Salacia reticulata and its polyphenolic constituents with lipase inhibitory and lipolytic activities have mild antiobesity effects in rats

The colloid and interface strategies to inhibit lipid digestion for designing low-calorie food

Although fat is one of the indispensable components of food flavor, excessive fat consumption could cause obesity, metabolism syndromes and an imbalance in the intestinal flora. In the pursuit of a healthy diet, designing fat reducing foods by inhibiting lipid digestion and calorie intake is a promising strategy. Altering the gastric emptying rates of lipids as well as acting on the lipase by suppressing the enzymatic activity or limiting lipase diffusion via interfacial modulation can effectively decrease lipolysis rates. In this review, we provide a comprehensive overview of colloid-based strategies that can be employed to retard lipid hydrolysis, including pancreatic lipase inhibitors, emulsion-based interfacial modulation and fat substitutes. Plants-/microorganisms-derived lipase inhibitors bind to catalytic active sites and change the enzymatic conformation to inhibit lipase activity. Introducing oil-in-water Pickering emulsions into the food can effectively delay lipolysis via steric hindrance of interfacial particulates. Regulating stability and physical states of emulsions can also affect the rate of hydrolysis by altering the active hydrolysis surface. 3D network structure assembled by fat substitutes with high viscosity can not only slow down the peristole and obstruct the diffusion of lipase to the oil droplets but also impede the transportation of lipolysis products to epithelial cells for adsorption. Their applications in low-calorie bakery, dairy and meat products were also discussed, emphasizing fat intake reduction, structure and flavor retention and potential health benefits. However, further application of these strategies in large-scale food production still requires more optimization on cost and lipid reducing effects. This review provides a comprehensive review on colloidal approaches, design, principles and applications of fat reducing strategies to meet the growing demand for healthier diet and offer practical insights for the low-calorie food industry.

The Effect of Salacia Reticulata Extract Biscuits on Blood Sugar Control of Type 2 Diabetes Mellitus Patients: A Two-Period, Two-Sequence, Crossover, Randomized, Triple-Blind, Placebo-Controlled, Clinical Trial

Background Traditional physicians in Sri Lanka and India use extracts from the plant Salacia reticulata,or Kothala Himbutu (KH) to treat diabetes. The effect of a KH biscuit, taken as a snack, on glycemic control was investigated in patients with type 2 diabetes. Methodology This triple-blind, randomized, placebo-controlled, two-period, two-sequence, crossover study was conducted in the Internal Medical Clinic, Teaching Hospital Anuradhapura. A research assistant opened computer-generated random numbers enclosed in a sealed envelope and performed treatment allocation. The group outcome was masked from the researchers, patients, and analysts. Both the placebo and the KH biscuit were identical. The primary outcome measure was HbA1c. Intention to treat analyses was used. Glycemic stability was assured in the run-in period, and patients with severe renal, liver, or heart disease were excluded. If patients needed insulin, they were withdrawn from the trial. Results From January 2014 to May 2016, 230 patients were screened, and 136 were randomized. Of them, 62 were allocated, 58 completed the placebo biscuit, 71 were allocated, and 69 completed the KH biscuit. After the washout period and crossover, 57 completed the KH and 65 completed the placebo biscuit. The baseline mean HbA1c level was 8.45% (68.9 mmol/mol) and 8.65% (71.0 mmol/mol) for the placebo-KH biscuit and KH-placebo biscuit groups. At the end of the trial, the HbA1c levels in the placebo-KH biscuit group and the KH-placebo biscuit group were 8.23% (66.4 mmol/mol) and 8.53% (69.3 mmol/mol), respectively. The unadjusted mean HbA1c reduced from the baseline with 0.10% (95% CI = -0.12, 0.32) after the placebo biscuit and 0.35% (95% CI = 0.10, 0.60) after the KH biscuit. After the placebo and KH biscuits, the HbA1c values were 8.46% (95% CI = 8.19, 8.73) (69 mmol/mol with 95% CI = 66, 72) and 8.19% (95% CI = 7.90, 8.48) (66 mmol/mol with 95% CI = 63, 69), respectively. The paired sample t-test shows that the reduction was not significant for placebo biscuits (p = 0.324), while it is significant for KH biscuits (p = 0.003). Analysis with multiple imputations confirmed a significant difference between the placebo and KH biscuit in reducing the HbA1c level. Conclusions KH biscuit taken as a snack reduces HbA1c by 0.25% compared to placebo without serious renal or liver adverse effects. The biscuit can be safely recommended as a snack to patients with type 2 diabetes.

