Effects of sodium-orthovanadate andTrigonella foenum-graecum seeds on hepatic and renal lipogenic enzymes and lipid profile during alloxan diabetes

Antidiabetic potential of fenugreek (Trigonella foenum-graecum): A magic herb for diabetes mellitus

Fenugreek (Trigonella foenum-graecum) is a widely grown dietary herb in Asia, and its seeds are traditionally used for several diseases, including diabetes. The seeds and leaves possess a variety of compounds that play an important role in regulating their hypoglycemic effect. However, so far, no extensive systematic review exists on its antidiabetic effect, highlighting the molecular mechanisms and isolated compounds. The purpose of this review is to summarize the preclinical and clinical antidiabetic properties of fenugreek and its isolated compounds by focusing on underlying mechanisms. PubMed, Google Scholar, Science Direct, and Scopus databases were searched to retrieve articles until June, 2024. Preclinical studies demonstrated that the antidiabetic effect of fenugreek was mostly associated with enhanced glucose transporter type-4 (GLUT4) translocation and hexokinase activity, decreased glucose-6-phosphatase and fructose-1,6-bisphosphatase activities, inhibited α-amylase and maltase activities, protected β cells, and increased insulin release. Furthermore, few studies have reported its role as a glucagon-like peptide-1 (GLP-1) modulator, 5'-AMP-activated kinase (AMPK) activator, and dipeptidyl peptidase-IV (DPP-IV) inhibitor. Further clinical trials showed that fenugreek seeds improved blood glucose levels, insulin resistance, insulin sensitivity, and lipid profiles. This study highlights significant evidence of the antidiabetic effect of fenugreek and its isolated compounds; therefore, it could be a potential therapy for diabetes.

Long term administration of thiamine disulfide improves FOXO1/PEPCK pathway in liver to reduce insulin resistance in type 1 diabetes rat model

OBJECTIVE

The main objective of this study was to find if thiamine disulfide (TD) lowers blood glucose level and improves insulin resistance (IR) in liver and muscle in rats with chronic type 1 diabetes (T1DM) using euglycemic-hyperinsulinemic clamp technique.

METHODS

A total of fifty male Wistar rats were assigned to five groups consisted of: non-diabetic control (NDC), diabetic control (DC), diabetic treated with thiamine disulfide (D-TD), diabetic treated with insulin (D-insulin), and diabetic treated with both TD and insulin (D-insulin+TD). Diabetes was induced by a 60 mg/kg dose of streptozotocin. Blood glucose levels, pyruvate tolerance test (PTT), intraperitoneal glucose tolerance test (IPGTT), levels of glycosylated hemoglobin (HbA1c), glucose infusion rate (GIR), liver and serum lipid profiles, liver glycogen stores, liver enzymes ([ALT], [AST]), and serum calcium and magnesium levels. were evaluated. Additionally, gene expression levels of phosphoenolpyruvate carboxykinase (Pepck), forkhead box O1 (Foxo1), and glucose transporter type 4 (Glut4) were assessed in liver and skeletal muscle tissues.

RESULTS

Blood glucose level was reduced by TD treatment. In addition, TyG index, HOMA-IR, serum and liver lipid profiles, HbA1c levels, and expressions of Foxo1 and Pepck genes were decreased significantly (P<0.05) in all the treated groups. However, TD did not influence Glut4 gene expression, but GIR as a critical index of IR were 5.0±0.26, 0.29±0.002, 1.5±0.07, 0.9±0.1 and 1.3±0.1 mg.min-1Kg-1 in NDC, DC, D-TD, D-insulin and D-insulin+TD respectively.

CONCLUSIONS

TD improved IR in the liver primarily by suppressing gluconeogenic pathways, implying the potential use of TD as a therapeutic agent in diabetes.

Sodium orthovanadate exhibits anti-angiogenic, antiapoptotic and blood glucose-lowering effect on colon cancer associated with diabetes

BACKGROUND

The presence of type 2 diabetes mellitus increases the risk of developing the colon cancer. The main objective of this study was to determine the role of sodium orthovanadate (SOV) in colon cancer associated with diabetes mellitus by targeting the competitive inhibition of PTP1B.

METHODS

For in vivo study, high fat diet with low dose streptozotocin model was used for inducing the diabetes mellitus. Colon cancer was induced by injecting 1,2-dimethylhydrazine (25 mg/kg, sc) twice a week. TNM staging and immunohistochemistry (IHC) was carried out for colon cancer tissues. In vitro studies like MTT assay, clonogenic assay, rhodamine-123 dye assay and annexin V-FITC assay using flow cytometry were performed on HCT-116 cell line. CAM assay was performed to examine the anti-angiogenic effect of the drug.

RESULTS

Sodium orthovanadate reduces the blood glucose level and tumor parameters in the animals. In vitro studies revealed that SOV decreased cell proliferation dose dependently. In addition, SOV induced apoptosis as depicted from rhodamine-123 dye assay and annexin V-FITC assay using flow cytometry as well as p53 IHC staining. SOV showed reduced angiogenesis effect on eggs which was depicted from CAM assay and also from CD34 and E-cadherin IHC staining.

CONCLUSIONS

Our data suggest that SOV exhibits protective role in colon cancer associated with diabetes mellitus. SOV exhibits anti-proliferative, anti-angiogenic and apoptotic inducing effects hence can be considered for therapeutic switching in diabetic colon cancer.

Vanadium and biomarkers of inflammation and oxidative stress in diabetes: A systematic review of animal studies

Background: Oxidative stress has a significant role in the commencement and development of hyperglycemia. Vanadium, as a transitional metal with redox properties, enters the redox process, produces free radicals, and distracts the pro-antioxidant balance. The present animal systematic review aimed to assess the effect of vanadium supplementation on inflammation and oxidative stress biomarkers in diabetes-induced animals. Methods: A systematic search was conducted using the PubMed, Scopus, and web of science databases from 1990 to 2021, according to the inclusion and exclusion criteria. The search strategy was based on the guidelines for systematic review of animal experiments and Preferred Reporting Items for Systematic Reviews (PRISMA). Criteria for eligibility were animal-based studies, evaluating the therapeutic effects of vanadium on inflammatory and oxidative stress biomarkers in diabetes. The Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool was used for assessing the methodological quality of included studies. Results: In the present study, 341 articles were evaluated out of which 42 studies were eligible for inclusion. The majority of the studies confirmed the advantageous properties of vanadium on inflammatory and oxidative stress biomarkers. A minor risk of bias was reported, based on the SYRCLE's tool. Conclusion: According to the findings, well-designed clinical trials are warranted to assess the long-lasting effects of various vanadium compounds on inflammatory and oxidative stress biomarkers.

