Modulatory Effects of Diosgenin on Attenuating the Key Enzymes Activities of Carbohydrate Metabolism and Glycogen Content in Streptozotocin-Induced Diabetic Rats

Fenugreek derived diosgenin as an emerging source for diabetic therapy

Diabetes is a chronic metabolic disease that endangers the entire body's tissues and organs. Diabetes impairs glucose and insulin regulation in the human body by causing pancreatic cell damage. Diabetes modifies pathways such as serine/threonine protein kinase (Akt) and Protein kinase C (PKC)/- glucose transporter 4 (GLUT4), peroxisome proliferator-activated receptor (PPAR) glucose absorption, and inhibits α-amylase and α-glucosidase, Sodium/glucose cotransporter 1 (SGLT-1), and Na+-K+-ATPase activity. Diabetes may also be caused by a decrease in the expression of sterol regulatory element binding protein 1 (SREBP-1) and its target genes, fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), and acetyl-CoA carboxylase α (ACC), as well as a decrease in the levels of C/EBP homologous protein (CHOP), Caspase12, and Caspase3 proteins. Diabetes has long been linked to diseases of the cardiovascular, nervous, skeletal, reproductive, hepatic, ocular, and renal systems. Diosgenin, a steroidal compound derived from fenugreek, aids in the prevention of diabetes by altering cellular pathways in favor of healthy bodily functions. Diosgenin is a new nutraceutical on the market that claims to cure diabetes in particular. This article focuses on diosgenin extraction and purification, fenugreek bioactive compounds, pharmacological properties of diosgenin, mode of action of diosgenin to cure diabetes, and dosages.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

New insights into anti-diabetes effects and molecular mechanisms of dietary saponins

Diabetes mellitus (DM) is a long-term metabolic disorder that manifests as chronic hyperglycemia and impaired insulin, bringing a heavy load on the global health care system. Considering the inevitable side effects of conventional anti-diabetic drugs, saponins-rich natural products exert promising therapeutic properties to serve as safer and more cost-effective alternatives for DM management. Herein, this review systematically summarized the research progress on the anti-diabetic properties of dietary saponins and their underlying molecular mechanisms in the past 20 years. Dietary saponins possessed the multidirectional anti-diabetic capabilities by concurrent regulation of various signaling pathways, such as IRS-1/PI3K/Akt, AMPK, Nrf2/ARE, NF-κB-NLRP3, SREBP-1c, and PPARγ, in liver, pancreas, gut, and skeletal muscle. However, the industrialization and commercialization of dietary saponin-based drugs are confronted with a significant challenge due to the low bioavailability and lack of the standardization. Hence, in-depth evaluations in pharmacological profile, function-structure interaction, drug-signal pathway interrelation are essential for developing dietary saponins-based anti-diabetic treatments in the future.

Diosgenin attenuates non-alcoholic fatty liver disease in type 2 diabetes through regulating SIRT6-related fatty acid uptake

BACKGROUND

More than 70% of patients with type 2 diabetes (T2DM) concomitantly suffer from Non-alcoholic fatty liver disease (NAFLD), and the coexistence and interaction of them increases the intractability of NAFLD. With the protective effect against hepatic steatosis and liver fibrosis, SIRT6 is becoming a notable target of NAFLD. Diosgenin, an active monomer from Chinese herbs, has been reported to protect against NAFLD.

PURPOSE

This study aims to figure out the mechanism how diosgenin alleviate NAFLD in T2DM and the relationship with SIRT6.

METHODS

In vivo studies used spontaneous diabetic db/db mice and divided them into two parts. The first part included four groups consisting of control (Con) group, model (Mod) group, low dose of diosgenin (DL) group and high dose of diosgenin (DH) group. The second part included four groups consisting of Con group, Mod group, DH+OSS (OSS_128167, inhibitor of SIRT6) group, MDL (MDL800, agonist of SIRT6) group. HepG2 cell line was selected in study in vitro, which was mainly composed of six groups including Con group, palmitic acid (PA) group, PA+DL group, PA+DH group, PA+DH+OSS group, PA+MDL group. OGTT, Biochemical biomarker (including TG, TC, AST, ALT), inflammatory biomarker (including IL-6 and TNF-α) were measured. HE, Oil Red O, and DHE staining were conducted. Immunohistochemistry, immunofluorescence, mRNA-seq, and qPCR were used to explore the mechanism.

RESULTS

Results in the first part of study in vivo indicated that diosgenin protected against lipid accumulation, oxidative stress, cell injury, and light inflammatory of liver in db/db mice and regulated the expression of SIRT6 and fatty acid transporter including CD36, FATP2, FABP1. The effect of diosgenin could be reversed in DH+OSS group and the same effect was observed in MDL group in the second part of study in vivo. The same results were also noted in followed study in vitro. Diosgenin inhibited the fatty acids uptake and regulated the expression of SIRT6 and fatty acid transporter including CD36, FATP2, and FABP1 in PA-induced hepG2 cells, and which was reversed in DH+OSS group and resembled in MDL group.

CONCLUSIONS

Diosgenin could attenuate non-alcoholic fatty liver disease in type 2 diabetes through regulating SIRT6-related fatty acid uptake.