Methodologies for Assessing Pancreatic Lipase Catalytic Activity: A Review

Obesity is a disease of epidemic proportions with a concerning increasing trend. Regarded as one of the main sources of energy, lipids can also represent a big part of an unnecessary intake of calories and be, therefore, directly related to the problem of obesity. Pancreatic lipase is an enzyme that is essential in the absorption and digestion of dietary fats and has been explored as an alternative for the reduction of fat absorption and consequent weigh loss.Literature describes a great variability of methodologies and experimental conditions used in research to evaluate the in vitro inhibitory activity of compounds against pancreatic lipase. However, in an attempt to choose the best approach, it is necessary to know all the reaction conditions and understand how these can affect the enzymatic assay.The objective of this review is to understand and summarize the methodologies and respective experimental conditions that are mainly used to evaluate pancreatic lipase catalytic activity.156 studies were included in this work and a detailed description of the most commonly used UV/Vis spectrophotometric and fluorimetric instrumental techniques are presented, including a discussion regarding the differences found in the parameters used in both techniques, namely enzyme, substrate, buffer solutions, kinetics conditions, temperature and pH.This works shows that both UV/Vis spectrophotometry and fluorimetry are useful instrumental techniques for the evaluation of pancreatic lipase catalytic activity, presenting several advantages and limitations, which make the choice of parameters and experimental conditions a crucial decision to obtain the most reliable results.

Amelioration of hyperglycemia and hyperlipidemia in a high-fat diet-fed mice by supplementation of a developed optimized polyherbal formulation

This study evaluated in vivo anti-diabetic and anti-obesity activity of a polyherbal formulation's methanolic extract containing an optimized ratio of edible seeds (Salvia hispanica, Chenopodium quinoa, Nelumbo nucifera). Diet-induced obese mice model (C57BL/6) was developed by feeding the mice a high-fat diet for 10 weeks resulting in hyperglycemia and obesity. Different doses (125, 250 and 500 mg/kg of body weight) of formulation were administered orally daily for 6 weeks. Fasting blood glucose and body weight were monitored throughout the study. At the end of the study, serum parameters were analyzed and histological examinations were performed. There was a significant reduction in fasting blood glucose levels and body weight in animal groups receiving polyherbal formulation. Lipid profile was improved as revealed by a reduction in serum triglycerides and total cholesterol. Histological study showed an improvement in liver, kidney and pancreatic sections of treated mice. High-performance thin layer chromatography was performed to identify the phytochemicals responsible for the above-mentioned bioactivities. The results revealed the presence of flavonoid (rutin) in seeds of N.nucifera and in the polyherbal formulation. For the first time, this study demonstrated the anti-diabetic and anti-obesity potential of the optimized formulation. The formulation can be used as a potential therapy for management of diabesity.

Phlorotannins of the Brown Algae Sargassum vulgare from the Mediterranean Sea Coast

Brown seaweeds are a good source of bioactive compounds, particularly of phlorotannins, which may exert a wide spectrum of pharmacological properties. In the present study, phlorotannins of S. vulgare were extracted using a 70% acetone solution and the crude extract was further purified through liquid–liquid partition, giving rise to n-hexane, ethyl acetate and aqueous residue fractions. The crude extract and the purified fractions were evaluated for potential antioxidant abilities as well as for inhibitory potential towards the digestive enzymes α-amylase and pancreatic lipase, and anti-inflammatory potential through the hindering of albumin denaturation. Overall, the ethyl acetate fraction was the richest in phlorotannins (9.4 ± 0.03 mg PGE/g) and was also the most promising regarding the tested bioactive properties. Of note, its inhibitory potential towards α-amylase was about nine times that of the commercial drug acarbose and its inhibitory activity against high temperature-induced protein denaturation was superior to that of the non-steroidal drug ketoprofen. According to UHPLC-DAD-ESI-MS/MS analysis, this fraction contained a range of phlorotannins with at least six units of phloroglucinol, including dibenzodioxine-1,3,6,8-tetraol, fuhalol, pentaphlorethol, fucopentaphlorethol and dihydroxypentafuhalol, in addition to several less common phlorotannin sulfate derivatives.

Changes in systolic blood pressure, postprandial glucose, and gut microbial composition following mango consumption in individuals with overweight and obesity

This study aimed to explore the impact of daily mango consumption (Mangifera indica) on cardiometabolic health and gut microbiota in individuals with overweight and obesity. Changes in cardiometabolic variables, gut microbiota diversity and composition, physical activity habits, and dietary intakes were assessed in 8 males and 19 females with overweight and obesity who consumed 280 g/day of mango pulp for 8 weeks. There were no significant changes in body weight, waist circumference, or plasma lipid levels. However, after consuming mangos for 8 weeks, participants showed a 3.5% reduction in systolic blood pressure (-4 ± 6 mm Hg, p = 0.011) as well as a 10.5% reduction in 2-hour plasma glucose concentration after a 75-g oral glucose tolerance test (-0.58 ± 1.03 mmol/L, p = 0.008). These beneficial cardiometabolic outcomes were accompanied with enhanced gut microbiota diversity and with changes in the abundance of specific gut bacterial species. Mango consumption may have beneficial effects on both blood pressure and glucose homeostasis in individuals with overweight and obesity. Further studies are warranted to determine the impact of long-term and regular mango intake on cardiometabolic risk factors of individuals with overweight and obesity, and the potential mechanisms linking gut microbial changes to those health benefits. This study was registered with clinicaltrials.gov as NCT03825276. Novelty: A 3.5% reduction in systolic blood pressure is noted after consuming mangos for 8 weeks. A 10.5% reduction in 2-hour plasma glucose concentration of an oral glucose tolerance test is observed after consuming mangos for 8 weeks. Mango consumption for 8 weeks may enhance gut microbial diversity and abundance of specific bacterial species.

