Protective effect of grape seed and skin extract against diabetes-induced oxidative stress and renal dysfunction in virgin and pregnant rat

Variations in nutritional quality and fatty acids composition of sardine (Sardina pilchardus) during canning process in grape seed and olive oils

Fish canning industries generally use different oils to ensure the juicing stage of canned sardines. In this context, we tested the use of grape seed oil (GSO) which could provide several health benefits to consumers. This study compared its effects on the quality of canned sardine to that of olive oil (OO). Total polyphenols, flavonoids and non flavonoids of the tested GSO were significantly higher than those of the OO. Also, The GSO was rich in polyunsaturated fatty acid (PUFA), namely linoleic acid (65.36% of total fatty acids). The use of GSO in the sardine sardines canning process increased significantly fat, protein and ash contents after 90 days of conservation. The fatty acid profile was dominated by PUFA for all the tested samples. Docosahexaenoic acid was the most abundant unsaturated fatty acid, followed by linoleic acid in GSO samples (20.86 ± 0.06% compared to 1.46 ± 0.05% in fresh sardine) and oleic acid in OO samples. Both atherogenic and thrombogenic indices decreased after the canning process in OO and GSO to less than 1. Thus GSO seems to improve the lipid nutritional quality in fresh sardine. In addition, the values for thiobarbituric acid and Total volatile base nitrogen did not exceed critical limits.

Tiliacora triandra extract and its major constituent attenuates diabetic kidney and testicular impairment by modulating redox imbalance and pro-inflammatory responses in rats

BACKGROUND

Literature has demonstrated that diabetes is associated with renal complication and testicular dysfunctions. The current study explored the potential of Tiliacora triandra extract and its major component against diabetic kidney and testicular damages in rats.

METHODS

Diabetes was induced by high fat diet/streptozotocin (HFD/STZ) and treated orally with Tiliacora triandra extract (TTE, 100 and 400 mg kg^-1 body weight) and its major component, 5,7-dihydroxy-6-oxoheptadecanoic acid (DHA, 25 mg kg^-1 body weight) for 30 consecutive days. Testicular activities of testicular enzymes, serum levels of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), sperm parameters and urinalysis for protein and albumin levels were evaluated. Renal and testicular biomarkers of oxidative stress and pro-inflammation were analysed along with histology.

RESULTS

The experimental diabetes induced significant alterations in the levels and activities of indices evaluated compared to non-diabetic normal rats. The 28-day treatment of diabetic rats with TTE and DHA markedly improved activities of testicular enzymes, restored levels of testosterone, LH and FSH and sperm parameters compared to untreated diabetic rats. TTE and DHA abrogated proteinuria and reversed urine albumin level. Testicular and renal oxidative stress and pro-inflammation were attenuated in diabetic rats treated with TTE and DHA. The diabetes-mediated histopathological damage was alleviated in the kidney and testis.

CONCLUSION

The protective effect of TTE and DHA against diabetes induced kidney and testicular damages may be related to its antioxidant and anti-inflammatory activities. © 2020 Society of Chemical Industry.

The Protective Effects of L-Carnitine and Zinc Oxide Nanoparticles Against Diabetic Injury on Sex Steroid Hormones Levels, Oxidative Stress, and Ovarian Histopathological Changes in Rat

