Mechanisms of Antidiabetic Activity of Methanolic Extract of Punica granatum Leaves in Nicotinamide/Streptozotocin-Induced Type 2 Diabetes in Rats

Abstract

The current study aimed to establish the mechanisms of antidiabetic activity of methanolic extract of Punica granatum leaves (MEPGL) in nicotinamide/streptozotocin-induced type 2 diabetes in rats. Phytochemical screening, HPLC analysis, and acute toxicity study of MEPGL were carried out. Various concentrations of MEPGL (100, 200, 400, and 600 mg/kg) were administered orally to diabetic rats for 45 days on a daily basis. The antidiabetic effect of MEPGL was examined by measuring blood glucose, plasma insulin, and glycated hemoglobin (HbA1c) levels, as well as with an oral glucose tolerance test. The antioxidant effect of MEPGL was determined by analyzing hepatic and renal antioxidant markers, namely superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), and lipid peroxidation. The other biochemical markers alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), urea, and creatinine, as well as total cholesterol, triglycerides, and high-density lipoprotein (HDL) were also studied. Type 2 diabetes significantly altered these parameters, while oral administration of the MEPGL significantly ameliorated them. Moreover, the pancreatic histopathological changes were attenuated with MEPGL treatment. In a nutshell, oral MEPGL administration in diabetic rats showed antidiabetic activity due to its antioxidant activity, most probably due to the gallic acid, ellagic acid, and apigenin found in MEPGL.

Variation of the Polyphenolic Composition and Antioxidant Capacity of Freshly Prepared Pomegranate Leaf Infusions over One-Day Storage

“…As shown in Table 3 , the r value of PCC demonstrated a positive significant correlation of TFs and CTs with radical scavenging and ferric reducing activities orderly measured by ABTS ( r = 0.98, r = 0.99), DPPH ( r = 0.89, r = 0.83), and FRAP ( r = 0.94, r = 0.86), respectively, indicating that the evolution of these phenolic compounds significantly contributed to the good antioxidant stability of PLI during one-day storage. This observation was strengthened by several studies [ 17 , 41 ] reporting that the antioxidant and anti-diabetic activity of PL extracts was linked to the presence of flavonoids and tannins.…”

“…Currently, some putative remedies of PLs can include the inhibition of microbial and inflammation [ 15 , 16 , 17 ]. Nevertheless, knowledge of the bioactive substances and the biological characteristics of pomegranate leaf infusion (PLI) remains scarce, including knowledge of the possible degradation of the polyphenolic composition and antioxidant capacity during 24 h of storage.…”

Determination of TLC fingerprint biomarker of Ipomoea batatas (L.) Lam leaves extracted with ethanol and its potential as antihyperglycemic agent

“…The role of GMC is to stimulate insulin secretion by pancreatic beta cells, and this ensure sufficient glucose uptake into cells. GMC was also reported to inhibit the initiation of lipid peroxide (LPO) formation when insufficient uptake occurred (Erejuwa et al 2010, Rabbani et al 2010, Obi et al 2015, Pandarekandy et al 2017, Pottathil et al 2020. Enhancement of lipid peroxide (LPO) was monitored through MDA as its main product.…”

“…Many studies reported that anthocyanin has potential an antidiabetic agent (Matsui et al 2002, Jayaprakasam et al 2005, Olivas-Aguirre et al 2016, Khoo et al 2017, Luo et al 2018, Al-Yousef et al 2020, Vilhena et al 2020. Their antihyperglycemic potency is presumed to be due to inhibition of oxidative stress, which leads to induction of pancreatic beta cells to produce sufficient insulin level (Vessal et al 2003, Jawi et al 2009, Pottathil et al 2020.…”

Comparison of the Efficiency of Lepidium sativum, Ficus carica, and Punica granatum Methanolic Extracts in Relieving Hyperglycemia and Hyperlipidemia of Streptozotocin-Induced Diabetic Rats

“…These doses were chosen for this study based on the results of previous toxicological studies [19][20][21].…”