Pentacyclic Triterpenoids Isolated from Celastraceae: A Focus in the 13C-NMR Data

The Celastraceae family comprises about 96 genera and more than 1.350 species, occurring mainly in tropical and subtropical regions of the world. The species of this family stand out as important plant sources of triterpenes, both in terms of abundance and structural diversity. Triterpenoids found in Celastraceae species display mainly lupane, ursane, oleanane, and friedelane skeletons, exhibiting a wide range of biological activities such as antiviral, antimicrobial, analgesic, anti-inflammatory, and cytotoxic against various tumor cell lines. This review aimed to document all triterpenes isolated from different botanical parts of species of the Celastraceae family covering 2001 to 2021. Furthermore, a compilation of their ¹³C-NMR data was carried out to help characterize compounds in future investigations. A total of 504 pentacyclic triterpenes were compiled and distinguished as 29 aromatic, 50 dimers, 103 friedelanes, 89 lupanes, 102 oleananes, 22 quinonemethides, 88 ursanes and 21 classified as others.

The Anti-Adiposity Mechanisms of Ampelopsin and Vine Tea Extract in High Fat Diet and Alcohol-Induced Fatty Liver Mouse Models

Ampelopsis grossedentata (AG) is an ancient medicinal plant that is mainly distributed and used in southwest China. It exerts therapeutic effects, such as antioxidant, anti-diabetic, and anti-inflammatory activities, reductions in blood pressure and cholesterol and hepatoprotective effects. Researchers in China recently reported the anti-obesity effects of AG extract in diet-induced obese mice and rats. To verify these findings, we herein investigated the effects of AG extract and its principal compound, ampelopsin, in high-fat diet (HFD)- and alcohol diet-fed mice, olive oil-loaded mice, and differentiated 3T3-L1 cells. The results obtained showed that AG extract and ampelopsin significantly suppressed increases in the weights of body, livers and abdominal fat and also up-regulated the expression of carnitine palmitoyltransferase 1A in HFD-fed mice. In olive oil-loaded mice, AG extract and ampelopsin significantly attenuated increases in serum triglyceride (TG) levels. In differentiated 3T3-L1 cells, AG extract and ampelopsin promoted TG decomposition, which appeared to be attributed to the expression of hormone-sensitive lipase. In alcohol diet-fed mice, AG extract and ampelopsin reduced serum levels of ethanol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) and liver TG. An examination of metabolic enzyme expression patterns revealed that AG extract and ampelopsin mainly enhanced the expression of aldehyde dehydrogenase and suppressed that of cytochrome P450, family 2, subfamily e1. In conclusion, AG extract and ampelopsin suppressed diet-induced intestinal fat accumulation and reduced the risk of fatty liver associated with HFD and alcohol consumption.

Dietary Intake of Hydrolyzable Tannins and Condensed Tannins to Regulate Lipid Metabolism

Lipid metabolism disorder is a multifactor issue, which contributes to several serious health consequences, such as obesity, hyperlipidemia, atherosclerosis diabetes, non-alcoholic fatty liver etc. Tannins, applied as natural derived plant, are commonly used in the study of lipid metabolism disease with excellent safety and effectiveness, while producing less toxic and side effects. Meanwhile, recognition of the significance of dietary tannins in lipid metabolism disease prevention has increased. As suggested by existing evidence, dietary tannins can reduce lipid accumulation, block adipocyte differentiation, enhance antioxidant capacity, increase the content of short-chain fatty acids, and lower blood lipid levels, thus alleviating lipid metabolism disorder. This study is purposed to sum up and analyze plenty of documents on tannins, so as to provide the information required to assess the lipid metabolism of tannins.

Pancreatic lipase inhibitors: The road voyaged and successes

Human pancreatic lipase (triacylglycerol acyl hydrolase EC3.1.1.3) is the most widely studied member of the human lipase superfamily related to carboxyl esterase. It is secreted from the acinar cell of pancreas and has strong preference for triacylglycerides over cholesterol esters, phospholipids, and galactolipids. Apart from the hydrolysis of triacylglycerides, pancreatic lipase may cause the hydrolysis of retinyl esters in vivo. So, it is very much evidenced that pancreatic lipase with its cofactor colipase has prominent role in efficient digestion of dietary fat. Hence, the modulation of human pancreatic lipase may represent a new insight in the discovery of a number of therapeutics that can inhibit the absorption of fat in body and can be used in obesity and other related metabolic disorders. Even, the only Food and drug administration (FDA) approved antiobesity drug, orlistat, is also an inhibitor of pancreatic lipase. This review summarizes studies about structure, mechanistic approach of pancreatic lipase enzyme while emphasizing on the various synthetic pancreatic lipase inhibitors with their structure activity relationship (SAR).

