Dietary supplementation with Ipomoea aquatica (whole leaf powder) attenuates maternal and fetal oxidative stress in streptozotocin-diabetic rats

N-3 polyunsaturated fatty acids effectively protect against neural tube defects in diabetic mice induced by streptozotocin

Folate cannot prevent all neural tube defects (NTD), indicating that other pathogeneses still exist except for the folate deficiency. Maternal diabetes mellitus during pregnancy can increase the risk of offspring NTD. Our previous study showed that polyunsaturated fatty acids (PUFA) were lower in the placenta of human NTD cases than in healthy controls, and the supplementation of fish oil (rich in long-chain (LC) n-3 PUFA, mainly C20:5n-3 and C22:6n-3) had a better prevention effect against sodium valproate induced NTD than corn oil (rich in C18:2n-6) and flaxseed oil (rich in C18:3n-3). The aim of the present study was to investigate whether PUFA could prevent diabetes-induced NTD in mice. Streptozotocin (STZ)-induced diabetic pregnant mice were fed with a normal diet (DMC), a diet containing a low dose of fish oil (DMLn-3), a diet containing a high dose of fish oil (DMHn-3) or a diet rich in corn oil (DMn-6). Healthy pregnant mice were fed with a normal diet (HC). Compared with the DMC group, the rate of NTD was significantly lower in the DMHn-3 group (4.44% vs. 12.50%), but not in the DMLn-3 (11.11%) or DMn-6 group (12.03%). The NTD rate in the DMHn-3 group was comparable with that in the HC group (1.33%) (p = 0.246), and lower than that in the DMn-6 group (p = 0.052). The NTD rate in DMLn-3 and DMn-6 groups was significantly higher than that in the HC group. No significant difference was observed in NTD rate between DMLn-3 and DMHn-3 groups, and between DMLn-3 and DMn-6 groups. Compared with the HC group, the DMC group had a significantly lower C22:6n-3 in both serum and embryos. Fish oil supplementation ameliorated neuroepithelial cell apoptosis, and the apoptotic rate was comparable between DMHn-3 and HC groups. Although the apoptotic rate was significantly lower in the DMn-6 group than the DMC group, it was still much higher than that in the HC group. The proteins P53 and Bax in embryos were higher, while the proteins Bcl-2 and Pax3 were lower in the DMC group than in the HC group. The disturbance of Pax3, P53 and Bax induced by diabetes was abolished in DMLn-3, DMHn-3 and DMn-6 groups. Importantly, Bcl-2 in embryos was restored to the normal level only in the DMHn-3 group but not in the DMLn-3 or DMn-6 group. In conclusion, LC n-3 PUFA enriched fish oil has a protective effect against NTD in diabetes induced by STZ through improving neuroepithelial cell apoptosis, and the mechanism may be by increasing the anti-apoptosis protein Bcl-2 independently of Pax3 and P53.

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.

Macro- and Micronutrients from Traditional Food Plants Could Improve Nutrition and Reduce Non-Communicable Diseases of Islanders on Atolls in the South Pacific

Pacific Islanders have paid dearly for abandoning traditional diets, with diabetes and other non-communicable diseases (NCD) widespread. Starchy root crops like sweet potato, taro, and cassava are difficult to grow on the potassium-deficient soils of atolls, and high energy, low nutrient imported foods and drinks are popular. Nutritious, leafy food plants adapted to alkaline, salty, coral soils could form part of a food system strategy to reduce NCD rates. This project targeted four atolls south of Tarawa, Kiribati, and was later extended to Tuvalu. Mineral levels in diverse, local leafy food plants were compared to reveal genotype–environment interactions. Food plants varied in ability to accumulate minerals in leaves and in tolerance of mineral-deficient soils. Awareness activities which included agriculture, health, and education officers targeted atoll communities. Agriculture staff grew planting material in nurseries and provided it to farmers. Rejuvenation of abandoned giant swamp taro pits to form diversified nutritious food gardens was encouraged. Factsheets promoted the most suitable species from 24 analyzed, with multiple samples of each. These included Cnidoscolus aconitifolius (chaya), Pseuderanthemum whartonianum (ofenga), Polyscias scutellaria (hedge panax), and Portulaca oleracea (purslane). The promoted plants have been shown in other studies to have anti-NCD effects. Inclusion of the findings in school curricula and practical application in the form of demonstration school food gardens, as well as increased uptake by farmers, are needed. Further research is needed on bioavailability of minerals in plants containing phytates and tannins.

The effect of cassia seed extract on the regulation of the LKB1-AMPK-GLUT4 signaling pathway in the skeletal muscle of diabetic rats to improve the insulin sensitivity of the skeletal muscle

BACKGROUND

This study aimed to observe the hypoglycemic effect of cassia seed extract in rats with type-2 diabetes mellitus and its effect on reducing insulin resistance in the skeletal muscle.

