The efficacy of Aesculus hippocastanum seeds on diabetic nephropathy in a streptozotocin-induced diabetic rat model

Esculin ameliorates obesity-induced insulin resistance by improving adipose tissue remodeling and activating the IRS1/PI3K/AKT/GLUT4 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cortex fraxini (also known as qinpi)-the bark of Fraxinus rhynchophylla Hance (Oleaceae)-is widely used as a Chinese traditional medicinal for its anti-inflammatory and anti-hyperuricemic activities.

AIM OF THE STUDY

Obesity-induced insulin resistance (IR) is driving the rising incidence of type 2 diabetes mellitus and is related to pathological adipose tissue remodeling. Esculin, a major active component of Cortex fraxini, has anti-diabetic effects. However, whether esculin improves obesity-induced IR by regulating adipose tissue remodeling is unclear. The aims of the present study were to assess the effects of esculin on obesity-induced IR and to explore the underlying mechanisms.

MATERIALS AND METHODS

Obese IR C57BL/6J mice were treated with esculin (40 or 80 mg/kg/day) for 4 weeks. Oral glucose tolerance tests were used to assess insulin sensitivity. Histological analyses were performed to analyze the number and size distribution of adipocytes. Glucose uptake was assessed using 2-NBDG.

RESULTS

Esculin had no effect on body weight gain but reduced fasting blood glucose, improved oral glucose tolerance, and increased insulin sensitivity. Esculin reduced adipocyte size and the expression levels of collagen 4A1 and tumor necrosis factor α and increased the number of adipocytes and the expression of vascular endothelial growth factor A. Esculin promoted the differentiation of 3T3-L1 cells and upregulated the mRNA expression of CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor-γ, activated the insulin receptor substrate 1 (IRS1)/phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, and enhanced the translocation of glucose transporter type 4 (GLUT4) and glucose uptake in adipocytes treated with palmitic acid.

CONCLUSIONS

These data suggest that esculin increases insulin sensitivity by improving adipose tissue remodeling and activating the IRS1/PI3K/AKT/GLUT4 pathway.

Raspberry Ketone Protects Kidney Damage in Diabetic Nephropathy by Improving Kidney Mitochondrial Dysfunction

Mitochondrial dysfunction and oxidative stress play essential roles in the pathogenesis of diabetic nephropathy (DN). The respiratory oxygen consumption and oxidative stress status of kidney mitochondria are closely associated with the development of DN. In this study, raspberry ketone (RK), the predominant bioactive component extracted from raspberry, was applied to treat the established DN mice model. This study investigated whether RK protects the kidneys of high-fat and high-sugar/streptozotocin (STZ)-induced diabetic rats by inhibiting oxidative stress and ameliorating mitochondrial dysfunction. Besides, the DN mice models were established by injecting high-fat and high-sugar/STZ (130 mg/kg, intraperitoneal injection). The animals were randomly divided into the control group (normal saline, ig), DN group (normal saline, ig), DN + RK group (200 mg/kg RK + normal saline, ig), DN + RK group (400 mg/kg RK + normal saline, ig), and DN + Metformin (Met) (200 mg/kg Met + normal saline, ig). Regular monitoring of fasting blood glucose (FBG) levels was observed in mice. After 10 weeks of drug treatment, the kidneys of mice in each group were analyzed using ultrasound, and the mice were euthanized humanely. Kidney weight (KW)/body weight (BW) and kidney injury, mitochondrial function, and oxidative stress indicators were determined. The histopathological changes in renal tissue were observed after hematoxylin and eosin (H&E) staining. The results recommended that RK has a renoprotective function on DN mice by improving mitochondrial dysfunction and inhibiting oxidative stress.

Tissue Culture Response of Ornamental and Medicinal Aesculus Species—A Review

Species of the genus Aesculus are very attractive woody ornamentals. Their organs contain numerous health-promoting phytochemicals. The most valuable of them—aescin—is used in commercial preparations for the treatment of venous insufficiency. The industrial source of aescin is horse chestnut seeds because the zygotic embryos are the main site of its accumulation. Horse chestnut somatic and zygotic embryos contain similar amount of aescin, hence somatic embryos could be exploited as an alternative source of aescin. Somatic embryogenesis, androgenesis and de novo shoot organogenesis were successfully achieved in several Aesculus species, as well as secondary somatic embryogenesis and shoot organogenesis, which enables mass production of embryos and shoots. In addition, an efficient method for cryopreservation of embryogenic tissue was established, assuring constant availability of the plant material. The developed methods are suitable for clonal propagation of elite specimens selected as the best aescin producers, the most attractive ornamentals or plants resistant to pests and diseases. These methods are also useful for molecular breeding purposes. Thus, in this review, the medicinal uses and a comprehensive survey of in vitro propagation methods established for Aesculus species, as well as the feasibility of in vitro production of aescin, are presented and discussed.