Four new triterpene glucosides from Salacia cochinchinensis Lour

Four new triterpene glucosides (1-4) were isolated from the 90% ethanol extract of Salacia cochinchinensis, together with five known compounds (5-9). The structures of the new compounds were elucidated by comprehensive spectroscopic analysis including HRESIMS, IR, 1 D and 2 D NMR analysis. All isolates were assayed for their α-glucosidase inhibitory activity. Compound 9 showed remarkable α-glucosidase inhibitory activity with an IC₅₀ value of 0.31 μM, and the triterpene glycosides (1-5) exhibited moderate α-glucosidase inhibitory activity.

Bioactive constituents from Salacia cochinchinensis

Two new isopimarane diterpenoids, named 1α-hydroxy-7-oxoisopimara-8, 15-diene (1), 11β-hydroxy-7-oxoisopimara-8(14), 15-diene (2), together with six known compounds (3-8), were isolated from the medicinal plant Salacia cochinchinensis. All isolates were assayed for their cytotoxicity and α-glucosidase inhibitory activity. Results suggested compounds 1, 3 possessed significant cytotoxic activity against HepG2, HL60, and Hela cell lines with IC₅₀ values ranging from 0.23 to 0.35 μM, and compounds 7, 8 exhibited noticeable α-glucosidase inhibitory ability with IC₅₀ values of 0.25 and 0.31 μM, respectively.

Inhibitory Activities of Polyphenolic Extracts of Bangladeshi Vegetables against α-Amylase, α-Glucosidase, Pancreatic Lipase, Renin, and Angiotensin-Converting Enzyme

The aim of the study was to determine the in vitro enzyme inhibition activities of aqueous polyphenolic extracts of nine popular Bangladeshi vegetables, namely ash gourd, bitter gourd, brinjal, Indian spinach, kangkong, okra, ridge gourd, snake gourd, and stem amaranth. Polyphenolic glycosides were the major compounds present in the extracts. Inhibition of α-amylase (up to 100% at 1 mg/mL) was stronger than α-glucosidase inhibition (up to 70.78% at 10 mg/mL). The Indian spinach extract was the strongest inhibitor of pancreatic lipase activity (IC₅₀ = 276.77 µg/mL), which was significantly better than that of orlistat (381.16 µg/mL), a drug. Ash gourd (76.51%), brinjal (72.48%), and snake gourd (66.82%) extracts were the most effective inhibitors of angiotensin-converting enzyme (ACE), an enzyme whose excessive activities have been associated with hypertension. Brinjal also had a significantly higher renin-inhibitory activity than the other vegetable extracts. We conclude that the vegetable extracts may have the ability to reduce enzyme activities that have been associated with hyperglycemia, hyperlipidemia, and hypertension.

Hypoglycemic Activity and the Mechanisms of Lycium Bark Extract in db/db Mice

The extract of Lycium bark (LBE), which is the root bark of Lycium chinense, has long been used in China for hypertension, inflammation, and diabetes. LBE has been reported to ameliorate hyperglycemia in mice with alloxan-induced type 1 diabetes, but evidence on the effect of LBE in diabetes had not been enough. Therefore, we investigated the effects of LBE on type 2 diabetes using db/db mice. Nine-week-old male db/db mice were orally administered LBE (425 mg/kg) for 10 weeks. Blood samples were collected under anesthesia for the determination of blood glucose and insulin levels. The blood glucose level was increased in the control group and was unchanged in the LBE group. The blood insulin level was increased in both groups within 4 weeks, but it decreased in the control group and was maintained at a relatively high level in the LBE group thereafter. Furthermore, LBE increased the glucose uptake, which was measured using C2C12 myotubes, in a concentration-dependent manner, independent of the addition of a phosphatidylinositol 3-kinase inhibitor (i.e., LY294002) and an AMP-activated kinase inhibitor (i.e., dorsomorphin). And LBE increased the mRNA expression of glucose transporter (GLUT) 1. These results suggested that LBE decreased the blood glucose level by additive effect such as improvement of the insulin secretion, promoting activity of glucose uptake. These findings suggested that LBE administration can be a novel therapeutic approach for type 2 diabetes.

