Alternative and complementary treatments for metabolic syndrome

Natural and Synthetic Agents Targeting Reactive Carbonyl Species against Metabolic Syndrome

Reactive carbonyl species (RCS) may originate from the oxidation of unsaturated fatty acids and sugar in conditions of pathology. They are known to have high reactivity towards DNA as well as nucleophilic sites of proteins, resulting in cellular dysfunction. It has been considered that various pathological conditions are associated with an increased level of RCS and their reaction products. Thus, regulating the levels of RCS may be associated with the mitigation of various metabolic and neurodegenerative disorders. In order to perform a comprehensive review, various literature databases, including MEDLINE, EMBASE, along with Google Scholar, were utilized to obtain relevant articles. The voluminous review concluded that various synthetic and natural agents are available or in pipeline research that hold tremendous potential to be used as a drug of choice in the therapeutic management of metabolic syndrome, including obesity, dyslipidemia, diabetes, and diabetes-associated complications of atherosclerosis, neuropathy, and nephropathy. From the available data, it may be emphasized that various synthetic agents, such as carnosine and simvastatin, and natural agents, such as polyphenols and terpenoids, can become a drug of choice in the therapeutic management for combating metabolic syndromes that involve RCS in their pathophysiology. Since the RCS are known to regulate the biological processes, future research warrants detailed investigations to decipher the precise mechanism.

Picolinic Acid, a Catabolite of Tryptophan, Has an Anabolic Effect on Bone In Vivo

Fractures attributable to osteoporosis have a severe impact on our older population. Reports of side effects with commonly prescribed osteoporosis drugs have led to the investigation of new and safer treatments with novel mechanisms of action. Picolinic acid (PIC), a catabolite of tryptophan, induces in vitro osteogenic differentiation of mesenchymal stem cells. Here we demonstrate that PIC has an anabolic effect on bone in vivo by increasing bone formation, bone mass, and bone strength in normal and ovariectomized C57BL/6 mice. Activation of the osteogenic pathways triggered this osteoanabolic response without any cross-related effects on mineral absorption or calciotropic hormones. Because PIC was also well tolerated and absorbed with no side effects, it is an ideal potential candidate for the treatment of osteoporosis. © 2020 American Society for Bone and Mineral Research.

Flaxseed and/or hesperidin supplementation in metabolic syndrome: an open-labeled randomized controlled trial

PURPOSE

The aim of the present study was to compare the clinical effect of flaxseed and hesperidin alone and with combination in patients with metabolic syndrome. Number of participants with treated metabolic syndrome was assessed as a primary end point.

METHODS

In this 12-week randomized controlled trial, ninety-eight patients with metabolic syndrome randomly assigned to receive either whole flaxseed powder (30 g/day), or hesperidin (1 g/day), or combination of 30 g flaxseed and 1 g hesperidin or no supplement while adhering a lifestyle modification program.

RESULTS

In comparison to control group, systolic blood pressure (- 5.68 vs. - 2.91 mmHg, P = 0.041) and serum concentrations of triglyceride (- 50.06 vs. 3.87 mg/dL, P = 0.033) in hesperidin group showed a significant reduction over 12 weeks of intervention. Comparison of the results of flaxseed group with the control group showed a significant improvement in serum concentrations of triglyceride (- 66 vs. 3.87 mg/dL, P = 0.028), insulin (- 4.27 vs. - 2.51 mU/L, P = 0.003) and accordingly insulin resistance (- 1.19 vs. - 0.76, P = 0.005) and sensitivity (0.03 vs. 0.01, P = 0.022) indices in flaxseed group. Combination of flaxseed and hesperidin improved three of five metabolic syndrome components including serum concentrations of triglyceride, glucose and systolic blood pressure as compared to placebo. Interestingly, co-administration of flaxseed and hesperidin with 77.3% reduction in the prevalence of defined metabolic syndrome was revealed to be most effective in controlling the metabolic syndrome, after which the group of flaxseed with 76% reduction and hesperidin group with 54.5% reduction were ranked second and third, respectively.

CONCLUSIONS

It can be concluded that co-administration of flaxseed and hesperidin appears to be superior to either supplementation alone on metabolic syndrome treatment, while the effects of flaxseed are stronger than hesperidin supplementation.

