Hibiscus sabdariffa L. calyx extract prevents the adipogenesis of 3T3-L1 adipocytes, and obesity-related insulin resistance in high-fat diet-induced obese rats

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.

Behaviour of Tunisian Psammomys obesus fed high-calorie diets: biochemical disturbance and histopathological alterations

This work investigated the biochemical disturbances and histological alteration in Psammomys obesus animal model fed different high calorie diets (HCDs) during three months. Four diets were used: a low-calorie natural diet, Chenopodiaceae halophyte plant used as control (LCD), a high standard carbohydrate diet rich in protein, HCD 0, a high carbohydrate diet rich in two concentrations of fat, HCD 1 and HCD 2. All animals having received HCDs developed dyslipidemia after one month of experiment with distinction of different sub-groups developing or not obesity and diabetes. HCDs induced a remarkable increasing in blood cholesterol, LDL-cholesterol and triglyceride levels indicating a fast induction of dyslipidemia and a significant increase of aminotransaminases activities revealing a pronounced hepatotoxicity. Animal developing diabetes showed a severe hepatic injury, a degeneration of the adipose tissue and a significant reduction of retinal thickness. P. obesus seems to be an excellent animal model to investigate nutritional metabolic diseases.

Antioxidant and anti-inflammatory effects of Boswellia dalzielii and Hibiscus sabdariffa extracts in alloxan-induced diabetic rats

Diabetes mellitus (DM) is one of the leading worldwide public health problems. It is characterized by hyperglycemia which induces oxidative stress and inflammation, both involved in the pathogenesis of diabetes. We previously showed that Boswellia dalzielii (BD) and Hibiscus sabdariffa (HS) extracts reduced hyperglycemia and hyperlipidemia in alloxan-induced diabetic rats. In the present study, we evaluated the antioxidant and anti-inflammatory activities of both plants in alloxan-induced diabetic rats. Two sets of experiments were conducted in male Wistar rats subjected to a single intraperitoneal injection of alloxan monohydrate (150 mg/kg, b. w.). Then, diabetic rats were daily administered with either BD (1st set of experiments) or HS (2nd set of experiments) at 100, 200, and 400 mg/kg orally for 21 consecutive days. Glibenclamide (10 mg/kg) was also administered as a reference drug. At the end of the study, the animals were anesthetized, and blood samples were collected from each animal. Then, oxidative stress and inflammatory biomarkers in the serum were determined. We found that treatment with BD and HS significantly reduced malondialdehyde (MDA) and enhanced the levels of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). These extracts also significantly decreased the inflammatory markers tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). From the results obtained, it can therefore be concluded that BD and HS have the potential to being developed as natural sources of antioxidant and anti-inflammatory agents that can be used for the prevention or treatment of DM.

Hibiscus acetosella: An Unconventional Alternative Edible Flower Rich in Bioactive Compounds

The interest in the consumption of edible flowers has increased since they represent a rich source of bioactive compounds, which are significantly beneficial to human health. The objective of this research was to access the bioactive compounds and antioxidant and cytotoxic properties of unconventional alternative edible flowers of Hibiscus acetosella Welw. Ex Hiern. The edible flowers presented pH value of 2.8 ± 0.00, soluble solids content of 3.4 ± 0.0 °Brix, high moisture content of about 91.8 ± 0.3%, carbohydrates (6.9 ± 1.2%), lipids (0.90 ± 0.17%), ashes (0.4 ± 0.0%), and not detectable protein. The evaluation of the scavenging activity of free radicals, such as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), of the flower extract was better than the results observed for other edible flowers (507.8 ± 2.7 μM TE and 783.9 ± 30.8 μM TE, respectively) as well as the total phenolic composition (TPC) value (568.8 ± 0.8 mg GAE/g). These flowers are rich in organic acids and phenolic compounds, mainly myricetin, and quercetin derivatives, kaempferol, and anthocyanins. The extract showed no cytotoxicity for the cell lineages used, suggesting that the extract has no directly harmful effects to cells. The important bioactive compound identified in this study makes this flower especially relevant in the healthy food area due to its nutraceutical potential without showing cytotoxicity.