PINK1-PRKN mitophagy suppression by mangiferin promotes a brown-fat-phenotype via PKA-p38 MAPK signalling in murine C3H10T1/2 mesenchymal stem cells

OBJECTIVE

Mangiferin (MF), a xanthonoid derived from Mangifera indica, has shown therapeutic effects on various human diseases including cancer, diabetes, and obesity. Nonetheless, the influence of MF on non-shivering thermogenesis and its underlying mechanism in browning remains unclear. Here, our aim was to investigate the effects of MF on browning and its molecular mechanisms in murine C3H10T1/2 mesenchymal stem cells (MSCs).

MATERIALS/METHODS

To determine the function of MF on browning, murine C3H10T1/2 MSCs were treated with MF in an adipogenic differentiation cocktail and the thermogenic and correlated metabolic responses were assessed using MF-mediated signalling. Human adipose-derived MSCs were differentiated and treated with MF to confirm its role in thermogenic induction.

RESULTS

MF treatment induced the expression of a brown-fat signature, UCP1, and reduced triglyceride (TG) in C3H10T1/2 MSCs. MF also induced the expression of major thermogenesis regulators: PGC1α, PRDM16, and PPARγ and up-regulated the expression of beiging markers CD137, HSPB7, TBX1, and COX2 in both murine C3H10T1/2 MSCs and human adipose-derived mesenchymal stem cells (hADMSC). We also observed that MF treatment increased the mitochondrial DNA and improved mitochondrial homeostasis by regulating mitofission-fusion plasticity via suppressing PINK1-PRKN-mediated mitophagy. Furthermore, MF treatment improved mitochondrial respiratory function by increasing mitochondrial oxygen consumption and expression of oxidative-phosphorylation (OXPHOS)-related proteins. Chemical-inhibition and gene knockdown experiments revealed that β3-AR-dependent PKA-p38 MAPK-CREB signalling is crucial for MF-mediated brown-fat formation via suppression of mitophagy in C3H10T1/2 MSCs.

CONCLUSIONS

MF promotes the brown adipocyte phenotype by suppressing mitophagy, which is regulated by PKA-p38MAPK-CREB signalling in C3H10T1/2 MSCs. Thus, we propose that MF may be a good browning inducer that can ameliorate obesity.

Targeting obesity with plant-derived pancreatic lipase inhibitors: A comprehensive review

The prevalence of obesity is alarmingly increasing in the last few decades and leading to many serious public health concerns worldwide. The dysregulated lipid homeostasis due to various genetic, environmental and lifestyle factors is considered one of the critical putative pathways mediating obesity. Nonetheless, the scientific advancements unleashing the molecular dynamics of lipid metabolism have provided deeper insights on the emerging roles of lipid hydrolysing enzymes, including pancreatic lipase. It is hypothesized that inhibiting pancreatic lipase would prevent the breakdown of triglyceride and delays the absorption of fatty acids into the systemic circulation and adipocytes. Whilst, orlistat is the only conventional pancreatic lipase enzyme inhibitor available in clinics, identifying the safe clinical alternatives from plants to inhibit pancreatic lipase has been considered a significant advancement. Consequently, plants which have shown significant potential to combat obesity are now revisited for its abilities to inhibit pancreatic lipase. In this regard, our review surveyed the potential of medicinal plants and its phytoconstituents to inhibit pancreatic lipase and to elicit anti-obesity effects. Thus, the review collate and critically appraise the potential of medicinal plants and phyto-molecules inhibiting pancreatic lipase enzyme and consequently modulating triglyceride absorption in gut, and discuss its implications in the development of novel therapeutic strategies to combat obesity.

Salacia chinensis L. Stem Extract Exerts Antifibrotic Effects on Human Hepatic Stellate Cells Through the Inhibition of the TGF-β1-Induced SMAD2/3 Signaling Pathway

Salacia chinensis L. (SC) stems have been used as an ingredient in Thai traditional medicine for treating patients with hepatic fibrosis and liver cirrhosis. However, there is no scientific evidence supporting the antifibrotic effects of SC extract. Therefore, this study aimed to determine the antifibrotic activity of SC stem extract in human hepatic stellate cell-line called LX-2. We found that upon TGF-β1 stimulation, LX-2 cells transformed to a myofibroblast-like phenotype with a noticeable increase in α-SMA and collagen type I production. Interestingly, cells treated with SC extract significantly suppressed α-SMA and collagen type I production and reversed the myofibroblast-like characteristics back to normal. Additionally, TGF-β1 also influenced the development of fibrogenesis by upregulation of MMP-2, TIMP-1, and TIMP-2 and related cellular signaling, such as pSmad2/3, pErk1/2, and pJNK. Surprisingly, SC possesses antifibrotic activity through the suppression of TGF-β1-mediated production of collagen type 1, α-SMA, and the phosphorylation status of Smad2/3, Erk1/2, and JNK. Taken together, the present study provides accumulated information demonstrating the antifibrotic effects of SC stem extract and revealing its potential for development for hepatic fibrosis patients.

Phenolic Profile, Antioxidant Activity, and Anti-obesogenic Bioactivity of Mao Luang Fruits (Antidesma bunius L.)

