Anti-obesity Effect of Dioscorea oppositifolia Extract in High-Fat Diet-Induced Obese Mice and Its Chemical Characterization

The genus Dioscorea L. (Dioscoreaceae), a review of traditional uses, phytochemistry, pharmacology, and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Dioscorea, a member of the Dioscoreaceae family, comprises approximately 600 species and is widely distributed across temperate and tropical regions such as Asia, South Africa, and North America. The traditional medicinal uses of Dioscorea have been documented in Asian and African pharmacological systems. In Asia, this genus is traditionally used to treat respiratory illnesses, rheumatism, diabetes, diarrhea, dysentery, and other conditions. In Africa, this genus has been used to treat human immunodeficiency virus and ring worms. However, the traditional medicinal practices in North America rarely mention the use of this genus.

AIM OF THE STUDY

The aim of this review is to comprehensively review the genus Dioscorea, focusing on its traditional uses, phytochemical constituents, pharmacological activities, and potential toxicities. The research also aims to highlight the valuable bioactive compounds within Dioscorea and emphasize the need for further investigations into acute and chronic toxicity, activity mechanisms, molecular markers, and other relevant factors to contribute to the discovery of novel pharmaceuticals.

MATERIALS AND METHODS

A search for available information on Dioscorea was conducted using scientific databases, including PubMed, ISI-WOS, Scopus, and Google Scholar, as well as recent academic publications from reputable publishers and other literature sources. The search was not limited by language and spanned the literature published between 1950 and 2022.

RESULTS

This article provides a comprehensive review of the Dioscorea genus, focusing on its traditional uses, phytochemical constituents, pharmacological activities, and potential toxicities. Extensive research has been conducted on this genus, resulting in the isolation and examination of over 1000 compounds, including steroids, terpenoids, and flavonoids, to determine their biological activities. These activities include anti-tumor, anti-inflammatory, immunomodulatory, neuroprotective, hypoglycemic, and hypolipidemic effects. However, some studies have indicated the potential toxicity of high doses of Dioscorea, highlighting the need for further investigations to assess the safety of this genus. Additionally, this review explores potential avenues for future research and discusses the challenges associated with a comprehensive understanding of the Dioscorea genus.

CONCLUSIONS

Based on the existing literature, it can be concluded that Dioscorea is a valuable source of bioactive compounds that have the potential to treat various disorders. Future research should prioritize the investigation of acute and chronic toxicity, activity mechanisms, molecular markers, and other relevant factors. This review provides a comprehensive analysis of the Dioscorea genus, emphasizing its potential to enable a deeper exploration of the biological activity mechanisms of these plants and contribute to the discovery of novel pharmaceuticals.

Unambiguous Characterization of Commercial Natural (Dihydro)phenanthrene Compounds Is Vital in the Discovery of AMPK Activators

These days, easy access to commercially available (poly)phenolic compounds has expanded the scope of potential research beyond the field of chemistry, particularly in the area of their bioactivity. However, the quality of these compounds is often overlooked or not even considered. This issue is illustrated in this study through the example of (dihydro)phenanthrenes, a group of natural products present in yams, as AMP-activated protein kinase (AMPK) activators. A study conducted in our group on a series of compounds, fully characterized using a combination of chemical synthesis, NMR and MS techniques, provided evidence that the conclusions of a previous study were erroneous, likely due to the use of a misidentified commercial compound by its supplier. Furthermore, we demonstrated that additional representatives of the (dihydro)phenanthrene phytochemical classes were able to directly activate AMPK, avoiding the risk of misinterpretation of results based on analysis of a single compound alone.