Effects of fenugreek supplementation on the components of metabolic syndrome: A systematic review and dose-response meta-analysis of randomized clinical trials

Metabolic syndrome (MetS) is a cluster of metabolic disorders with a heavy disease burden. Fenugreek was reported to be effective in some components of MetS. Therefore, a comprehensive review and meta-analysis of randomized controlled trials was conducted to study the effects of fenugreek on MetS indices. From the beginning until August 2022, PubMed, Embase, Scopus, and Web of science were searched. Data were analyzed using the random-effect model, and presented as weighted mean difference (WMD) and associated 95 % confidence interval (CI). This meta-analysis comprised from a total of 29 eligible RCTs with 31 arms measuring fasting plasma glucose (FPG), Triglyceride (TG), high-density lipoprotein (HDL), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP). The results indicated significant improving effects of fenugreek on FPG (WMD: -16.75 mg/dL; 95 % CI: -23.36, -10.15; P < 0.001), TG (-20.12 mg/dL; 95 % CI: -34.238, -5.994; P < 0.001), HDL (WMD: 3.55 mg/dL; 95 % CI: 1.98, 5.12; P < 0.001), WC (WMD: -2.51; 95 % CI: -3.78, -1.24; P < 0.001) and SBP (WMD: -3.45 mmHg; 95 % CI: -6.38, -0.52; P = 0.021); However the effect on DBP (WMD: 3.17; 95 % CI: -5.40, 11.73; P = 0.469) and BMI (WMD: -0.40 kg/m2; 95 % CI: -1.114, 0.324; P = 0.281) was not significant. Administration of fenugreek can meaningfully reduce FPG, TG, WC, and SBP and increase HDL. The overall results support possible protective and therapeutic effects of fenugreek on MetS parameters.

Diosgenin: An ingress towards solving puzzle for diabetes treatment

The consumption and composition of food in daily life predict our health in long run. The relation of diabetes to sweets is quite popular. Diabetes hampers the glucose and insulin regulation in the human body by damaging pancreatic β cells. Diabetes has a strong potential towards altering cellular mechanisms of organs causing unlawful performance. Diabetes alters pathways like TLR4, AChE, NF-ĸB, LPL, and PPAR at different sites that affect the normal cellular machinery and cause damage to the local tissue and organ. The long-lasting effect of diabetes was observed in vascular, cardia, nervous, skeletal, reproductive, hepatic, ocular, and renal systems. The increasing awareness of diabetes and its concern has awakened the common people more enthusiastically. Due to rising harm from diabetes, scientific researchers tend to have more eyes toward it. While searching for diabetes solutions, fenugreek diosgenin could pop up with some positive effects in curing the same. Diosgenin helps to lower the scathe of diabetes by modifying cellular pathways in favor of healthy bodily functions. Diosgenin altered the pathways for renewal of pancreatic β cells for better insulin secretion, initiate GLUT4, enhanced DHEA, modify ER-α-mediated PI3K/Akt pathways. Diosgenin can be an appropriate insult for diabetes in a much evolving way for a healthy lifestyle. PRACTICAL APPLICATIONS: Diabetes is one of the most death causing diseases in the medical world. Regrettably the cure of diabetes is yet to be found. Various scientific team working on the same to look after the most appropriate way for diabetes treatment. There is enormous growth of nutraceutical in the market claiming for cure of different metabolic disorders. Among various bioactive compound fenugreek's diosgenin could took a leap over other in curing and preventing the damage caused by diabetes to different organs. The role of diosgenin in curing various metabolic disorders is quite popular from some time. This article also emphasizes over beneficiary effect of diosgenin in curing the damages caused by diabetes by altering cellular metabolism processes. Hence diosgenin could be a better way for researchers to develop a method for diabetes treatment.

Diosgenin protects against podocyte injury in early phase of diabetic nephropathy through regulating SIRT6

BACKGROUND

Diabetic nephropathy (DN) is a serious complication of diabetes mellitus. DN is the main cause of end-stage renal disease (ESRD). SIRT6 becomes the important target of DN. Diosgenin (a monomer from Chinese herbs) is probable to bind to SIRT6.

PURPOSE

Based on studies presented in the literature on kidney injuries plus screening for the binding effects of the drug to Sirt6, we aimed to carry out the study to assess the effects of diosgenin involved in improving podocyte damage in the early phase of DN..

METHODS

DN model was established in spontaneous diabetic db/db mice. Animal experiment was in two parts. The first part includes four groups consisting of control (Con) group, model (Mod) group, low dose of diosgenin (DL) group and high dose of diosgenin (DH) group. The second part includes four groups consisting of control group, model group, DH+OSS_128167 (OSS, inhibitor of SIRT6) group, MDL800 (agonist of SIRT6) group. MPC5 cell line was selected in cell experiment, which was mainly composed of six groups including Con group, palmitic acid (PA) group, PA+DL group, PA+DH group, PA+DH+OSS group, PA+MDL800 group. Some procedures such as transcriptomics, RT-qPCR and so on were used in the study to explore and verify the mechanism.

RESULTS

The abnormal changes of mesangial matrix expansion, glomerular basement membrane (GBM) thickness, foot process (FP) width, urine albumin/creatinine (UACR), DESMIN, ADRP, NEPHRIN, PODOCIN, SIRT6 in Mod group were alleviated in DH group rather than DL group in the first part of animal experiment. The effect in DH group could be reversed in DH+OSS group and the same effect was observed in MDL800 group in the second part of animal experiment. The same results were also found in cell experiment. Protein level and mRNA expression of pyruvate dehydrogenase kinase 4 (PDK4) and Angiopoietin-like-4 (ANGPTL4) were increased in PA group, which could be alleviated in DH group, MDL800 group rather than DH+OSS group.

CONCLUSIONS

Diosgenin could protect against podocyte injury in early phase of diabetic nephropathy by regulating SIRT6.

