Aktivitas Antioksidan dan Antibakteri Nanopartikel Simplisia Daun Afrika (Vernonia amygdalina Del)

Abstract

Background: Excessive amounts of free radicals can cause oxidative stress damage. Oxidative stress plays a role in the development of chronic disease. The presence of bacteria in food is caused by unclean food equipment, giving rise to pathogenic bacteria. African leaves have quite large antioxidant activity and can inhibit bacterial growth. Objective: This research was carried out experimentally including preparation of simplicia, characterization of simplicia nanoparticles. Testing the antioxidant activity of African leaf simplicia nanoparticles using the DPPH (1,1-diphenyl-2-picrlhydrazil) method with quercetin as a comparison was the measured using UV-Vis spectrophotometry. And testing the antibacterial activity of African leaf simplicia nanoparticles against Escherichia colli and Salmonella thypii bacteria using the disc diffusion method. Result: The result showed that the African leaf simplicia nanoparticles had a PSA value of 430 nm, SEM with 50000x magnification showed irregular result, fine lumps and uneven distribution, TEM showed a round shape, the particle distribution was uneven and almost uniform in each part, Zeta potential with a value 0f -29,5 mV. The IC50 value of African leaf simplicia nanoparticles using the DPPH method was 54,59 μg/mL, which means that African leaf simplicia nanoparticles have quite strong antioxidant activity. Result of testing the antibacterial activity of African leaf simplicia nanoparticles with a concentration of 300 mg/mL; 200 mg/mL; 100 mg/mL; 50 mg/mL; 25 mg/mL; 12,5 mg/mL can inhibit Escherichia colli bacteria with an average zone of inhibition of 8,33±0,45 mm; 8,17±0,35 mm; 7,63±0,21 mm; 6,57±0,31 mm; 6,60±0,20 mm; 6,67±0,21 mm. And for Salmonella thypii bacteria with a concentration of 300 mg/mL; 200 mg/mL can inhibit with an average of inhibition of 11,8±2,62 mm; 11,2±2,54 mm. Conclusion: It can be concluded that African leaf simplicia nanoparticles have strong antioxidant and antibacterial activity of African leaf simplicia nanoparticles against Escherichia colli with minimum inhibitory concentration of 100 mg/mL and Salmonella thypii bacteria with minimum inhibitory concentration of 200 mg/mL.