A sub-acute oral toxicity analysis and comparative in vivo anti-diabetic activity of zinc oxide, cerium oxide, silver nanoparticles, and Momordica charantia in streptozotocin-induced diabetic Wistar rats

Type 2 diabetes mellitus (T2DM) is one of the most threatening, non-communicable ailments worldwide. The use of nanoparticles as a medicine in the treatment of T2DM is an attractive proposition. In the current study, zinc oxide nanoparticles (ZnO NPs), cerium oxide nanoparticles (CeO2 NPs), silver nanoparticles (Ag NPs), and Momordica charantia (MC) were evaluated for their in vivo anti-diabetic activity. The resulting ZnO, CeO2, and Ag NPs were characterized via various techniques such as XRD, FT-IR, PSA, and SEM. The synthesized NPs and MC extract were tested for toxicity using a sub-acute oral toxicity model by following the OECD 425 guidelines. The male Wistar rats with weights in the range of 180-200 g were grouped as follows: normal control: who did not receive any treatment; diabetic control: who received a single intraperitoneal dose of streptozotocin (40 mg kg(-1)); standard: who received a single daily oral dose of streptozotocin 50 mg per kg body weight; diabetic and ZnO NPs: who received a single daily oral dose of 100 mg kg(-1) and 200 mg kg(-1) of ZnO NPs; diabetic and CeO2 NPs: who received a single daily oral dose of 100 mg kg(-1) and 200 mg kg(-1) of CeO2 NPs; diabetic and Ag NPs: who received a single daily oral dose of 100 mg kg(-1) and 200 mg kg(-1) of Ag NPs; and diabetic and MC: who received a single daily oral dose of 100 mg kg(-1) and 200 mg kg(-1) of MC. In conclusion, the green-synthesized NPs showed no toxic effect and were considered safe. From the experimental results, it may be concluded that due to the extensive biological and pharmacological properties, the ZnO NPs and Ag NPs had more potent anti-hyperglycemic activity than MC and CeO2 NPs. Further pharmacokinetic studies are required to establish the exact mechanism of action (of NPs).