In vivo antihyperglycaemic and antihyperlipidemic activities and chemical constituents of Solanum anomalum

Solanum anomalum is a plant used ethnomedically for the treatment of diabetes. The study was aimed to validate ethnomedical claims in rat model and identify the likely antidiabetic compounds. Leaf extract (70-210 mg/kg/day) and fractions (140 mg/kg/day) of S. anomalum were evaluated in hyperglycaemic rats induced using alloxan for effects on blood glucose, lipids and pancreas histology. Phytochemical characterisation of isolated compounds and their identification were performed using mass spectrometry and NMR spectroscopy. Bioinformatics tool was used to predict the possible protein targets of the identified bioactive compounds. The leaf extract/fractions on administration to diabetic rats caused significant lowering of fasting blood glucose of the diabetic rats during single dose study and on repeated administration of the extract. The hydroethanolic leaf extracts also enhanced glucose utilization capacity of the diabetic rats and caused significant lowering of glycosylated hemoglobin levels and elevation of insulin levels in the serum. Furthermore, triglycerides, LDL-cholesterol, and VLDL-cholesterol levels were lowered significantly, while HDL-cholesterol levels were also elevated in the treated diabetic rats. There was absence or few pathological signs in the treated hyperglycaemic rat pancreas compared to that present in the pancreas of control group. Diosgenin, 25(R)-diosgenin-3-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside, uracil, thymine, 1-octacosanol, and octacosane were isolated and identified. Protein phosphatases along with secreted proteins are predicted to be the major targets of diosgenin and the diosgenin glycoside. These results suggest that the leaf extract/fractions of S. anomalum possess antidiabetic and antihyperlipidemic properties, offer protection to the pancreas and stimulate insulin secretion, which can be attributable to the activities of its phytochemical constituents.

The role of diosgenin in crohn’s disease

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammation that can grossly affect the entire gastrointestinal tract (GIT) from the mouth to the anus. Crohn’s disease is the most known type of IBD and has been the focus of attention due to its increase in prevalence worldwide. Although the etiology is yet to be elucidated, recent studies have pointed out Crohn’s disease to arise from a complex interaction between environmental influences, genetic predisposition, and altered gut microbiota, resulting in dysregulated adaptive and innate responses. The presenting hallmarks of Crohn’s disease may include weight loss, nausea, vomiting, abdominal pain, diarrhea, fever, or chills. Treatment is usually done with many approved immunosuppressive drugs and surgery. However, a promising avenue from natural compounds is a safer therapy due to its safe natural active ingredients and the strong activity it shows in the treatment and management of diseases. Diosgenin, “a major biologically active natural steroidal sapogenin found in Chinese yam,” has been widely reported as a therapeutic agent in the treatment of various classes of disorders such as hyperlipidemia, inflammation, diabetes, cancer, infection, and immunoregulation. In this review, an analysis of literature data on diosgenin employed as a therapeutic agent for the treatment of Crohn’s disease is approached, to strengthen the scientific database and curtail the dreadful impact of Crohn’s disease.

Diosgenin: An Updated Pharmacological Review and Therapeutic Perspectives

Plants including Rhizoma polgonati, Smilax china, and Trigonella foenum-graecum contain a lot of diosgenin, a steroidal sapogenin. This bioactive phytochemical has shown high potential and interest in the treatment of various disorders such as cancer, diabetes, arthritis, asthma, and cardiovascular disease, in addition to being an important starting material for the preparation of several steroidal drugs in the pharmaceutical industry. This review aims to provide an overview of the in vitro, in vivo, and clinical studies reporting the diosgenin's pharmacological effects and to discuss the safety issues. Preclinical studies have shown promising effects on cancer, neuroprotection, atherosclerosis, asthma, bone health, and other pathologies. Clinical investigations have demonstrated diosgenin's nontoxic nature and promising benefits on cognitive function and menopause. However, further well-designed clinical trials are needed to address the other effects seen in preclinical studies, as well as a better knowledge of the diosgenin's safety profile.

Diosgenin Attenuates Cognitive Impairment in Streptozotocin-Induced Diabetic Rats: Underlying Mechanisms

OBJECTIVE

Prolonged diabetes mellitus causes impairments of cognition and attentional dysfunctions. Diosgenin belongs to a group of steroidal saponins with reported anti-diabetic and numerous protective properties. This research aimed to assess the effect of diosgenin on beneficially ameliorating learning and memory decline in a rat model of type 1 diabetes caused by streptozotocin (STZ) and to explore its modes of action including involvement in oxidative stress and inflammation.

METHODS

Rats were assigned to one of four experimental groups, comprising control, control under treatment with diosgenin, diabetic, and diabetic under treatment with diosgenin. Diosgenin was given daily p.o. (40 mg/kg) for 5 weeks.

RESULTS

The administration of diosgenin to the diabetic group reduced the deficits of functional performance in behavioral tests, consisting of Y-maze, passive avoidance, radial arm maze, and novel object discrimination tasks (recognitive). Furthermore, diosgenin treatment attenuated hippocampal acetylcholinesterase activity and malon-dialdehyde, along with improvement of antioxidants such as superoxide dismutase and glutathione. Meanwhile, the hippocampal levels of inflammatory indicators, namely interleukin 6, nuclear factor-κB, toll-like receptor 4, tumor necrosis factor α, and astrocyte-specific biomarker glial fibrillary acidic protein, were lower and, on the other hand, tissue levels of nuclear factor (erythroid-derived 2)-related factor 2 were elevated upon diosgenin administration. Besides, the mushroom-like spines of the pyramidal neurons of the hippocampal CA1 area decreased in the diabetic group, and this was alleviated following diosgenin medication.

CONCLUSIONS

Taken together, diosgenin is capable of ameliorating cognitive deficits in STZ-diabetic animals, partly due to its amelioration of oxidative stress, inflammation, astrogliosis, and possibly improvement of cholinergic function in addition to its neuroprotective potential.