Diabetes mellitus is a common chronic metabolic disorder. This study aimed to investigate the effects of co-treatment with L-carnitine (LC) and zinc oxide nanoparticles (ZnONPs) on serum levels of sex hormones, oxidative stress, and ovarian histopathology in streptozotocin (STZ)-induced diabetic rats. Female Wistar rats (n = 56, 180-220 g) received a single intraperitoneal (IP) injection of STZ (65 mg/kg). They were randomly assigned into the following groups: diabetic group (Dia), Dia+Met group (100 mg metformin/kg/day), Dia+LC group (200 mg/kg/day), Dia+ZnONPs group (10 mg/kg/day), and Dia+LC+ZnONPs group (200 mg LC/kg/day and 10 mg ZnONPs/kg/day). Control group (Ctl) received the same volume of STZ solvent. After 21 days of treatment, blood serum was centrifuged for sex hormone assays. The right ovary was used for biochemical analysis, and the left ovary was fixed in 10% neutral buffered formalin for histological assessment. The levels of estradiol, progesterone, FSH, and LH significantly increased in the Dia+ZnONPs+LC group (P < 0.001) compared with the Dia group. Co-treatment with LC and ZnONPs reduced malondialdehyde and carbonyl protein and increased glutathione, catalase, and superoxide dismutase activities in ovarian tissue compared with the Dia group (P < 0.05). Moreover, the number of all ovarian follicles significantly increased in this group compared with the Dia group (P < 0.05). The results of this study indicated that co-treatment with LC and ZnONPs could preserve ovarian function by increasing sex hormones levels and antioxidant activity and decreasing lipid peroxidation in diabetic rats. Therefore, this compound supplementation may improve ovulation and fertility in people with diabetes mellitus.

Health Effects of Grape Seed and Skin Extracts and Their Influence on Biochemical Markers

This review is focused on the study of the effects of grape seed and skin extract (GSSE) on human health. GSSE contains high concentrations of important polyphenolic substances with high biological activity. This review is a summary of studies that investigate the effects of GSSE on diabetes mellitus, cardiovascular disease and cancer, its neuroprotective effect, and its effects on the gastrointestinal tract and other health complications related to these diseases. The results of the studies confirm that the anti-inflammatory, antiapoptotic, and pro-proliferative effects of “Vitis vinifera L.” seed extract reduce the level of oxidative stress and improve the overall lipid metabolism.

Grape Seed Extract Polyphenols Improve Resistance Artery Function in Pregnant eNOS-/- Mice

Hypertension during pregnancy is a leading cause of maternal and fetal morbidity and mortality worldwide, increasing the risk of complications including preeclampsia, intracerebral hemorrhage and fetal growth restriction. Increased oxidative stress is known to contribute to poor vascular function; however, trials of antioxidant supplementation have raised concerns about fetal outcomes, including risk of low birthweight. Grape seed extract polyphenols (GSEP) have been suggested to promote cardiovascular protection, at least in part through antioxidant actions. We tested the hypothesis that administration of GSEP during pregnancy would reduce oxidative stress and improve resistance artery function with no detrimental effects on fetal growth, in an established model of maternal hypertension associated with vascular dysfunction, the endothelial NO synthase knockout (eNOS^-/-) mouse. Pregnant C57BL/6J (WT) and eNOS^-/- mice received either GSEP (200 mg/kg/day) or drinking water, between gestational (GD) day 10.5 and GD18.5. At GD17.5, maternal systolic blood pressure (SBP) was measured; at GD18.5, maternal malondialdehyde (MDA) concentrations, vascular function of aortic, mesenteric, uterine and posterior cerebral arteries was assessed, and fetal outcome evaluated. GSEP reduced maternal SBP (P < 0.01) and plasma MDA concentrations (P < 0.01) in eNOS^-/- mice. Whilst there was no effect of GSEP on vascular reactivity of aortas, GSEP improved endothelial-dependent relaxation in mesenteric and uterine arteries of eNOS^-/- mice (P < 0.05 and P < 0.001, respectively) and normalized lumen diameters of pressurized posterior cerebral arteries in eNOS^-/- mice (P < 0.001). Supplementation with GSEP had no effect in WT mice and did not affect fetal outcomes in either genotype. Our data suggest that GSEP improve resistance artery function, potentially through antioxidant actions, and provide a basis to further investigate these beneficial effects including in the prevention of intracerebral hemorrhage. Maternal supplementation with GSEP may be a safe intervention to improve outcomes in pregnancies associated with hypertension and vascular dysfunction.

Beneficial effects of walnut (Juglans regia L.) oil-derived polyunsaturated fatty acid prevents a prooxidant status and hyperlipidemia in pregnant rats with diabetes

BACKGROUND

Gestational diabetes mellitus has a long-term effect on pregnant women. Walnut (Juglans regia L.) oil-derived polyunsaturated fatty acid (PUFA) possesses multifarious pharmacological activities. This study investigated the beneficial effects of walnut oil-derived PUFA on glucose metabolism, pregnancy outcomes, oxidative stress, and lipid metabolism in gestational diabetes mellitus.

