seasonal variation of the essential oil and the microscopic characteristics of M. charantia, as well as to investigate the allelopathic potential of its essential oil and leaf extracts on the germination and initial growth of Crotalaria ochroleuca G. Don (Fabaceae).The first manuscript assessed the yield and chemical composition of the essential oil extracted from the aerial parts (leaves and stems) of M. charantia over 12 consecutive months. The essential oil was obtained by hydrodistillation and subsequently analyzed by gas chromatography coupled to mass spectrometry (GC-MS), in addition to microscopic and histochemical analyses of leaves and stems. The results revealed significant variations in essential oil yield and chemical composition, with March 2026 showing the highest yield (0.53%), followed by December 2025 (0.50%). These variations were mainly influenced by the plant’s phenological stage, with predominance of the compounds (Z)-3-hexenol and linalool.The second manuscript investigated the allelopathic effects of aqueous and methanolic extracts and the essential oil of M. charantia on the germination and early growth of C. ochroleuca. The results indicated no significant effect on germination; however, pronounced inhibitory effects were observed on root growth, particularly associated with the methanolic extract, demonstrating allelopathic potential dependent on extract type, concentration, and exposure time. Taken together, these findings expand the knowledge on the chemical variability of M. charantia and its role in ecological interactions, contributing to the understanding of its potential application in sustainable strategies, especially for the management of plants of agricultural interest.