Mangiferin protects against adverse skeletal muscle changes and enhances muscle oxidative capacity in obese rats

Recent Advances in the Anti-Obesity Benefits of Phytoconstituents: From Phytochemistry to Targeting Novel-Systems

Obesity is a metabolic disorder that has become a global health concern. The existing pharmaceutical drugs for treating obesity have some side effects. Compounds from natural sources are prospective substitutes for treating chronic diseases such as obesity, with the added advantages of being safe and cost-effective. However, due to factors such as poor solubility, low bioavailability, and instability in the physiological environment, the therapeutic efficacy of phytoconstituents is limited. Nowadays, developing nanoscaled systems has emerged as a vital strategy for enhancing the delivery and therapeutic effect of phytoconstituents. The present study discusses and categorizes phytoconstituents with anti-obesity effects and concludes the main mechanisms underlying their effects. Importantly, strategies used to develop phytoconstituent-based nano-drug delivery systems (NDDS) for obesity treatment that show improved efficacy relative to traditional administration routes are reviewed. Finally, the progress of research on phytoconstituent-based NDDS for obesity treatment is summarized to provide a reference for the development of safe and effective treatment strategies for obesity.

Luteolin alleviates muscle atrophy, mitochondrial dysfunction and abnormal FNDC5 expression in high fat diet-induced obese rats and palmitic acid-treated C2C12 myotubes

Obesity is associated with a series of skeletal muscle impairments and dysfunctions, which are characterized by metabolic disturbances and muscle atrophy. Luteolin is a phenolic phytochemical with broad pharmacological activities. The present study aimed to evaluate the protective effects of Luteolin on muscle function and explore the potential mechanisms in high-fat diet (HFD)-induced obese rats and palmitic acid (PA)-treated C2C12 myotubes. Male Sprague-Dawley (SD) rats were fed with a control diet or HFD and orally administrated 0.5% sodium carboxymethyl cellulose (vehicle) or Luteolin (25, 50, and 100 mg/kg, respectively) for 12 weeks. The results showed that Luteolin ameliorated HFD-induced body weight gain, glucose intolerance and hyperlipidemia. Luteolin also alleviated muscle atrophy, decreased ectopic lipid deposition and prompted muscle-fiber-type conversion in the skeletal muscle. Meanwhile, we observed an evident improvement in mitochondrial quality control and respiratory capacity, accompanied by reduced oxidative stress. Mechanistic studies indicated that AMPK/SIRT1/PGC-1α signaling pathway plays a key role in the protective effects of Luteolin on skeletal muscle in the obese states, which was further verified by using specific inhibitors of AMPK and SIRT1. Moreover, the mRNA expression levels of markers in brown adipocyte formation were significantly up-regulated post Luteolin supplementation in different adipose depots. Taken together, these results revealed that Luteolin supplementation might be a promising strategy to prevent obesity-induced loss of mass and biological dysfunctions of skeletal muscle.

A botanical extract blend of Mangifera indica and Sphaeranthus indicus combined with resistance exercise training improves muscle strength and endurance over exercise alone in young men: a randomized, blinded, placebo-controlled trial

Resistance exercise training (RET) is used to improve muscular strength and function. This study tested the hypothesis that RET alongside daily supplementation of a Sphaeranthus indicus and Mangifera indica extract blend (SMI) would augment bench press (BP) and leg extension (LE) strength and repetitions to failure (RTF) compared to RET alone. Ninety-nine men (age 22 ± 3) completed the trial after randomization into one of four groups: (A1) 425 mg SMI plus one RET set; (A2) 850 mg SMI plus one RET set; (P1) placebo plus one RET set; and (P2) placebo plus two RET sets. RET sets were 6-8 BP and LE repetitions at 80% of a progressive one repetition maximum (1-RM), performed 3x/week for 8 weeks. Strength and RTF were evaluated at baseline and days 14, 28, and 56 while serum values of total testosterone (TT), free testosterone (FT), and cortisol (C) values were evaluated at baseline and day 56. RET significantly (p < 0.05) increased 1-RM, RTF, and T measures above baselines regardless of group assignment, but the increases were greater in the supplemented groups. At week 8, A1 bench pressed more than P1 (71.5.5 ± 17.5 kg vs. 62.0 ± 15.3 kg, p = 0.003), while A2 pressed 13.8 ± 3.0 kg more (95% CI 5.7-21.8, p < 0.001) than P1 and 9.9 ± 13.0 kg more (95% CI 1.7-18.2, p = 0.01) than P2. Also at week 8, the mean LE 1-RM of A1 (159.4 ± 22.6 kg) and A2 (162.2 ± 22.9 kg) was greater (p < 0.05) than that of P1 (142.2 ± 25.6 kg) and P2 (146.5 ± 19.7 kg). Supplementation improved RTF, TT, and FT values over those measured in exercise alone (p < 0.05), while C levels in A2 (9.3 ± 3.8 μg/dL) were lower than P2 (11.7 ± 3.8 μg/dL, p < 0.05). Daily supplementation with SMI was well tolerated and may help optimize muscle adaptive responses to RET in men.