METHODS

The GDM rat model was generated by intraperitoneal injection of streptozotocin (40 mg/kg) on gestational day (GD) 6, GD7 and GD8. The differences between groups were estimated using one-way ANOVA followed by the Tukey's multiple comparison test for post-hoc analysis.

RESULTS

The results indicated that PUFA could mitigate GDM in pregnant diabetic rats, as embodied by the decrease of fasting blood glucose and the increase of plasma insulin and hepatic glycogen levels. Also, PUFA could suppress oxidative stress in pregnant diabetic rats, as reflected by the decrease of malondialdehyde content, an increase of superoxide dismutase, catalase and gutathione peroxidase activities. PUFA could also mitigate the abnormal changes of lipid profiles in plasma and hepatic tissue. Moreover, the relative mRNA expression of sterol regulatory element-binding transcription factor-1, stearoyl-CoA desaturase-1, fatty acid synthase, and acetyl-coenzyme A carboxylase, was suppressed by PUFA in pregnant diabetic rats.

CONCLUSIONS

These results suggested that PUFA supplementation during pregnancy is beneficial in preventing diabetic complications in pregnant rats.

Inhibition of Valproic Acid-Induced Prenatal Developmental Abnormalities with Antioxidants in Rats

Valproic acid (VP) is a very effective therapy for the management of generalized epilepsy. However, its use during pregnancy leads to increased risk of teratogenesis and cognitive malfunctioning in postnatal growing children. Antioxidants are used commercially as a palliative therapy. This study compares the different antioxidants effects on VP-induced teratogenicity. Pregnant female rats (n = 80) were divided into eight groups (n = 10) as follows: Group I, control group; Group II, disease group valproic acid (500 mg/kg); Groups III and IV, treated with 2000 and 8000 mg/kg vitamin C, respectively; Groups V and VI, treated with selenium 100 and 200 μg/kg dose, respectively; and Groups VII and VIII, administered grape seed extract 300 and 600 mg/kg, respectively. Groups III-VIII received valproic acid (500 mg/kg) along with their respective treatments. All treatments were given via an oral route. The fetuses were double stained, and levels of superoxide dismutase (SOD), catalase (CAT), nitrite, glutathione (GSH), and malondialdehyde (MDA) were estimated. Resorption rate was significantly reduced in Vit. C treated groups at both dose levels. Maternal death rate was decreased remarkably in all treatment groups. Vit. C at a high dose (8000 mg/kg) and grape seed at a high dose (600 mg/kg) significantly reduced the incidence of delayed cervical ossification. The values of MDA were significantly reduced in all groups except the Vit. C group (2000 mg/kg). However, no significant elevation was observed in the values of SOD, CAT, and GSH. The current study concluded that vitamin C at a high dose (8000 mg/kg) and grape seed extract at a high dose (600 mg/kg) had partially protected the fetuses exposed to VP.

A review of the molecular mechanisms of hyperglycemia-induced free radical generation leading to oxidative stress

The prevalence of diabetes is growing worldwide with an increasing morbidity and mortality associated with the development of diabetes complications. Free radical production is a normal biological process that is strictly controlled and has been shown to be important in normal cellular homeostasis, and in the bodies response to pathogens. However, there are several mechanisms leading to excessive free radical production that overcome the normal protective quenching mechanisms. Studies have shown that many of the diabetes complications result from excessive free radical generation and oxidative stress, and it has been shown that chronic hyperglycemia is a potent inducer for free radical production, generated through several pathways and triggering multiple molecular mechanisms. An understanding of these processes may help us to improving our preventive or therapeutic strategies. In this review, the major molecular pathways involved in free radical generation induced by hyperglycemia are described.