Treatment with crocin suppresses diabetic nephropathy progression via modulating TGF-β1 and oxidative stress in an experimental model of pinealectomized diabetic rats

One of the most common complications of diabetes is diabetic nephropathy (DN). Uncontrolled hyperglycemia leads to histopathologic alterations in the kidney that prevent normal renal function. This study aimed to explore the effects of crocin treatment via virtue of its numerous beneficial properties in streptozotocin-induced pinealectomized diabetic rats. The pinealectomy procedure was conducted on the first day of the study. On the 30th day following pinealectomy, streptozotocin (STZ) (50 mg/kg) was administered intraperitoneally in Wistar rats for induction of diabetes. Diabetes was confirmed on the 3rd day following STZ administration by determining the glucose levels. Daily crocin treatment intraperitoneally for 15 days (50 mg/kg) ameliorated impaired renal oxidant/antioxidant balance, reduced TGF-β1 immuno-staining around tubules, and promoted improvement of renal architecture. Moreover, crocin administration improved altered renal function parameters, including serum Cr and BUN, and also increased creatinine clearance. In conclusion, the protective effects of crocin on diabetic nephropathy might be associated with its powerful antioxidant properties, its ability to improve tissue antioxidant status, and its ability to prevent inflammatory pathways.

Whey Proteins as a Potential Co-Surfactant with Aesculus hippocastanum L. as a Stabilizer in Nanoemulsions Derived from Hempseed Oil

The use of natural surfactants including plant extracts, plant hydrocolloids and proteins in nanoemulsion systems has received commercial interest due to demonstrated safety of use and potential health benefits of plant products. In this study, a whey protein isolate (WPI) from a byproduct of cheese production was used to stabilize a nanoemulsion formulation that contained hempseed oil and the Aesculus hippocastanum L. extract (AHE). A Box-Behnken experimental design was used to set the formulation criteria and the optimal nanoemulsion conditions, used subsequently in follow-up experiments that measured specifically emulsion droplet size distribution, stability tests and visual quality. Regression analysis showed that the concentration of HSO and the interaction between HSO and the WPI were the most significant factors affecting the emulsion polydispersity index and droplet size (nm) (p < 0.05). Rheological tests, Fourier transform infrared spectroscopy (FTIR) analysis and L*a*b* color parameters were also taken to characterize the physicochemical properties of the emulsions. Emulsion systems with a higher concentration of the AHE had a potential metabolic activity up to 84% in a microbiological assay. It can be concluded from our results that the nanoemulsion system described herein is a safe and stable formulation with potential biological activity and health benefits that complement its use in the food industry.

Phytochemical, ethanomedicinal and pharmacological applications of escin from Aesculus hippocastanum L. towards future medicine

Medicinal plants are used from ancient times for treatment of various ailments. Aesculus hippocastanum (Horse chestnut), is the popular and most valuable tree native to the South East Europe. It's seed extracts and their concentrates contain phytocompounds like flavonoids, polyphenols, triterpenoid saponin glycosides (escin), epicatechin, tannins, kaempferol, esculin, fraxin, carbohydrate, essential fatty acids (linoleic acid), oleic acid and purine bases (adenine and guanine). Due to these vital phyto-constituents, horse chestnut is used in phytomedicine for the prevention and treatment of diverse disorders as in venous congestion in leg ulcers, bruises, arthritis, rheumatism, diarrhoea, phlebitis etc. We collected the pharmacological applications of Aesculus hippocastanum L. extracts and escin as the cheif bioactive compound and their uses in traditionally and clinically for the management of various disorders. This review describes the efficacy of A. hippocastanum L. extracts and their bioactive compounds. So in the furtue this plant may be useful for the alternative treatment measure for various ailments via incorporating either extract or escin into novel delivery systems for improving the social health in future and would provide improved quality of life.

