Gonad Extracts of Diadema setosum as Potential Antibacterial Agent Derived from Wakatobi District Sea Waters Southeast Sulawesi Province-Indonesia

Abstract

High incidence rates of typhoid fever and urinary tract infections in developing countries are aggravated by the overuse of antibiotics that lead to higher resistance of strains of bacteria, including Salmonella typhi and uropathogenic E. coli (UPEC). This dilemma instigates recent studies to find alternative drugs derived from marine resources to reduce the resistance of these harmful bacteria through the utilization of bioactive compounds in the gonad of Diadema setosum. For that reason, this study was conducted to explore the antibacterial properties of ethyl acetate extract in the gonad of Diadema setosum on S.typhi and E. coli bacteria. Chemical screening of bioactive compounds in the gonad of Diadema setosum used ethyl acetate solvent, whereas the antibacterial sensitivity test was conducted by diluting the gonad extracts in 10% DMSO. Preparation of 10% DMSO was made by mixing 10 ml DMSO with a 90 ml aquadest. Each gonad extract of 1 g, 2 g, 4 g, and 8 g was diluted in 10 ml DMSO with the extract concentrations of 10%, 20%, 40%, and 80%, respectively. Results of the chemical screening of the gonad extracts of Diadema setosum showed that the gonad extracts contained flavonoids (orange to red color), steroids (greenish color), and saponin was marked in the form of foam for 15 minutes. Meanwhile, results of the culture test proved that ethyl acetate extract of the gonad of Diadema setosum inhibited the growth of E. coli and S. typhi at 80% concentration classified into high inhibition response with mean inhibition response was 21 mm for E. coli and mean inhibition response was 20 mm for S. typhi compared to the concentrations of 40%, 20%, and 10 %. It was concluded that the gonad extracts of Diadema setosum could be used as a potential novel drug for reducing the resistance of these bacteria. In addition, the gonad of Diadema setosum delivers a potential alternative foodstuff to improve health status and prevents the negative effects of these bacterial strains