Influence of extruded lentil containing high chromium nutritional yeast on the main physiological factors associated with metabolic syndrome in rodent models

Insulin resistance, obesity and dyslipidemia are the main physiological factors associated with metabolic syndrome. The objectives of this study were to understand the effects of diets containing extruded lentil fortified with high chromium nutritional yeast (YCr) or chromium picolinate on glucose tolerance, clearance and fasting blood glucose concentrations in Normal and Obese (Ob/Ob) mice and to determine the effects of the diets on the mice plasma lipid profiles. Diets A, B and C contained YCr in different doses and concentrations, as follows: Diet A = 15.7 g and 16 ppm, B = 157.1 g and 16 ppm, and C = 299.3 g and 27 ppm, respectively. Diet D contained chromium picolinate at a dose and concentration of 15.7 g and 16 ppm, respectively. Intraperitoneal glucose tolerance tests and intraperitoneal insulin tolerance tests were conducted at 4-weeks and 8-weeks post diet initiation, in addition to, plasma lipoprotein profiles and organ weights. Normal mice showed only slight variability with respect to the studied biological parameters compared to the Ob/Ob mice group. Results indicated that following 4-weeks of diet supplementation, Ob/Ob mice fed diets A, C and D had significantly (p < 0.05) lower fasting blood glucose (FBG) than Ob/Ob mice fed Diet B. However, after 8-weeks Ob/Ob mice fed Diet C, containing YCr, had a significantly (p < 0.05) lower FBG than mice supplemented with Diet D, containing chromium picolinate. Therefore, based on these findings, it was concluded that YCr at the highest concentration and dose was more effective than chromium picolinate. These results indicate that ready-to-eat snacks and breakfast cereal type products supplemented with chromium in the form of YCr could be used as vehicles for the amelioration of main physiological factors associated with metabolic syndrome.

The kynurenine pathway of tryptophan degradation is activated during osteoblastogenesis

The mechanisms involved in the anabolic effect of interferon gamma (IFNγ) on bone have not been carefully examined. Using microarray expression analysis, we found that IFNγ upregulates a set of genes associated with a tryptophan degradation pathway, known as the kynurenine pathway, in osteogenic differentiating human mesenchymal stem cells (hMSC). We, therefore, hypothesized that activation of the kynurenine pathway plays a role in osteoblastogenesis even in the absence of IFNγ. Initially, we observed a strong increase in tryptophan degradation during osteoblastogenesis with and without IFNγ in the media. We next blocked indoleamine 2,3-dioxygenase-1 (IDO1), the most important enzyme in the kynurenine pathway, using a siRNA and pharmacological approach and observed a strong inhibition of osteoblastogenesis with a concomitant decrease in osteogenic factors. We next examined the bone phenotype of Ido1 knockout (Ido1(-/-)) mice. Compared to their wild-type littermates, Ido1(-/-) mice exhibited osteopenia associated with low osteoblast and high osteoclast numbers. Finally, we tested whether the end products of the kynurenine pathway have an osteogenic effect on hMSC. We identified that picolinic acid had a strong and dose-dependent osteogenic effect in vitro. In summary, we demonstrate that the activation of the kynurenine pathway plays an important role during the commitment of hMSC into the osteoblast lineage in vitro, and that this process can be accelerated by exogenous addition of IFNγ. In addition, we found that mice lacking IDO1 activity are osteopenic. These data therefore support a new role for the kynurenine pathway and picolinic acid as essential regulators of osteoblastogenesis and as potential new targets of bone-forming cells in vivo.

Targeting metabolic disorders by natural products

The most prevalent metabolic disorders are diabetes mellitus, obesity, dyslipidemia, osteoporosis and metabolic syndrome, which are developed when normal metabolic processes are disturbed. The most common pathophysiologies of the above disorders are oxidative stress, Nrf2 pathways, epigenetic, and change in miRNA expression. There is a challenge in the prevention and treatment of metabolic disorders due to severe adverse effects of some synthetic drugs, their high cost, lack of safety and poverty in some conditions, and insufficient accessibility for the general population in the world. With increasing interest in shifting from synthetic drugs to phytotherapy as an alternative treatment, there is still a gap in scientific evidences of plant-derived therapeutic benefits. One reason may be slow rate of translation of animal studies' findings into human clinical trials. Since metabolic disorders are multifactorial, it seems that poly-herbal medications, or drug-herbal combination are needed for their treatment. However, further researches to determine the most effective plant-derived metabolites, and their cellular mechanism in order to set priorities for well-designed animal and clinical trials, and also more studies with strong scientific evidences such as systematic review and meta-analysis of controlled studies are needed.

Effects of rhaponticum carthamoides versus glycyrrhiza glabra and punica granatum extracts on metabolic syndrome signs in rats

Background

Rhaponticum cathamoides (RC) is an endemic wild Siberian herb with marked medicinal properties that are still poorly understood. The aim of this study is to investigate the therapeutic potential of RC extract (ERC) compared to the effects of Glycyrrhiza glabra (EGG) and Punica granatum extracts (EPG) in a rat model with high-fat diet-(HFD)-induced signs of metabolic syndrome; therefore, this study addresses a significant global public health problem.