Vanadium and diabetic dyslipidemia: A systematic review of animal studies

BACKGROUND

Diabetic dyslipidemia is caused by hyperglycemia and excessive mobilization of storage lipids, leading to increasing concentrations of triglycerides and total cholesterol. Due to the insulin-mimetic or insulin-enhancer features of vanadium, it has been recognized as a regulator of cell metabolism with hypoglycemic and hypolipidemic properties. The purpose of the current animal systematic review was to evaluate the effect of vanadium administration on diabetic dyslipidemia in diabetic animals.

METHODS

This is, to our knowledge, the first systematic review with the aim of investigating the relationship between vanadium and diabetic dyslipidemia among diabetes induced animals. Searches were performed in PubMed, Scopus, and web of science databases for animal studies examining the effect of vanadium on diabetic dyslipidemia in diabetic animals.

RESULTS

Of 124 full-text articles assessed, 48 animal studies were included in the present study with minor risk of bias. The majority of the studies confirmed the beneficial effects of different vanadium compounds in at least one of the parameters of lipid profile, especially regarding triglyceride and total cholesterol.

CONCLUSION

Current findings lend support to assess the long-term effects of different forms and doses of vanadium on lipid profile through well-designed clinical trials.

The Potential Impact of Moringa oleifera for Diminishing the Microbial Contamination and Prolonging the Quality and Shelf-Life of Chilled Meat

This study was implemented to assess the mechanism by which Moringa oleifera leaf extract (MOLE) improves the quality and prolongs shelf-life of the broilers’ breast meat. Ninety Cobb chicks were randomly allocated to 3 groups. A control group received the standard diet, whereas the other two groups received diets containing MOLE at the doses of 250 and 500 mg/kg for 21 days. Inclusion of MOLE in broilers diet significantly reduced the detrimental changes in the overall sensory attribute scores, characteristic color and odor, and the loss of breast muscle elasticity during storage. Furthermore, it significantly reduced concentrations of thiobarbituric acid, total volatile nitrogen, non-esterified fatty acids, and peroxide, during storage compared to the control samples. No effect on the concentrations of heavy metals, such as copper, cadmium, and lead, was observed. Decomposition of samples was delayed as indicated by lower pH values and higher sensory scores at 4 and 6 days of storage in the MOLE groups. Reduced contamination with E. coli and Salmonella species indicated an antibacterial effect of MOLE. Finally, the present study highlights that MOLE supplementation may play a role in improving quality and shelf-life of the chilled breast meat in broilers.

Potential preventive and protective perspectives of different spice powders and their mixtures in rat model

BACKGROUND

The spices based dietary interventions are in lime light among the scientific community owing to their promising therapeutic perspective. The bioactive components in spices can be used to exert various health promoting functions in human body such as prompting weight loss, inhibit diet-induced obesity, hypercholesterolemia, hyperglycemia, allergies and various other maladies. In current study extraction and in vitro characterization of coriander seed (CS), black cumin seed (BCS) and fenugreek seed (FS) polyphenols was conducted for further development of dietary intervention against lipid and glycemia related abnormalities in experimental Sprague Dowley rats fed with control and different spice powder supplemented diets.

METHODS

Purposely, extraction of Coriander (CS), Black cumin (BCS) and Fenugreek seeds (FS) were carried out by using water and aqueous methanol (70:30 v/v). Afterwards, the resultant extracts were thoroughly investigated for their antioxidant potential through different indices like TPC, TFC, FRAP and β Carotene Bleaching Assay and ABTS. Furthermore, HPLC quantification were also conducted with special reference to thymoquinone, disogenin, chlorogenic acid, caffeic acid and kaempferol alongside in vitro pancreatic lipase inhibitory activity estimation. Bio-evaluation trial was consisting of three modules i.e. study-I (normal diet), study-II (high cholesterol diet) and study-III (high sucrose diet). Furthermore, rats were sub-divided in five groups in each module on the basis of diet provision including T₀ (control), T₁ (Diet containing CS), T₂ (Diet containing BCS), T₃ (Diet containing FS) and T₄ (Diet containing CSP + BCSP + FSP). At the beginning of trial, some rats were dissected to evaluate the baseline values whilst rest of the rats was killed at the termination (56th day). Feed and drink intakes were quantified on daily bases whereas, body weight was calculated weekly. Cholesterol level, serum low density lipoproteins (LDL), high density lipoproteins (HDL), triglycerides, glucose concentration and insulin level of collected sera was measured by standard procedures.

RESULTS

The in vitro characterization showed better extraction of spices antioxidant through aqueous methanol as compared to water. Among the spices, Black cumin seed alone or in combination revealed highest antioxidant activity in T2 (BCS) followed by T4 (CS + BCS), T7 (CS + BCS + FS), T1 (CS), T6 (BCS + FS), T5 (CS + FS) and lowest in T3 (FS). Likewise, the HPLC characterization showed the presence of thymoquinone in BCS, Dosignienin FGS and chlorogenic acid, caffeic acid and kaempferol in the other treatments. Furthermore, all the treatments showed dose dependent inhibition in Pancreatic lipase activity and order of inhibition was BCS > CS + BCS > CS + BCS + FS > CS > BCS + FC > CS + FS > FS. The maximum feed intake, drink intake and weight gain was observed in T0 (control) trailed by T1, T2, T3 and T4 group in experimental study I, II and III, respectively. The resultant diet T4 enhanced the high density lipoprotein from T0 (58.58 ± 2.51) to 61.71 ± 1.62 (T4) in hypercholesterolemia rats whereas in hyperglycaemia rats the HDL was varied from 38.77 ± 1.2 to 40.02 ± 0.99 in T0 and T4, respectively. Similarly, T2 significantly lowered the low density lipoprotein from 62.53 ± 1.22 (T1) & 46.53 ± 0.99 to 54.88 ± 0.52 & 40.94 ± 1.99 (T2) in hypercholesteraemic and diabetic rats. Moreover, T4 treatment showed maximum reduction as 10.01 & 11.53% in respective studies.

CONCLUSIONS

The diet prepared from the different combination of spices has been proven effective against Oxidative stress related physiological malfunctioning.

