Butanol fraction of Alstonia boonei De Wild. leaves ameliorate oxidative stress and modulate key hypoglycaemic processes in diabetic rats.

OBJECTIVE: The effect of Alstonia boonei fractions on glucose homeostasis was investigated via in vitro enzyme inhibition activity, ex vivo glucose uptake assay, and in vivo methods in diabetic rats. METHODOLOGY: A. boonei fractions were subjected to in vitro α-glucosidase inhibitory assay and then ex vivo glucose uptake activity. The butanol fraction of the leaves (ABBF) was picked for the in vivo assay since it showed more activity in the initial tests conducted. ABBF was administrated via oral dosing to six-weeks old fructose-fed STZ-induced type 2 diabetic rats over a 5-week experimental period. RESULTS: ABBF treatment at a low dose of 150 mg/kg bw, significantly (p < .05) reduced blood glucose level, enhanced oral glucose tolerance ability, restored insulin secretion and hepatic glycogen synthesis as well as promoted islet regeneration than the high dose (300 mg/kg bw). CONCLUSION: These results suggest that ABBF could be exploited as a therapeutic potential for treating T2D.

Metabolic Effects of Vitamin B1 Therapy under Overnutrition and Undernutrition Conditions in Sheep.

As a precursor for a universal metabolic coenzyme, vitamin B1, also known as thiamine, is a vital nutrient in all living organisms. We previously found that high-dose thiamine therapy prevents overnutrition-induced hepatic steatosis in sheep by enhancing oxidative catabolism. Based on this capacity, we hypothesized that thiamine might also reduce whole-body fat and weight. To test it, we investigated the effects of high-dose thiamine treatment in sheep under overnutrition and calorie-restricted undernutrition to respectively induce positive energy balance (PEB) and negative energy balance (NEB). Eighteen mature ewes were randomly assigned to three treatment groups (n = 6 each). The control group (CG) was administered daily with subcutaneous saline, whereas the T5 and T10 groups were administered daily with equivoque of saline containing 5 mg/kg and 10 mg/kg of thiamine, respectively. Bodyweight and blood biochemistry were measured twice a week for a period of 22 days under PEB and for a consecutive 30 days under NEB. Surprisingly, despite the strong effect of thiamine on liver fat, no effect on body weight or blood glucose was detectable. Thiamine did, however, increase plasma concentration of non-esterified fatty acids (NEFA) during NEB (575.5 ± 26.7, 657.6 ± 29.9 and 704.9 ± 26.1 µEqL-1 for CG, T5, and T10, respectively: p < 0.05), thereby favoring utilization of fatty acids versus carbohydrates as a source of energy. Thiamine increased serum creatinine concentrations (p < 0.05), which paralleled a trending increase in urea (p = 0.09). This may indicate an increase in muscle metabolism by thiamine. Reduction of fat content by thiamine appears more specific to the liver than to adipose tissue. Additional studies are needed to evaluate the potential implications of high-dose vitamin B1 therapy in muscle metabolism.

High-dose vitamin B1 therapy prevents the development of experimental fatty liver driven by overnutrition.

Fatty liver is an abnormal metabolic condition of excess intrahepatic fat. This condition, referred to as hepatic steatosis, is tightly associated with chronic liver disease and systemic metabolic morbidity. The most prevalent form in humans, i.e. non-alcoholic fatty liver, generally develops due to overnutrition and sedentary lifestyle, and has as yet no approved drug therapy. Previously, we have developed a relevant large-animal model in which overnourished sheep raised on a high-calorie carbohydrate-rich diet develop hyperglycemia, hyperinsulinemia, insulin resistance, and hepatic steatosis. Here, we tested the hypothesis that treatment with thiamine (vitamin B1) can counter the development of hepatic steatosis driven by overnutrition. Remarkably, the thiamine-treated animals presented with completely normal levels of intrahepatic fat, despite consuming the same amount of liver-fattening diet. Thiamine treatment also decreased hyperglycemia and increased the glycogen content of the liver, but it did not improve insulin sensitivity, suggesting that steatosis can be addressed independently of targeting insulin resistance. Thiamine increased the catalytic capacity for hepatic oxidation of carbohydrates and fatty acids. However, at gene-expression levels, more-pronounced effects were observed on lipid-droplet formation and lipidation of very-low-density lipoprotein, suggesting that thiamine affects lipid metabolism not only through its known classic coenzyme roles. This discovery of the potent anti-steatotic effect of thiamine may prove clinically useful in managing fatty liver-related disorders.This article has an associated First Person interview with the joint first authors of the paper.