Methods

Six-month-old male Wistar Albino Glaxo rats were subjected to eight weeks of a standard diet (SD), HFD, or HFD in which ERC, EGG, or EPG powders were incorporated at 300 mg/kg/day. The serum lipid profile, corticosterone and cytokine concentrations, glucose tolerance, systolic blood pressure, triacylglycerol accumulation, and PPARα DNA-binding activities in the liver samples were determined.

Results

In contrast to EGG and EPG, an ERC supplement significantly reduced the weight of epididymal tissue (19.0%, p < 0.01) and basal serum glucose level (19.4%, p < 0.05). ERC improved glucose intolerance as well as dyslipidemia more efficiently than EGG and EPG. EGG but not ERC or EPG supplementation decreased systolic blood pressure by 12.0% (p < 0.05). All of the tested extracts reduced serum IL6 and corticosterone levels induced by HFD. However, the lowering effects of ERC consumption on the serum TNF-α level and its restoring effect on the adrenal corticosterone level significantly exceeded the improvements induced by EGG and EPG. ERC intake also reduced triacylglycerol accumulation and increased the PPARα DNA-binding activity in the liver more significantly than EGG and EPG.

Conclusions

ERC powder supplementation improved glucose and lipid metabolism more significantly than EGG and EPG in rats fed on HFD, supporting the strategy of R. carthamoides use for safe relief of metabolic syndrome and its related disturbances such as inflammation, stress, and hepatic steatosis.

Protective nature of mangiferin on oxidative stress and antioxidant status in tissues of streptozotocin-induced diabetic rats

Oxidative stress plays an important role in the progression of diabetes complications. The aim of the present study was to investigate the beneficial effect of oral administration of mangiferin in streptozotocin (STZ)-induced diabetic rats by measuring the oxidative indicators in liver and kidney as well as the ameliorative properties. Administration of mangiferin to diabetic rats significantly decreased blood glucose and increased plasma insulin levels. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and level of reduced glutathione (GSH) were significantly (P < 0.05) decreased while increases in the levels of lipidperoxidation (LPO) markers were observed in liver and kidney tissues of diabetic control rats as compared to normal control rats. Oral treatment with mangiferin (40 mg/kg b.wt/day) for a period of 30 days showed significant ameliorative effects on all the biochemical and oxidative parameters studied. Diabetic rats treated with mangiferin restored almost normal architecture of liver and kidney tissues, which was confirmed by histopathological examination. These results indicated that mangiferin has potential ameliorative effects in addition to its antidiabetic effect in experimentally induced diabetic rats.

Differential effect of oral dehydroepiandrosterone-sulphate on metabolic syndrome features in pre- and postmenopausal obese women

OBJECTIVE

To analyze the effect in obese pre- and postmenopausal women of a daily dose of 100 mg dehydroepiandrosterone-sulphate (DHEA-S) provided over a period of 3 months as replacement therapy against metabolic syndrome.

CONTEXT

Although DHEA-S appears to be effective against certain features of metabolic syndrome, its usefulness against this syndrome as a whole has not been evaluated to date.

DESIGN/PATIENTS

A randomized, double-blind placebo-controlled trial was conducted involving 61 postmenopausal women, who received DHEA-S (n = 41) or placebo (n = 20) for 3 months. The effect of DHEA-S treatment on the same postmenopausal women was compared with the effects observed in a group of premenopausal women (n = 20).

MEASUREMENTS

Anthropometric measurements were taken at the beginning and at the end of the treatment. Similarly, different parameters that define metabolic syndrome and other cardiometabolic variables were determined.

RESULTS

Dehydroepiandrosterone-sulphate replacement produced weight loss in the obese women studied. Moreover, waist circumference, glucose and systolic and diastolic blood pressure, among other metabolic syndrome parameters, improved in the postmenopausal group, who showed a significant reduction in the total metabolic syndrome score (P < 0·05). In contrast, in premenopausal women, the effect of DHEA-S was limited to obesity parameters, and no effect was observed on metabolic syndrome components. No significant changes were evident in the placebo group.

CONCLUSIONS

An oral dose of DHEA-S is useful for weight loss. In obese postmenopausal women, the hormone significantly improves plasma biochemical levels and anthropometric characteristics, leading to a better metabolic profile, which highlights the usefulness of this therapy against metabolic syndrome in this group of women.