Identification of ß-Sitosterol as in Vitro Anti-Inflammatory Constituent in Moringa oleifera.

ß-Sitosterol is a well known phytosterol in plants, but owing to its poor solubility in typical media, determining its cellular mechanisms has been proven to be difficult. In this study, we investigated the anti-inflammatory activity of ß-sitosterol (BSS) isolated from Moringa oleifera in two cell lines. Over a dose range of 7.5 to 30 µM, BSS dispersed well in the medium as nanoparticles with diameters of 50 ± 5 nm and suppressed the secretion of inflammatory factors from keratinocytes and macrophages induced by PGN, TNF-α, or LPS, such as TNF-α, IL-1ß, IL-6, IL-8, and ROS, separately. In addition, BSS significantly reduced the expression of NLRP3, a key component of NLRP3 inflammasomes, and inhibited the activation of caspase-1. There was partial inhibition of NF-κB in macrophages. This is the first study to report an increase in the solubility of nearly water-insoluble phytosterols via the formation of nanoparticles and to delineate the formulation's capacity to inhibit the signal transduction pathways of inflammation in macrophages.

Sweet potato [Ipomoea batatas (L.) Lam. "Tainong 57"] starch improves insulin sensitivity in high-fructose diet-fed rats by ameliorating adipocytokine levels, pro-inflammatory status, and insulin signaling.

The aim of this study was to investigate the effects of low-glycemic index (GI) sweet potato starch on adipocytokines, pro-inflammatory status, and insulin signaling in the high-fructose diet-induced insulin-resistant rat. We randomly divided 24 insulin-resistant rats and 16 normal rats into two groups fed a diet containing 575 g/kg of starch: a low-GI sweet potato starch (S) or a high-GI potato starch (P). The four experimental groups were labeled as follows: insulin-resistant P (IR-P), insulin-resistant S (IR-S), normal P (N-P) and normal S (N-S). After 4 wk on the experimental diets, an intraperitoneal glucose tolerance test (IPGTT) was conducted, and the homeostasis model assessment (HOMA), adipocytokines, pro-inflammatory cytokines levels, and insulin signaling-related protein expression were measured. The homeostasis model assessment values were significantly lower in the IR-S than in the IR-P group, suggesting that insulin sensitivity was improved among sweet potato starch-fed rats. Levels of tumor necrosis factor-α, interleukin-6, resistin, and retinol binding protein-4 were significantly lower in the IR-S versus the IR-P group, indicating an improvement of pro-inflammatory status in sweet potato starch-fed rats. The sweet potato starch diet also significantly enhanced the protein expression of phospho-Tyr-insulin receptor substrate-1 and improved the translocation of glucose transporter 4 in the skeletal muscle. Our results illustrated that sweet potato starch feeding for 4 wk can improve insulin sensitivity in insulin-resistant rats, possibly by improving the adipocytokine levels, pro-inflammatory status, and insulin signaling.

Effects of rice bran oil on the blood lipids profiles and insulin resistance in type 2 diabetes patients.

The aim of this study was to investigate the influence of rice bran oil consumption on plasma lipids and insulin resistance in patients with type 2 diabetes. Thirty-five patients with type 2 diabetes were randomly assigned to a placebo group or a rice bran oil group. The placebo group consumed 250 mL soybean oil-modified milk (18 g soybean oil) daily for 5 weeks, and the rice bran oil group consumed 250 mL rice bran oil modified milk (18 g rice bran oil) daily for 5 weeks. At week 0 and week 5, anthropometric measurements, hematology tests, and an oral-glucose-tolerance test were conducted. The results showed that the homeostasis model assessment index of insulin resistance, the area under the curve for postprandial serum insulin, and serum low-density-lipoprotein cholesterol concentrations increased significantly in the placebo group. In the rice bran oil group, fasting and 2-h postprandial blood glucose concentrations and the area under the curve for postprandial plasma glucose increased significantly; however, total serum cholesterol and low-density-lipoprotein cholesterol concentrations decreased significantly. However, the homeostasis model assessment index of insulin resistance was not significantly different. Consumption of 18 g rice bran oil modified milk daily for 5 weeks significantly decreased total serum cholesterol concentrations and tended to decrease low-density-lipoprotein cholesterol concentrations in patients with type 2 diabetes. However, no significant influence on insulin resistance was observed.

Gamma-oryzanol ameliorates insulin resistance and hyperlipidemia in rats with streptozotocin/nicotinamide-induced type 2 diabetes.