Hyperglycemia-stimulating diet induces liver steatosis in sheep.

Hepatic steatosis is strongly associated with chronic liver disease and systemic metabolic disorder. Adipose lipolysis is a recognized principal source of intrahepatic fat in various metabolic disorders, including non-alcoholic fatty liver disease. We hypothesized that, in the premorbid state, hepatic de novo lipogenesis (DNL) driven by excess carbohydrates abundance might play a more significant role. We employed a novel nutritional model in sheep of two distinct carbohydrates abundances. During 4 months of the dietary treatment, lambs were monitored for metabolic and terminal liver parameters. Lambs grown on the high-calorie (HC) diet were consistently more hyperglycemic and hyperinsulinemic than lambs grown on the lower-calorie (LC) diet (P < 0.0001). As a result, the HC lambs developed systemic- (HOMA-IR of 7.3 vs. 3.1; P < 0.0001), and adipose- (ADIPO-IR of 342.7 vs. 74.4; P < 0.0001) insulin resistance, significant adiposity (P < 0.0001), and higher plasma triglycerides (P < 0.05). Circulating leukocytes in the HC lambs had higher mRNA expression levels of the proinflammatory markers CCL2 (P < 0.01) and TNF-alpha (P < 0.04), and IL1B trended higher (P < 0.1). Remarkably, lambs on the HC diet developed substantial liver steatosis (mean fat content of 8.1 vs. 5.3% in the LC group; P < 0.0001) with a higher histological steatosis score (2.1 vs. 0.4; P < 0.0002). Hepatic steatosis was most-strongly associated with blood glucose and insulin levels but negatively correlated with circulating fatty acids-indicating a more significant contribution from hepatic DNL than from adipose lipolysis. Sheep may prove an attractive large-animal model of fatty liver and metabolic comorbidities resulting from excess carbohydrate-based energy early in life.

Improved Folch Method for Liver-Fat Quantification.

Fatty liver represents a significant metabolic pathology of excess intrahepatic fat in domestic animals and humans. Quantification of hepatic-fat content is therefore essential for diagnosis and investigation of liver and metabolic disease. However, the reproducibility of hepatic steatosis analysis is often low due to subjective and technical factors. We hypothesized that improvement in tissue-lipids extraction efficiency would contribute to the accuracy and precision of liver-fat determination. To test it, we investigated the effect of standardized tissue sonication on liver-fat quantification by the Folch method in sheep. Liver samples from grownup lambs of lean (n = 16) and fatty (n = 15) livers, and from pregnant ewes (n = 6) who died from pregnancy toxemia (PT), were used for hepatic-fat content determination with or without tissue sonication. In the grown lambs, an average hepatic-fat content of 6.6% was determined in sonicated compared to 5.1% in non-sonicated specimens (P = 0.0002). Similarly, in ewes with PT, an average of 12.5% was determined with sonication compared to 10.8% without it (P = 0.0006), and the reproducibility was higher with sonication (CV of 3.1 vs. 6.1%, respectively). Thus, tissue sonication improved the efficiency of liver-lipids extraction and was significant to the accuracy and precision of hepatic-fat determination. Enzymatic quantification of triglycerides was moderately correlated with the results obtained gravimetrically (r = 0.632, P < 0.005). The reported data provide reliable reference values for pregnancy toxemic sheep. The significant improvement in liver-fat quantification observed with the reported revised protocol is likely applicable to most mammals and humans.

