Yerba Mate Stimulates Mitochondrial Biogenesis and Thermogenesis in High-Fat-Diet-Induced Obese Mice

White adipocyte-derived exosomal miR-23b inhibits thermogenesis by targeting Elf4 to regulate GLP-1R transcription

Promoting non-trembling thermogenesis of brown adipose tissue (BAT) and browning of white adipose tissue (WAT) helps prevent obesity. MiR-23b is highly expressed in adipose tissue-derived exosomes obtained from obese people, but the role of exosomal miR-23b in regulating thermogenesis and obesity progression remains to be further explored. Here, a mouse obesity model was established through high-fat diet (HFD), and inguinal WAT (iWAT)-derived exosomes and miR-23b antagomir were administered by intraperitoneal injection. The results showed that WAT-derived exosomal miR-23b upregulated body weight and adipocyte hypertrophy and enhanced insulin resistance. Moreover, exosomal miR-23b restrained mtDNA copy number and the expression of genes related to thermogenesis and mitochondrial biogenesis in BAT, and suppressed the expression of WAT browning-related genes under cold stimulation, indicating that exosomal miR-23b hindered non-trembling thermogenesis of BAT and WAT browning. Mechanism studies found that miR-23b targeted Elf4 to inhibit its expression. And Elf4 bound to the GLP-1R promoter region to promote GLP-1R transcription. In addition, silencing miR-23b effectively abolished the inhibitory effect of WAT-derived exosomes on thermogenic gene expression and mitochondrial respiration in adipocytes isolated from BAT and iWAT, which was reversed by GLP-1R knockdown. In conclusion, WAT-derived exosomal miR-23b suppressed thermogenesis by targeting Elf4 to regulate GLP-1R transcription, which contributed to the progression of obesity.

Medicinal Plant Extracts against Cardiometabolic Risk Factors Associated with Obesity: Molecular Mechanisms and Therapeutic Targets

Obesity has increasingly become a worldwide epidemic, as demonstrated by epidemiological and clinical studies. Obesity may lead to the development of a broad spectrum of cardiovascular diseases (CVDs), such as coronary heart disease, hypertension, heart failure, cerebrovascular disease, atrial fibrillation, ventricular arrhythmias, and sudden cardiac death. In addition to hypertension, there are other cardiometabolic risk factors (CRFs) such as visceral adiposity, dyslipidemia, insulin resistance, diabetes, elevated levels of fibrinogen and C-reactive protein, and others, all of which increase the risk of CVD events. The mechanisms involved between obesity and CVD mainly include insulin resistance, oxidative stress, inflammation, and adipokine dysregulation, which cause maladaptive structural and functional alterations of the heart, particularly left-ventricular remodeling and diastolic dysfunction. Natural products of plants provide a diversity of nutrients and different bioactive compounds, including phenolics, flavonoids, terpenoids, carotenoids, anthocyanins, vitamins, minerals, fibers, and others, which possess a wide range of biological activities including antihypertensive, antilipidemic, antidiabetic, and other activities, thus conferring cardiometabolic benefits. In this review, we discuss the main therapeutic interventions using extracts from herbs and plants in preclinical and clinical trials with protective properties targeting CRFs. Molecular mechanisms and therapeutic targets of herb and plant extracts for the prevention and treatment of CRFs are also reviewed.

Yerba mate consumption by ovariectomized rats alters white adipose tissue

INTRODUCTION

Menopause and post-menopause are characterized by low levels of estrogen that can be associated with the emergence of metabolic diseases. While hormone replacement therapy can alleviate many symptoms, it can also exacerbate other diseases such as breast cancer. In the search for natural alternatives, Ilex paraguariensis (Yerba Mate) has been identified as a potential therapy for the onset of obesity. Here, the effect of MATE consumption on white adipose tissue (WAT) was studied in ovariectomized rats, an animal model for post-menopause hormone loss.

METHODS

Four groups of animals were used: ovariectomy with MATE (OVX MATE) and without MATE (OVX), as well as sham surgery with MATE (Sham MATE) and without MATE (Sham). MATE was provided by gavage at 1 g/kg of body weight for eight weeks before measuring biochemical parameters in plasma and characterizing WAT morphology.

RESULTS

The consumption of Yerba MATE significantly decreased weight gain in ovariectomized rats and presented near control levels of triglycerides, total cholesterol, and LDL. A morphometric analysis of WAT showed a significant decrease in the area occupied by adipocytes in the group that consumed MATE. Finally, MATE consumption increased the UCP1 content in the WAT of the ovariectomized group. Yerba MATE treatment was also associated with higher levels of SIRT1 protein.