Zeaxanthin ameliorates high glucose-induced mesangial cell apoptosis through inhibiting oxidative stress via activating AKT signalling-pathway

Oxidative stress is a critical factor in the pathophysiology of diabetic kidney disease. Previous study shows that hyperglycaemia aggravates renal injury through oxidative stress in diabetic model, and antioxidants have beneficial effect on diabetic kidney disease. However, the role of antioxidants in the progression of diabetic kidney disease is poorly understood. The aim of this study was to clarify whether zeaxanthin, an antioxidant, could ameliorate mesangial cell injury and if so, identify the related mechanism underlying this protective effect. To that end, superoxide dismutase (SOD) activity and methane dicarboxylic aldehyde (MDA) levels were measured by an assay kit, and mesangial cell apoptosis and ROS levels were assessed using flow cytometry analysis. Furthermore, The levels of a phosphorylated ser/thr protein kinase (p-AKT), phosphorylated glycogen synthase kinase-3 beta (p-GSK-3β), Bcl-2 associated X protein (Bax) and cleaved cysteinyl aspartate-specific proteinase-3 (caspase-3) were detected by western blot. We found that zeaxanthin decreases MDA levels and increased SOD activity, as well as inhibits apoptosis and decreases ROS levels in mesangial cells in a high sugar environment. Furthermore, zeaxanthin increased p-AKT levels while decreased the levels of p-GSK-3β, Bax and cleaved-caspase-3. In addition, LY294002 reversed the protective effect of zeaxanthin on mesangial cells. In conclusion, zeaxanthin ameliorated mesangial cell apoptosis may be involved in inhibiting oxidative stress through activating of the AKT signalling pathway.

Daily Intake of Grape Powder Prevents the Progression of Kidney Disease in Obese Type 2 Diabetic ZSF1 Rats

Individuals living with metabolic syndrome (MetS) such as diabetes and obesity are at high risk for developing chronic kidney disease (CKD). This study investigated the beneficial effect of whole grape powder (WGP) diet on MetS-associated CKD. Obese diabetic ZSF1 rats, a kidney disease model with MetS, were fed WGP (5%, w/w) diet for six months. Kidney disease was determined using blood and urine chemical analyses, and histology. When compared to Vehicle controls, WGP intake did not change the rat bodyweight, but lowered their kidney, liver and spleen weight, which were in parallel with the lower serum glucose and the higher albumin or albumin/globin ratio. More importantly, WGP intake improved the renal function as urination and proteinuria decreased, or it prevented kidney tissue damage in these diabetic rats. The renal protection of WGP diet was associated with up-regulation of antioxidants (Dhcr24, Gstk1, Prdx2, Sod2, Gpx1 and Gpx4) and downregulation of Txnip (for ROS production) in the kidneys. Furthermore, addition of grape extract reduced H₂O₂-induced cell death of cultured podocytes. In conclusion, daily intake of WGP reduces the progression of kidney disease in obese diabetic rats, suggesting a protective function of antioxidant-rich grape diet against CKD in the setting of MetS.

Network Pharmacology Studies on the Bioactive Compounds and Action Mechanisms of Natural Products for the Treatment of Diabetes Mellitus: A Review

Diabetes mellitus (DM) is a kind of chronic and metabolic disease, which can cause a number of diseases and severe complications. Network pharmacology approach is introduced to study DM, which can combine the drugs, target proteins and disease and form drug-target-disease networks. Network pharmacology has been widely used in the studies of the bioactive compounds and action mechanisms of natural products for the treatment of DM due to the multi-components, multi-targets, and lower side effects. This review provides a balanced and comprehensive summary on network pharmacology from current studies, highlighting different bioactive constituents, related databases and applications in the investigations on the treatment of DM especially type 2. The mechanisms related to type 2 DM, including α-amylase and α-glucosidase inhibitory, targeting β cell dysfunction, AMPK signal pathway and PI3K/Akt signal pathway are summarized and critiqued. It suggests that the network pharmacology approach cannot only provide a new research paradigm for natural products, but also improve the current antidiabetic drug discovery strategies. Furthermore, we put forward the perspectives on the reasonable applications of network pharmacology for the therapy of DM and related drug discovery.