Dioscorea spp.: Bioactive Compounds and Potential for the Treatment of Inflammatory and Metabolic Diseases

Dioscorea spp. belongs to the Dioscoreaceae family, known as "yams", and contains approximately 600 species with a wide distribution. It is a major food source for millions of people in tropical and subtropical regions. Dioscorea has great medicinal and therapeutic capabilities and is a potential source of bioactive substances for the prevention and treatment of many diseases. In recent years, increasing attention has been paid to the phytochemicals of Dioscorea, such as steroidal saponins, polyphenols, allantoin, and, in particular, polysaccharides and diosgenin. These bioactive compounds possess anti-inflammatory activity and are protective against a variety of inflammatory diseases, such as enteritis, arthritis, dermatitis, acute pancreatitis, and neuroinflammation. In addition, they play an important role in the prevention and treatment of metabolic diseases, including obesity, dyslipidemia, diabetes, and non-alcoholic fatty liver disease. Their mechanisms of action are related to the modulation of a number of key signaling pathways and molecular targets. This review mainly summarizes recent studies on the bioactive compounds of Dioscorea and its treatment of inflammatory and metabolic diseases, and highlights the underlying molecular mechanisms. In conclusion, Dioscorea is a promising source of bioactive components and has the potential to develop novel natural bioactive compounds for the prevention and treatment of inflammatory and metabolic diseases.

The Hypoglycemic and Hypocholesterolemic Activity of Dioscorea deltoidea, Tribulus terrestris and Panax japonicus Cell Culture Biomass in Rats with High-Fat Diet-Induced Obesity

Obesity, and its consequences for human health, is a huge and complicated problem that has no simple solution. The constant search for natural and safe compounds with systemic action that can be used for obesity prophylactics and treatment is hampered by the limited availability and variable quality of biomass of wild medicinal plants. Plant cell biotechnology is an alternative approach for the sustainable production of vegetative biomass or individual phytochemicals with high therapeutic potential. In this study, the suspension cell biomass of the medicinal plants, Dioscorea deltoidea Wall., Tribulus terrestris L., and Panax japonicus (T. Nees) C.A. Mey, produced in 20 L and 630 L bioreactors, were tested for therapeutic effects in rat models with alimentary-induced obesity. Three-month intake of water infusions of dry cell biomass (100 mg/g body weight) against the background of a hypercaloric diet reduced weight gain and the proportion of fat mass in the obese animals. In addition, cell biomass preparation reduced the intracellular dehydration and balanced the amounts of intra- and extracellular fluids in the body as determined by bioimpedance spectroscopy. A significant decrease in the glucose and cholesterol levels in the blood was also observed as a result of cell biomass administration for all species. Hypocholesterolemic activity reduced in the line P. japonicus > D. deltoidea > T. terrestris/liraglutide > intact group > control group. By the sum of parameters tested, the cell culture of D. deltoidea was considered the most effective in mitigating diet-induced obesity, with positive effects sometimes exceeding those of the reference drug liraglutide. A safety assessment of D. deltoidea cell phytopreparation showed no toxic effect on the reproductive function of the animals and their offspring. These results support the potential application of the biotechnologically produced cell biomass of medicinal plant species as safe and effective natural remedies for the treatment of obesity and related complications, particularly for the long-term treatment and during pregnancy and lactation periods when conventional treatment is often contraindicated.

Antiobesity Activity of Two Polyherbal Formulations in High-Fat Diet-Induced Obese C57BL/6J Mice

Obesity and overweight have posed a severe threat to humanity, needing urgent efforts for the development of safe and effective therapeutic interventions. In this research work, we have developed two polyherbal formulations A and B basically consisting of Helianthus tuberosus root powder (also called inulin of synanthrin) along with other herbs for the treatment of obesity. Evaluation of the antioxidant activity of both formulations using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging assays showed good antioxidant potentials. Both formulations A and B showed good antiobesity activity on a diet-induced obesity (DIO) model of mice by effectively lowering the body weight of mice compared to the high-fat diet (HFD) control mice, mainly by reducing the food efficiency ratio (FER). Furthermore, both formulations ameliorated lipoprotein misbalances induced by obesity and thus decreased the atherogenic index. Treatment with both formulations significantly decreased the liver and epididymal white adipose tissue (WAT) weight. This was supported by the improvement in steatosis of the liver and reduced hypertrophy in WAT on histological examination. In addition, formulations A and B have been seen as effective in controlling fasting blood glucose levels probably by alleviating HFD-induced insulin resistance. All of these results collectively suggest that formulations A and B serve as potentially safe and effective herbal interventions to control obesity and its comorbidities.