Naringin Ameliorates Skeletal Muscle Atrophy and Improves Insulin Resistance in High-Fat-Diet-Induced Insulin Resistance in Obese Rats

Obesity causes progressive lipid accumulation and insulin resistance within muscle cells and affects skeletal muscle fibres and muscle mass that demonstrates atrophy and dysfunction. This study investigated the effects of naringin on the metabolic processes of skeletal muscle in obese rats. Male Sprague Dawley rats were divided into five groups: the control group with normal diet and the obese groups, which were induced with a high-fat diet (HFD) for the first 4 weeks and then treated with 40 mg/kg of simvastatin and 50 and 100 mg/kg of naringin from week 4 to 8. The naringin-treated group showed reduced body weight, biochemical parameters, and the mRNA expressions of protein degradation. Moreover, increased levels of antioxidant enzymes, glycogen, glucose uptake, the expression of the insulin receptor substrate 1 (IRS-1), the glucose transporter type 4 (GLUT4), and the mRNA expressions of protein synthesis led to improved muscle mass in the naringin-treated groups. The in vitro part showed the inhibitory effects of naringin on digestive enzymes related to lipid and glucose homeostasis. This study demonstrates the potential benefits of naringin as a supplement for treating muscle abnormalities in obese rats by modulating the antioxidative status, regulating protein metabolism, and improved insulin resistance in skeletal muscle of HFD-induced insulin resistance in obese rats.

Hibiscus sabdariffa in Diabetes Prevention and Treatment—Does It Work? An Evidence-Based Review

Diabetes is currently a global health problem that is already reported as an epidemic. This metabolic disease, characterized by a disturbance in the carbohydrate, protein, and lipid metabolism, is often accompanied by disorders of several organs. Its treatment is expensive and often difficult to control. Therefore, it seems necessary to search for new drugs and solutions to facilitate therapy and reduce treatment costs. Herbal medicines are becoming more and more popular. Hibiscus sabdariffa (roselle) is a plant that grows wild in a tropical climate. It has been used in folk medicine for thousands of years. Thanks to the numerous active compounds, including polyphenols, polysaccharides, organic acids, or pectins, it is reported to exhibit hypoglycemic, antioxidant, hypotensive, and anti-lipidemic activities and numerous indirect effects that are related to them. The aim of this review was to update the knowledge about the therapeutic effects of roselle in diabetes and its comorbidities based on in vitro, animal, and human studies. After a careful analysis of the scientific literature, it can be stated that roselle is a promising product that can be used either on its own or as an addition to the conventional treatment regimens to prevent or treat diabetes and its accompanying diseases.

The Ameliorative Role of Hibiscetin against High-Fat Diets and Streptozotocin-Induced Diabetes in Rodents via Inhibiting Tumor Necrosis Factor-α, Interleukin-1β, and Malondialdehyde Level

Hibiscetin, as one of the main bioactive constituents of Hibiscus sabdariffa, has many pharmacological activities, but its antihyperglycemic activity has not been fully interpreted yet. The current research was developed from this perspective. The study intended to appraise the antidiabetic capability of hibiscetin in a high-fat diet (HFD) and streptozotocin (STZ; 50 mg/kg, intraperitoneally)-induced diabetes in an experimental animal. The efficiency of hibiscetin at 10 mg/kg in an “HFD/STZ model” remedy in rats with experimentally caused diabetes was explored for 42 days. The efficacy of hibiscetin was observed on several diabetes parameters. The average body weight and an array of biochemical markers were determined, including blood glucose, insulin, total protein (TP), lipid profile, aspartate aminotransferase (AST), alanine aminotransferase (ALT), IL-6, IL-1β, tumor necrosis factor-α (TNF-α), adiponectin, leptin, resistin, malondialdehyde (MDA), catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD). The antidiabetic benefits of hibiscetin were proven by a substantial reduction in blood glucose, lipid profile (TC and TG), total protein, IL-6, IL-1β, MDA, TNF-α, leptin, adiponectin, ALT, and AST in the therapy group compared to the diabetic disease standard. Furthermore, hibiscetin therapy also reversed the lowered levels of insulin, resistin, GSH, SOD, and CAT in diabetic rats. It was determined that hibiscetin may be beneficial in terms of reducing diabetes problems due to its effects on both oxidative stress and inflammation and that more research for this design should be conducted.