Gamma-oryzanol is a component of rice bran oil (RBO) with purported health benefits. This study evaluated the effects of gamma-oryzanol on insulin resistance and lipid metabolism in Wistar rats with type 2 diabetes (T2DM). The rats were divided into three groups and consumed one of the following diets for 5 weeks: 15 % soybean oil (control group); 15 % palm oil (PO); and 15 % PO with the addition of 5.25 g gamma-oryzanol (POO). The results showed that PO markedly increased plasma low-density-lipoprotein cholesterol, plasma triglycerides, and hepatic triglyceride levels, but did not reduce the area under the curve for glucose and insulin significantly, compared with the control group. Adding gamma-oryzanol to PO improved the negative influence of PO on lipid metabolism in T2DM rats. In addition, gamma-oryzanol tended to increase insulin sensitivity in T2DM rats compared to control and PO groups. Longer-term studies are needed to evaluate these effects further.

Ameliorative effects of stabilized rice bran on type 2 diabetes patients.

BACKGROUND/AIM: While it has been demonstrated that rice bran might lower the cholesterol level in hypercholesterolemic individuals, its effects on the levels of adiponectin and glycated hemoglobin (HbA1c) in patients with type 2 diabetes mellitus remain unknown. METHODS: Twenty-eight volunteers with type 2 diabetes were randomly divided into 2 groups, one of which received a dietary supplement of 20 g of stabilized rice bran and the other placebo once daily for 12 weeks. Parameters such as the level of HbA1c, glucose, insulin, homeostasis model assessment for estimation of relative insulin resistance, high-density and low-density lipoprotein (LDL) cholesterol and adiponectin were evaluated. RESULTS: At the end of the study period, postprandial glucose and the area under the glucose curve of the rice bran group were significantly lower than baseline levels by 14.4 and 15.7%, respectively. Compared to baseline, the HbA1c values in the rice bran group were also significantly lower. Serum total cholesterol and LDL cholesterol concentrations in the rice bran group were 9.2 and 13.7% lower, respectively, than in the placebo group. The plasma free fatty acid and adiponectin concentrations were 20% lower and 40% higher in the rice bran group compared to the placebo group. CONCLUSIONS: This study demonstrated that stabilized rice bran can lower the level of HbA1c and blood lipids and increase blood adiponectin concentrations in type 2 diabetic subjects. In light of this, we conclude that stabilized rice bran may represent an important functional nutrient to ameliorate lipid and glycemic anomalies in type 2 diabetic subjects.

A rice bran oil diet improves lipid abnormalities and suppress hyperinsulinemic responses in rats with streptozotocin/nicotinamide-induced type 2 diabetes.

The aim of this study was to determine the effects of rice bran oil (RBO) on lipid metabolism and insulin resistance in rats with streptozotocin/nicotinamide-induced type 2 diabetes mellitus (T2DM). Rats were divided into two groups: the control group (15% soybean oil, contains 0 g gamma-oryzanol and 0 g gamma-tocotrienol/150 g oil for 5 weeks) and the RBO group (15% RBO, contains 5.25 g gamma-oryzanol and 0.9 g gamma-tocotrienol/150 g oil for 5 weeks). Compared with the control group, the RBO group had a lower plasma nonesterified fatty acid concentration, ratio of total to high-density-lipoprotein cholesterol, hepatic cholesterol concentration, and area under the curve for insulin. The RBO group had a higher high-density-lipoprotein cholesterol concentration and greater excretion of fecal neutral sterols and bile acid than did the control group. RBO may improve lipid abnormalities, reduce the atherogenic index, and suppress the hyperinsulinemic response in rats with streptozotocin/nicotinamide-induced T2DM. In addition, RBO can lead to increased fecal neutral sterol and bile acid excretion.

Cytomic screening of immuno-modulating activity compounds from Calocedrus formosana.

Procedures for cytomic screening were developed for identifying compounds with immuno-modulating properties from the crude extracts of natural products. Human peripheral blood mononuclear cells (hPB-MNCs) were first cultured with different natural crude extracts for 12 hours in culture media. By analyzing the expression of early activation CD69 marker, the potential immuno-activating properties of ethanol extracts of Calocedrus formosana were observed. By the double staining of antibodies recognizing CD69 and specific cell type markers, the increase of CD69 expressions was observed in CD3 and CD14 cell populations. To examine the immuno-activating properties in CD3 T cells and CD14 monocytes, the extracts were further purified. From NMR and mass spectra, sugiol was identified as a pure functional compound, and its immuno-enhancing activities were confirmed by CD69 expressions in the affected cell populations. Furthermore, to clarify the sugiol-affected subpopulations in CD3 T cells, CD3 T cell activation in association with increase in CD8 cytotoxic T cells subpopulation was observed. To address the effect of sugiol on each isolated cell population, we found that the expression of CD69, CD80, and CD86 increased in CD14 monocytes upon exposure to sugiol, whereas for CD3 T cells, sugiol failed to induce the expressions of CD69 and CD25. However, T cell activation by co-culturing monocytes and T cells suggests that the sugiol activation of T cells in hPB-MNCs involved the accessory mechanisms of sugiol-primed monocytes. Therefore, cytomic screening as a multiple-parameter screening strategy reveals the plasticity for immuno-functional studies, leading to the applications to discover new drugs of specific immuno-modulating activities.

