Quercetin, a Plant Flavonol Attenuates Diabetic Complications, Renal Tissue Damage, Renal Oxidative Stress and Inflammation in Streptozotocin-Induced Diabetic Rats

Abstract

Diabetes mellitus is a metabolic syndrome characterized by increased glucose levels, oxidative stress, hyperlipidemia, and frequently decreased insulin levels. The current research was carried out for eight consecutive weeks to evaluate the possible reno-protective effects of quercetin (50 mg/kg b.w.) on streptozotocin (STZ) (55 mg/kg b.w.) induced diabetes rat models. Various physiological, biochemical, and histopathological parameters were determined in control, diabetic control, and quercetin-treated diabetic rats. The current findings demonstrated that diabetes control rats showed significantly decreased body weights (198 ± 10 vs. 214 ± 13 g) and insulin levels (0.28 ± 0.04 vs. 1.15 ± 0.05 ng/mL) in comparison to normal control. Besides this, the other parameters showed increased values, such as fasting blood glucose, triglyceride (TG), and total cholesterol levels (99 ± 5 vs. 230 ± 7 mg/dL, 122.9 ± 8.7 vs. 230.7 ± 7.2 mg/dL, 97.34 ± 5.7 vs. 146.3 ± 8 mg/dL) (p < 0.05). In addition, the urea and creatinine levels (39.9 ± 1.8 mg/dL and 102.7 ± 7.8 μmol/L) were also high in diabetes control rats. After 8 weeks of quercetin treatment in STZ-treated animals, body weight, insulin, and fasting blood sugar levels were significantly restored (p < 0.05). The inflammatory markers (TNF-α, IL-6, and IL-1β) were significantly increased (52.64 ± 2, 95.64 ± 3, 23.3 ± 1.2 pg/mL) and antioxidant enzymes levels (SOD, GST, CAT, and GSH) were significantly decreased (40.3 ± 3 U/mg, 81.9 ± 10 mU/mg, 14.2 ± 2 U/mg, 19.9 ± 2 μmol/g) in diabetic rats. All the parameters in diabetic animals treated with quercetin were restored towards their normal values. Histopathological findings revealed that the quercetin-treated group showed kidney architecture maintenance, reduction of fibrosis, and decreased expression of COX-2 protein. These results determined that quercetin has reno-protective effects, and conclude that quercetin possesses a strong antidiabetic potential and might act as a therapeutic agent in the prevention or delay of diabetes-associated kidney dysfunction.

Quercetin Alleviates Pulmonary Fibrosis in Silicotic Mice by Inhibiting Macrophage Transition and TGF-β-Smad2/3 Pathway

“…Quercetin is ubiquitously present in vegetables, fruit, tea, and wine and has anti-inflammatory, anti-oxidative, and anti-carcinogenic properties that form the basis for potential benefits to overall health and disease resistance [ 20 ]. In addition, there are many studies focusing on the protective effect of quercetin against fibrosis [ 6 , 7 , 8 , 9 ]. Previous studies have reported that the early and late therapeutic administration of quercetin ameliorated silicosis in vivo [ 10 ].…”

“…Quercetin is a 3,3′,4′,5,7-pentahydroxy flavonol and a plant flavonoid found in edible fruits and vegetables [ 3 , 4 , 5 ]. Quercetin also has a suppressive effect on fibrosis [ 6 , 7 , 8 , 9 ]. Previous research has revealed that quercetin plays a role in silicosis by inhibiting macrophage senescence, possibly via the senescence-associated secretory phenotype (SASP) [ 10 ].…”

Therapeutic Potential of Curcumin, a Bioactive Compound of Turmeric, in Prevention of Streptozotocin-Induced Diabetes through the Modulation of Oxidative Stress and Inflammation

“…Lipid peroxidation was measured by estimating the malondialdehyde (MDA) concentration, which was evaluated by the absorbance of color development with thiobarbituric acid. The absorbance of the resulting product was estimated at 532 nm, and the results are expressed in nmol/g [ 52 ].…”

Myricetin: A Significant Emphasis on Its Anticancer Potential via the Modulation of Inflammation and Signal Transduction Pathways

“…Moreover, the chronic inflammation can lead to cancer in target organs as well as several tissues via multiple pathways [42]. Various natural compounds show antiinflammatory potential via inhibiting the production of inflammatory mediators or related signalling molecules [43][44][45][46][47][48].…”