The effects of Ficus carica on the activity of enzymes related to metabolic syndrome.

The present study aimed to investigate the effects of the various parts of Ficus carica L. (figs) on antioxidant, antidiabetic, and antiobesogenic effects in vitro. Fruit, leaves, and stembark of the F. carica plant were sequentially extracted using organic and inorganic solvents and their total polyphenol and flavonoid contents were estimated. The effects of the extracts on antioxidative, antidiabetic (inhibition of α-amylase and α-glucosidase enzymes), and antiobesogenic (antilipase) activities were measured using several experimental models. The fruit ethanolic extract contained a high quantity of polyphenols and flavonoids (104.67±5.51 µg/mL and 81.67±4.00 µg/mL) compared with all other extracts. The activity of the ethanolic extract of F. carica fruit was significantly (p<0.05) higher than all other extracts and parts of the plant in terms of antioxidative, antidiabetic, and antiobesogenic effects. The IC50 values of the fruit ethanolic extract in terms of antioxidative (134.44±18.43 µg/mL), and inhibition of α-glucosidase (255.57±36.46 µg/mL), α-amylase (315.89±3.83 µg/mL), and pancreatic lipase (230.475±9.65 µg/mL) activity indicate that the activity of fruit ethanolic extract is better than all other extracts of the plant. The gas chromatography-mass spectroscopy analysis of the fruit ethanolic extract showed the presence of a number of bioactive compounds such as butyl butyrate, 5-hydroxymethyl furfural, 1-butoxy-1-isobutoxy butane, malic acid, tetradecanoic acid, phytol acetate, trans phytol, n-hexadecanoic acid, 9Z,12Z-octadecadienoic acid, stearic acid, sitosterol, 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one, and 2,4,5-trimethyl-2,4-dihydro-3H-pyrazol-3-one. The results of this study suggest that the ethanolic extract of the fruit of F. carica may have potential antidiabetic and antiobesogenic agents.

Erythritol reduces small intestinal glucose absorption, increases muscle glucose uptake, improves glucose metabolic enzymes activities and increases expression of Glut-4 and IRS-1 in type 2 diabetic rats.

PURPOSE: Studies have reported that erythritol, a low or non-glycemic sugar alcohol possesses anti-hyperglycemic and anti-diabetic potentials but the underlying mode of actions is not clear. This study investigated the underlying mode of actions behind the anti-hyperglycemic and anti-diabetic potentials of erythritol using different experimental models (experiment 1, 2 and 3). METHODS: Experiment 1 examined the effects of increasing concentrations (2.5-20%) of erythritol on glucose absorption and uptake in isolated rat jejunum and psoas muscle, respectively. Experiments 2 and 3 examined the effects of a single oral dose of erythritol (1 g/kg bw) on intestinal glucose absorption, gastric emptying and postprandial blood glucose increase, glucose tolerance, serum insulin level, muscle/liver hexokinase and liver glucose-6 phosphatase activities, liver and muscle glycogen contents and mRNA and protein expression of muscle Glut-4 and IRS-1 in normal and type 2 diabetic animals. RESULTS: Experiment 1 revealed that erythritol dose dependently enhanced muscle glucose ex vivo. Experiment 2 demonstrated that erythritol feeding delayed gastric emptying and reduced small intestinal glucose absorption as well as postprandial blood glucose rise, especially in diabetic animals. Experiment 3 showed that erythritol feeding improved glucose tolerance, muscle/liver hexokinase and liver glucose-6 phosphatase activities, glycogen storage and also modulated expression of muscle Glut-4 and IRS-1 in diabetic animals. CONCLUSION: Data suggest that erythritol may exert anti-hyperglycemic effects not only via reducing small intestinal glucose absorption, but also by increasing muscle glucose uptake, improving glucose metabolic enzymes activity and modulating muscle Glut-4 and IRS-1 mRNA and protein expression. Hence, erythritol may be a useful dietary supplement for managing hyperglycemia, particularly for T2D.