Fenugreek Counters the Effects of High Fat Diet on Gut Microbiota in Mice: Links to Metabolic Benefit

Fenugreek (Trigonella foenum-graecum) is an annual herbaceous plant and a staple of traditional health remedies for metabolic conditions including high cholesterol and diabetes. While the mechanisms of the beneficial actions of fenugreek remain unknown, a role for intestinal microbiota in metabolic homeostasis is likely. To determine if fenugreek utilizes intestinal bacteria to offset the adverse effects of high fat diets, C57BL/6J mice were fed control/low fat (CD) or high fat (HFD) diets each supplemented with or without 2% (w/w) fenugreek for 16 weeks. The effects of fenugreek and HFD on gut microbiota were comprehensively mapped and then statistically assessed in relation to effects on metrics of body weight, hyperlipidemia, and glucose tolerance. 16S metagenomic analyses revealed robust and significant effects of fenugreek on gut microbiota, with alterations in both alpha and beta diversity as well as taxonomic redistribution under both CD and HFD conditions. As previously reported, fenugreek attenuated HFD-induced hyperlipidemia and stabilized glucose tolerance without affecting body weight. Finally, fenugreek specifically reversed the dysbiotic effects of HFD on numerous taxa in a manner tightly correlated with overall metabolic function. Collectively, these data reinforce the essential link between gut microbiota and metabolic syndrome and suggest that the preservation of healthy populations of gut microbiota participates in the beneficial properties of fenugreek in the context of modern Western-style diets.

Sodium Orthovanadate Changes Fatty Acid Composition and Increased Expression of Stearoyl-Coenzyme A Desaturase in THP-1 Macrophages

Vanadium compounds are promising antidiabetic agents. In addition to regulating glucose metabolism, they also alter lipid metabolism. Due to the clear association between diabetes and atherosclerosis, the purpose of the present study was to assess the effect of sodium orthovanadate on the amount of individual fatty acids and the expression of stearoyl-coenzyme A desaturase (SCD or Δ⁹-desaturase), Δ⁵-desaturase, and Δ⁶-desaturase in macrophages. THP-1 macrophages differentiated with phorbol 12-myristate 13-acetate (PMA) were incubated in vitro for 48 h with 1 μM or 10 μM sodium orthovanadate (Na₃VO₄). The estimation of fatty acid composition was performed by gas chromatography. Expressions of the genes SCD, fatty acid desaturase 1 (FADS1), and fatty acid desaturase 2 (FADS2) were tested by qRT-PCR. Sodium orthovanadate in THP-1 macrophages increased the amount of saturated fatty acids (SFA) such as palmitic acid and stearic acid, as well as monounsaturated fatty acids (MUFA)-oleic acid and palmitoleic acid. Sodium orthovanadate caused an upregulation of SCD expression. Sodium orthovanadate at the given concentrations did not affect the amount of polyunsaturated fatty acids (PUFA) such as linoleic acid, arachidonic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). In conclusion, sodium orthovanadate changed SFA and MUFA composition in THP-1 macrophages and increased expression of SCD. Sodium orthovanadate did not affect the amount of any PUFA. This was associated with a lack of influence on the expression of FADS1 and FADS2.

The vital role of ATP citrate lyase in chronic diseases

Chronic or non-communicable diseases are the leading cause of death worldwide; they usually result in long-term illnesses and demand long-term care. Despite advances in molecular therapeutics, specific biomarkers and targets for the treatment of these diseases are required. The dysregulation of de novo lipogenesis has been found to play an essential role in cell metabolism and is associated with the development and progression of many chronic diseases; this confirms the link between obesity and various chronic diseases. The main enzyme in this pathway-ATP-citrate lyase (ACLY), a lipogenic enzyme-catalyzes the critical reaction linking cellular glucose catabolism and lipogenesis. Increasing lines of evidence suggest that the modulation of ACLY expression correlates with the development and progressions of various chronic diseases such as neurodegenerative diseases, cardiovascular diseases, diabetes, obesity, inflammation, and cancer. Recent studies suggest that the inhibition of ACLY activity modulates the glycolysis and lipogenesis processes and stimulates normal physiological functions. This comprehensive review aimed to critically evaluate the role of ACLY in the development and progression of different diseases and the effects of its downregulation in the prevention and treatment of these diseases.

Is there a Role for Sodium Orthovanadate in the Treatment of Diabetes?

BACKGROUND

Diabetes is a metabolic disorder, whose incidences are increasing day by day. Various classes of anti-diabetic drugs are clinically approved by the Food and Drug Administration (FDA) for the treatment of diabetes mellitus, but unfortunately, none of them is able to treat this condition. Thus, the exploration of novel mechanistic pathways of existing molecules may help to develop more safe and effective anti-diabetic agents. Sodium orthovanadate is a well known common laboratory agent used to preserve the protein tyrosyl phosphorylation state of the protein.

METHODS

The data related to sodium orthovanadate and diabetes mellitus has been collected from Pubmed.

RESULTS

Various reports have indicated the potential of sodium orthovanadate as Protein Tyrosine Phosphatase (PTP1B) inhibitors which play an important role in the pathogenesis of diabetes. However, safety of Sodium orthovanadate is still questionable.

CONCLUSION

The sodium orthovanadate could be developed as an anti-diabetic agent. However, further studies are required to confirm its safety profile in the treatment of diabetes mellitus before starting a clinical trial.

Sterol regulatory element binding protein (SREBP) -1 mediates oxidized low-density lipoprotein (oxLDL) induced macrophage foam cell formation through NLRP3 inflammasome activation

Macrophage foam cell formation (FCF) has long been known to play a critical role during atherosclerotic plaque development. In the presence of atherogenic molecules such as oxidized low-density lipoprotein (oxLDL) macrophages accumulate massive amounts of lipid through uptake. However, in the presence of oxLDL mechanism of dysregulated lipid homeostasis in the macrophages remains largely unknown. Herein we have investigated the role of Sterol regulatory element binding protein (SREBP)-1 in oxLDL-induced inflammation and altered lipid homeostasis in macrophages. The U937 monocytes and monocyte-derived macrophages (MDMs) were stimulated with different doses of oxLDL. MTT assay to study the effect of oxLDL on cell viability, Oil-Red-O (ORO) staining to observe cytosolic lipid accumulation, semi-quantitative PCR and Western blotting to analyze mRNA and protein expressions, respectively, and spectrophotometric assay to measure the lipid synthesizing enzyme's activity were performed. Our results indicate that oxLDL increased proliferation in monocytes and decreased the viability in MDMs in a time- and dose-dependent manner. The oxLDL (100 μg/ml) enhanced lipid accumulation via increased expressions of SREBP-1 and its downstream proteins such as fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) at both RNA and protein levels in monocytes as well as in MDMs. Inhibiting SREBP-1 by a synthetic inhibitor prevented excessive lipid accumulation by downregulating the expression of its downstream proteins. Further, oxLDL increased reactive oxygen species (ROS) levels, NLRP3 inflammasome activation and active interleukin 1β (IL-1β) release in both the cell types. The oxLDL-induced NLRP3 could be responsible for SREBP-1 and downstream proteins overexpression as siRNA silencing of NLRP3 decreased SERBP-1 levels. In summary, we have demonstrated that SREBP-1 could be a key player in oxLDL-induced excessive lipid accumulation leading to macrophage FCF via ROS-mediated NLRP3/IL-1β/SREBP-1 pathway.