A Comprehensive Review on Anti-obesity Potential of Medicinal Plants and their Bioactive Compounds

Background:

Obesity is a complex health and global epidemic issue. It is an increasing global health challenge covering significant social and economic costs. Abnormal accumulation of fat in the body may increase the health risks including diabetes, hypertension, osteoarthritis, sleep apnea, cardiovascular diseases, stroke and cancer. Synthetic drugs available on the market reported to have several side effects. Therefore, the management of obesity got to involve the traditional use of medicinal plants which helps to search the new therapeutic targets and supports the research and development of anti-obesity drugs.

Objective:

This review aim to update the data and provide a comprehensive report of currently available knowledge of medicinal plants and phyto-chemical constituents reported for their anti-obesity activity.

Methodology:

An electronic search of the periodical databases like Web of Science, Scopus, PubMed, Scielo, Niscair, ScienceDirect, Springerlink, Wiley, SciFinder and Google Scholar with information reported the period 1991-2019, was used to retrieve published data.

Results:

A comprehensive report of the present review manuscript is an attempt to list the medicinal plants with anti-obesity activity. The review focused on plant extracts, isolated chemical compounds with their mechanism of action and their preclinical experimental model, clinical studies for further scientific research.

Conclusion:

This review is the compilation of the medicinal plants and their constituents reported for the managements of obesity. The data will fascinate the researcher to initiate further research that may lead to the drug for the management of obesity and their associated secondary complications. Several herbal plants and their respective lead constituents were also screened by preclinical In-vitro and In-vivo, clinical trials and are effective in the treatment of obesity. Therefore, there is a need to develop and screen large number of plant extracts and this approach can surely be a driving force for the discovery of anti-obesity drugs from medicinal plants.

A Review on Obesity Management through Natural Compounds and a Green Nanomedicine-Based Approach

Obesity is a serious health complication in almost every corner of the world. Excessive weight gain results in the onset of several other health issues such as type II diabetes, cancer, respiratory diseases, musculoskeletal disorders (especially osteoarthritis), and cardiovascular diseases. As allopathic medications and derived pharmaceuticals are partially successful in overcoming this health complication, there is an incessant need to develop new alternative anti-obesity strategies with long term efficacy and less side effects. Plants harbor secondary metabolites such as phenolics, flavonoids, terpenoids and other specific compounds that have been shown to have effective anti-obesity properties. Nanoencapsulation of these secondary metabolites enhances the anti-obesity efficacy of these natural compounds due to their speculated property of target specificity and enhanced efficiency. These nanoencapsulated and naive secondary metabolites show anti-obesity properties mainly by inhibiting the lipid and carbohydrate metabolizing enzymes, suppression of adipogenesis and appetite, and enhancing energy metabolism. This review focuses on the plants and their secondary metabolites, along with their nanoencapsulation, that have anti-obesity effects, with their possible acting mechanisms, for better human health.

Anti-Obesity Attributes; UHPLC-QTOF-MS/MS-Based Metabolite Profiling and Molecular Docking Insights of Taraxacum officinale

The naturopathic treatment of obesity is a matter of keen interest to develop efficient natural pharmacological routes for disease management with low or negligible toxicity and side effects. For this purpose, optimized ultrasonicated hydroethanolic extracts of Taraxacum officinale were evaluated for antiobesity attributes. The 2,2-diphenyl-1-picrylhydrazyl method was adopted to evaluate antioxidant potential. Porcine pancreatic lipase inhibitory assay was conducted to assess the in vitro antiobesity property. Ultra-high performance chromatography equipped with a mass spectrometer was utilized to profile the secondary metabolites in the most potent extract. The 60% ethanolic extract exhibited highest extract yield (25.05 ± 0.07%), total phenolic contents (123.42 ± 0.007 mg GAE/g DE), total flavonoid contents (55.81 ± 0.004 RE/g DE), DPPH-radical-scavenging activity (IC50 = 81.05 ± 0.96 µg/mL) and pancreatic lipase inhibitory properties (IC50 = 146.49 ± 4.24 µg/mL). The targeted metabolite fingerprinting highlighted the presence of high-value secondary metabolites. Molecular-binding energies computed by docking tool revealed the possible contribution towards pancreatic lipase inhibitory properties of secondary metabolites including myricetin, isomangiferin, icariside B4, kaempferol and luteolin derivatives when compared to the standard drug orlistat. In vivo investigations revealed a positive impact on the lipid profile and obesity biomarkers of obese mice. The study presents Taraxacum officinale as a potent source of functional bioactive ingredients to impart new insights into the existing pool of knowledge of naturopathic approaches towards obesity management.

