Antidiabetic effect of bio-enhanced preparation of turmeric in streptozotocin-nicotinamide induced type 2 diabetic Wistar rats

Antidiabetic effect of combined extract of Coccinia grandis and Blumea balsamifera on streptozotocin-nicotinamide induced diabetic rats

BACKGROUND

Coccinia grandis and Blumea balsamifera are two medicinal plants that have been known to have good antidiabetic properties. Combining these two plant extracts may generate a greater effect that can increase efficacy and decrease the dose.

OBJECTIVE

This research investigated the antidiabetic activity of the combination of C. grandis and B. balsamifera leaves extracts on experimental diabetic rats.

MATERIALS AND METHODS

The dried leaves of C. grandis and B. balsamifera were powdered and macerated with ethanol 70% (v/v). A diabetic condition in male Wistar albino rats was generated by intraperitoneal injection of a single dose of streptozotocin (65 mg/kg) followed by nicotinamide (110 mg/kg). Diabetes-confirmed rats were then given glibenclamide (4.5 mg/kg), C. grandis extract (300 mg/kg), B. balsamifera extract (150 mg/kg), and the combined extracts with a dose ratio of 1:1, 1:3, and 3:1. The treatment was performed for 28 days and fasting blood glucose was tested once a week. The pancreas and liver organs were taken on day 29 for antioxidant, histological, and immunohistochemical assessment.

RESULTS

Among all the extracts, the combined extract with a ratio of 1:3 showed the greatest glucose lowering effect. This combination also lowered malondialdehyde levels while increasing superoxide dismutase and catalase levels in the pancreas and liver organs. Histological examination showed this combination regenerated the islet of Langerhans. It also increased pancreatic insulin expression in immunohistochemical evaluation.

CONCLUSION

This study revealed that the combined extracts of C. grandis and B. balsamifera exhibited enhanced antidiabetic activity via ameliorating oxidative stress, regenerating β-cells, and increasing insulin expression.

Ameliorative Effects of Curcumin on Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM), a multifactorial and complicated metabolic disorder, is a growing public health problem. Numerous studies have indicated that bioactive compounds from herbal medicine have beneficial effects on T2DM prevention and treatment, owing to their numerous biological properties. Curcumin, the major curcuminoid of turmeric, is one of the most studied bioactive components of herbal supplements, and has a variety of biological activities. Clinical trials and preclinical research have recently produced compelling data to demonstrate the crucial functions of curcumin against T2DM via several routes. Accordingly, this review systematically summarizes the antidiabetic activity of curcumin, along with various mechanisms. Results showed that effectiveness of curcumin on T2DM is due to it being anti-inflammatory, anti-oxidant, antihyperglycemic, anti-apoptotic, and antihyperlipidemic, among other activities. In light of these results, curcumin may be a promising prevention/treatment choice for T2DM.

Curcuma longa extract reduces serum inflammatory markers and postprandial hyperglycemia in healthy but borderline participants with overweight and glycemia in the normal/prediabetes range: a randomized, double-blind, and placebo-controlled trial

The spice turmeric, which has the Latin name Curcuma longa (C. longa), has various physiological effects. This study evaluated the effects of a hot water mixture with supercritical carbon dioxide C. longa extracts, CLE, and the potential active components of C. longa, turmeronols A and B and bisacurone on inflammation and glucose metabolism. First, we investigated the effect of CLE and the potential active components of C. longa on lipopolysaccharide-induced inflammation in RAW264.7 macrophages. We found a significant decrease in the production of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide with CLE, turmeronol A, and bisacurone, Significant inhibition of each of these substances was also observed, except for TNF-α with turmeronol B. The second part of our work was a 12-week randomized, double-blind, placebo-controlled study in healthy but borderline adults aged 40 to 69 years with overweight and normal/prediabetes glycemia. We compared blood inflammatory and glycometabolic markers in the CLE (n = 55) and placebo groups (n = 55). We found significantly lower serum high-sensitivity C-reactive protein and hemoglobin A1c levels in the CLE group. This group also showed significant improvements in postprandial hyperglycemia and insulin sensitivity indices. Our findings indicate that CLE may reduce low-grade inflammation and thus improve insulin sensitivity and postprandial hyperglycemia. Clinical trial registration: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000051492, UMIN-CTR, UMIN000045106.

