Green synthesis of silver nanoparticles using alagaw (Premma odorata) leaves extract and its antibacterial activity against Escherichia coli / by Julianna Marie A. Basinang, Samantha Gale P. Gemarino, Dranel Genesis S. Grecia, & Gabriel Anthony A. Tinsay.

Escherichia coli poses a significant public health threat in the Philippines, with a total of 10,451 reported cases during 2022. Green synthesis of silver nanoparticles exhibits significant antimicrobial actions to bacterial infections. Alagaw (Premna odorata) has been reported to possess antibacterial properties. Thus, this study generally aims to determine the antibacterial activity of the synthesized silver nanoparticles using Alagaw leaves extract against E. coli.

This study utilized 200 g of Alagaw leaves extracted using 95% ethanol and used to synthesize silver nanoparticles. The synthesized silver nanoparticles were then subjected to Ultraviolet Spectrometer for characterization and tested for antibacterial activity through zone inhibition using Disk diffusion method after 18-24 hours of incubation. The treatments were replicated thrice and are as follows: Treatment A - 5μl, B- 10μl, C - 20μl of green synthesized silver nanoparticles from Alagaw leaves extract, positive control (Ciprofloxacin) and negative control (Sterile Ultrapure Water). The mean was determined using Kruskal-Wallis test and computed at 5% level
of significance.

Results revealed that the positive control (45 mm), got the best result followed by C (13. 33 mm), B (10.33 mm), A (10 mm), and the negative control (o mm). Kruskal- Wallis results revealed that the p-value (0.011) is less than 5% level of significance, therefore the null hypothesis was rejected. Hence, there is a significant difference. Based on the results gathered, it is concluded that the synthesized silver nanoparticles using Alagaw leaves extract have the potential to inhibit the growth of E. coli.

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