Bioactivities of Nek Kara (Dillenia excelsa (Jack) Martelli ex. Gilg) leaves from forest medicinal plants of Kutai Ethnic

Abstract

The utilization of traditional medicine and treatment within the community of Kutai Kartanegara, East Kalimantan, Indonesia is characterized by a wide range of practices. Medicinal plant extracts containing secondary metabolites, possessing diverse molecular structures and biological activities, exhibit promising potential for the development of medicines targeting various diseases. Phenolic compounds, present in plants, exhibit numerous biological effects, including antioxidant and antimicrobial properties. These secondary metabolite compounds play a crucial role in safeguarding against disease-induced damage. Nek Kara (Dillenia excelsa (Jack) Martelli ex. Gilg), a forest plant, has been traditionally employed by the local population for the treatment of diabetes. The objective of this study is to investigate the biological activities of the ethanol extract derived from Nek Kara leaves. The analysis encompasses the examination of phytochemical content, toxicity, as well as antioxidant and antimicrobial activities of the extract. The antioxidant activity is assessed through DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity using a spectrophotometer, while toxicity is determined via the BSLT (Brine Shrimp Lethality Test). The antimicrobial activity is evaluated using the diffusion method. The findings reveal the presence of phytochemical content, such as alkaloids, flavonoids, tannins, and steroids, within the ethanol extract derived from Nek Kara leaves. The BSLT results indicate the absence of toxic bioactivities in the ethanol extract. Furthermore, the Nek Kara leaf extract demonstrates potent antioxidant activity and exhibits inhibitory effects on the growth of bacterial and fungal colonies.