Dietary polyherbal supplementation decreases CD3+ cell infiltration into pancreatic islets and prevents hyperglycemia in nonobese diabetic mice

Artemisia dracunculus L. Ethanolic Extract and an Isolated Component, DMC2, Ameliorate Inflammatory Signaling in Pancreatic β-Cells via Inhibition of p38 MAPK

Non-resolving pancreatic islet inflammation is widely viewed as a contributor to decreases in β-cell mass and function that occur in both Type 1 and Type 2 diabetes. Therefore, strategies aimed at reducing or eliminating pathological inflammation would be useful to protect islet β-cells. Herein, we described the use of 2′,4′-dihydroxy-4-methoxydihydrochalcone (DMC2), a bioactive molecule isolated from an ethanolic extract of Artemisia dracunculus L., as a novel anti-inflammatory agent. The ethanolic extract, termed PMI 5011, reduced IL-1β-mediated NF-κB activity. DMC2 retained this ability, indicating this compound as the likely source of anti-inflammatory activity within the overall PMI 5011 extract. We further examined NF-κB activity using promoter-luciferase reporter constructs, Western blots, mRNA abundance, and protein secretion. Specifically, we found that PMI 5011 and DMC2 each reduced the ability of IL-1β to promote increases in the expression of the Ccl2 and Ccl20 genes. These genes encode proteins that promote immune cell recruitment and are secreted by β-cells in response to IL-1β. Phosphorylation of IκBα and the p65 subunit of NF-κB were not reduced by either PMI 5011 or DMC2; however, phosphorylation of p38 MAPK was blunted in the presence of DMC2. Finally, we observed that while PMI 5011 impaired glucose-stimulated insulin secretion, insulin output was preserved in the presence of DMC2. In conclusion, PMI 5011 and DMC2 reduced inflammation, but only DMC2 did so with the preservation of glucose-stimulated insulin secretion.

Botanical Interventions to Improve Glucose Control and Options for Diabetes Therapy

Diabetes mellitus is a major public health problem worldwide. This endocrine disease is clustered into distinct subtypes based on the route of development, with the most common forms associated with either autoimmunity (T1DM) or obesity (T2DM). A shared hallmark of both major forms of diabetes is a reduction in function (insulin secretion) or mass (cell number) of the pancreatic islet beta-cell. Diminutions in both mass and function are often present. A wide assortment of plants have been used historically to reduce the pathological features associated with diabetes. In this review, we provide an organized viewpoint focused around the phytochemicals and herbal extracts investigated using various preclinical and clinical study designs. In some cases, crude extracts were examined directly, and in others, purified compounds were explored for their possible therapeutic efficacy. A subset of these studies compared the botanical product with standard of care prescribed drugs. Finally, we note that botanical formulations are likely suspects for future drug discovery and refinement into class(es) of compounds that have either direct or adjuvant therapeutic benefit.

Effects of Zingiber officinale extract supplementation on metabolic and genotoxic parameters in diet-induced obesity in mice

Obesity is an epidemic associated with many diseases. The nutraceutical Zingiber officinale (ZO) is a potential treatment for obesity; however, the molecular effects are unknown. Swiss male mice were fed a high-fat diet (59 % energy from fat) for 16 weeks to generate a diet-induced obesity (DIO) model and then divided into the following groups: standard diet + vehicle; standard diet + ZO; DIO + vehicle and DIO + ZO. Those in the ZO groups were supplemented with 400 mg/kg per d of ZO extract (oral administration) for 35 d. The animals were euthanised, and blood, quadriceps, epididymal fat pad and hepatic tissue were collected. DIO induced insulin resistance, proinflammatory cytokines, oxidative stress and DNA damage in different tissues. Treatment with ZO improved insulin sensitivity as well as decreased serum TAG, without changes in body weight or adiposity index. TNF-α and IL-1β levels were lower in the liver and quadriceps in the DIO + ZO group compared with the DIO group. ZO treatment reduced the reactive species and oxidative damage to proteins, lipids and DNA in blood and liver in obese animals. The endogenous antioxidant activity was higher in the quadriceps of DIO + ZO. These results in the rat model of DIO may indicate ZO as an adjuvant on obesity treatment.