Fenugreek supplementation during high-fat feeding improves specific markers of metabolic health

To assess the metabolically beneficial effects of fenugreek (Trigonella foenum-graecum), C57BL/6J mice were fed a low- or high-fat diet for 16 weeks with or without 2% (w/w) fenugreek supplementation. Body weight, body composition, energy expenditure, food intake, and insulin/glucose tolerance were measured regularly, and tissues were collected for histological and biochemical analysis after 16 weeks of diet exposure. Fenugreek did not alter body weight, fat mass, or food intake in either group, but did transiently improve glucose tolerance in high fat-fed mice. Fenugreek also significantly improved high-density lipoprotein to low-density lipoprotein ratios in high fat-fed mice without affecting circulating total cholesterol, triglycerides, or glycerol levels. Fenugreek decreased hepatic expression of fatty acid-binding protein 4 and increased subcutaneous inguinal adipose tissue expression of adiponectin, but did not prevent hepatic steatosis. Notably, fenugreek was not as effective at improving glucose tolerance as was four days of voluntary wheel running. Overall, our results demonstrate that fenugreek promotes metabolic resiliency via significant and selected effects on glucose regulation, hyperlipidemia, and adipose pathology; but may not be as effective as behavioral modifications at preventing the adverse metabolic consequences of a high fat diet.

Melittin, a Potential Natural Toxin of Crude Bee Venom: Probable Future Arsenal in the Treatment of Diabetes Mellitus

Since diabetes mellitus (DM) is one of the most common and serious endocrine metabolic disorders, it is important to elucidate novel antidiabetic therapeutic agents from various sources, including natural products. Bee venom (BV) is a complex mixture of proteins, peptides, and low molecular components, and melittin is the main constituent. Melittin is a peptide consisting of 26 amino acids with the sequence GIGAVLKVLTTGLPALISWIKRKRQQ. It has several important biological effects and has a relatively low toxicity. Recent studies using animal models have confirmed that melittin has significant glucose and lipid lowering activities by acting on several mechanistic pathways. The main antidiabetic activity of melittin is increasing insulin secretion via depolarization of pancreatic β-cells. Other possible mechanisms may involve stimulation of phospholipase A2, increase of glucose uptake, improving lipid profile, and/or reduction of inflammation. This review summarizes the various sources, proteomics, biological roles, adverse effects, and medical applications of melittin and its mechanism of action in combating DM.

4-Hydroxyisoleucine from Fenugreek (Trigonella foenum-graecum): Effects on Insulin Resistance Associated with Obesity

Obesity and insulin resistance (IR) are interdependent multifactorial processes that cannot be understood separately. Obesity leads to systemic inflammation and increased levels of free fatty acids that provoke IR and lipotoxicity. At the same time, IR exacerbates adipose cell dysfunction, resulting in chronic inflammation and major lipotoxic effects on nonadipose tissues. 4-Hydroxyisoleucine (4-OHIle), a peculiar nonprotein amino acid isolated from fenugreek (Trigonella foenum-graecum) seeds, exhibits interesting effects on IR related to obesity. 4-OHIle increases glucose-induced insulin release, and the insulin response mediated by 4-OHIle depends on glucose concentration. The beneficial effects observed are related to the regulation of blood glucose, plasma triglycerides, total cholesterol, free fatty acid levels, and the improvement of liver function. The mechanism of action is related to increased Akt phosphorylation and reduced activation of Jun N-terminal kinase (JNK)1/2, extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB. Here, we present a review of the research regarding the insulinotropic and insulin-sensitising activity of 4-OHIle in in vitro and in vivo models.

Effect of cocoyam (Colocasia esculenta), unripe plantain (Musa paradisiaca) or their combination on glycated hemoglobin, lipogenic enzymes, and lipid metabolism of streptozotocin-induced diabetic rats

CONTEXT

The possibility of combining unripe plantain [Musa paradisiacae Linn (Plantaginaceae)] and cocoyam [Colocassia esculenta Linn (Araceae)] in the management of diabetes has not been investigated.

OBJECTIVE

The objective of this study is to evaluate the antihyperglycemic and antihyperlipidemic actions of unripe plantain and cocoyam.

MATERIALS AND METHODS

Diabetes was induced in rats by intraperitoneal injection of streptozotocin (STZ) (65 mg/kg body weight). Twelve days after STZ induction, respective groups of diabetic rats were fed cocoyam (810 g/kg), unripe plantain (810 g/kg), and unripe plantain + cocoyam (405:405 g/kg) for 28 d. Body weights, feed intake, biochemical parameters, namely serum glucose, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), atherogenic index, coronary risk index, triacylglycerol, glycated hemoglobin (HbA1C), hepatic isocitrate dehydrogenase, malic enzyme, and glucose-6-phosphate dehydrogenase of the rats and phytochemical composition of the test and standard rat feeds were measured.

RESULTS AND DISCUSSION

Cocoyam or unripe plantain alone significantly (p < 0.05) ameliorated the body weights (18.89 and 19.95% decreases, respectively) and biochemical parameters as compared with those of STZ controls (31.21% decrease). While combination of cocoyam and unripe plantain significantly (p < 0.05) ameliorated the biochemical parameters of the rats (except HbA1C), it did not ameliorate their body weights (28.53% decrease). The feed intake of the experimental rats did not differ from each other (p > 0.05) at the end of experimentation and the feed samples contained considerable amounts of saponins, alkaloids, flavonoids, and tannins.

CONCLUSION

Cocoyam or unripe plantain alone showed better antihyperglycemic and anihyperlipidemic action than their combination.

Diabetes mellitus and its management with medicinal plants: A perspective based on Iranian research

ETHNOPHARMACOLOGICAL RELEVANCE

Complementary and alternative medicine has been increasingly used to treat chronic illnesses, such as diabetes mellitus. However, various limitations in terms of their application and efficacies exist. Furthermore, there is still much to be done to discover the right herbal medicine for diabetes.

AIM OF THE STUDY

This paper aims to evaluate previous herbal studies on the management of diabetes mellitus, to address their strengths and weaknesses and propose a general framework for future studies.

APPROACH AND METHODS

Data sources such as PubMed, ScienceDirect, Scopus, SpringerLink, and Wiley were searched, limited to Iran, using 36 search terms such as herbal, traditional, medicine, and phytopharmacy in combination with diabetes and related complications. Reviewed articles were evaluated regarding the use of botanical nomenclature and included information on (1) identity of plants and plant parts used, (2) the processing procedure, and (3) the extraction process. The main outcomes were extracted and then surveyed in terms of the efficacies of herbs in the management of diabetes mellitus. Then a comparative study was performed between Iranian and non-Iranian studies with respect to herbs best studied in Iran.