METHODS

50 rats were randomly divided into the normal, model, high-dose, middle-dose, and low-dose groups of cassia seed extract (n = 10 each). A high-fat diet combined with streptozotocin administration was adopted to build type 2 diabetes models. The cassia seed extract groups were fed different concentrations cassia seed extract while the normal and model groups were fed the same volume of normal saline. The weight, FINS, GIR, insulin tolerance, blood glucose and blood lipid level, oxidative stress indices and expressions related to the LKB1-AMPK-GLUT4 pathway were detected and compared between the two groups.

RESULTS

Compared with the normal group, the model group showed lower weight, glucose infusion rate and expressions related to LKB1-AMPK-GLUT4 pathway and higher FINS, insulin tolerance, blood glucose and blood lipid level and oxidative stress indices (all P < 0.05). Compared with the model group, higher weight, glucose infusion rate and expressions related to LKB1-AMPK-GLUT4 pathway and lower FINS, insulin tolerance, blood glucose and blood lipid level and oxidative stress indices were observed in all groups that were administered cassia see extract (all P < 0.05).

CONCLUSION

Cassia seed extract could noticeably improve the insulin resistance of diabetic rats and enhance the insulin sensitivity of their skeletal muscles. Its mechanism may be related to damage repair of the LKB1-AMPK-GLUT4 signaling pathway and oxidative stress in the skeletal muscle.

Efficacy of Spirulina platensis in improvement of the reproductive performance and easing teratogenicity in hyperglycemic albino mice

Objectives:

The present study evaluates the therapeutic efficacy of cell suspension of Spirulina platensis (SP) on estrous cycle, fetal development and embryopathy in alloxan (AXN) induced hyperglycemic mice.

Materials and Methods:

Diabetes was induced by intra-peritoneal administration of AXN. Mice with blood glucose level above 200 mg/dl were divided into Group I (control), Group II (diabetic control), Group III (diabetic control mice fed with SP), and Group IV (control mice fed with SP). Litter counts, estrous cycles, percent survival of litter, and gestation length were recorded.

Results:

In hyperglycemic mice, a significant (P < 0.05) increase in duration of diestrus (14.48%), estrus (84.21%), and metestrus (164.15%) with concomitant decrease in proestrus phase by 26.13% was recorded when compared with control. Reduction in litter count and survival of litter was 68.67% and 88.38%, respectively, whereas gestation length increased to 14.51% day in diabetic mice, but recovery in these parameters was observed (P < 0.05) when subjected to SP treatment. SP resulted in increased fertility rate from 77.5% to 82.5% and dropped off resorption of the fetus to 33.73% while the survival rate of offspring of diabetic mice went up to 88.89% from 83.61%.

Conclusions:

These findings suggest that SP is effective in improving the reproductive performance and easing teratogenic effects in diabetic mice and hence warrants further detailed dose-dependent studies to understand its mechanism of action.

Comparison on hypoglycemic and antioxidant activities of the fresh and dried Portulaca oleracea L. in insulin-resistant HepG2 cells and streptozotocin-induced C57BL/6J diabetic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Fresh Portulaca oleracea L. (family: Portulacaceae; POL) has been used as a folk medicine for the treatment of diabetes mellitus for a long time. More bioactive components with higher activity could be retained in fresh medicinal herbs compared to the dried ones. The present study was conducted to compare different antidiabetic activity between fresh and dried POL, including hypoglycemic and antioxidant activities both in vivo and in vitro. Furthermore, in order to explore which components were responsible for the antidiabetic activity, the difference on chemical components between fresh and dried POL was analyzed and compared.

MATERIALS AND METHODS

Insulin-resistant HepG2 cells induced by insulin were used to evaluate the promoting effect of the fresh and dried POL on glucose utilization in vitro. Streptozotocin (STZ)-induced C57BL/6J diabetic mice were used to compare the differences on hypoglycemic and antioxidant activities of fresh and dried POL, including the fasting blood glucose, glucose tolerance, serum insulin level, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in vivo. UPLC/Q-TOF-MS method was performed to analyze the difference of antidiabetic components between fresh and dried POL.

RESULTS

Compared with the dried POL extract, the fresh POL extract significantly increased the consumption of extracellular glucose in insulin-resistant HepG2 cells (P<0.05). In STZ-induced C57BL/6J diabetic mice, both fresh and dried extracts decreased markedly the fasting blood glucose (FBG) levels, and improved significantly oral glucose tolerance test (OGTT), as well as enhanced significantly insulin secretion and antioxidative activities (P<0.05; P<0.01). Furthermore, the fresh extract showed stronger antidiabetic activity (P<0.05). The UPLC/Q-TOF-MS analysis results also revealed that the relative contents of polyphenols and alkaloids in the fresh herbs were more abundant than those in the dried POL.

CONCLUSION

Our results indicated that both fresh and dried POL possessed antidiabetic activities, besides stronger activity was observed in the fresh herb. These findings provided evidence for the application and development of fresh POL in the treatment of diabetes mellitus.