Conversion of dietary polyunsaturated fats between humans and rodents: A review of allometric scaling models

The purpose of this research was to explore various allometric scaling models for dietary nutrients to improve translational validity between preclinical experimental rodent models and humans, focusing on polyunsaturated fats. Currently, there is no authoritative document that provides standardized guidelines for which dietary designs can be based on to improve translational fidelity between species. This paper reviews the challenges of using a rodent model, the major allometric scaling models, the use of these mathematical models to extrapolate human equivalent doses, and then tests one of these models using data generated in mice, with comparisons of data generated in human clinical trials. Mice were fed diets containing micro- and macronutrient compositions that approximated the US diet based on energy distribution and were then supplemented with increasing levels of various n-3 and n-6 polyunsaturated fatty acids at human equivalent doses. Changes in plasma and erythrocyte fatty acid phospholipid compositions were determined and compared to corresponding data generated in humans. Our findings suggest that basing lipid composition on percent of energy may result in comparable outcomes between mice and humans and that extrapolation of non-energy producing nutrients between species might be done using differences in energy needs (based on food intake).

Postprandial Glucose Levels Are Better Associated with the Risk Factors for Diabetes Compared to Fasting Glucose and Glycosylated Hemoglobin (HbA1c) Levels in Elderly Prediabetics: Beneficial Effects of Polyherbal Supplements-A Randomized, Double-Blind, Placebo Controlled Trial

Backgrounds

Prediabetes is a condition in which a person's blood glucose levels are higher than normal physiological levels but lower compared to patients with diabetes. Up to 70% of individuals with prediabetes will eventually develop diabetes. To date, there have been no pharmaceutical drugs to treat diabetes. It is believed that early diagnosis and nonpharmacological intervention for prediabetes are critical for effective prevention of diabetes. Most individuals with prediabetes remain undiagnosed even after being evaluated using the standard tests for fasting glucose (FG) and HbA1c. We investigated if postprandial glucose levels (2h-PG) were associated with pre/diabetes and if polyherbal supplements could be beneficial for individuals with prediabetes.

Materials and Methods

100 elderly individuals with impaired 2h-PG or fasting glucose levels were recruited to receive either a 12-week supplement of GlucoVita (an antioxidative polyherbal formulation) (n=50) or placebo (n=50).

Results

No baseline differences were observed for FG, HbA1c, or 2h-PG. Individuals who received a twelve-week administration of GlucoVita supplements had significantly reduced 2h-PG (8.15±1.67 versus 7.35±2.06 mmol/l, P<0.05) levels compared to individuals in the placebo group. In addition, HbA1c levels were lower in individuals who received GlucoVita (5.81±0.49 %) compared to the individuals in the placebo group (6.00±0.51%) (P=0.08) after 12-weeks. Stratified analysis, based on impaired fasting glucose (IFG), 2h-PG, metabolic symptom, and age, demonstrated that, after the 12-week intervention, HbA1c levels were significantly lower in the GlucoVita administered group compared to the placebo group (IFG subgroup; 5.85±0.46%, n= 27 versus 6.14±0.50, n=33, P<0.05) and the metabolic symptom-free subgroup (5.73±0.45%, n=23 versus 6.04±0.52%, n=24, P<0.05). GlucoVita also reduced FG in individuals with normal 2h-PG (6.37±0.27 versus 6.08±0.38 mmol/l, P<0.05). Baseline 2h-PG levels, but not HbA1c or FG levels, were significantly correlated with body weight, waist circumference, and BMI (r=0.25, P<0.05; r=0.31, P<0.01; r=0.22, P<0.05, respectively).