Mangiferin, a Potential Supplement to Improve Metabolic Syndrome: Current Status and Future Opportunities

Metabolic syndrome (MetS) represents a considerable clinical and public health burden worldwide. Mangiferin (MF), a flavonoid compound present in diverse species such as mango (Mangifera indica L.), papaya (Pseudocydonia sinensis (Thouin) C. K. Schneid.), zhimu (Anemarrhena asphodeloides Bunge), and honeybush tea (Cyclopia genistoides), boasts a broad array of pharmacological effects. It holds promising uses in nutritionally and functionally targeted foods, particularly concerning MetS treatment. It is therefore pivotal to systematically investigate MF's therapeutic mechanism for MetS and its applications in food and pharmaceutical sectors. This review, with the aid of a network pharmacology approach complemented by this experimental studies, unravels possible mechanisms underlying MF's MetS treatment. Network pharmacology results suggest that MF treats MetS effectively through promoting insulin secretion, targeting obesity and inflammation, alleviating insulin resistance (IR), and mainly operating via the phosphatidylinositol 3 kinase (PI3K)/Akt, nuclear factor kappa-B (NF-[Formula: see text]B), microtubule-associated protein kinase (MAPK), and oxidative stress signaling pathways while repairing damaged insulin signaling. These insights provide a comprehensive framework to understand MF's potential mechanisms in treating MetS. These, however, warrant further experimental validation. Moreover, molecular docking techniques confirmed the plausibility of the predicted outcomes. Hereafter, these findings might form the theoretical bedrock for prospective research into MF's therapeutic potential in MetS therapy.

Pharmacological properties of mangiferin: bioavailability, mechanisms of action and clinical perspectives

This review aims to provide an in-depth analysis of the pharmacological properties of mangiferin, focusing primarily on its bioavailability and mechanisms of action, and its potential therapeutic applications, especially in the context of chronic diseases. We conducted a comprehensive examination of in vitro and in vivo studies, as well as clinical trials involving mangiferin or plant extracts containing mangiferin. The primary source of mangiferin is Mangifera indica, but it's also found in other plant species from the families Anacardiaceae, Gentianaceae, and Iridaceae. Mangiferin has exhibited a myriad of therapeutic properties, presenting itself as a promising candidate for treating various chronic conditions including neurodegenerative disorders, cardiovascular diseases, renal and pulmonary diseases, diabetes, and obesity. Despite the promising results showcased in many in vitro studies and certain animal studies, the application of mangiferin has been limited due to its poor solubility, absorption, and overall bioavailability. Mangiferin offers significant therapeutic potential in treating a spectrum of chronic diseases, as evidenced by both in vitro and clinical trials. However, the challenges concerning its bioavailability necessitate further research, particularly in optimizing its delivery and absorption, to harness its full medicinal potential. This review serves as a comprehensive update on the health-promoting and therapeutic activities of mangiferin.