CONCLUSION

MATE consumption has a preventive effect on the weight gain observed in ovariectomized rats and potential benefits in naturally avoiding the onset of obesity post menopause.

Malvidin Protects against and Repairs Peptic Ulcers in Mice by Alleviating Oxidative Stress and Inflammation

Peptic ulcer episodes cause damage to the stomach and intestine, with inflammatory cell infiltration and oxidative stress as the main players. In this study, we investigated the potential of anthocyanidin malvidin for preventive and curative peptic ulcer treatment. The anthocyanidin effects were examined in gastric ulcer mouse models induced by ethanol, non-steroidal anti-inflammatory drugs (NSAIDs), ischemia-reperfusion (IR), acetic acid and duodenal ulcer induced by polypharmacy. Expression levels of oxidative and inflammatory genes were measured to investigate the mechanism of anthocyanin activity. At a dose of 5 mg·kg⁻¹, Malvidin prevented gastric ulcer induction by ethanol, NSAID and repaired the tissue after 6 days of IR. Moreover, the anthocyanidin accelerated the healing of acetic acid-induced ulcer, increased the gene expression of EGF and COX-1, and downregulated MMP-9. Anthocyanin treatment mitigated the effect of polypharmacy on inflammation and oxidative stress observed in the intestine. Additionally, the compound downregulated cytokine expression and TLR4 and upregulated HMOX-1 and IL-10, exhibiting protective activity in the mouse gut. Malvidin thus prevented gastric and duodenal ulcers due to prominent anti-inflammatory and antioxidative effects on the gastrointestinal tract that were related to gene expression modulation and an increase in endogenous defense mechanisms.

Targeting Mitochondrial Biogenesis with Polyphenol Compounds

Appropriate mitochondrial physiology is an essential for health and survival. Cells have developed unique mechanisms to adapt to stress circumstances and changes in metabolic demands, by meditating mitochondrial function and number. In this context, sufficient mitochondrial biogenesis is necessary for efficient cell function and haemostasis, which is dependent on the regulation of ATP generation and maintenance of mitochondrial DNA (mtDNA). These procedures play a primary role in the processes of inflammation, aging, cancer, metabolic diseases, and neurodegeneration. Polyphenols have been considered as the main components of plants, fruits, and natural extracts with proven therapeutic effects during the time. These components regulate the intracellular pathways of mitochondrial biogenesis. Therefore, the current review is aimed at representing an updated review which determines the effects of different natural polyphenol compounds from various plant kingdoms on modulating signaling pathways of mitochondrial biogenesis that could be a promising alternative for the treatment of several disorders.

Exploring Phytotherapeutic Alternatives for Obesity, Insulin Resistance and Diabetes Mellitus

At present, the pathologic spectrum of obesity-insulin resistance (IR)-diabetes mellitus (DM) represents not only a pressing matter in public health but also a paramount object of study in biomedical research, as they constitute major risk factors for cardiovascular disease (CVD), and other chronic non-communicable diseases (NCD). Phytotherapy, the use of medicinal herbs (MH) with treatment purposes, offers a wide array of opportunities for innovation in the management of these disorders; mainly as pharmacological research on small molecules accumulates. Several MH has displayed varied mechanisms of action relevant to the pathogenesis of obesity, IR and DM, including immunological and endocrine modulation, reduction of inflammation and oxidative stress (OS), regulation of appetite, thermogenesis and energy homeostasis, sensitisation to insulin function and potentiation of insulin release, among many others. However, the clinical correlates of these molecular phenomena remain relatively uncertain, with only a handful of MH boasting convincing clinical evidence in this regard. This review comprises an exploration of currently available preclinical and clinical research on the role of MH in the management of obesity, IR, and DM.

Investigation of the effects of dichlorvos poisoning on AMPK signaling pathway in chicken brain tissues