Conclusion

2h-PG levels were better associated with body weight, waist circumference, and BMI risk factors compared to FG and HbA1c levels in elderly individuals with prediabetes. Polyherbal formulation GlucoVita supplements improved 2h-PG and HbA1c levels only in elderly individuals who were overweight but were symptom-free and under 65 years of age. Due to the small cohort size of this pilot study, future studies are required to validate our findings.

Glycated Whey Proteins Protect NOD Mice against Type 1 Diabetes by Increasing Anti-Inflammatory Responses and Decreasing Autoreactivity to Self-Antigens

Our previous studies suggested that early glycation products (EGPs) generated in the first step of Maillard reaction/glycation were anti-inflammatory. The objectives of the present study were to determine the effects of EGPs derived from the whey protein isolate-glucose system on type 1 diabetes (T1D), and the underlying immunological mechanisms. In non-obese diabetic (NOD) mice, EGPs at the physiological dose of 600 mg/kg/day increased glucose metabolism, decreased non-fasting blood glucose levels and T1D incidence, decreased insulin resistance, and decreased the pancreatic immune infiltration. The protective effects were accompanied with decreases in CD4^-CD8⁺ thymocytes, CD8⁺ T cells and serum insulin autoantibody levels, and increases in splenic CD4⁺CD25⁺ T cells, macrophage M2/M1 ratio and serum IL-10 level. However, similar treatment with EGPs produced minimal effect on the multiple low-dose streptozotocin-induced hyperglycemia. In conclusion, EGPs protected NOD mice against T1D via increasing anti-inflammatory immune responses and decreasing autoreactivity to self-antigens.

Metabolomics Approach in the Study of the Well-Defined Polyherbal Preparation Zyflamend

Zyflamend is a highly controlled blend of 10 herbal extracts that synergistically impact multiple cell signaling pathways with anticancer and anti-inflammatory properties. More recently, its effects were shown to also modify cellular energetics, for example, activation of fatty acid oxidation and inhibition of lipogenesis. However, its general metabolic effects in vivo have yet to be explored. The objective of this study was to characterize the tissue specific metabolomes in response to supplementation of Zyflamend in mice, with a comparison of equivalent metabolomics data generated in plasma from humans supplemented with Zyflamend. Because Zyflamend has been shown to activate AMPK, the "energy sensor" of the cell, in vitro, the effects of Zyflamend on adiposity were also tested in the murine model. C57BL/6 mice were fed diets that mimicked the macro- and micronutrient composition of the U.S. diet with and without Zyflamend supplementation at human equivalent doses. Untargeted metabolomics was performed in liver, skeletal muscle, adipose, and plasma from mice consuming Zyflamend and in plasma from humans supplemented with Zyflamend at an equivalent dose. Adiposity in mice was significantly reduced in the Zyflamend-treated animals (compared with controls) without affecting body weight or weight gain. Based on KEGG pathway enrichment, purine and pyrimidine metabolism (potential regulators of AMPK) were particularly responsive to Zyflamend across all tissues, but only in mice. Consistent with the metabolomics data, Zyflamend activated AMPK and inhibited acetyl CoA-carboxylase in adipose tissue, key regulators of lipogenesis. Zyflamend reduces adipose tissue in mice through a mechanism that likely involves the activation of AMPK.

Transcriptional regulation of chemokine genes: a link to pancreatic islet inflammation?

Enhanced expression of chemotactic cytokines (aka chemokines) within pancreatic islets likely contributes to islet inflammation by regulating the recruitment and activation of various leukocyte populations, including macrophages, neutrophils, and T-lymphocytes. Because of the powerful actions of these chemokines, precise transcriptional control is required. In this review, we highlight what is known about the signals and mechanisms that govern the transcription of genes encoding specific chemokine proteins in pancreatic islet β-cells, which include contributions from the NF-κB and STAT1 pathways. We further discuss increased chemokine expression in pancreatic islets during autoimmune-mediated and obesity-related development of diabetes.