Optimization of diosgenin extraction from Dioscorea deltoidea tubers using response surface methodology and artificial neural network modelling

INTRODUCTION

Dioscorea deltoidea var. deltoidea (Dioscoreaceae) is a valuable endangered plant of great medicinal and economic importance due to the presence of the bioactive compound diosgenin. In the present study, response surface methodology (RSM) and artificial neural network (ANN) modelling have been implemented to evaluate the diosgenin content from D. deltoidea. In addition, different extraction parameters have been also optimized and developed.

MATERIALS AND METHODS

Firstly, Plackett-Burman design (PBD) was applied for screening the significant variables among the selected extraction parameters i.e. solvent composition, solid: solvent ratio, particle size, time, temperature, pH and extraction cycles on diosgenin yield. Among seven tested parameters only four parameters (particle size, solid: solvent ratio, time and temperature) were found to exert significant effect on the diosgenin extraction. Moreover, Box-Behnken design (BBD) was employed to optimize the significant extraction parameters for maximum diosgenin yield.

RESULTS

The most suitable condition for diosgenin extraction was found to be solid: solvent ratio (1:45), particle size (1.25 mm), time (45 min) and temperature (45°C). The maximum experimental yield of diosgenin (1.204% dry weight) was observed close to the predicted value (1.202% dry weight) on the basis of the chosen optimal extraction factors. The developed mathematical model fitted well with experimental data for diosgenin extraction.

CONCLUSIONS

Experimental validation revealed that a well trained ANN model has superior performance compared to a RSM model.

The renoprotective effect of diosgenin on aristolochic acid I-induced renal injury in rats: impact on apoptosis, mitochondrial dynamics and autophagy

Aristolochic acid I (AA-I) remains a leading cause of aristolochic acid nephropathy (AAN), however few prevention and treatment strategies exist. In this work, the nephroprotective effect of diosgenin, a steroidal saponin distributed abundantly in several plants, on AA-I-induced renal injury and its underlying mechanism were investigated. Sprague-Dawley rats were intragastrically administered with 30 mg kg-1 d-1 diosgenin two hours before exposure to 10 mg kg-1 d-1 AA-I for consecutive four weeks, and the histological change, the renal and liver function, apoptosis, autophagy and the involved pathways were investigated. The results showed that diosgenin relieved AA-I-induced renal histological damage, including mild edematous disorder of renal tubular arrangement and widening of renal tubular lumen. No obvious changes in the hepatic tissue structure were observed in all treatment groups. Moreover, diosgenin up-regulated the expression of Bcl-2 and down-regulated Bax, and subsequently inhibited AIF expression and the cleaved form of Caspase-3, thereby alleviating apoptosis triggered by AA-I. Diosgenin also mitigated AA-I-induced renal mitochondrial dynamics disorder by increasing the expression of mitochondrial dynamics-related proteins including DRP1 and MFN2. Diosgenin inhibited AA-I-evoked autophagy via ULK1-mediated inhibition of the mTOR pathway. Overall, these results suggest that diosgenin has a protective effect against AA-I-induced renal damage and it may be a potential agent for preventing AA-I-induced AAN.

Mitigating Perspectives of Asiatic Acid in the Renal Derangements of Streptozotocin-Nicotinamide Induced Diabetic Rats

BACKGROUND

The present study was conducted to evaluate the mitigating effects of Asiatic Acid (AA), on the changes in carbohydrate metabolism, insulin signaling molecules and renal function markers in Streptozotocin (STZ)-Nicotinamide (NAD) induced diabetic rats.

METHODS

AA (20 mg/kg BW) was supplemented orally to the diabetic rats for 42 days. The levels of plasma glucose, Hemoglobin (Hb), glycosylated hemoglobin (HbA1c) insulin and renal function markers, carbohydrate metabolic enzymes in the kidney and insulin signaling molecules in skeletal muscle were measured.

RESULTS

The administration of AA elicited a significant decrease in the levels of plasma glucose, insulin resistance, HbA1c, urea, uric acid, creatinine, glycogen, glycogen synthase, glucose-6- phosphatase, and fructose-1,6-bisphosphatase and a significant increase of body weight development, insulin, Hb, hexokinase, and glycogen phosphorylase and mRNA expressions of insulin signaling molecule like insulin receptor 1, insulin receptor 2 and glucose transporter-4 in the STZ-NAD induced diabetic rats. Further, the protective effect of AA was evidenced by its histological annotation of the kidney tissues.

CONCLUSION

Hence, this study concluded that AA can protect against renal dysfunction by attenuating carbohydrate metabolic disorder and subsequently enhances glucose utilization and renal function in STZ-NAD-induced diabetic rats.

Effect of Curculigo pilosa supplemented diet on blood sugar, lipid metabolism, hepatic oxidative stress and carbohydrate metabolism enzymes in streptozotocin-induced diabetic rats

BACKGROUND

Diabetes mellitus (DM) has continued to raise concern globally and Curculigo pilosa (CP) is used for its treatment and management in folkloric medicine. In this study, the in vitro antioxidant abilities of CP and the effects of CP-supplemented diets on blood sugar, lipid metabolism, oxidative stress and key carbohydrate metabolizing enzymes in streptozotocin (STZ)-induced diabetic rats were investigated.

METHODS

Polyphenol contents (total phenolic and total flavonoid) and antioxidant ability of different extracts of CP were determined in vitro. Diabetes mellitus were stimulated in healthy rats by single intraperitoneal administration of 50 mg/kg streptozotocin and it was confirmed by elevated blood glucose level after 3 days. Thirty six rats were distributed into six groups of six rats each and diabetic rats were fed with 5 and 10% CP-supplemented diet for 21 days. Thereafter, the effects of the dietary regimen were evaluated on blood glucose, body weight, hepatic carbohydrate metabolizing enzymes, lipid profile, oxidative stress markers, serum markers of hepatic and renal damages and histopathology studies.