Dacryodes edulis enhances antioxidant activities, suppresses DNA fragmentation in oxidative pancreatic and hepatic injuries; and inhibits carbohydrate digestive enzymes linked to type 2 diabetes.

The leaves of Dacryodes edulis were investigated for their anti-oxidative and anti-diabetic potentials in vitro. Extracts from sequential extraction with solvents of increasing polarity (n-hexane, ethyl acetate, ethanol and aqueous) of the leaves were subjected to in vitro antioxidant assays using the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging and Ferric reducing antioxidant power (FRAP) protocols respectively. Their inhibitory effects were investigated on α-glucosidase, pancreatic lipases, pancreatic ATPase and glucose-6-phospatase activities. Their antioxidant and anti-apoptotic effects on Fe2+ - induced oxidative injuries in pancreatic and hepatic tissues were also investigated ex vivo. The ethanol extract was subjected to Gas chromatography mass spectroscopy (GC-MS) and Fourier transform infrared (FTIR) spectroscopic analysis to identify its bioactive chemical constituents. The extracts showed potent free radical scavenging activity and significantly (p<0.05) inhibited all studied enzymes, with the ethanol extract showing greater activities. Superoxide Dismutase (SOD) and Catalase (CAT) activities were significantly (p<0.05) increased in both pancreatic and hepatic tissues with concomitant elevation of reduced glutathione (GSH) levels as well as reduced levels of malondialdehyde (MDA). The extracts significantly inhibited DNA fragmentation. These activities were dose - dependent. Amongst compounds identified, only Kaur-15-ene, Urs-12-ene-3-ol acetate and 2,3,23-trihydroxyolean-12-en-28-oic acid methyl ester showed strong binding affinities when docked with α-glucosidase (PDB ID:3TON). These results indicate the anti-oxidative, anti-diabetic and anti-obesogenic potentials of D. edulis leaves, which gives credence to its antidiabetic folkloric claims.

Molecular assessment of protective effect of Vitex negundo in ISO induced myocardial infarction in rats.

Myocardial infarction (MI) is the one of the major causes of death worldwide, however the molecular mechanisms hidden under this disease conditions remain unknown. This demands serious attention to unravel the molecular mechanisms to identify the therapeutic strategies either to prevent or to control MI. Ayurveda is becoming one of the best alternatives for the modern medicines. On the other hand, Vitex negundo is one of the medicinally important plants used for various diseases and to date, its cardioprotective role is not fully elucidated. In the present study, we made an attempt to understand the cardiac signaling cascade of Akt1 and NF-κB in isoproterenol (ISO)-induced MI, and targeting these signaling molecules by using V. negundo leaf ethanolic extract (VNE). Our findings demonstrate that VNE significantly protects the ISO-induced MI by regulating NF-κB and Akt1experssion in rats.

Medicinal plants and phytochemicals with anti-obesogenic potentials: A review.

Human mortality has been significantly increased in last few decades due to the increased prevalence of obesity and associated chronic disorders such as type 2 diabetes, non-alcoholic fatty liver disease, coronary heart disease and atherosclerosis. Apart from genetic and medicine or drug related side effects, nearly 90-95% people became obese due to the imbalanced calorie intake and lack of nutritional knowledge. The anti-obesogenic drugs, Orlistat and Sibutramine, which have been duly approved by Food and Drug Administration (FDA), USA, work very well on diet-induced obesity however they are not getting popular to the people with overweight/obesity due to the higher cost and severe side effects. In contrast, plant based drugs have been considered as a better alternative due to their lower cost and negligible side effects. A number of medicinal plants and their bioactive constituents have received attention from scientists not only for their anti-obesity activity in vitro and in vivo but also in clinical trials. However, there is no systematic review of data available in the scientific domain in order to guide researchers to conduct further in depth research. In our present review, we differentiated the anti-obesogenic effects of various medicinal plant extracts, fractions and their bioactive compounds at in vitro, in vivo and clinical conditions. During our review, we could also identify the most effective plants with strong anti-obesogenic effects at in vitro or in vivo studies with lack of clinical trials when no one tried to isolate pure bioactive compounds from these plants. Hence, scientific community, government agencies/pharmaceutical industries should work together not only to isolate pure bioactive compounds but also to conduct clinical trials including toxicity to develop better alternative anti-obesity drugs.