The Dioscorea Genus (Yam)-An Appraisal of Nutritional and Therapeutic Potentials

The quest for a food secure and safe world has led to continuous effort toward improvements of global food and health systems. While the developed countries seem to have these systems stabilized, some parts of the world still face enormous challenges. Yam (Dioscorea species) is an orphan crop, widely distributed globally; and has contributed enormously to food security especially in sub-Saharan Africa because of its role in providing nutritional benefits and income. Additionally, yam has non-nutritional components called bioactive compounds, which offer numerous health benefits ranging from prevention to treatment of degenerative diseases. Pharmaceutical application of diosgenin and dioscorin, among other compounds isolated from yam, has shown more prospects recently. Despite the benefits embedded in yam, reports on the nutritional and therapeutic potentials of yam have been fragmented and the diversity within the genus has led to much confusion. An overview of the nutritional and health importance of yam will harness the crop to meet its potential towards combating hunger and malnutrition, while improving global health. This review makes a conscious attempt to provide an overview regarding the nutritional, bioactive compositions and therapeutic potentials of yam diversity. Insights on how to increase its utilization for a greater impact are elucidated.

Antiobesity effect of ethanolic extract of Ramulus mori in differentiated 3T3-L1 adipocytes and high-fat diet-induced obese mice

ETHNOPHARMACOLOGICAL RELEVANCE

The mulberry (Morus alba L.) is a plant that mainly grows in East Asian countries such as Korea and China and has been used as a folk remedy for improving inflammation, cancer, and diabetes. Ramulus mori, the twig of Morus alba L., is known as "sangzhi" or "ppongnamugazhi" in Korea and used as a traditional medicine. Moreover, its effective compounds show some health benefits such as cholesterol reduction and attenuation of acute colitis.

AIM OF THE STUDY

As the number of obese people is increasing worldwide, the demand for diet drugs or products to treat obesity is also increasing. In this study, we investigated the antiobesity effect of the ethanolic extract of Ramulus mori (ERM) using differentiated 3T3-L1 adipocytes and a high-fat diet (HFD)-induced obese mouse model.

METHODS

The expression levels of genes and proteins related to adipogenesis, lipogenesis, and lipolysis were analyzed by quantitative real-time PCR (qPCR) and western blot, respectively. Oil red O staining was carried out to determine the amount of neutral lipids deposited in the liver.

RESULTS

Compared with the ERM-untreated group, the ERM-treated groups exhibited reduced expression levels of genes involved in adipogenesis and lipogenesis in differentiated adipocytes and in HFD-induced obese mice, while the expression levels of genes involved in lipolysis increased. The administration of ERM to HFD-induced obese mice reduced the body weight, liver weight, and epididymal adipose tissue weight. Compared with the untreated HFD-induced obese mice, the ERM-treated mice exhibited decreased serum lipid levels. ERM treatment also reduced lipid accumulation in the liver, which was confirmed by oil red O staining.

CONCLUSION

ERM has the potential to be an effective natural material for reducing obesity.

Plant Extracts and Reactive Oxygen Species as Two Counteracting Agents with Anti- and Pro-Obesity Properties

Obesity is a complex disease of great public health significance worldwide: It entails several complications including diabetes mellitus type 2, cardiovascular dysfunction and hypertension, and its prevalence is increasing around the world. The pathogenesis of obesity is closely related to reactive oxygen species. The role of reactive oxygen species as regulatory factors in mitochondrial activity in obese subjects, molecules taking part in inflammation processes linked to excessive size and number of adipocytes, and as agents governing the energy balance in hypothalamus neurons has been examined. Phytotherapy is the traditional form of treating health problems using plant-derived medications. Some plant extracts are known to act as anti-obesity agents and have been screened in in vitro models based on the inhibition of lipid accumulation in 3T3-L1 cells and activity of pancreatic lipase methods and in in vivo high-fat diet-induced obesity rat/mouse models and human models. Plant products may be a good natural alternative for weight management and a source of numerous biologically-active chemicals, including antioxidant polyphenols that can counteract the oxidative stress associated with obesity. This review presents polyphenols as natural complementary therapy, and a good nutritional strategy, for treating obesity without serious side effects.