Muscle plasticity is influenced by renal function and caloric intake through the FGF23-vitamin D axis

Skeletal muscle, the main metabolic engine in the body of vertebrates, is endowed with great plasticity. The association between skeletal muscle plasticity and two highly prevalent health problems: renal dysfunction and obesity, which share etiologic links as well as many comorbidities, is a subject of great relevance. It is important to know how these alterations impact on the structure and function of skeletal muscle because the changes in muscle phenotype have a major influence on the quality of life of the patients. This literature review aims to discuss the influence of a nontraditional axis involving kidney, bone, and muscle on skeletal muscle plasticity. In this axis, the kidneys play a role as the main site for vitamin D activation. Renal disease leads to a direct decrease in 1,25(OH)₂-vitamin D, secondary to reduction in renal functional mass, and has an indirect effect, through phosphate retention, that contributes to stimulate fibroblast growth factor 23 (FGF23) secretion by bone cells. FGF23 downregulates the renal synthesis of 1,25(OH)₂-vitamin D and upregulates its metabolism. Skeletal production of FGF23 is also regulated by caloric intake: it is increased in obesity and decreased by caloric restriction, and these changes impact on 1,25(OH)₂-vitamin D concentrations, which are decreased in obesity and increased after caloric restriction. Thus, both phosphate retention, that develops secondary to renal failure, and caloric intake influence 1,25(OH)₂-vitamin D that in turn plays a key role in muscle anabolism.

Sesamol Reverses Myofiber-Type Conversion in Obese States via Activating the SIRT1/AMPK Signal Pathway

Obesity can evoke changes of skeletal muscle structure and function, which are characterized by the conversion of myofiber from type I to type II, leading to a vicious cycle of metabolic disorders. Reversing the muscle fiber-type conversion in obese states is a novel strategy for treating those with obesity. Sesamol, a food ingredient compound isolated from sesame seeds, exerted potential antiobesity effects. The present research aimed to explore the therapeutic effects of sesamol on obesity-related skeletal muscle-fiber-type conversion and elucidate the underlying molecular mechanisms through utilizing a high-fat-diet-induced obese C57BL/6J mice model and palmitic acid-exposed C2C12 myotubes. The results showed that sesamol attenuated obesity-related metabolic disturbances, elevated exercise endurance of obese mice, and decreased lipid accumulation and insulin resistance in skeletal muscle. After the treatment with sesamol, the muscular mitochondrial content and biogenesis were increased, accompanied by the enzyme activities and myosin heavy-chain isoform changed from type II fiber to type I fiber. Mechanistic studies revealed that the effects of sesamol on reversing skeletal muscle-fiber-type conversion in obese states were associated with the stimulation of the muscular sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) signal pathway, and these effects could be inhibited by a specific inhibitor of SIRT1, EX-527. In conclusion, our research provided novel evidence that sesamol could regulate myofiber-type conversion to treat obesity and obesity-related metabolic disorders by stimulating the muscular SIRT1/AMPK signal pathway.

Effect of Ecdysterone on the Hepatic Transcriptome and Lipid Metabolism in Lean and Obese Zucker Rats

Conflicting reports exist with regard to the effect of ecdysterone, the predominating representative of steroid hormones in insects and plants, on hepatic and plasma lipid concentrations in different rodent models of obesity, fatty liver, and diabetes, indicating that the effect is dependent on the rodent model used. Here, the hypothesis was tested for the first time that ecdysterone causes lipid-lowering effects in genetically obese Zucker rats. To test this hypothesis, two groups of male obese Zucker rats (n = 8) were fed a nutrient-adequate diet supplemented without or with 0.5 g ecdysterone per kg diet. To study further if ecdysterone is capable of alleviating the strong lipid-synthetic activity in the liver of obese Zucker rats, the study included also two groups of male lean Zucker rats (n = 8) which also received either the ecdysterone-supplemented or the non-supplemented diet. While hepatic and plasma concentrations of triglycerides and cholesterol were markedly higher in the obese compared to the lean rats (p < 0.05), hepatic and plasma triglyceride and cholesterol concentrations did not differ between rats of the same genotype fed the diets without or with ecdysterone. In conclusion, the present study clearly shows that ecdysterone supplementation does not exhibit lipid-lowering actions in the liver and plasma of lean and obese Zucker rats.