RESULTS

Of the 82 herbs studied in Iran, only six herbs were endemic and 19 were studied in detail. Although most of the reviewed herbs were found to decrease the level of blood glucose (BG) and/or glycated hemoglobin (HbA1C) in both Iranian and non-Iranian studies, information on their pharmacological mechanisms is scarce. However, the level of HbA1C was measured in a limited number of clinical trials or animal studies. Available information on both short- and long-term use of studied herbs on diabetes related complications and functions of involved organs as well as comorbid depression and/or simultaneous changes in lifestyle is also insufficient. Furthermore, little or no information on their phytochemical, toxicological, and herb-drug interaction properties is available. It is worth noting that the efficacy of the reviewed herbs has been studied scarcely in both humans and animals regarding both Iranian and non-Iranian studies. A significant number of reviewed articles failed to cite the scientific name of herbs and include information on the processing procedure and the extraction process.

CONCLUSIONS

Treatment of diabetes mellitus as a multifactorial disease using herbal medicines requires a comprehensive approach. In order to discover the right herbal medicine for the management of diabetes many other important factors than the levels of BG, HbA1C and insulin should be considered. According to our criteria, all the reviewed herbs suffered from inadequate investigation in human, animal and in vitro models in this respect, whereas they are worth investigating further. However, more research on endemic plants and the traditional history of herbal medicine is warranted. In our opinion, the pharmacological, toxicological, and phytochemical information should be obtained before clinical trials. Furthermore, information such as botanical scientific nomenclature, side effects, and toxicity will improve the quality and validity of publications in herbal research. In particular, designing a database covering all valid information about herbs and/or diseases will decrease unnecessary costs and increase the efficiency of research.

Effect of diallyl disulphide on diabetes induced dyslipidemia in male albino rats

BACKGROUND

Diabetes Mellitus is a chronic metabolic disorder which may lead to various complications, the important being dyslipidemia leading to Coronary Heart Disorders (CHD), the major cause for morbidity and mortality in diabetic patients. Diabetes Mellitus could be treated by nutritional therapy/drug therapy and others. But the drug therapy would have its own limitations and side effects. To overcome from this an herbal extract is recommended, such as Diallyl Disulphide (DADS) a principle compound of Garlic oil.

AIM

To assess the hypolipidemic effect of Diallyl Disulphide (DADS) in alloxan induced diabetic rats.

MATERIALS AND METHODS

Healthy adult wistar strain male albino rats weighing around 100-150 grams were randomly selected from the animal house at BLDE University's Shri B.M.Patil Medical College, Hospital and Research Centre, Bijapur, India. Diabetes was induced using alloxan and was treated with DADS. After a stipulated time the rats were anesthetised and sacrificed to collect the blood and liver tissue. Various Lipid parameters, HMG CoA Reductase, Fecal bile acids were estimated in the blood, feces and homogenised liver tissue using standard procedures.

STATISCAL ANALYSIS

One-way ANOVA followed by post-hoc t-test is done.

RESULT

There was significant decrease in the blood and liver tissue lipid parameters of DADS treated alloxan induced diabetic rats when compared to the alloxan induced diabetic rats.

CONCLUSION

From this study it can be concluded that the DADS a principle compound of garlic, definitely has the hypolipidemic effect in diabetic rats, which is reducing the morbidity in diabetic cases due to dyslipidemia without the adverse effects.

Use of unripe plantain (Musa paradisiaca) in the management of diabetes and hepatic dysfunction in streptozotocin induced diabetes in rats

AIM

This study aims to investigate the effect of unripe plantain (Musa paradisiaca) on markers of hepatic dysfunction in streptozotocin induced diabetic rats.

METHODS

Blood glucose; relative liver weight (RLW); relative kidney weight (RKW); relative heart weight (RHW); relative pancreatic weight (RPW); serum and hepatic serum aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP); serum amylase, lipase, total, and conjugated bilirubin; and chemical analysis of the test feed were determined using standard techniques.

RESULTS

The diabetic rats had significant alteration (P < 0.05) of blood glucose; RLW; RKW; RPW; serum and hepatic AST, ALT, and ALP; serum total and conjugated bilirubin; and serum lipase activities compared with nondiabetic while these parameters were significantly improved (P < 0.05) in the rats fed unripe plantain. There were no significant differences (P > 0.05) in the RHW of the rats in the three groups, as well as significant decreases (P < 0.05) in the amylase levels of the diabetic rats compared with the nondiabetic, but there was nonsignificant increase (P > 0.05) in the amylase levels of the rats fed unripe plantain compared with the nondiabetic rats. The test and standard rat feeds contained considerable amount of proteins, carbohydrates, fats, phenols, and crude fiber.

CONCLUSION

Amelioration of acute pancreatitis by unripe plantain could play a key role in its management of diabetes and related complications.

Saponins: Anti-diabetic principles from medicinal plants - A review

Diabetes mellitus (DM) represents a global health problem. It is the most common of the endocrine disorders and is characterized by chronic hyperglycemia due to relative or absolute lack of insulin secretion or insulin actions. According to the World Health Organization projections, the diabetes population is likely to increase to 300 million or more by the year 2025. Current synthetic agents and insulin used effectively for the treatment of diabetes are scarce especially in rural areas, expensive and have prominent adverse effects. Complementary and alternative approaches to diabetes management such as isolation of phytochemicals with anti-hyperglycemic activities from medicinal plants is therefore imperative. Saponins are phytochemical with structural diversity and biological activities. This paper reviews saponins and various plants from which they were isolated as well as properties that make them ideal for antidiabetic remedy.

Moringa oleifera leaf extract ameliorates alloxan-induced diabetes in rats by regeneration of β cells and reduction of pyruvate carboxylase expression

Moringa oleifera Lam. contains many active ingredients with nutritional and medicinal values. It is commonly used in folk medicine as an antidiabetic agent. The present study was designed to investigate how an aqueous extract from the leaves of M. oleifera reveals hypoglycemia in diabetic rats. M. oleifera leaf extract counteracted the alloxan-induced diabetic effects in rats as it normalized the elevated serum levels of glucose, triglycerides, cholesterol, and malondialdehyde, and normalized mRNA expression of the gluconeogenic enzyme pyruvate carboxylase in hepatic tissues. It also increased live body weight gain and normalized the reduced mRNA expression of fatty acid synthase in the liver of diabetic rats. Moreover, it restored the normal histological structure of the liver and pancreas damaged by alloxan in diabetic rats. This study revealed that the aqueous extract of M. oleifera leaves possesses potent hypoglycemic effects through the normalization of elevated hepatic pyruvate carboxylase enzyme and regeneration of damaged hepatocytes and pancreatic β cells via its antioxidant properties.