Natural anti-obesity agents and their therapeutic role in management of obesity: A future trend perspective

In the present scenario, obesity is a challenging health problem and its prevalence along with comorbidities are on the rise around the world. According to world health organization and organisation for economic co-operation and development epidemiology reports, overweight and obesity are the fifth foremost causes of deaths globally. The increasing rate of obesity is becoming a mammoth problem which enormously affects an individual's quality of life. The conventional therapy of obesity mainly involves synthetic moieties and surgical procedures, which has many harmful side effects and chances of recurrence with severity. Hence, the Present review is a metanalysis of all the available data on the use of the plants with their biological source, active phytochemical constituents and a probable mechanism of action as natural anti-obesity agents. The metanalysis of data during the period of 2000-2018 was performed with the help of scientific data search engine National Center for Biotechnology Information (NCBI/PubMed). This data reveals the need and scope of further research in the development of new natural phytoconstituents for the management of obesity.

Modulatory Effect of Polyphenolic Compounds from the Mangrove Tree Rhizophora mangle L. on Non-Alcoholic Fatty Liver Disease and Insulin Resistance in High-Fat Diet Obese Mice

No scientific report proves the action of the phytochemicals from the mangrove tree Rhizophora mangle in the treatment of diabetes. The aim of this work is to evaluate the effects of the acetonic extract of R. mangle barks (AERM) on type 2 diabetes. The main chemical constituents of the extract were analyzed by high-performance liquid chromatography (HPLC) and flow injection analysis electrospray-iontrap mass spectrometry (FIA-ESI-IT-MS/MS). High-fat diet (HFD)-fed mice were used as model of type 2 diabetes associated with obesity. After 4 weeks of AERM 5 or 50 mg/kg/day orally, glucose homeostasis was evaluated by insulin tolerance test (kiTT). Hepatic steatosis, triglycerides and gene expression were also evaluated. AERM consists of catechin, quercetin and chlorogenic acids derivatives. These metabolites have nutritional importance, obese mice treated with AERM (50 mg/kg) presented improvements in insulin resistance resulting in hepatic steatosis reductions associated with a strong inhibition of hepatic mRNA levels of CD36. The beneficial effects of AERM in an obesity model could be associated with its inhibitory α-amylase activity detected in vitro. Rhizophora mangle partially reverses insulin resistance and hepatic steatosis associated with obesity, supporting previous claims in traditional knowledge.

Physicochemical Characterization, Microbiological Quality and Safety, and Pharmacological Potential of Hancornia speciosa Gomes

Hancornia speciosa Gomes is a fruit tree, commonly known as the mangaba tree, which is widespread throughout Brazil. The leaves of this plant are used in traditional medicine for medicinal purposes. Thus, the objective of this study was to perform a physicochemical characterization, identify the lipophilic antioxidants and fatty acids, and determine the microbiological quality and safety of H. speciosa leaves. In addition, the antioxidant, antimutagenic, and inhibitory activities of the ethanolic extract of H. speciosa leaves (EEHS) against enzymes related to neurodegenerative diseases, inflammation, obesity, and diabetes were investigated. Furthermore, this study aimed at assessing the in vivo effects of the EEHS on the glycemia of normoglycemic and diabetic Wistar rats. Physicochemical characterization was performed by colorimetry and gas-liquid chromatography with flame ionization detection (GC-FID). The total number of colonies of aerobic mesophiles, molds, and yeasts was determined. The total coliforms and Escherichia coli were counted using the SimPlates kit, and sulphite-reducing Clostridium spores were quantified using the sulphite-polymyxin-sulfadiazine agar method. Salmonella spp. were detected using the 1-2 Test. The antioxidant activity of the EEHS was measured by its inhibition of 2,2'-azobis(2-amidinopropane) dihydrochloride- (AAPH-) induced oxidative hemolysis of human erythrocytes. The antimutagenic activity was determined using the Ames test. The acetylcholinesterase, butyrylcholinesterase, tyrosinase, hyaluronidase, lipase, α-amylase, and α-glycosidase enzyme-inhibiting activities were assessed and compared with commercial controls. The in vivo effects of the EEHS were assessed using the oral glucose tolerance test in normoglycemic Wistar rats and measuring the blood glucose levels in diabetic rats. The results demonstrated physical-chemical parameters of microbiological quality and safety in the leaves of H. speciosa, as well as antioxidant and antimutagenic activities and inhibition of enzymes related to neurodegenerative diseases, inflammation, obesity, and diabetes. In in vivo assays, it was shown that the normoglycemic rats challenged with glucose overload show significantly decreased blood glucose levels when treated with the EEHS. Taken together, the results ensure the microbiological quality and safety as well as showing the contents of carotenoids and polyunsaturated fatty acids of H. speciosa leaves. Additionally, the antioxidant, antimutagenic, anti-inflammatory, anti-Alzheimer's disease, anti-Parkinson's disease, antiobesity, and antihyperglycemic activities of the EEHS were demonstrated.

