Cytotoxicity and Anticancer Potentials of Secondary Metabolites of Soil Actinobacteria Isolated from Soraya Research Station, Gunung Leuser National Park, Aceh

Abstract

Actinobacteria are known as major producers of secondary metabolites that are widely applied as anticancer agents. Actinobacteria can be found in various soil habitats, including the soil of the Soraya Research Station, Gunung Leuser National Park, Aceh. This study aimed to explore the soil actinobacteria at the Soraya Research Station, evaluate their potential cytotoxic and anticancer activities, and identify their secondary metabolites. Soil samples were randomly collected from two plots, and the actinobacteria were isolated, purified, and characterized according to standard procedures. The cytotoxic activity of the actinobacteria isolates were evaluated using the Brine Shrimp Lethality Test (BSLT). The anticancer activity of the most cytotoxic isolate was investigated against T47D breast cancer cell line using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. The secondary metabolites of the most active isolate were identified by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Seven distinct soil actinobacteria strains (ATS-1 – ATS-7) were successfully isolated and purified from the soil samples. The BSLT revealed that isolate ATS-7 exhibited the highest toxicity with an LC50 of 19.91 ppm, indicating potent bioactivity. However, anticancer investigation of ATS-7 supernatant against T47D breast cancer cells demonstrated non-toxic effects, with an IC50 of 556.8 ppm, suggesting limited anticancer efficacy. GC-MS analysis of ATS-7 supernatant identified 13 compounds with acetic acid, Acetoin, 2-Propanone (1-Hydroxy-), and 2,3-Butanediol as the most abundant metabolites.