Effect of livingstonepotato (Plectranthus esculenthus N.E.Br) on hyperglycemia, antioxidant activity and lipid metabolism of streptozotocin induced diabetic rats

The effect of livingstone potato (Plectranthus esculenthus N.E.Br) on serum glucose, glycated hemoglobin (HbA1C), serum triglyceride, total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), hepatic malic enzyme (ME), isocitrate dehydrogenase (IDH) and catalase activities of Streptozotocin induced diabetic rats were investigated using standard techniques. The atherogenic index (AI) and coronary risk index (CRI) of the rats were calculated as the ratios of LDL to HDL and total cholesterol to HDL, respectively. The serum glucose of the non-diabetic, diabetic control and diabetic rats given livingstone potato incorporated feeds (test feed) were 92.58 ± 3.97, 352.30 ± 4.88 and 165.50 ± 7.88 mg/dl, respectively. Intake of the test feed by the diabetic rats of group 3, resulted in significant (P < 0.05) decrease of their serum glucose, HbA1c, triglyceride, cholesterol, LDL, VLDL, AI and CRI but significant increase (P < 0.05) of hepatic levels of ME, IDH, catalase and serum HDL compared with the diabetic control rats that had significant alteration of these parameters (P < 0.05) compared with the non-diabetic rats. The feed intakes of the non-diabetic, diabetic control and diabetic rats given the test feed were 133.34 ± 1.32, 137.84 ± 5.77 and 146.38 ± 4.33 g/rat/week by the last week of experimentation. The diabetic control rats recorded significant loss of weight (P < 0.05) compared with the non diabetic rats despite increased feed intake. Chemical analysis of the standard and test feeds showed that the standard rat feed contained 15.00 ± 0.78% protein, 7.24 ± 1.20% fat, 31.55 ± 2.62% carbohydrates, energy value of 290.65 ± 4.77 kcal/100 g, 10% crude fiber and 0.12 ± 0.04 mg Gallic Acid Equivalent while the test feed contained 40.10 ± 0.16% carbohydrates, 17.22 ± 0.40% protein, 22.16 ± 0.34% fat, energy value of 428.70 ± 2.12 kcal/100 g, 8.51 ± 0.16% crude fiber, 1.3 ± 0.2 mg Gallic Acid Equivalent/g of sample and strong antioxidant activity comparable to standard quercetin. The study shows the potentials of livingstone potato in the management of diabetes and hyperlipidemia.

Saponin as regulator of biofuel: implication for ethnobotanical management of diabetes

There has been a sharp rise in the global prevalence of diabetes, obesity, and their comorbid conditions within the last decade prompting significant research into possible causes and cure via therapeutic intervention and lifestyle adjustments. Here, the molecular bases of antidiabetic plants used in the prehistorical treatment of diabetes and obesity are reviewed with particular focus on saponin as the phytotherapeutic principle. Until recently, the phytotherapeutic potentials of saponins have been masked in the heterogeneity of phytochemicals co-extractable during traditional preparations. With improved technique of purification and cutting edge biological assay methods, saponins have emerged as a regulator of primary biofuel availability through direct interaction with energy metabolism, cell signaling, and gene expression. Specific cases of lipoprotein lipase/peroxisome proliferator-activated receptor (PPAR)-gamma/phosphatidylinositide 3-kinase (PI-3-K)/protein kinase B (Akt) activation, adiponectin gene upregulation, fatty acid binding protein 4 repression (FABP4), and glucose transporter type 4 (Glut4) membrane exocytosis have been documented which provide molecular basis for hypocholesterolemic, hypoglycemic, and anti-obesity manifestations observed in experimental animals following saponin treatment. Although intensified research is required to characterize the pharmacophoric features in saponins exhibiting these interactions, however, this preliminary lead is valuable if the world will be free of diabetes, obesity, hypertension, hyperlipidemia, and atherosclerosis in no distant future.

Pharmacological effects of Trigonella foenum-graecum L. in health and disease

CONTEXT

The health benefits and medicinal properties of herbal food products are known since antiquity. Fenugreek [Trigonella foenum-graecum Linn. (Fabaceae)], a seed spice used to enhance flavor, color and texture of food, is employed for medicinal purposes in many traditional systems. A number of epidemiological studies and laboratory research have unraveled the biological actions of fenugreek.

OBJECTIVE

Research on fenugreek in recent years has identified a number of health benefits and physiological attributes in both experimental animals as well as clinical trials in humans. In this study we have reviewed the available scientific literature on fenugreek.

METHODS

This review article summarizes and reviews published experimental studies and scientific literature from the databases including PubMed, Google and local library searches.

RESULTS

The information available in the literature on the health benefits and pharmaceutical effects of Trigonella accounts for its known medicinal properties and adds new therapeutic effects in newer indications. Besides its known medicinal properties such as carminative, gastric stimulant, antidiabetic and galactogogue (lactation-inducer) effects, newer research has identified hypocholesterolemic, antilipidemia, antioxidant, hepatoprotective, anti-inflammatory, antibacterial, antifungal, antiulcer, antilithigenic, anticarcinogenic and other miscellaneous medicinal effects of fenugreek. Although most of these studies have used whole seed powder or different forms of extracts, some have identified active constituents from seeds and attributed them medicinal values for different indications.

CONCLUSION

The resarch on Trigonella exhibits its health benefits and potential medicinal properties in various indications and has little or no side effects, suggesting its pharmaceutical, therapeutic and nutritional potential.

In vitro effects of cinnamic acid derivatives on protein tyrosine phosphatase 1B

Protein Tyrosine Phosphatase 1B (PTP1B) is a major negative regulator of insulin signaling pathways. Finding selective PTP1B inhibitors from natural sources has been widely recognized as a potential drug target for the treatment of diabetes mellitus and obesity. In the present study, we evaluated the inhibitory activity of cinnamic acid derivatives against PTP1B in vitro. Among 14 cinnamic acid derivatives and related compounds, the most potent inhibitor PTP1Bs were o-hydroxycinnamic acid and p-hydroxycinnamic acid, which had IC50 values of 137.67 ± 13.37 and 181.60 ± 9.34 µM, respectively. The kinetics analysis revealed that PTP1B was inhibited by o-hydroxycinnamic acid and p-hydroxycinnamic acid in a non-competitive manner. o-Hydroxycinnamic acid (25 μM) and p-hydroxycinnamic acid (25 μM), in combination with sodium orthovanadate (0.0125 μM), demonstrated a synergistic effect to inhibit PTP1B activity. In conclusion, the findings provide a new insight into naturally occurring PTP1B inhibitors that could be useful for treatment of diabetes and obesity.