Phytochemicals and their Potential Mechanisms against Insulin Resistance

Insulin's inception dates back to 1921 and was unveiled through a momentous revelation. Diabetes is a dangerous, long-term disease in which the body fails to generate enough insulin or utilize the insulin it creates adequately. This causes hyperglycemia, a state of high blood sugar levels, which can even put a person into a coma if not managed. Activation of the insulin receptor corresponds to two crucial metabolic functions, i.e., uptake of glucose and storage of glycogen. Type 2 diabetes mellitus (T2DM) exists as one of the most challenging medical conditions in the 21st century. The sedentary lifestyle and declining quality of food products have contributed to the rapid development of metabolic disorders. Hence, there is an urgent need to lay some reliable, significant molecules and modalities of treatment to combat and manage this epidemic. In this review, we have made an attempt to identify and enlist the major phytoconstituents along with the associated sources and existing mechanisms against insulin resistance. The conducted study may offer potential sustainable solutions for developing and formulating scientifically validated molecules and phytoconstituents as formulations for the management of this metabolic disorder.

Mechanistic insights into the beneficial effects of curcumin on insulin resistance: opportunities and challenges

The past couple of decades in particular have seen a rapid increase in the prevalence of type 2 diabetes mellitus (T2DM), a debilitating metabolic disorder characterised by insulin resistance. The insufficient efficacy of current management strategies for insulin resistance calls for additional therapeutic options. The preponderance of evidence suggests potential beneficial effects of curcumin on insulin resistance, while modern science provides a scientific basis for its potential applications against the disease. Curcumin combats insulin resistance by increasing the levels of circulating irisin and adiponectin, activating PPARγ, suppressing Notch1 signalling, and regulating SREBP target genes, among others. In this review, we bring together the diverse areas pertaining to our current understanding of the potential benefits of curcumin on insulin resistance, associated mechanistic insights, and new therapeutic possibilities. Teaser: Current approaches to manage insulin resistance are not highly efficacious, which necessitates additional therapeutic options; curcumin combats insulin resistance by improving the levels of circulating irisin and adiponectin, upregulating and activating PPARγ, and suppressing Notch‑1 signalling.

The role of lutein-rich purple sweet potato leaf extract on the amelioration of diabetic retinopathy in streptozotocin-induced Sprague-Dawley rats

The objective of this study is to access the effect of purple sweet potato leaf (PSPL) extract on diabetic retinopathy (DR) of streptozotocin (STZ)-induced male Sprague-Dawley (SD) rats. In this study, rats were injected intraperitoneally with a single dose of 60 mg/kg STZ, and diabetes was confirmed on day 7. Rats were further divided into a few groups, which were then orally administered with one of the following treatments: 25 mg/kg of gliclazide (D25G), 200 mg/kg of PSPL extract (DT 200), and 400 mg/kg of PSPL extract (DT 400). However, the normal control (NS) and control group for diabetic (DNS) were given normal saline (NS) for 12 weeks. The results show that the treated group demonstrated a reduction in serum oral glucose tolerance test (OGTT) levels of DT 200 and DT 400, and an increase in the serum and retinal insulin levels, and restored oxidative stress markers in serum and retina on week 12. The PSPL extract exhibited protective effects in maintaining the kidney, liver, retina, and pancreas architecture in 400 mg/kg compared to the 200 mg/kg treated group and D25G, thereby restoring fully transparent lenses in diabetes-induced rats. In conclusion, 400 mg/kg PSPL is the most effective dose for the amelioration of STZ-induced DR pathology in male SD rats.

Anti-diabetic effects of fungal Ergosta-4, 6, 8(14), 22-tetraen-3-one from Pholiota adiposa

OBJECTIVE

Pholiota adiposa is a valuable edible and medicinal fungus. In this research, Ergosta-4, 6, 8(14), 22-tetraen-3-one (ETO) was obtained from Pholiota adiposa which is the first time to study the anti-diabetic and related mechanism.

METHODS

Ergosta-4, 6, 8 (14), 22-tetraen-3-one (ETO) was defined by IR and NMR. Relevant biochemical indicators were detected by ELISA assay, hematoxylin-eosin staining (H & E), fasting glucose levels (FBG), oral glucose tolerance test (OGTT), tissue homogenate biochemical measurements, immunohistochemical staining and western blot.

RESULTS

In this research, the ETO treatment groups exhibited a significant reduction in fasting blood glucose (FBG) levels, the High dose group (HD) was about 10 mmol/L lower than the diabetic control group (DC), and increase in body weight, the HD group weighed about 5 g more than the DC group on average. Also, the levels of triacylglycerol (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) were found to be decreased, while the levels of high-density superoxide dismutase (SOD), lipoproteincholesterol (HDL-C), catalase (CAT), and glutathione peroxidase (GSH-Px) were increased in the ETO treatment groups. The pancreatic and liver sections of diabetic control group (DC) exhibited several histopathological changes, but the ETO treatment groups exhibited improvements. ETO treatment led to the significant restoration of islet morphology and function. Moreover, the results of the western blot analysis indicate that ETO could be used for the treatment of diabetes, since it modifies part of the IRS1 / PI3K / AKT signaling pathway.