Computer-aided identification of cholinergic and monoaminergic inhibitory flavonoids from Hibiscus sabdariffa L

BACKGROUND

The reduced levels of acetylcholine and dopamine lead to Alzheimer's disease AD and Parkinson disease PD, respectively, due to the action of cholinesterase and monoamine oxidase B.

METHODS

Therapeutic options for AD and PD involve respective cholinergic and monoaminergic inhibitors, and considering the adverse outcomes of cholinergic- and monoaminergic- inhibitory therapeutics, phytoconstituents may be promising alternatives. Reports have shown that different extracts of the calyx of Hibiscus sabdariffa exhibit anticholinesterase and monoamine oxidase B inhibitory properties with potential to delay and prevent the development of AD and PD. However, there is limited knowledge on the multitarget cholinergic and monoaminergic inhibitory activities of individual compounds in this plant. Computational methods were used to identify the specific compounds responsible for the observed cholinergic and monoaminergic inhibitory activities of the H. sabdariffa calyx extracts.

RESULTS

Results confirm that three flavonoids: delphinidin-3-sambubioside, kaempferol-3-O-rutinoside and quercetin-3-rutinoside showed strong binding affinity with acetylcholinesterase, butyrylcholinesterase and monoamine oxidase B while the observed stability of the ligands-enzymes complexes over the MD simulation time suggests their cholinergic and monoaminergic inhibitory properties.

CONCLUSION

The three flavonoids may be responsible for the reported anticholinergic and monoaminergic inhibitory potentials of H. sabdariffa extracts and could be enlisted as multi-target inhibitory agents for cholinesterases and monoamine oxidase B.

Hibiscus sabdariffa extract improves hepatic steatosis, partially through IRS-1/Akt and Nrf2 signaling pathways in rats fed a high fat diet

Non-alcoholic fatty liver disease (NAFLD) has become a major world-wide health problem and is characterized by lipid accumulation in the liver induced by high fat diet (HFD) consumption. It is usually associated with inflammation, oxidative stress, and insulin resistance. Roselle extract (Hibiscus sabdariffa) is an herb which is used in traditional medicine. However, further study is necessary to represent the mechanism of NAFLD and find new preventive strategies. This study aims to investigate the protective effects of roselle extract on NAFLD rat models. Male Sprague-Dawley rats (n = 35) were divided into 5 groups, control, HFD, HFD + Simvastatin (HFD + SIM), HFD + 250 mg/kg BW, and HFD + 500 mg/kg BW of roselle extract (HFD + R250 and HFD + R500, respectively). The results showed that roselle extract reduced hepatic lipid contents, de novo lipogenesis enzymes, microsomal triglyceride transfer protein, inflammatory cytokines, malondialdehyde, and increased antioxidant properties, transporter related with lipoprotein uptake, and insulin signal proteins. Comparing to SIM, the HFD + R500 group exhibited the greater benefit in terms of anti-hepatic steatosis, antioxidant properties, and an ability to improve insulin resistance. This study demonstrates that roselle extract improved antioxidant properties and attenuated hepatic steatosis, liver inflammation, oxidative stress, and insulin resistance in HFD-induced NAFLD in rats, which could be used for NAFLD prevention.