Dichlorvos is a common crop insecticide widely used by people which causes extensive and serious environmental pollution. However, it has been shown that organophosphorus poisoning causes energy metabolism and neural disorders. The overall purpose of this study was to investigate the damage to brain tissue and the changes in AMPK signaling pathway-related gene expression after dichlorvos poisoning in chickens. White-feathered broiler chickens, as the research subjects of this experiment, were divided into three groups: control group, low-dose group (77.5% dichlorvos at 1.13 mg/kg dose) and high-dose group (77.5% dichlorvos at 10.2 mg/kg dose). Clinical symptoms were observed after modeling, and an integrative analysis was conducted using HE staining microscopy, immune-histochemical microscopy, electron microscopy and PCR arrays. The results showed that the high-dose group had more obvious dyspnea, salivation, convulsion and other neurological phenomena. Pathological sections showed that nuclear disintegration of neurons was most obvious in the low-dose group, and apoptosis of brain cells was most obvious in the high-dose group, and the mitochondrial structure was destroyed in the two poisoned group, i.e. low-dose group and high-dose group. PCR arrays showed that AMPK signaling pathway was inhibited and the expressions of genes involved in energy metabolism (ACACA and PRKAA1) were significantly changed. Furthermore, genes associated with protein synthesis (EIF4EBP1) were significantly upregulated. FASN and HMGCR expressions were significantly increased. There were significant changes in the expressions of cell cycle-related genes (STK11, TP53 and FOXO3). Organophosphate poisoning can cause a lot of nuclear disintegration of brain neurons, increases cell apoptosis, disrupts the energy metabolism of mitochondrial structure, and inhibits the AMPK signaling pathway. These results provide a certain idea and basis for studying the mechanism of AMPK signaling after organophosphorus poisoning and provide a research basis for the prevention and treatment of organophosphorus poisoning.

Withania somnifera Extract Enhances Energy Expenditure via Improving Mitochondrial Function in Adipose Tissue and Skeletal Muscle

Withania somnifera (WS), commonly known as ashwagandha, possesses diverse biological functions. WS root has mainly been used as an herbal medicine to treat anxiety and was recently reported to have an anti-obesity effect, however, the mechanisms underlying its action remain to be explored. We hypothesized that WS exerts its anti-obesity effect by enhancing energy expenditure through improving the mitochondrial function of brown/beige adipocytes and skeletal muscle. Male C57BL/6J mice were fed a high-fat diet (HFD) containing 0.25% or 0.5% WS 70% ethanol extract (WSE) for 10 weeks. WSE (0.5%) supplementation significantly suppressed the increases in body weight and serum lipids, and lipid accumulation in the liver and adipose tissue induced by HFD. WSE supplementation increased oxygen consumption and enhanced mitochondrial activity in brown fat and skeletal muscle in the HFD-fed mice. In addition, it promoted browning of subcutaneous fat by increasing mitochondrial uncoupling protein 1 (UCP1) expression. Withaferin A (WFA), a major compound of WS, enhanced the differentiation of pre-adipocytes into beige adipocytes and oxygen consumption in C2C12 murine myoblasts. These results suggest that WSE ameliorates diet-induced obesity by enhancing energy expenditure via promoting mitochondrial function in adipose tissue and skeletal muscle, and WFA is a key regulator in this function.

Chrysin Modulates Genes Related to Inflammation, Tissue Remodeling, and Cell Proliferation in the Gastric Ulcer Healing

Chrysin exhibits anti-inflammatory and antioxidant activities. Here, the gastroprotective effect of chrysin was investigated in mouse models of gastric ulcer induced by absolute ethanol, acetic acid, and ischemia-reperfusion injury. The gastric-healing effect was evaluated at 7 and 14 days after treatment; the mechanism of action was verified using the expression of metalloproteinase 2 (MMP-2) and 9 (MMP-9), caspase-3, cyclooxygenase 1 (COX-1) and 2 (COX-2), epidermal growth factor (EGF), and interleukin-10. Chrysin (10 mg/kg) inhibited macroscopic lesions and increased catalase activity in the mouse model established using absolute ethanol. It ameliorated the gastric ulcer caused by acetic acid by improving the expression of inflammatory genes such as COX-2, inhibiting negative remodeling promoted by MMP-9, increasing cell proliferation effect via EGF, and reducing cellular apoptosis by modulating caspase-3. A faster healing effect was evident in the first 7 days of treatment compared to 14 days of treatment, indicating the pharmacological potential of chrysin. Overall, these results demonstrate the potent effect of chrysin in the gastrointestinal tract and elucidate the genes involved in the healing of gastric ulcers. Moreover, an increase in the levels of gastric mucosa defensive factors is involved in the activity of chrysin in the gastric mucosa.

Maternal Eicosapentaenoic Acid Feeding Decreases Placental Lipid Deposition and Improves the Homeostasis of Oxidative Stress Through a Sirtuin-1 (SIRT1) Independent Manner

SCOPE

Maternal obesity has been associated with increased placental lipotoxicity and impaired mitochondrial function. Sirtuin-1 (SIRT1) is an important regulator of both lipid metabolism and mitochondrial biogenesis. The present study aims to determine whether supplementation of the maternal diet with eicosapentaenoic acid (EPA) can decrease placental lipid deposition and improve antioxidant ability, in a SIRT1-dependent manner.