Antioxidant effects and insulin resistance improvement of chromium combined with vitamin C and e supplementation for type 2 diabetes mellitus.

To determine the effects of combined supplementation with chromium (Cr) and vitamins C and E on oxidative stress in type 2 diabetes, adult subjects with HbA1c >8.5%. Subjects (n = 30) in this randomized, double blind, placebo-control study were divided into three groups (placebo, Cr or Cr + C + E) on daily treatment. The Cr group received 1000 microg of Cr (as Cr yeast); the Cr + C + E group received Cr (1000 microg as Cr yeast) together with vitamins C (1000 mg) and E (800 IU); and, a control group received a placebo. Baseline plasma Cr levels were not significant differences comparing the supplementation and placebo groups. Thiobarbituric acid reactive substances (TBARS) and total antioxidative status (TAS) were also not significant different. Following the 6-month study period, the plasma TBARS levels, fasting glucose, HbA1c and insulin resistance were significantly decreased in the Cr and Cr + C + E groups, but not for the placebo group. Plasma TAS and glutathione peroxidase were significantly higher for Cr and Cr + C + E groups relative to the placebo group. These findings suggest that Cr supplementation alone and combined of Cr together with vitamins C and E was effective for minimization of oxidative stress and improvement of glucose metabolism in type 2 DM patients.

Chromium yeast supplementation improves fasting plasma glucose and LDL-cholesterol in streptozotocin-induced diabetic rats.

Chromium yeast supplementation has been studied for its ability to improve carbohydrate and lipid abnormalities. There have been some earlier literature-reported studies involving chromium supplementation amongst patients suffering diabetes, but the results would appear to be somewhat varied. Forty male Wistar rats (ten weeks old, 300 g in average body mass) were divided into one of four groups, namely (i) controls; (ii) controls treated with chromium yeast; (iii) diabetic controls; and (iv) diabetic rats treated with chromium yeast. In the present investigation, the effect of a four-week oral administration of chromium yeast (600 microg of Cr/kg body mass/day, by gavage) upon the glucose and lipid metabolism in streptozotocin (STZ)-induced diabetic rats was assessed. Supplemental Cr yeast decreased the fasting blood glucose amongst the STZ-diabetic rats. No significant difference was observed in plasma fructosamine levels of rats treated with chromium yeast compared to control rats. Supplemental Cr yeast did decrease the plasma low-density lipoprotein (LDL)-cholesterol level for the STZ-diabetic rats as compared to controls. We noted no significant effect of chromium supplementation upon plasma high-density lipoprotein (HDL)-cholesterol or triglycerides compared to controls. Treatment with chromium yeast significantly increased the blood and urine chromium levels for both the diabetic and normal rats compared to respective control groups. The results of these studies suggest that Cr yeast decreased the fasting blood glucose and LDL-cholesterol levels in STZ-induced diabetic rats. This raises the possibility that Cr yeast supplementation can be considered to improve carbohydrate and lipid metabolism amongst human patients featuring type 2 diabetes mellitus.

Antioxidant effects of chromium supplementation with type 2 diabetes mellitus and euglycemic subjects.

To determine the effects of chromium (Cr) supplementations on oxidative stress of type 2 diabetes and euglycemic (EU) subjects, adult having HbA(1C) values of <6.0% (EU), 6.8-8.5% (mildly hyperglycemic, MH), and >8.5% (severely hyperglycemic, SH) were supplemented for 6 months with 1000 microg/day of Cr (as Cr yeast) or with a placebo. In the beginning, the levels of the plasma Cr in the MH and SH groups were 25-30% lower than those of the EU subjects. The values of thiobarbituric acid reactive substances (TBARS) and total antioxidative status (TAS) of the MH and SH groups were significantly higher than those of the EU ones. Following supplementations, the levels of plasma TBARS in the Cr groups of MH and SH groups were significantly decreased (the inverse was found in the EU) and showed no significant changes in the placebo group. The levels of plasma TAS in the Cr groups of EU and MH were significantly decreased (the inverse was found in the SH) and showed no significant changes in the placebo group. No significant difference was found in the antioxidant enzyme (superoxide dismutase, glutathione peroxidase, catalase) activities during supplementations. These data suggest that Cr supplementation was an effective treatment strategy to minimize increased oxidative stress in type 2 diabetes mellitus patients whose HbA(1C) level was >8.5%, and the Cr in EU groups might act as a prooxidant.