RESULTS

Different extracts of CP contained polyphenol contents and exhibited antioxidant properties in different models used. Diabetic rats showed elevated level of blood glucose and body weight loss. Treatment of diabetic rats with CP-supplemented diet significantly (p < 0.05) lowered the blood glucose and improved body weight loss. Also, the treatment with the CP-supplemented diet significantly (p < 0.05) enhanced the activities of hepatic glycolytic (hexokinase and glucose-6-dehydrogenase) and lowered the gluconeogenic (fructose 1, 6 biphosphatase and glucose-6-phosphatase) enzymes in diabetic rats. The lipid profile, oxidative stress markers and serum markers of hepatic and renal damages were significantly (p < 0.05) restored to near normalcy in the diabetic rats. Histopathological slides also showed improvements in pancreas and hepatic tissues of diabetic rats treated with CP-supplemented diet.

CONCLUSION

Data obtained in this study suggested that CP-supplemented diet could be used as dietary regimen in the management of DM.

Steroidal saponins and sapogenins from fenugreek and their inhibitory activity against α-glucosidase

The seed of Trigonella foenum-graecum L. (fenugreek) has been reported to be rich in saponins, especially the dioscin or diosgenin, which are natural anti-diabetic agents with relatively low toxicity. Thus, the present study was to purify the saponins and sapogenins from fenugreek and to evaluate their α-glucosidase inhibitory activity in vitro. As a result, 33 steroidal saponins and sapogenins were isolated, including six undescribed ones and 27 previously known molecules. Among them, compounds 10, 12, 17, 22 and 29 were five 25R and 25S isomer mixtures of spirostanol saponins or sapogenins. The structures of compound 1-6 were established by 1D and 2D NMR spectroscopic analyses, high-resolution mass spectrometry, and chemical evidence. Compared to the positive control, sapogenins 26, 27, 14 and saponins 18 and 23 considerably inhibited α-glucosidase at IC₅₀ values of 15.16, 8.98, 7.26, 5.49 and 14.01 μM, respectively. These results support the therapeutic potential of fenugreek in the treatment of diabetes with saponins and sapogenins as the active constituents.

Diosgenin, a steroidal saponin, and its analogs: Effective therapies against different chronic diseases

BACKGROUND

Chronic diseases are a major cause of mortality worldwide, and despite the recent development in treatment modalities, synthetic drugs have continued to show toxic side effects and development of chemoresistance, thereby limiting their application. The use of phytochemicals has gained attention as they show minimal side effects. Diosgenin is one such phytochemical which has gained importance for its efficacy against the life-threatening diseases, such as cardiovascular diseases, cancer, nervous system disorders, asthma, arthritis, diabetes, and many more.

AIM

To evaluate the literature available on the potential of diosgenin and its analogs in modulating different molecular targets leading to the prevention and treatment of chronic diseases.

METHOD

A detailed literature search has been carried out on PubMed for gathering information related to the sources, biosynthesis, physicochemical properties, biological activities, pharmacokinetics, bioavailability and toxicity of diosgenin and its analogs.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and clinical trials that reported the efficacy of diosgenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK, etc., which play a crucial role in the development of most of the diseases. Reports have also revealed the safety of the compound and the adaptation of nanotechnological approaches for enhancing its bioavailability and pharmacokinetic properties.

SIGNIFICANCE

Thus, the review summarizes the efficacy of diosgenin and its analogs for developing as a potent drug against several chronic diseases.

Effects of diosgenin on the skeletal system in rats with experimental type 1 diabetes

There is a great interest in substances of plant origin, which may exert health-promoting activities in diabetes and its complications. Previous studies suggested that diosgenin may favorably affect both glucose metabolism and osteoporosis. The aim of the study was to investigate the effects of diosgenin on the skeletal disorders induced by experimental type 1 diabetes (T1D) in rats. The experiments were performed on 3-month-old female rats, divided into three groups: I - healthy control rats, II - streptozotocin-induced diabetic control rats, III - diabetic rats receiving diosgenin. T1D was induced by a single streptozotocin injection (60 mg/kg i.p.). Diosgenin administration (50 mg/kg/day p.o.) started two weeks later and lasted four weeks. Serum bone turnover markers and other biochemical parameters, bone mass and mineralization, mechanical properties and histomorphometric parameters were examined. Diabetes induced profound metabolic disturbances and disorders of cancellous bone microarchitecture and strength. Diosgenin did not favorably affect the serum bone turnover markers and other biochemical parameters, bone mass, mineralization and mechanical properties in the diabetic rats. However, it counteracted the effect of diabetes on the growth plate and cancellous bone microarchitecture in the distal femur, indicating some limited beneficial influence on the skeleton.

Neuroprotective effect of diosgenin in a mouse model of diabetic peripheral neuropathy involves the Nrf2/HO-1 pathway

Background

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. Diosgenin is a natural steroidal saponin with a variety of beneficial effects, including antidiabetic effects, and is a raw material for the synthesis of carrier hormones. In our study, we aimed to assess the antioxidant effects of diosgenin in diabetic mice.

