Green-Synthesized Silver Nanoparticles from Green Tea and Papaya Leaf Extracts: Potential for Anti-Diabetic Activity

Abstract

ABSTRACT

Introduction

Green tea and papaya leaves have been reported to be rich sources of antioxidants which contain active compounds like polyphenols, caffeine, minerals, and vitamins. Green tea, in particular, is well-known for its catechins content, which have been used to regulate blood sugar levels. Conversely, papaya leaf extract offers antimicrobial, antioxidant, and antiviral properties, and its ability to enhance insulin production contributes to its effectiveness in lowering blood sugar levels. Therefore, the aim of the present study is to explore the therapeutic potential of silver nanoparticles synthesized using extracts from green tea and papaya leaves for the treatment of type 2 diabetes mellitus and its associated complications.

Methods

In this study, silver nanoparticles were synthesized using aqueous extracts of green tea and papaya leaves. These nanoparticles were evaluated for their ability to inhibit the two key carbohydrate metabolizing enzymes, namely α-amylase and α-glucosidase. Additionally, the impact of silver nanoparticles on diabetes associated complications such as retinopathy and nephropathy were also examined. Specifically, the inhibitory effects of the synthesized silver nanoparticles on sorbitol accumulation and the formation of advanced glycation end products (AGEs) were assessed.

Results

The anti-diabetic effect of the synthesized silver nanoparticles (PL-GT-Ag NPs) and standard acarbose was evaluated at different concentrations of 5 μg/ml-160 μg/ml. The results showed that the silver nanoparticles showed marked inhibition against α-amylase and α-glucosidase with a maximum inhibition of 80% and 78% respectively at 160 μg/ml. A maximum inhibition of 88% and 84% was observed for standard acarbose at a similar concentration of 160 μg/ml. The aldolase reductase activity was dose-dependently inhibited by different concentrations of silver nanoparticles with minimum inhibitory percentage of 1.13% at 5 μg/ml to maximum inhibition of 78.93% at 160 μg/ml. Similarly advanced glycation end products (AGEs) were also inhibited in a concentration-dependent manner.

Conclusion

Overall, this study underscores the promising, enduring anti-diabetic effects of silver nanoparticles derived from green tea and papaya extracts, hinting at their potential as a therapeutic approach for diabetes treatment. Moreover, the silver nanoparticles were found to be effective in reducing sorbitol accumulation and inhibiting AGE formation, indicating their potential in addressing diabetes-related complications.