Volume 16, Issue 37, January - June, 2022

Evaluation of Flavonoid and Phenol content and Antioxidant Properties of Silver Nanoparticles of Unripe Pawpaw and Banana peel

Adesipe TI^1,2♦, Iweala EJ^1,3,4

¹Dept. of Biochemistry, College of Science and Technology, Covenant University, Ota, Ogun State, Nigeria
²Dept of Science Laboratory Technology, Federal Polytechnic, Ilaro, Ogun State, Nigeria
³Covenant Applied Informatics and Communication African Centre of Excellence (CApIC-ACE), Covenant University, PMB 1023, Ota, Ogun State, Nigeria.
⁴Covenant University Public Health and Wellbeing Research Cluster (CUPHWERC), Covenant University, PMB 1023, Ota, Ogun State, Nigeria

^♦Corresponding author
Email : iyanugbemie@gmail.com; Telephone:(+234)7066025250

ABSTRACT

The present study is aimed at determining the total flavonoid and phenol contents and antioxidant properties of Silver nanoparticles (AgNPs) biosynthesized using unripe pawpaw peel (UPPAE) and banana peel (UBPAE) aqueous extracts. AgNPs of UPPAE and UBPAE were synthesized separately by reducing AgNO3 with UPPAE and UBPAE respectively. Primary characterization was done on the synthesized AgNPs with a UVvisible spectrophotometer, and their antioxidant properties were evaluated using DDPH, ABTS, FRAP assays. The reaction mixtures of AgNO3 solution and the agro-waste extracts turned dark brown for AgNO3 + UPPAE and light brown for AgNO3 + UBPAE and also displayed a UV-visible spectrum of 450 nm and 421 nm respectively which is characteristic of silver nanoparticles. The result of the total flavonoid contents revealed that AgNPs-UPPAE had the highest amount of flavonoid content (499.89 ± 1.96 mgQE/g) and phenol content (85.30 ± 0.57 mgGAE/g). However, the antioxidant result revealed that AgNPs-UBPAE displayed the highest DPPH scavenging activity with an IC50 value of 52.98 µg/ml when compared to AgNPs-UPPAE (52.98 µg/ml) and Ascorbic acid (59.93 µg/ml). AgNPs-UPPAE and AgNPs-UBPAE showed maximum ABTs scavenging activities with IC50 values of 52.20 µg/ml and 52.45 µg/ml respectively which is comparable to Ascorbic acid (50.95 µg/ml). The result of FRAP revealed that AgNPs-UPPAE and AgNPs-UBPAE had the highest FRAP value at a concentration of 25µg/ml unlike Ascorbic acid whose highest FRAP value was at 100 µg/ml. This result reveals the potential use of AgNPs-UPPAE and AgNPs-UBPAE as alternative natural antioxidants for the management of oxidative stress-induced ailments.

Keywords: Silver nanoparticles, Agro-waste, Total phenol and flavonoid contents, Antioxidant properties

Drug Discovery, 2022, 16(37), 1-8

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