Cardioprotective effect of Vitex negundo on isoproterenol-induced myocardial necrosis in wistar rats: A dual approach study.

Cardiovascular diseases (CVDs) are becoming the major cause of deaths worldwide, and their treatment demands novel therapeutic strategies. In this connection, we have identified p21 activated kinase 1 (PAK1) as a novel therapeutic target for the treatment of myocardial infarction (MI), where its expression is decreased when MI is induced with isoproterenol (ISO), which was brought back normal with pretreatment of Vitex negundo leaf ethanolic extract (VNE). These results were also supported by histopathological studies, cardiac markers, antioxidants, and inflammatory cytokines (NF-κB and IL-1ß). Further studies with GC-MS analysis of VNE and in silico experiments confirmed 5,7-dihydroxy-6,4',-dimethoxy flavonone and 3',5-dihydroxy-6,7,4',-trimethoxyflavone are responsible for either maintaining or inducing the expression of PAK1 to protect from MI. Our findings for the first time revealed the use of phytoconstituents in the treatment of MI.

A review on possible therapeutic targets to contain obesity: The role of phytochemicals.

The prevalence and severity of obesity has increased markedly in recent decades making it a global public health concern. Since obesity is a potential risk factor in the development of hypertension, type-2 diabetes, cardiovascular diseases, infertility, etc., it is no more viewed as a cosmetic issue. Currently, only a few FDA-approved anti-obesity drugs like Orlistat, Lorcaserin and Phentermine-topiramate are available in the market, but they have considerable side effects. On the other hand, bariatric surgery as an alternative is associated with high risk and expensive. In view of these there is a growing trend towards natural product-based drug intervention as one of the crucial strategies for management of obesity and related ailments. In Asian traditional medicine and Ayurvedic literature a good number of plant species have been used and quoted for possible lipid-lowering and anti-obesity effects; however, many of them have not been evaluated rigorously for a definite recommendation and also lack adequate scientific validation. This review explores and updates on various plant species, their used parts, bioactive components and focuses multiple targets/pathways to contain obesity which may pave the way to develop novel and effective drugs. We also summarised different drugs in use to treat obesity and their current status. Nature is future promise of our wellbeing.

Evaluation of anti-obesity activities of ethanolic extract of Terminalia paniculata bark on high fat diet-induced obese rats.

BACKGROUND: The prevalence and severity of obesity and associated co-morbidities are rapidly increasing across the world. Natural products-based drug intervention has been proposed as one of the crucial strategies for management of obesity ailments. This study was designed to investigate the anti-obesity activities of ethanolic extract of Terminalia paniculata bark (TPEE) on high fat diet-induced obese rats. METHODS: LC-MS/MS analysis was done for ethanolic extract of T. paniculata bark. Male Sprague-Dawley (SD) rats were randomly divided into six groups of six each, normal diet fed (NC), high fat diet-fed (HFD), HFD+ orlistat (standard drug control) administered, and remaining three groups were fed with HFD + TPEE in different doses (100,150 and 200 mg/kg b. wt). For induction of obesity rats were initially fed with HFD for 9 weeks, then, (TPEE) was supplemented along with HFD for 42 days. Changes in body weight, body composition, blood glucose, insulin, tissue and serum lipid profiles, atherogenic index, liver markers, and expression of adipogenesis-related genes such as leptin, adiponectin, FAS, PPARgamma, AMPK-1alpha and SREBP-1c, were studied in experimental rats. Also, histopathological examination of adipose tissue was carried out. RESULTS: Supplementation of TPEE reduced significantly (P < 0.05) body weight, total fat, fat percentage, atherogenic index, blood glucose, insulin, lipid profiles and liver markers in HFD-fed groups, in a dose-dependent manner. The expression of adipogenesis-related genes such as Leptin, FAS, PPARgamma, and SREBP-1c were down regulated while Adiponectin and AMPK-1alpha were up regulated in TPEE + HFD-fed rats. Furthermore, histopathological examination of adipose tissue revealed the alleviating effect of TPEE which is evident by reduced size of adipocytes. CONCLUSIONS: Together, the biochemical, histological and molecular studies unambiguously demonstrate the potential anti adipogenic and anti obesity activities of TPEE promoting it as a formidable candidate to develop anti obesity drug.