Methods

Male C57 mice were fed a high-fat diet for 8 weeks and intraperitoneally injected with streptozotocin (STZ) at a dose of 100 mg/kg for 2 consecutive days. Eligible mice were divided into the normal control group (CON), diabetic group (DM), low-dose diosgenin (50 mg/kg) group (DIO50) and high-dose diosgenin (100 mg/kg) group (DIO100). Treatment was started 6 weeks after the induction of diabetes by STZ and continued for 8 weeks. Blood sugar and body weight were monitored dynamically. The behavioural effects of diosgenin were detected by a hot tail immersion test and paw tactile responses. HE staining was used to evaluate edema and degeneration of the sciatic nerve. The levels of SOD, MDA and GPx were tested according to the instructions of the respective kits. The levels of Nrf2, HO-1 and NQO1 were detected by immunofluorescence and Western blotting. Statistical analysis was performed using SPSS, and P < 0.05 was considered statistically significant.

Results

Diosgenin decreased the blood glucose levels and increased the body weight of diabetic mice. There was a significant increase in the tail withdrawal latency of diabetic animals, and mechanical hyperalgesia was significantly alleviated after diosgenin treatment. Histopathological micrographs of HE-stained sciatic nerves showed improvement after diosgenin treatment. Diosgenin attenuated the level of MDA but increased the activities of SOD and GPx. Diosgenin increased the expression of Nrf2, HO-1 and NQO1.

Conclusions

Our results demonstrate that diosgenin can ameliorate behavioural and morphological changes in DPN by reducing oxidative stress. The Nrf2/HO-1 signalling pathway was involved in its neuroprotective effects.

Hypoglycemic effects and biochemical mechanisms of Pea oligopeptide on high-fat diet and streptozotocin-induced diabetic mice

The aim of this study was to evaluate the hypoglycemic effects of Pea oligopeptide on the glycemic and lipidemic status of mice with type 2 diabetes (T2D) induced by a high-fat diet and streptozotocin (STZ). Using HPLC-MS/MS spectra processing, 70 significant peptide (2-3 amino acids) sequences were identified, noting four peptides from Pea oligopeptide with a proline residue at the C-terminus, which might have dipeptidase-IV (DPP-IV) inhibitory activity for the treatment of T2D. After a 4-week administration of Pea oligopeptide and metformin, various blood biochemical indexes and organic histopathologies were detected to aid the discussion regarding potential mechanisms. The results showed a significant reduction in the levels of blood glucose, lipid profiles, and liver fat deposition in diabetic mice. Furthermore, Pea oligopeptide and metformin improved glucose tolerance, promoted glycogen synthesis, and protected the liver and kidney structures in diabetic mice. The results indicated that Pea oligopeptide played an essential role in the hypoglycemic effect in the T2D mice model. Practical applications This paper examined the preliminary hypoglycemic activities of Pea oligopeptide in a high-fat diet and STZ-induced T2D mice. Furthermore, four kinds of dipeptides and tripeptides that might exhibit antidiabetic functions were detected using HPLC-MS/MS. The results provided practical knowledge regarding the hypoglycemic effects of Pea oligopeptide and established the foundation of its structure-function relationships.

Spice-Derived Bioactive Ingredients: Potential Agents or Food Adjuvant in the Management of Diabetes Mellitus

Spices possess tremendous therapeutic potential including hypoglycemic action, attributed to their bioactive ingredients. However, there is no study that critically reviewed the hypoglycemic potency, safety and the bioavailability of the spice-derived bioactive ingredients (SDBI). Therefore, the aim of the study was to comprehensively review all published studies regarding the hypoglycemic action of SDBI with the purpose to assess whether the ingredients are potential hypoglycemic agents or adjuvant. Factors considered were concentration/dosages used, the extent of blood glucose reduction, the IC50 values, and the safety concern of the SDBI. From the results, cinnamaldehyde, curcumin, diosgenin, thymoquinone (TQ), and trigonelline were showed the most promising effects and hold future potential as hypoglycemic agents. Conclusively, future studies should focus on improving the tissue and cellular bioavailability of the promising SDBI to achieve greater potency. Additionally, clinical trials and toxicity studies are with these SDBI are warranted.

Fenugreek (Trigonella Foenum-Graecum) Seed Flour and Diosgenin Preserve Endothelium-Dependent Arterial Relaxation in a Rat Model of Early-Stage Metabolic Syndrome

Fenugreek is a common herb possessing several bioactive components including diosgenin. Here, dietary fenugreek seed flour and diosgenin were evaluated on a model of endothelium-dependent vasorelaxation by abdominal aortas isolated from rats receiving high-fat, high-sugar diet (HFHSD). 60 male Wistar rats were randomized into six groups: (i) negative control getting conventional rat feed regimen; (ii) positive control receiving HFHSD; (iii) a test group fed 2 g/kg bw/day fenugreek seed flour (containing 10 mg/kg bw/day diosgenin) + HFHSD; (iv) three test groups fed 1, 10 and 50 mg/kg bw/day diosgenin + HFHSD. Alimentary treatments were carried out for six weeks. The abdominal aortas were isolated, and 2 mm wide rings were sectioned off and mounted at a resting tension of 10 mN in organ baths containing Krebs solution (36 °C) exposed to 95% O₂ and 5% CO₂. After 60-min incubation, a norepinephrine concentration-response (E/c) curve was generated to determine their half-maximal effective concentration (EC₅₀) value. After 60-min wash-out, a pre-contraction with norepinephrine EC₅₀ was made, followed by an acetylcholine E/c curve. Plasma glutathione levels, glutathione-handling enzyme activities and blood antioxidant capacities were also determined. HFHSD significantly decreased the dilatory response to acetylcholine and increased plasma glutathione levels and these effects were significantly reversed by fenugreek seed flour, 10 and 50 mg/kg bw/day diosgenin. Both fenugreek and diosgenin treatments prevent HFHSD-induced endothelial dysfunction and redox changes. As fenugreek treatment was more effective at lower acetylcholine concentrations than diosgenin treatments, components of fenugreek other than diosgenin may contribute to the beneficial effects of dietary fenugreek seed flour.