Physiological Effects and Human Health Benefits of Hibiscus sabdariffa: A Review of Clinical Trials

Hibiscus sabdariffa Linn. Malvaceae (HS) is characterized by its edible calyxes. The HS calyxes are widely used for cosmetic, food, and medicinal applications. According to ethnobotanical evidence, decoction, infusion, or maceration extracts from HS calyxes have been used in folk medicine to treat many ailments. Moreover, several in vitro and in vivo studies have demonstrated the pharmacological properties and potential human health benefits of HS consumption. On the other hand, the evaluation of the physiological effects and health benefits of HS in clinical studies is most challenging. Therefore, this narrative review summarizes and discusses the physiological effects and health benefits of HS calyxes reported in clinical trials. Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. The most-reported HS health benefits are its antihypertensive, antidyslipidemic, hypoglycemic, body fat mass reduction, nephroprotective, antianemic, antioxidant, anti-inflammatory, and anti-xerostomic activities; these effects are associated with the phytochemicals found in HS. Moreover, no adverse effects were reported during the clinical trials. However, clinical studies exhibited some limitations; thus, further studies are required to validate the clinical efficacy of HS in large-scale studies with higher doses and a good experimental design

A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers

Context

Hibiscus sabdariffa (hibiscus) has been proposed to affect cardiovascular risk factors.

Objective

To review the evidence for the effectiveness of hibiscus in modulating cardiovascular disease risk markers, compared with pharmacologic, nutritional, or placebo treatments.

Data Sources

A systematic search of the Web of Science, Cochrane, Ovid (MEDLINE, Embase, AMED), and Scopus databases identified reports published up to June 2021 on randomized controlled trials using hibiscus as an intervention for lipid profiles, blood pressure (BP), and fasting plasma glucose levels in adult populations.

Data Extraction

Seventeen chronic trials were included. Quantitative data were examined using a random effects meta-analysis and meta-regression with trial sequential analysis to account for type I and type II errors.

Data Analysis

Hibiscus exerted stronger effects on systolic BP (−7.10 mmHg [95%CI, −13.00, −1.20]; I² = 95%; P = 0.02) than placebo, with the magnitude of reduction greatest in those with elevated BP at baseline. Hibiscus induced reductions to BP similar to that resulting from medication (systolic BP reduction, 2.13 mmHg [95%CI, −2.81, 7.06], I² = 91%, P = 0.40; diastolic BP reduction, 1.10 mmHg [95%CI, −1.55, 3.74], I² = 91%, P = 0.42). Hibiscus also significantly lowered levels of low-density lipoprotein compared with other teas and placebo (−6.76 mg/dL [95%CI, −13.45, −0.07]; I² = 64%; P = 0.05).

Conclusions

Regular consumption of hibiscus could confer reduced cardiovascular disease risk. More studies are warranted to establish an effective dose response and treatment duration.

Systematic Review Registration

PROSPERO registration no. CRD42020167295

Natural Dietary and Medicinal Plants with Anti-Obesity Therapeutics Activities for Treatment and Prevention of Obesity during Lock Down and in Post-COVID-19 Era

Overweight and obesity have become global epidemics, especially during the lockdown due to the COVID-19 pandemic. The potential of medicinal plants as a better and safe option in treating obesity and overweight has gained attention in recent years. Obesity and overweight has become a major public health concern, and its incidence rising at an alarming rate. Obesity is one of the major types of metabolic syndrome, resulting in various types of problems such as hypertension, diabetes, dyslipidemia, and excess fat accumulation. The current searching was done by the keywords in main indexing systems including Scopus, PubMed/MEDLINE, the search engine of Google Scholar, and Institute for Scientific Web of Science. The keywords were traditional medicine, health benefits, pharmaceutical science, pomegranate, punicalin, punicalagin, and ellagitannins. Google Scholar was searched manually for possible missing manuscripts, and there was no language restriction in the search. This review was carried out to highlight the importance of medicinal plants which are common in traditional medicinal sciences of different countries, especially Asia to prevent and treatment of obesity and overweight during the global pandemic and the post-COVID-19 era.