In vitro anti oxidant activity and acute oral toxicity of Terminalia paniculata bark ethanolic extract on Sprague Dawley rats.

OBJECTIVE: To ensure the safety and evaluate the anti oxidant activity of Terminalia paniculata (T. paniculata) ethanolic extract in Sprague Dawley rats. METHODS: The solvent extracts (hexane, ethyl acetate and ethanol) of T. paniculata were subjected to phytochemical analysis and their DPPH radical scavenging activity was assayed. The oral acute toxicity was evaluated using ethanolic extract of T. paniculata. RESULTS: Ethyl acetate and ethanolic extracts showed more phytochemicals, whereas highest DPPH scavenging activity was found in ethanolic extract. In an acute toxicity study, T. paniculata ethanolic extract was orally administered (1 000 mg/kg body weight) to rats and observed for 72 h for any toxic symptoms and the dose was continued up to 14 d. On the 15th day rats were sacrificed and blood samples were collected from control and test animals and analyzed for some biochemical parameters. We did not observe any behavioral changes in test groups in comparison with their controls. Also, there were no significant alterations in biochemical, hematological (hemoglobin content and blood cells count) and liver function parameters such as serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase, alkaline phosphatase, total proteins, albumin and bilirubin levels between T. paniculata ethanolic extract treated and normal control groups. CONCLUSIONS: Together our results demonstrated that T. paniculata ethanolic possessed potent antioxidant activity and it was safer and non toxic to rats even at higher doses and therefore could be well considered for further investigation for its medicinal and therapeutic efficacy.

Insecticidal, antimicrobial and antioxidant activities of bulb extracts of Allium sativum.

OBJECTIVE: To evaluate the insecticidal, antimicrobial and antioxidant activities of bulb extracts of Allium sativum (A. sativum). METHODS: Dried bulbs of A. sativum were extracted with different solvents and evaluated for insecticidal, antimicrobial and antioxidant activities. METHODS: Aqueous and methanol extracts showed highest insecticidal activity (mortality rate of 81% and 64% respectively) against the larvae of Spodoptera litura (S. litura) at a concentration of 1 000 ppm. With regard to antimicrobial activity, aqueous extract exhibited antibacterial activity against gram positive (Bacillus subtilis, Staphylococcus aureu,) and gram negative (Escherichia coli and Klebsiella pneumonia) strains and antifungal activity against Candida albicans. While methanol extract showed antimicrobial activity against all the tested micro organisms except two (Staphylococcus aureus and Candida albicans), the extracts of hexane, chloroform and ethyl acetate did not show any anti microbial activity. Minimum inhibitory concentration of aqueous and methanol extracts against tested bacterial and fungal strains was 100-150 µg/mL. Antioxidant activity of the bulb extracts was evaluated in terms of inhibition of free radicals by 2, 2'-diphenly-1-picrylhydrazyl. Aqueous and methanol extracts exhibited strong antioxidant activity (80%-90% of the standard). CONCLUSIONS: Antioxidant and antimicrobial activity of A. sativum against the tested organisms therefore, provides scientific basis for its utilization in traditional and folk medicine. Also, our results demonstrated the insecticidal efficacy of A. sativum against S. litura, a polyphagous insect.