Flavonoid-Rich Extract of Paulownia fortunei Flowers Attenuates Diet-Induced Hyperlipidemia, Hepatic Steatosis and Insulin Resistance in Obesity Mice by AMPK Pathway

The flavonoid-rich extract from Paulownia fortunei flowers (EPF) has been reported to prevent obesity and other lipid metabolism disease. However, the mechanism of its protective effects is not yet clear. The objective of this study was to investigate molecular factors involved in the hypoglycemic and hypolipidemic effects of EPF in obese mice fed a high-fat diet (HFD). Male h ICR (Institute of Cancer Research) mice were fed a HFD containing or not containing the EPF (50 or 100 mg/kg) for eight weeks. EPF reduced body weight gain, lipid accumulation in livers and levels of lipid, glucose and insulin in plasma as well as reduced insulin resistance as compared with the HFD group. EPF significantly decreased serum aminotransferase activity of the HFD group. We observed that EPF administration significantly increased the level of AMP-activated kinase (AMPK) phosphorylation and prevented fat deposits in livers and HepG2 cells, but these effects were blocked by compound C (an AMPK inhibitor). The protective effects of EPF were probably associated with the decrease in HMGCR, SREBP-1c and FAS expressions and the increase in CPT1 and phosphor-IRS-1 expressions. Our results suggest that EPF might be a potential natural candidate for the treatment and/or prevention of overweight and hepatic and metabolic-related alterations induced by HFD.

Daesiho-Tang Is an Effective Herbal Formulation in Attenuation of Obesity in Mice through Alteration of Gene Expression and Modulation of Intestinal Microbiota

Background

Obesity has become a major global health challenge due to its increasing prevalence, and the associated health risk. It is the main cause of various metabolic diseases including diabetes, hypertension, cardiovascular disease, stroke and certain forms of cancer.

Methods and Results

In the present study we evaluated the anti-obesity property of Daesiho-tang (DSHT), an herbal medicine, using high fat diet (HFD)-induced obese mice as a model. Our results showed that DSHT ameliorated body weight gain, decreased total body fat, regulated expression of leptin and adiponectin genes of adipose tissue and exerted an anti-diabetic effect by attenuating fasting glucose level and serum insulin level in HFD-fed animals. In addition, DSHT-treatment significantly reduced total cholesterol (TC), triglycerides (TG) and increased high density lipoprotein-cholesterol (HDL), glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) levels in serum and reduced deposition of fat droplets in liver. DSHT treatment resulted in significantly increased relative abundance of bacteria including Bacteroidetes, Bacteroidetes/Firmicutes ratio, Akkermansia Bifidobacterium., Lactobacillus, and decreased the level of Firmicutes. Using RT2 profiler PCR array, 39 (46%) genes were found to be differentially expressed in HFD-fed mice compared to normal control. However, normal gene expressions were restored in 36 (92%) genes of HFD-fed mice, when co-exposed to DSHT.

Conclusion/Major Findings

The results of this study demonstrated that DSHT is an effective herbal formulation in attenuation of obesity in HFD-fed mice through alteration of gene expressions and modulation of intestinal microbiota.