Hypoglycemic effect of the polyphenols rich extract from Rose rugosa Thunb on high fat diet and STZ induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Rosa rugosa Thunb is a traditional Uygur medicine that has been used in the treatment of diabetes in Uygur ancient recipe for hundreds of years. However, the mechanism of Rosa rugosa Thunb activity is still unclear. This study was designed to address this issue by studying the polyphenols enriched extract (RPE) of Rosa rugosa Thunb in diabetic rats.

MATERIALS AND METHODS

RPE were tested in the inhibition of α-glucosidase and oxidative stress in vitro. RPE was administrated at dosages of 37.5, 75 and 150mg/kg body weight in the type 2 diabetic rats, which were made by high fat diet feeding plus a low dose of STZ injection (30mg/kg). The therapeutic effect was evaluated four weeks later. Oral glucose tolerance test (OGTT), insulin tolerance test (ITT) and insulin signal pathway (PI3K/AKT) were examined to determine insulin sensitivity. Blood glucose levels and body weight were measured weekly in the study.

RESULTS

In vitro, RPE exhibited an activity in the inhibition of α-glucosidase and had an excellent antioxidant activity in the liver of diabetic rats. RPE significantly decreased the fasting blood glucose, improved insulin sensitivity (HOMA-IR), OGTT, ITT and blood lipid profile. The glycogen synthesis and hexokinase activity were increased together with the improved signaling activity of insulin as indicated by p-IRS, p-IR, p-AKT, and p-GSK-3β.

CONCLUSIONS

The results suggest that RPE reduced blood glucose in type 2 diabetic rats by improvement of insulin sensitivity. The effect is likely achieved by inhibition of oxidative stress and α-glucosidase.

Reversal of endothelial dysfunction in aorta of streptozotocin-nicotinamide-induced type-2 diabetic rats by S-Allylcysteine

Dietary measures and plant-based therapies as prescribed by native systems of medicine have gained attraction among diabetics with claims of efficacy. The present study investigated the effects of S-Allylcysteine (SAC) on body weight gain, glucose, insulin, insulin resistance, and nitric oxide synthase in plasma and argininosuccinate synthase (AS) and argininosuccinate lyase (ASL), lipid peroxides and antioxidant enzymes in aorta of control and streptozotocin-nicotinamide (STZ-NA)-induced diabetic rats. Changes in body weight, glucose, insulin, insulin resistance, and antioxidant profiles of aorta and mRNA expressions of nitric oxide synthase, AS, and ASL were observed in experimental rats. SAC (150 mg/kg b.w) showed its therapeutic effects similar to gliclazide in decreasing glucose, insulin resistance, lipid peroxidation, and increasing body weight; insulin, antioxidant enzymes, and mRNA levels of nitric oxide synthase, argininosuccinate synthase, and argininosuccinate lyase genes in STZ-NA rats. Histopathologic studies also revealed the protective nature of SAC on aorta. In conclusion, garlic and its constituents mediate the anti-diabetic potential through mitigating hyperglycemic status, changing insulin resistance by alleviating endothelial dysregulation in both plasma and tissues.

Combination of Morroniside and Diosgenin Prevents High Glucose-Induced Cardiomyocytes Apoptosis

Cornus officinalis and Dioscorea opposita are two traditional Chinese medicines widely used in China for treating diabetes mellitus and its complications, such as diabetic cardiomyopathy. Morroniside (Mor) of Cornus officinalis and diosgenin (Dio) of Dioscorea opposita formed an innovative formula named M + D. The aims of the present study were to investigate myocardial protective effect of M + D on diabetic cardiomyopathy (DCM) through the inhibition of expression levels of caspase-3 protein, and identify the advantage of M + D compared with Mor, Dio, and the positive drug metformin (Met). We detected cell viability, cell apoptosis, intracellular reactive oxygen species (ROS) levels, and the expression levels of Bcl-2, Bax, and caspase-3 protein in rat cardiomyocytes. In result, Mor, Dio, and M + D increased cell viability, inhibited cell apoptosis and decreased ROS levels. Additionally, the expression of Bax and Bcl-2 protein was modulated and the expression levels of caspase-3 protein were markedly decreased. Among the treatment groups, M + D produced the most prominent effects. In conclusion, our data showed for the first time that Mor, Dio, and M + D prevented high glucose (HG)-induced myocardial injury by reducing oxidative stress and apoptosis in rat cardiomyocytes. Among all the groups, M + D produced the strongest effect, while Mor and Dio produced weaker effects.

Diosgenin: Recent Highlights on Pharmacology and Analytical Methodology

Diosgenin, a steroidal sapogenin, occurs abundantly in plants such as Dioscorea alata, Smilax China, and Trigonella foenum graecum. This bioactive phytochemical not only is used as an important starting material for the preparation of several steroidal drugs in the pharmaceutical industry, but has revealed also high potential and interest in the treatment of various types of disorders such as cancer, hypercholesterolemia, inflammation, and several types of infections. Due to its pharmacological and industrial importance, several extraction and analytical procedures have been developed and applied over the years to isolate, detect, and quantify diosgenin, not only in its natural sources and pharmaceutical compositions, but also in animal matrices for pharmacodynamic, pharmacokinetic, and toxicological studies. Within these, HPLC technique coupled to different detectors is the most commonly analytical procedure described for this compound. However, other alternative methods were also published. Thus, the present review aims to provide collective information on the most recent pharmacological data on diosgenin and on the most relevant analytical techniques used to isolate, detect, and quantify this compound as well.