In Vivo Evaluation of Nanoemulsion Formulations for Metformin and Repaglinide Alone and Combination

Repaglinide and Metformin are used to treat Type 2 diabetes. Repaglinide with poor water solubility has relatively low oral bioavailability (56%) and undergoes hepatic first-pass metabolism. The oral bioavailability of metformin HCl is also low (about 50-60%). The purpose of this study was to prepare nanoemulsion formulations containing metformin HCl or repaglinide alone or in combination and characterize them in vitro and in vivo. Nanoemulsion formulations containing metformin HCl and/or repaglinide were successfully prepared and in vitro characterized. In addition, in vivo efficacy of nanoemulsion formulations was evaluated in a streptozotocin-nicotinamide-induced diabetic rat model. Biochemical, histopathological, and immunohistochemical evaluations were also performed. The mean droplet size and zeta potential values of nanoemulsion formulations were in the range of 110.15±2.64-120.23±2.16 nm and -21.95 - -24.33 mV, respectively. The percent entrapment efficiency values of nanoemulsion formulations were in the range of 93.600%-96.152%. All nanoemulsion formulations had a PDI of ≤0.223. A statistically significant decrease was observed in the blood glucose values of the diabetic rats treated with nanoemulsion formulations containing active substance/substances, compared to diabetic rats (control) (p<0.05). Nanoemulsion formulations (especially nanoemulsion containing metformin HCl and repaglinide combination) have a better antidiabetic activity and are more effective in reducing oxidative stress caused by diabetes.

Design, synthesis and chemical stability of indolizine derivatives for antidiabetic activity

Prodrugs of metformin were synthesized with the goal of enhancing biological activity of metformin. They were synthesized by combining metformin with 2-substituted indolizine (C7-C12). The synthesized prodrugs were characterized by IR, ¹H NMR, ¹³C NMR, and mass spectroscopy. The chemical hydrolysis of C7-C12 was carried out at pH 1.2, 6.8, and 7.4. All compounds showed encouraging chemical stability at pH 1.2 and 6.8, whereas mild hydrolysis was shown at pH 7.4. Further prodrugs were screened for antidiabetic activity using a streptozotocin-induced model in rat. These derivatives showed substantial results. Among them C8 showed significant activity in the reduction of streptozotocin-induced blood glucose in rats when compared to that of metformin, indicating the effectiveness of prodrug.

Effect of sakuranin on carbohydrate-metabolizing enzyme activity modifications in streptozotocin-nicotinamide-induced diabetic wistar rats

This study is to assess the glucose lowering activity of sakuranin in diabetes induced rats by streptozotocin (STZ) and nicotinamide (NA). Diabetic rats were treated sakuranin for 45 days (20, 40, 80 mg/kg) by orally. Sakuranin (80 mg/kg body weight) was normalized the changes of abnormal blood glucose plasma glucose and plasma insulin levels. Hence, we have continued the further research with this active dose of 80 mg/kg sakuranin. The plasma glucose and glycosylated hemoglobin (HbA1c) reduced and insulin, glycogen and hemoglobin levels increased by Sakuranin administration in diabetic rats. Additionally, hexokinase and glucose-6-phophate dehydrogenase activities increased and glucose-6-phosphatase and fructose-1,6-bisphosphatase activities decreased in diabetic condition while administration of treated compound. In this observed result signified that sakuranin may have potential role of diabetic condition rats by evidenced with reducing glucose and increasing insulin and also protect the carbohydrate metabolic changes.

Metformin hydrochloride entrapment in sorbitan monostearate for intestinal permeability enhancement and pharmacodynamics

Penetration enhancement of metformin hydrochloride via its molecular dispersion in sorbitan monostearate microparticles is reported. This represents basic philosophy to maximize its entrapment for maximum penetration effect. Drug dispersion in sorbitan monostearate with different theoretical drug contents (TDC) were prepared. Products showed excellent micromeritics and actual drug content (ADC) increased by increasing TDC. The partition coefficient of the drug products showed huge improvement. This indicates the drug entrapped in the polar part of sorbitan monostearate as a special image which effects on the drug release. The drug permeation profiles from the different products are overlapped with nearly equal permeation parameters. The permeation results suggested the main driving force for improving the drug paracellular pathway is its dispersion in sorbitan monostearate and is independent of ADC. Pharmacodynamic of the products showed a significant improvement than the drug alone at p ˂ 0.05. ANOVA test indicated the insignificant pharmacodynamic difference between the low, middle, and high ADC of the products. An excellent correlation founded between the drug permeation and pharmacodynamic precents. Drug permeation driving force via the paracellular pathway is its entrapment in sorbitan monostearate and independent on ADC. The technique is simple and the products had excellent micromeritics.