To investigate the anti-obesity potential of Antidesma bunius L. (MM), a Thai local fruit which is named "Mao Luang," we have focused on the effects on pancreatic α-amylase and lipase enzyme activity and on adipocyte life cycle using the 3T3-L1 cell line as a model. In addition, the phytochemical composition and anti-oxidation potential were also analyzed using HPLC-PDA UV and colorimetric methods. The ethanolic extract of MM fruits prepared by a maceration method was used in the experiments. MM extract, yield 12.08% w/w, is composed primarily of phenolics and anthocyanins as the major phytochemicals, among which, gallic acid, catechin, anthocyanin-3-glucoside, and protocatechuic acid were initially identified. In addition, susceptibly inhibitory effects on oxidation in a DPPH assay; on lipase enzyme activity rather than amylase enzyme; and on adipocyte adipogenesis of MM were demonstrated. Interestingly, a concentration-dependent bi-modular manner of activity on adipocyte adipogenesis was discovered, whereby a significant anti-adipogenic effect was demonstrated at high concentration, whilst low concentrations of MM showed adipogenic induction. Lipolytic induction was manifested. Conclusively, the ethanolic MM extract was discovered to be a potential anti-obesity agent contributed by inhibitory effects on lipase enzyme and anti-differentiation and -adipogenesis in adipocytes which significantly correlated to the total phenolics content, as well as anti-oxidation as the mechanism of action. Nevertheless, to achieve effective application, further investigation in in vivo models should be considered.

Adipose tissue as a possible therapeutic target for polyphenols: A case for Cyclopia extracts as anti-obesity nutraceuticals

Obesity is a significant contributor to increased morbidity and premature mortality due to increasing the risk of many chronic metabolic diseases such as type 2 diabetes, cardiovascular disease and certain types of cancer. Lifestyle modifications such as energy restriction and increased physical activity are highly effective first-line treatment strategies used in the management of obesity. However, adherence to these behavioral changes is poor, with an increased reliance on synthetic drugs, which unfortunately are plagued by adverse effects. The identification of new and safer anti-obesity agents is thus of significant interest. In recent years, plants and their phenolic constituents have attracted increased attention due to their health-promoting properties. Amongst these, Cyclopia, an endemic South African plant commonly consumed as a herbal tea (honeybush), has been shown to possess modulating properties against oxidative stress, hyperglycemia, and obesity. Likewise, several studies have reported that some of the major phenolic compounds present in Cyclopia spp. exhibit anti-obesity effects, particularly by targeting adipose tissue. These phenolic compounds belong to the xanthone, flavonoid and benzophenone classes. The aim of this review is to assess the potential of Cyclopia extracts as an anti-obesity nutraceutical as underpinned by in vitro and in vivo studies and the underlying cellular mechanisms and biological pathways regulated by their phenolic compounds.

Maytenus macrocarpa (Ruiz & Pav.) Briq.: Phytochemistry and Pharmacological Activity

Maytenus macrocarpa (Celastraceae) is a tree native to Amazonia. Its roots, leaves, bark, and combinations of these are used in traditional medicine mainly to treat rheumatism and, to a lesser extent, to heal wounds and to combat bronchitis and diarrhea. To date, mainly triterpenes and dihydro-β-agarofuran sesquiterpenes were isolated from M. macrocarpa. Extracts and selected pure compounds isolated from the leaves, roots, and stem bark showed antibacterial, antiviral, antiparasitic, anti-inflammatory, and cytotoxic activities in vitro. The aim of this review is to summarize the available ethnobotanical, phytochemical, and pharmacological information about this traditional Amazonian medicinal tree, as well as to attract the attention of phytochemists and pharmacognosists to this potentially interesting source of ethnopharmaceuticals.

Identification of a new natural gastric lipase inhibitor from star anise

The identification and isolation of bioactive compounds are of great interest in the drug delivery field, despite being a difficult task. We describe here an innovative strategy for the identification of a new gastric lipase inhibitor from star anise for the treatment of obesity. After plant screening assays for gastric lipase inhibition, star anise was selected and investigated by bioactivity guided fractionation. MALDI-TOF mass spectrometry and peptide mass fingerprinting allowed the detection of an inhibitor covalently bound to the catalytic serine of gastric lipase. A mass-directed screening approach using UPLC-HRMS and accurate mass determination searching identified the flavonoid myricitrin-5-methyl ether (M5ME) as a lipase inhibitor. The inhibitory activity was rationalized based on molecular docking, showing that M5ME is susceptible to nucleophilic attack by gastric lipase. Overall, our data suggest that M5ME may be considered as a potential candidate for future application as a gastric lipase inhibitor for the treatment of obesity.