Effect of hesperidin treatment on α-Klotho/FGF-23 pathway in rats with experimentally-induced diabetes

Objective Non-alcoholic fatty liver disease, steatohepatitis and nephropathy are considered among the most important complications of diabetes mellitus (DM), which recently increased due to increased frequency of DM and the prolonged life span of diabetic patients The aim of the present study was to reveal the possible effect of hesperidin (HP) on alpha-klotho (α-KL)/ fibroblast growth factor-23 (FGF-23) pathway in rats with diabetes induced by streptozotocin (STZ). Materials and methods Thirty six male Sprague-Dawley rats were randomly divided into three groups. The rats of the control, diabetes, and treatment groups were fed with standard feed and water throughout the 2-week study. In order to induce diabetes mellitus in rats, those in the diabetes group were administered a single dose of 50 mg/kg STZ. For the DM + HP group, a single dose of 50 mg/kg STZ, when diabetes was induced, hesperidin was administered orally at a dose of 100 mg/kg by gavage. Results The α-KL levels of our study groups, both the liver and kidney α-KL levels and serum α-KL of the STZ-induced diabetic group were statistically significantly lower than the control group (respectively, p < 0.05, p < 0.001, p < 0.05). It was observed that hesperidin administration statistically significantly increased α-KL levels in serum, liver and renal tissue (p < 0.001). Liver, kidney and serum FGF-23 levels of the diabetic group increased significantly in comparison to the control group (respectively, p < 0.05, p < 0.01, p < 0.001). FGF-23 levels that increased in kidney tissue and serum samples of the diabetic group decreased statistically significantly with hesperidin administration (respectively, p < 0.01, p < 0.001). Conclusion The α-KL/FGF-23 pathway is a promising bio-indicator in various cases of systemic toxicity and pathology. In addition, the strong positive effects of hesperidin administration on diabetic toxicity in the liver and kidneys suggest that it may be included in the alternative treatment methods in the future.

Lycium chinense leaves extract ameliorates diabetic nephropathy by suppressing hyperglycemia mediated renal oxidative stress and inflammation

Diabetic nephropathy is one of the most serious and most frequently encountered diabetic complication, accounting for the highest cause of end-stage renal disease. This present study was aimed at exploring the protective/attenuative effect of Lycium chinense leaf extract (MELC) on streptozotocin induced diabetic nephropathy in experimental Sprague Dawley rats. The oral administration of diabetic rats with MELC markedly ameliorated renal dysfunction as observed in the significant reduction in the serum levels of creatinine, blood urea nitrogen (BUN), albumin and TGF-β1 as compared to the untreated diabetic control rats. In addition, the elevated levels of renal oxidative stress markers and pro-inflammatory parameters (GSH, SOD, CAT, MDA, TNF-α, IL-6 and IL-1β) were significantly reduced in MELC treated diabetic rats. The results obtained in this study suggests that L. chinense leaf might have the potential as possible pharmacological agent against diabetic nephropathy by suppressing renal oxidative stress and inflammation.

ALA/LA ameliorates glucose toxicity on HK-2 cells by attenuating oxidative stress and apoptosis through the ROS/p38/TGF-β1 pathway

BACKGROUND

Growing evidence indicates that oxidative stress (OS) plays a pivotal role in Diabetic nephropathy (DN). In a previous study we demonstrated that ALA/LA protected HK-2 cells against high glucose-induced cytotoxicity. So we aimed to establish the glucose injury model of HK-2 cells and investigate the beneficial effects of ALA/LA on high glucose-induced excessive production of TGF-β1 and the possible mechanisms mediating the effects.

METHODS

The expression of OS markers in high glucose-induced HK-2 cells treated with ALA/LA., including the antioxidant enzymes and reactive oxygen species (ROS) production, as well as the apoptosis rate were assayed by ELISA and flow cytometry. The p38/transforming growth factor β1 (TGF-β1) signal pathway were measured by real-time RT-PCR and western blot.

RESULTS

The modeling condition of glucose toxicity on HK-2 cells was at the glucose concentration of 40.9 mM. ALA/LA can significantly increase the activities of antioxidant enzymes and decrease ROS production stimulated by high glucose. The study also found that ALA/LA caused a decrease in the apoptosis rate and TGF-β1 level of HK-2 cells under high glucose stress through the ROS/p38 pathway.

CONCLUSIONS

ALA/LA exerts protective effects in vitro through inhibition of ROS generation, down regulation of the activation of the p38MAPK pathway and the expression of TGF-β1 in HK-2 cells.