Inhibition of key digestive enzymes involved in glucose metabolism by biosynthesized zinc oxide nanoparticles from Syzygium cumini (L.): An in vitro and in silico approach

Synthesis of zinc oxide nanoparticles using methanol propolis extract (Pro-ZnO NPs) as antidiabetic and antioxidant

In recent times, the overall health of individuals has been declining due to unhealthy lifestyles, leading to various diseases, including diabetes. To address this issue, antidiabetic and antioxidant agents are required to back-up human well-being. Zinc oxide (ZnO) is one such substance known for its antidiabetic and antioxidant effects. To enhance its capability and effectiveness, propolis was utilized to synthesize zinc oxide nanoparticles (Pro-ZnO NPs). The objective of this study was to synthesize Pro-ZnO NPs and assess their performance by conducting inhibition assays against α-amylase and α-glucosidase enzymes, as well as a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. The results showed that Pro-ZnO NPs were formed in a hexagonal wurtzite structure, with particle sizes ranging from 30 to 50 nm and an absorption band observed at 341 nm. The stability, chemical properties, and crystallography of Pro-ZnO NPs were also thoroughly examined using appropriate methods. The Pro-ZnO NPs demonstrated significant inhibitory effects against α-amylase and α-glucosidase enzymes, with inhibition rates reaching 69.52% and 73.78%, respectively, whereas the antioxidant activity was as high as 70.76%. Consequently, with their high inhibition rates, the Pro-ZnO NPs demonstrate the potential to be employed as a natural agent for combating diabetes and promoting antioxidant effects.

Potential Application of Alternative Materials for Organic Pollutant Removal

The work aims to synthesize and characterize vegetal charcoal (or biochar) from Syzygium cumini (AC-SC), evaluating the adsorption capacity for dexamethasone drug (DEX) removal, using the kinetic and equilibrium adsorption. The samples were characterized by N₂ porosimetry, X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, zeta potential, and zero charge point. Adsorption equilibrium was carried out applying the Langmuir, Freundlich, Redlich-Peterson, Sips, and Toth models, and kinetic adsorption applied the pseudo-first order, pseudo-second order, Elovich, Avrami, and Weber-Morris models. AC-SC showed a heterogeneous and porous surface, negatively charged, crystalline structure, specific surface area of the 2.14 m² g^-1 and pH_ZCP = 7.36. About the effect of the AC-SC concentration, 5.0 g L^-1 showed the best DEX removal (53.02%), about the others' concentration (2.0 and 7.5 g L^-1). About the equilibrium and kinetic adsorption, the Sips model and pseudo-second order showed the best experimental data adjusted, indicating that the adsorption monolayer was dependent on the ions onto the biosorbent, with a maximum adsorption capacity of 0.744 mg g^-1 after 180 min. Therefore, AC-SC can be used as an alternative material in the removal of organic pollutants, such as drug removal.

Protective role of biosynthesised zinc oxide nanoparticles on pancreatic beta cells: an in vitro and in vivo approach

Sulphonylureas are extensively used in the treatment of type II diabetes; however, these drugs have complications of hypoglycaemia and weight gain. The current study aims at developing a potent antidiabetic drug that has lesser side effects and better management of its associated conditions. Zinc oxide nanoparticles (ZnO NPs) were synthesised using Syzygium cumini seed extract with an average size of 18.92 nm. In vitro studies on rat insulinoma (RIN-5F) cells revealed that cells treated with synthesised ZnO NPs showed a dose-dependent increase in insulin secretion. Streptozotocin-fructose-induced type II diabetic rats treated with ZnO NPS exhibited a significant reduction (p < 0.01) in the blood glucose levels, total cholesterol, triglycerides, and low-density lipoprotein levels and increase (p < 0.01) in serum insulin and liver antioxidant enzyme levels proclaiming its role as a hypoglycaemic and hypolipidaemic drug. Treatment of ZnO NPs in diabetic rats exhibited an increased number of beta cells which was responsible for its increased insulin levels and reduced glucose levels. From the overall observations, biosynthesised ZnO NPs exhibited an efficacious hypoglycaemic effect in diabetic rats, so it can be suggested as a potent antidiabetic drug.