Beneficial effects of Trigonella foenum graecum and sodium orthovanadate on metabolic parameters in experimental diabetes

Oxidative stress in diabetic tissues is accompanied by high-level of free radicals with simultaneously declined antioxidant enzymes status leading to cell membrane damage. The present study was carried out to observe the effect of sodium orthovanadate (SOV) and Trigonella foenum graecum seed powder (TSP) administration on blood glucose and insulin levels, antioxidant enzymes, lipid peroxidation, pyruvate kinase, lactate dehydrogenase and protein kinase C in heart, muscle and brain of the alloxan-induced diabetic rats to see whether the treatment with SOV and TSP was capable of reversing the diabetic effects. Diabetes was induced by administration of alloxan monohydrate (15 mg/100 g body weight), and rats were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP in the diet and a combination of 0.2 mg/ml SOV and 5% TSP separately for 21 days. Blood glucose levels increased markedly in diabetic rats, animals treated with a combined dose of SOV and TSP had glucose levels almost comparable with controls, similar results were obtained in the activities of pyruvate kinase, lactate dehydrogenase, antioxidant enzymes and protein kinase C in diabetic animals. Our results showed that lower doses of SOV (0.2 mg/ml) could be used in combination with TSP to effectively reverse diabetic alterations in experimental diabetes.

Metabolic and molecular action of Trigonella foenum-graecum (fenugreek) and trace metals in experimental diabetic tissues

Diabetes mellitus is a heterogeneous metabolic disorder characterized by hyperglycaemia resulting in defective insulin secretion, resistance to insulin action or both. The use of biguanides, sulphonylurea and other drugs are valuable in the treatment of diabetes mellitus; their use, however, is restricted by their limited action, pharmacokinetic properties, secondary failure rates and side effects. Trigonella foenum-graecum, commonly known as fenugreek, is a plant that has been extensively used as a source of antidiabetic compounds from its seeds and leaf extracts. Preliminary human trials and animal experiments suggest possible hypoglycaemic and antihyperlipedemic properties of fenugreek seed powder taken orally. Our results show that the action of fenugreek in lowering blood glucose levels is almost comparable to the effect of insulin. Combination with trace metal showed that vanadium had additive effects and manganese had additive effects with insulin on in vitro system in control and diabetic animals of young and old ages using adipose tissue. The Trigonella and vanadium effects were studied in a number of tissues including liver, kidney, brain peripheral nerve, heart, red blood cells and skeletal muscle. Addition of Trigonella to vanadium significantly removed the toxicity of vanadium when used to reduce blood glucose levels. Administration of the various combinations of the antidiabetic compounds to diabetic animals was found to reverse most of the diabetic effects studied at physiological, biochemical, histochemical and molecular levels. Results of the key enzymes of metabolic pathways have been summarized together with glucose transporter, Glut-4 and insulin levels. Our findings illustrate and elucidate the antidiabetic/insulin mimetic effects of Trigonella, manganese and vanadium.

Streptozotocin-induced diabetes affects in rat liver citrate carrier gene expression by transcriptional and posttranscriptional mechanisms

Citrate carrier (CiC), also known as tricarboxylate carrier, is an integral protein of the mitochondrial inner membrane. It is an essential component of the shuttle system by which mitochondrial acetyl-CoA, primer for both fatty acid and cholesterol synthesis, is transported into the cytosol, where lipogenesis occurs. Here, we report the effect of streptozotocin-induced diabetes on the activity and expression of CiC in rat liver mitochondria. A significant reduction of CiC activity and a parallel decline in the abundance of CiC mRNA were found in liver from diabetic rats. Diabetes did not influence CiC mRNA stability, whereas nuclear run-on assay revealed that the transcriptional rate of CiC mRNA decreased, when compared to control, in the nuclei from diabetic rats. The ratio of mature to precursor CiC RNA decreased in diabetic animals, indicating that the splicing of CiC RNA was also affected. The 3'-end processing rate of CiC mRNA was not altered in diabetes. These results suggest that diabetes affects CiC expression at both transcriptional and posttranscriptional levels. In addition, by in vitro transfection experiments in rat hepatocytes cultured in the absence of insulin, a reduction of CiC promoter activity was observed, and this was ascribed to a decreased expression of sterol regulatory element-binding protein-1 transcriptional factor. Furthermore, the binding of sterol regulatory element-binding protein-1 to the CiC promoter was reduced in STZ-diabetic rats with respect to control ones, and it was restored to the control values after insulin treatment.

Teucrium polium complex with molybdate enhance cultured islets secretory function

Islet transplantation has become a promising treatment in the therapy of type 1 diabetes. Its function improvement, after isolation and before transplantation, is crucial because of their loss both in number and function of islets after isolation procedures. Trace elements sodium orthovanadate (SOV) and sodium molybdate (SM), as well as medicinal plant Teucrium polium L. (TP), showed and possessed high beneficial antioxidative potential and even hypoglycemic properties via their effect on islets. We evaluated the effect of these components in combination on cultured islet function in order to improve pancreatic islet transplantation. Rat pancreatic islets were cultured for 24 h then incubated with different concentrations of TP (0.01 and 0.1 mg/mL) alone and in combination with SOV (1 mM) or SM (1 mM). Insulin concentration in buffer media was measured as islet secretory function. Administration of TP (0.01 mg/mL), SM, and SOV alone or in combination with each other significantly increased insulin secretion at high glucose concentration (16.7 mM); insulin secretion was significantly greater in the group containing both TP and SM than other treated groups (p < 0.05). The combination of the mentioned trace elements especially molybdate with TP could improve islet cells function before transplantation.

Circadian Variations in the Activities of 6‐Phosphogluconate Dehydrogenase and Glucose‐6‐Phosphate Dehydrogenase in the Liver of Conrol and Streptozotocin‐Induced Diabetic Rats

The aim of this study was to examine: the 24 h variation of 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase activities, key enzymes for the maintenance of intracellular NADPH concentration, in rat liver in control and streptozotocin-induced diabetic animals. Adult male rats were fed ad libitum and synchronized on a 12:12 h light-dark cycle (lights on 08:00 h). One group of animals was treated with streptozotocin (STZ, 55 mg/kg, intraperitoneal) to induce experimental diabetes. Eight weeks after STZ injection, the animals were sacrificed at six different times of day--1, 5, 9, 13, 17 and 21 Hours After Lights On (HALO)--and livers were obtained. Enzyme activities were determined spectrophotometrically in triplicate in liver homogenates and expressed as units per mg protein. 6-phosphogluconate dehydrogenase activity was measured by substituting 6-phosphogluconate as substrate. Glucose-6-phosphate dehydrogenase activity was determined by monitoring NADPH production. Treatment, circadian time, and interaction between treatment and circadian time factors were tested by either one or two way analysis of variance (ANOVA). Two-way ANOVA revealed that 6-phosphogluconate dehydrogenase activity significantly depended on both the treatment and time of sacrifice. 6-phosphogluconate dehydrogenase activity was higher in control than diabetic animals; whereas, glucose-6-phosphate dehydrogenase activity did not vary over the 24 h in animals made diabetic by STZ treatment. Circadian variation in the activity of 6-phosphogluconate dehydrogenase was also detected in both the control and STZ treatment groups (one-way ANOVA). Time-dependent variation in glucose-6-phosphate dehydrogenase activity during the 24 h was detected in control but not in diabetic rats. No significant interaction was detected between STZ-treatment and time of sacrifice for both hepatic enzyme activities. These results suggest that the activities of NADPH-generating enzymes exhibit 24 h variation, which is not influenced by diabetes.