Potential Anti-obesity and Lipid Lowering Natural Products: A Review

Obesity has reached epidemic proportions globally, with more than 1 billion adults overweight - at least 300 million of them clinically obese. In Ayurveda, obesity is called ‘medoroga’. The detailed features and treatments of the disease have been described in an old Ayurvedic text, Charak and Sushrut Samhita. There are some native plants that are commonly used for the treatment of obesity in Ayurveda. Unfortunately, only few medications are available in the market, with side effects and unacceptable efficacy. With the current view that botanical drugs can be developed faster and more cheaply than conventional single entity pharmaceuticals, the review mainly focuses on the rationality of their use with appropriate literature data support.

Cyanidin and cyanidin-3-glucoside derived from Vigna unguiculata act as noncompetitive inhibitors of pancreatic lipase

The consumption of legumes positively correlated with the reduction of body weight. In the present study, we identified and evaluated pancreatic lipase inhibitors from Vigna unguiculata and unraveled their mode of inhibition. The highly sensitive fluorometric method was adopted to access the pancreatic lipase activity and the ethanolic extract of Vigna unguiculata showed the maximum inhibition (IC₅₀ of 15.2 µg/ml). Cyanidin and cyanidin-3-glucoside are the major anthocyanins observed in Vigna unguiculata. The IC₅₀ value of cyanidin was 28.29 µM which was 6.5-fold higher than the cyanidin-3-glucoside (188.28 µM). We determined an apparent K_i of 27.28 µM for cyanidin and cyanidin-3-glucoside (88.97 µM) with noncompetitive inhibition. Collectively, these results suggest that the glycosylation of the anthocyanidins significantly reduces lipase inhibition. The noncompetitive inhibition of pancreatic lipase by Vigna unguiculata anthocyanins may exert significant pharmacological activities toward obesity complications by calorie restriction. PRACTICAL APPLICATIONS: The results of this study emphasize the importance of legumes in our diet to combat obesity-related complications. Consumption of legumes minimizes fat absorption by inhibiting the action of the fat-digesting enzyme.

Evaluation of Cycloferin Supplement on Health Parameters in Experimentally Induced Diabetic Rats with and Without Exogenous Insulin

Cycloferin is an extract of the chemicals from the Cyclopia species, which grows only in small areas in the southwest and southeast of South Africa and has been consumed traditionally as a nourishing tea to treat numerous health issues and illnesses. Previous studies report that some of the active compounds in Cycloferin, such as pinitol (a modified sugar) and mangiferin (a glucoside), may reduce blood sugar levels and therefore may be used as a treatment for diabetes. Mangiferin, in particular, has been shown to stimulate carbohydrate oxidation and alleviate some effects of insulin resistance and hyperglycemia. Other active components of Cycloferin include flavones, isoflavones, coumestans, luteolin, 4-hydroxycinnamic acid, polyphenols, and xanthones. These active compounds are antioxidants, which can enhance glucose breakdown, lower blood lipids, and reduce the number of highly reactive compounds known as free radicals, which can alter cellular structure and function when present in large amounts. In this study, we explored the ameliorative effects of Cycloferin by treating streptozotocin- (STZ) injected rats with Cycloferin and evaluating its long-term and short-term effect on blood glucose levels and kidney and liver conditions of the diabetic-rendered rats. Our results demonstrated the ability of Cycloferin to both lower the blood glucose levels and reduce evidence of damage in kidney and liver in diabetic rats with and without exogenous insulin treatment for partial control of diabetic state.

Evaluation of the effects of extracts of Maytenus imbricata (Celastraceae) on the treatment of inflammatory and metabolic dysfunction induced by high-refined carbohydrate diet

The Maytenus genus is a member of the Celastraceae family. Numerous medicinal uses were assigned to species of this genus, with the use of roots, bark, and leaves for the treatment of gastric ulcers, as anti-inflammatory, analgesic, antiallergic, antitumor, among others. Several studies have demonstrated that natural products derived from plants have an important role in the prevention and treatment of obesity. Accordingly, we evaluated the effect of Maytenus imbricata extracts in the treatment of obesity induced by diet rich in refined carbohydrate (HC). BALB/c mice were fed chow or HC diet for 8 weeks. At the beginning of the 9th week, the HC group was subdivided into three groups: (i) group of animals that continued to consume only HC diet; (ii) the group of animals fed HC diet supplemented with ethyl acetate extract of M. imbricata roots (HC + EAE); (iii) the group of animals fed HC diet supplemented with extract in hexane/ethyl ether (HC + HEE). The period of extracts supplementation was 4 weeks. It was observed that EAE and EHE when added to the HC diet modulated the metabolic and inflammatory changes, such as: reduced the adipocytes area, improved glucose intolerance, reduced the levels of triglycerides and resistin in serum, and the number of total leukocytes in blood. In the epididymal adipose tissue, the extracts reduced proinflammatory mediators' concentration. According to the results, it was concluded that the species Maytenus imbricata has the potential to be used for the treatment of obesity.