Pharmacokinetic Comparisons of Mangiferin and Mangiferin Monosodium Salt in Rat Plasma by UPLC-MS/MS

Mangiferin (MG) is an active component in natural medicines, and various studies have been reported on pharmacological effects, but the low solubility and bioavailability of MG limit its wide application. The aim of the present study was to investigate the pharmacokinetic profiles of mangiferin (MG) and mangiferin monosodium salt (MG-Na) in rat plasma by UPLC-MS/MS, which were then compared between the two groups. An appropriate high sensitivity and selectivity ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was applied to the comparison of plasma pharmacokinetics in MG and MG-Na using carbamazepine as internal standard (IS). These results showed that there were statistically significant differences in the pharmacokinetic parameters between MG and MG-Na after a single oral administration at 100 mg/kg. When compared with pharmacokinetic parameters of MG, the AUC(0-t), AUC(0–∞), Cmax,K10, and Ka of MG-Na were increased by 5.6-, 5.7-, 20.8-, 8-, and 83.6-fold, while the Tmax and CL/F were decreased by 4- and 5.7-fold (P<0.001), respectively. t1/2 value showed an increasing trend, but was statistically significant between the two groups. Moreover, the AUC value in the MG-Na group was significantly increased and the relative bioavailability was calculated to be 570% when compared with that of the MG group. These results suggested that the salification reaction of MG can effectively enhance gastrointestinal absorption and relative bioavailability by improving solubility and membrane permeability.

Adipose tissue as a possible therapeutic target for polyphenols: A case for Cyclopia extracts as anti-obesity nutraceuticals

Obesity is a significant contributor to increased morbidity and premature mortality due to increasing the risk of many chronic metabolic diseases such as type 2 diabetes, cardiovascular disease and certain types of cancer. Lifestyle modifications such as energy restriction and increased physical activity are highly effective first-line treatment strategies used in the management of obesity. However, adherence to these behavioral changes is poor, with an increased reliance on synthetic drugs, which unfortunately are plagued by adverse effects. The identification of new and safer anti-obesity agents is thus of significant interest. In recent years, plants and their phenolic constituents have attracted increased attention due to their health-promoting properties. Amongst these, Cyclopia, an endemic South African plant commonly consumed as a herbal tea (honeybush), has been shown to possess modulating properties against oxidative stress, hyperglycemia, and obesity. Likewise, several studies have reported that some of the major phenolic compounds present in Cyclopia spp. exhibit anti-obesity effects, particularly by targeting adipose tissue. These phenolic compounds belong to the xanthone, flavonoid and benzophenone classes. The aim of this review is to assess the potential of Cyclopia extracts as an anti-obesity nutraceutical as underpinned by in vitro and in vivo studies and the underlying cellular mechanisms and biological pathways regulated by their phenolic compounds.

Mangiferin Accelerates Glycolysis and Enhances Mitochondrial Bioenergetics

One of the main causes of hyperglycemia is inefficient or impaired glucose utilization by skeletal muscle, which can be exacerbated by chronic high caloric intake. Previously, we identified a natural compound, mangiferin (MGF) that improved glucose utilization in high fat diet (HFD)-induced insulin resistant mice. To further identify the molecular mechanisms of MGF action on glucose metabolism, we conducted targeted metabolomics and transcriptomics studies of glycolyic and mitochondrial bioenergetics pathways in skeletal muscle. These data revealed that MGF increased glycolytic metabolites that were further augmented as glycolysis proceeded from the early to the late steps. Consistent with an MGF-stimulation of glycolytic flux there was a concomitant increase in the expression of enzymes catalyzing glycolysis. MGF also increased important metabolites in the tricarboxylic acid (TCA) cycle, such as α-ketoglutarate and fumarate. Interestingly however, there was a reduction in succinate, a metabolite that also feeds into the electron transport chain to produce energy. MGF increased succinate clearance by enhancing the expression and activity of succinate dehydrogenase, leading to increased ATP production. At the transcriptional level, MGF induced mRNAs of mitochondrial genes and their transcriptional factors. Together, these data suggest that MGF upregulates mitochondrial oxidative capacity that likely drives the acceleration of glycolysis flux.