Biochemical study of the anti-diabetic action of the Egyptian plants fenugreek and balanites

Fenugreek and Balanites are two plants commonly used in Egyptian folk medicine as hypoglycemic agents. In the present study, the effects of 21 days oral administration of Fenugreek seed and Balanites fruit extracts (1.5 g/kg bw) on the liver and kidney glycogen content and on some key liver enzymes of carbohydrate metabolism in STZ-diabetic rats were studied. In addition, the effects of these two plant extracts on the intestinal alpha-amylase activity in vitro and starch digestion and absorption in vivo were also examined. Results indicated that single injection of STZ (50 mg/kg bw) caused 5-folds increase in the blood glucose level, 80% reduction in serum insulin level, 58% decrease in liver glycogen and 7-folds increase in kidney glycogen content as compared to the normal levels. The activity of glucose-6-phosphatase was markedly increased, whereas, the activities of both glucose-6-phosphate dehydrogenase and phospho-fructokinase were significantly decreased in the diabetic rat liver. Administration of Fenugreek extract to STZ-diabetic rats reduced blood glucose level by 58%, restored liver glycogen content and significantly decreased kidney glycogen as well as liver glucose-6-phosphatase activity. Meanwhile, Balanites extract reduced blood glucose level by 24% and significantly decreased liver glucose-6-phosphatase activity in diabetic rats. On the other hand, our results demonstrated that both the Fenugreek and Balanites extracts were able to in vitro inhibit alpha-amylase activity in dose-dependent manner. Fenugreek was more potent inhibitor than Balanites. This inhibition was reversed by increasing substrate concentration in a pattern which complies well with the effect of competitive inhibitors. Furthermore, this in vitro inhibition was confirmed by in vivo suppression of starch digestion and absorption induced by both plant extracts in normal rats. These findings suggest that the hypoglycemic effect of Fenugreek and Balanites is mediated through insulinomimetic effect as well as inhibition of intestinal alpha-amylase activity.

Alleviation of hepatic steatosis accompanied by modulation of plasma and liver TNF-α levels by Trigonella foenum graecum (fenugreek) seeds in Zucker obese (fa/fa) rats

OBJECTIVE

Oral supplements of fenugreek (Trigonella foenum graecum) seeds (Fen) have been shown to treat glucose and lipid homeostasis in several metabolic disorders; however, its ability to alleviate obesity-associated pathologies is not known. The main objective of this study was to evaluate the effect of Fen in Zucker obese rats (Ob), an animal model of obesity and related disorders, such as dyslipidemia and hepatic steatosis.

METHODS

Female Zucker (6-week-old) Ob and lean (Ln) rats were randomly grouped (n = 8 rats/group) to receive either basal or 5% Fen-supplemented AIN-93G diets for 8 weeks, and then were euthanized. Histopathology and biochemical parameters in the liver together with plasma biochemistry were assessed.

RESULTS

Obese rats had significantly higher (P < 0.05) body and liver weight, as well as plasma insulin, lactate, cholesterol, triglyceride and tumor necrosis factor (TNF)-alpha compared to their Ln counterparts. Fen significantly reduced (P < 0.05) the liver-weight of Ob rats in comparison to Ob rats fed basal diet (Control), while no effect was observed in the Ln rats. Fen treatment resulted in a lower P-value (P < 0.05). In addition, Ob rats on Fen-supplemented diets had fasting plama cholesterol and TNF-alpha levels, and significantly higher (P < 0.05) triglycerides in comparison to the control rats. Hepatic triglyceride level was significantly lower (P < 0.05) in Ob rats fed Fen supplemented diets in comparison to control. The levels of bound and soluble liver TNF-alpha (26 and 17 kDa, respectively) and TNF receptor-II (TNFR-II, 75 kDa) proteins were significantly lower (P < 0.05) in Ob than in Ln rats. Fen significantly lowered (P < 0.05) both the soluble and bound forms of TNF-alpha protein while significantly elevating (P < 0.05) TNFR-II in the livers of Ob rats compared to Ob Controls.

CONCLUSION

These results demonstrate unequivocally that in a short-term preclinical evaluation, dietary Fen supplementation reduced the triglyceride accumulation in the liver, a hallmark feature of hepatic steatosis without affecting the plasma insulin or glucose levels in Zucker obese rats and suggest that TNF-alpha may play an important role in this process.

Combined treatment of sodium orthovanadate and Momordica charantia fruit extract prevents alterations in lipid profile and lipogenic enzymes in alloxan diabetic rats

Momordica charantia Linn., commonly called bitter gourd, is a medicinal plant used in the Ayurvedic system of medicine for treating various diseases including diabetes mellitus. Sodium orthovanadate (SOV) is also well-known insulin mimetic and an antidiabetic compound. Our laboratory has been using reduced doses of SOV along with administration of herbal extracts to alloxan diabetic rats and has established this combination as a good antihyperglycemic agent. The present study was undertaken to investigate the effects of treatment of Momordica fruit extract (MFE) and sodium orthovanadate, separately and in combination, on serum and tissue lipid profile and on the activities of lipogenic enzymes in alloxan induced diabetic rats. The results show that there was a significant (p < 0.01) increase in serum total lipids, triglycerides and total cholesterol levels after 21 days of alloxan diabetes. In the liver and kidney of diabetic rats the levels of total lipids and triglycerides also increased significantly (p < 0.01) while levels of total cholesterol decreased significantly (p < 0.01 and p < 0.05, respectively). The lipogenic enzymes showed decreased activity in the diabetic liver, while in kidney they showed an increased activity. When compared with the controls these changes were significant. The treatment of alloxan diabetic rats with MFE and SOV prevented these alterations and maintained all parameters near control values. Most effective prevention was however observed in a combined treatment of Momordica with a reduced dose of SOV (0.2%). The results suggest that Momordica fruit extract and SOV exhibit hypolipidemic as well as hypoglycemic effect in diabetic rats and their effect is pronounced when administered in combination.