METHODS AND RESULTS

Pregnant SIRT1^+/- mice (mated with male SIRT1^+/- ) are fed a high-fat diet consisting of 60% of the kcal from fat, or an equienergy EPA diet for 18.5 d. Supplementation with EPA significantly changes maternal plasma, placental and fetal fatty acid composition, and decreases placental and fetal lipid content. In addition, placental antioxidant capacity and lipid peroxidation products are increased, placental uncoupling protein 1 (UCP1) and PPARγ coactivator-1 α (PGC1α) expression are activated, and mitochondrial swelling decreases. While SIRT1 deficiency has little effect on placental fatty acid composition and lipid content, decreased fetal lipid deposition is observed, placental PGC1α expression decreases, mitochondrial swelling increases, and placental total superoxide dismutase (T-SOD) activity increases. Both EPA and SIRT1 have no effect on BODIPY-FL-C16 uptake. Interestingly, there is no significant interaction between diet and genotype.

CONCLUSION

Maternal EPA feeding decreases placental lipid deposition and improves placental oxidative stress homeostasis independent of SIRT1.

Development of Caco-2 cells-based gene reporter assays and evaluation of herb-drug interactions involving CYP3A4 and CYP2D6 gene expression

The indiscriminate use of medicinal plants and herbal medicinal products concomitantly with conventional drugs may result in herb-drug interactions that may lead to fluctuations in drug bioavailability, therapeutic failure, and/or toxic effects. CYP450 enzymes play an important role in drug biotransformation and herb-drug interactions. Thus, the aim of this study was to develop and apply Caco-2 cells-based gene reporter assays to study in vitro the potential occurrence of CYP3A4 and CYP2D6 gene expression modulation by standardized extracts of selected medicinal plants. Reporter cell lines developed showed a significant increase in CYP3A4 and CYP2D6 reporter fluorescent emission, 4 and 16-fold respectively, when compared to the controls. The standardized extracts of Cecropia glaziovii, Bauhinia forficata and Echinacea sp. significantly increased CYP3A4 reporter fluorescence, and those of Ilex paraguariensis, Bauhinia forficata and Echinacea sp. significantly decreased CYP2D6 reporter fluorescence in Caco-2 cells-based gene reporter assays. The data obtained suggest that CYP3A4 and CYP2D6 gene expression seem to be modulated by the extracts tested. In addition, the reporter cell lines developed are functional assays that could be used to study drug-drug and herb-drug interactions during the research and development of new drugs.

Potential Usefulness of a Wakame/Carob Functional Snack for the Treatment of Several Aspects of Metabolic Syndrome: From In Vitro to In Vivo Studies

Metabolic syndrome (MetS) greatly increases the risk of cardiovascular diseases and type 2 diabetes mellitus. The aim of this study was to evaluate the efficacy of functional snacks containing a combination of wakame (W) and carob pod (CP) flours in reducing markers associated with MetS. The mechanisms of action underlying these effects were also evaluated. In vitro approaches were carried out in mature 3T3-L1 adipocytes and RAW 264.7 macrophages treated with different doses of extracts from W, CP, or a combination of both. Furthermore, an in vivo experiment was conducted in rats with MetS treated with normal-caloric diets containing different snack formulations with combinations of 1/50 (snack A) or 1/5 of wakame/carob (snack B). In vitro experiments results indicated that both W and CP had delipidating effects, but only the latter induced anti-inflammatory and anti-hypertensive effects. As far as the in vivo study is concerned, snack B was ineffective and snack A showed an anti-hypertensive effect in rats with MetS. The present study shows for the first time the in vitro efficacy of a W and CP combination as an anti-inflammatory, delipidating, and anti-hypertensive tool, and its potential usefulness in treating MetS.

Effects of Polyphenols on Thermogenesis and Mitochondrial Biogenesis

Obesity is a health problem worldwide, and energy imbalance has been pointed out as one of the main factors responsible for its development. As mitochondria are a key element in energy homeostasis, the development of obesity has been strongly associated with mitochondrial imbalance. Polyphenols are the largest group of phytochemicals, widely distributed in the plant kingdom, abundant in fruits and vegetables, and have been classically described as antioxidants owing to their well-established ability to eliminate free radicals and reactive oxygen species (ROS). During the last decade, however, growing evidence reports the ability of polyphenols to perform several important biological activities in addition to their antioxidant activity. Special attention has been given to the ability of polyphenols to modulate mitochondrial processes. Thus, some polyphenols are now recognized as molecules capable of modulating pathways that regulate mitochondrial biogenesis, ATP synthesis, and thermogenesis, among others. The present review reports the main benefits of polyphenols in modulating mitochondrial processes that favor the regulation of energy expenditure and offer benefits in the management of obesity, especially thermogenesis and mitochondrial biogenesis.