Diosgenin and 5-Methoxypsoralen Ameliorate Insulin Resistance through ER-α/PI3K/Akt-Signaling Pathways in HepG2 Cells

To determine the effects and the underlying mechanism of diosgenin (DSG) and 5-methoxypsoralen (5-MOP), two main active components in the classical Chinese prescription Hu-Lu-Ba-Wan (HLBW), on insulin resistance, HepG2 cells were incubated in medium containing insulin. Treatments with DSG, 5-MOP, and their combination were performed, respectively. The result showed that the incubation of HepG2 cells with high concentration insulin markedly decreased glucose consumption and glycogen synthesis. However, treatment with DSG, 5-MOP, or their combination significantly reversed the condition and increased the phosphorylated expression of estrogen receptor-α (ERα), sarcoma (Src), Akt/protein kinase B, glycogen synthase kinase-3β (GSK-3β), and the p85 regulatory subunit of phosphatidylinositol 3-kinase p85 (PI3Kp85). At the transcriptional level, expression of the genes mentioned above also increased except for the negative regulation of GSK-3β mRNA. The increased expression of glucose transport-4 (GLUT-4) was meanwhile observed through immunofluorescence. Nevertheless, the synergistic effect of DSG and 5-MOP on improving glycometabolism was not obvious in the present study. These results suggested that DSG and 5-MOP may improve insulin resistance through an ER-mediated PI3K/Akt activation pathway which may be a new strategy for type 2 diabetes mellitus, especially for women in an estrogen-deficient condition.

Diosgenin reorganises hyperglycaemia and distorted tissue lipid profile in high-fat diet-streptozotocin-induced diabetic rats

BACKGROUND

Diabetes is often connected with significant morbidity, mortality and also has a pivotal role in the development of cardiovascular diseases. Diet intervention, particularly naturaceutical antioxidants have anti-diabetic potential and avert oxidative damage linked with diabetic pathogenesis. The present study investigated the effects of diosgenin, a saponin from fenugreek, on the changes in lipid profile in plasma, liver, heart and brain in high-fat diet-streptozotocin (HFD-STZ)-induced diabetic rats. Diosgenin was administered to HFD-STZ induced diabetic rats by orally at 60 mg kg(-1) body weight for 30 days to assess its effects on body weight gain, glucose, insulin, insulin resistance and cholesterol, triglycerides, free fatty acids and phospholipids in plasma, liver, heart and brain.

RESULTS

The levels of body weight, glucose, insulin, insulin resistance, cholesterol, triglycerides, free fatty acids, phospholipids, VLDL-C and LDL-C were increased significantly (P < 0.05) whereas HDL-C level decreased in the HFD/STZ diabetic rats. Administration of diosgenin to HFD-STZ diabetic rats caused a decrease in body weight gain, blood glucose, insulin, insulin resistance and also it modulated lipid profile in plasma and tissues.

CONCLUSION

The traditional plant fenugreek and its constituents mediate its anti-diabetic potential through mitigating hyperglycaemic status, altering insulin resistance by alleviating metabolic dysregulation of lipid profile in both plasma and tissues.

Diosgenin, 4-hydroxyisoleucine, and fiber from fenugreek: mechanisms of actions and potential effects on metabolic syndrome

Metabolic syndrome and its complications continue to rise in prevalence and show no signs of abating in the immediate future. Therefore, the search for effective treatments is a high priority in biomedical research. Products derived from botanicals have a time-honored history of use in the treatment of metabolic diseases including type 2 diabetes. Trigonella foenum-graecum, commonly known as fenugreek, is an annual herbaceous plant that has been a staple of traditional herbal medicine in many cultures. Although fenugreek has been studied in both clinical and basic research settings, questions remain about its efficacy and biologic mechanisms of action. Diosgenin, 4-hydroxyisoleucine, and the fiber component of the plant are the most intensively studied bioactive constituents present in fenugreek. These compounds have been demonstrated to exert beneficial effects on several physiologic markers including glucose tolerance, inflammation, insulin action, liver function, blood lipids, and cardiovascular health. Although insights into the molecular mechanisms underlying the favorable effects of fenugreek have been gained, we still do not have definitive evidence establishing its role as a therapeutic agent in metabolic disease. This review aims to summarize the currently available evidence on the physiologic effects of the 3 best-characterized bioactive compounds of fenugreek, with particular emphasis on biologic mechanisms of action relevant in the context of metabolic syndrome.

High-dose diosgenin reduces bone loss in ovariectomized rats via attenuation of the RANKL/OPG ratio

The aim of this study was to evaluate effect of diosgenin (DG) on rats that had osteoporosis-like features induced by ovariectomy (OVX). Seventy-two six-month-old female Wistar rats were subjected to either ovariectomy (n = 60) or Sham operation (SHAM group, n = 12). Beginning at one week post-ovariectomy, the OVX rats were treated with vehicle (OVX group, n = 12), estradiol valerate (EV group, n = 12), or DG at three doses (DG-L, -M, -H group, n = 12, respectively). After a 12-week treatment, administration of EV or DG-H inhibited OVX-induced weight gain, and administration of EV or DG-H or DG-M had a significantly uterotrophic effect. Bone mineral density (BMD) and indices of bone histomorphometry of tibia were measured. Levels of protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) in tibia were evaluated by immunohistochemistry and in situ hybridization. Our results show that DG at a high dose (DG-H) had a significant anti-osteoporotic effect compared to OVX control. DG-H treatment down-regulated expression of RANKL and up-regulated expression of OPG significantly in tibia from OVX rats compared to control, and thus lowered the RANKL/OPG ratio. This suggests that the anti-osteoporotic effect of DG might be associated with modulating the RANKL/OPG ratio and DG had potential to be developed as alternative therapeutic agents of osteoporosis induced by postmenopause.