Weight Loss Associated With Consumption of Apples: A Review

Apples are known as a major source of polyphenols, dietary fiber, carotenoids, and other nutrients. There are many documents and studies that show fruit polyphenols likely promote anti-obesity effects and exert their beneficial effects via scavenging free radicals, regulating gene expression, and altering signal transduction in target cells and tissues, especially fat tissues.The goal of this review is to presenti the major components of apple and the evidence that indicates its potential to diminution weight gain risk from in vitro, animal, and epidemiological and clinical studies. This review summarizes data about the apple and apple products that been have reported to reduce weight gain by various mechanisms, including antioxidant, antiproliferative, and cell signaling pathways. An extensive search was performed in PubMed, Science Direct, Scopus, and Google Scholar to identify human, animal, and cell culture studies on the association between weight loss and apple consumption, published from inception up to journey 15, 2017. The feeding of apples rats (7-10 mg/kg/d) in different forms in 8 experiments have shown that this caused weight loss during 3 to 28 weeks. In agreement with this, the obtained results from 5 experiments on humans have revealed that consumption of the whole apple or apple juice (240-720 mg/d) in 4-12 weeks by fat people can cause weight loss. Experiments on animals and humans have shown that the consumption of apples in different forms can cause weight loss in overweight ones. However, the main questions are which kind of apple, which part of it, how much, and how long overweight persons should consume them to reduce their body fat and body mass index (BMI). Then, it is necessary to do a meta-analysis to show how these factors affect the body fat percentage and whether this weight-lowering effect is statistically significant or not.

Saponins fromBoussingaultia gracilisprevent obesity and related metabolic impairments in diet-induced obese mice

Saponins fromBoussingaultia gracilisattenuate obesity and its related metabolic disorders in diet-induced obese mice.

Effect of Salacia reticulata W. and Clitoria ternatea L. on the cognitive and behavioral changes in the streptozotocin-induced young diabetic rats

BACKGROUND

Diabetes mellitus (DM) of juvenile onset affects both the peripheral and central nervous systems (CNS). However, central effects are less documented and studied than peripheral deficits. Currently, the only feasible treatment available for type 1 DM (T1DM) is insulin which has its own limitations. Hence, an alternative therapy, especially a newer herbal formulation is very much the need of the time. The present study aimed to determine the effects of the alcoholic extracts of roots of the Salacia reticulata W. (SR) and Clitoria ternatea L. (CT) on cognitive and behavioral changes in juvenile diabetic rats.

METHODS

Diabetes was induced in 25-day-old Wistar rats by streptozotocin (50 mg/kg bw, IP). Animals were divided into seven groups (n=6). Rats were treated with root extracts of SR and CT (100 mg/kg BW each) for 30 days, from day 1 and day 20 of diabetes confirmation. Then, rats were tested in elevated plus maze (EPM) and Morris water maze (MWM).

RESULTS

A statistically significant (p<0.05) difference was observed between the SRCT group and diabetic groups of rats. Apart from decreasing FBS, the combined therapy also proved beneficial as nootropic agent in rats with early-onset diabetes. However, significant improvement is observed only in the learning and memory among preventive group, but not in the curative group.

CONCLUSIONS

SRCT, a herbal formula, when used in combination, has a more potent effect in preventing the deleterious effects of juvenile diabetes on cognitive and behavioral changes.

Fructooligosaccharides suppress high-fat diet-induced fat accumulation in C57BL/6J mice

Two experiments were performed to examine the effects of fructooligosaccharides (FOS) on the development of obesity. In the first experiment, Wistar rats were orally administered a 2.5 g/kg body weight lipid emulsion containing FOS, and the subsequent elevation of plasma triglycerides was significantly suppressed compared with that in rats receiving lipid emulsion alone. In the second experiment, C57BL/6J male mice were fed a high-fat "western" diet with or without 2.5% FOS supplementation (n = 10/group) ad libitum for 12 weeks. Body weight and percent body fat were lower in mice fed FOS than in controls. Furthermore, the weight of the visceral adipose tissue, and the weight and triglyceride content of the liver were significantly lower in the high-fat + FOS group. Fecal excretion of lipids was markedly enhanced by FOS consumption. These results indicate that dietary FOS suppress high-fat diet-induced body fat accumulation, and inhibit intestinal absorption of dietary fat.

Anti-obesity effect of ethanolic extract from Cosmos caudatus Kunth leaf in lean rats fed a high fat diet

Background

Obesity is a major health concern both in developed and developing countries. The use of herbal medicines became the subject of interest for the management of obesity due to its natural origin, cost effectiveness and minimal side effects. The present study aimed at investigating anti-obesity potential of ethanolic extract from Cosmos caudatus Kunth leaf (EECCL).

Methods

In this study, the rats were randomly divided into six groups i.e., (1) Normal Diet (ND); (2) Normal Diet and 175 mg/kgBW of EECCL (ND + 175 mg/kgBW); (3) Normal Diet and 350 mg/kgBW of EECCL (ND + 350 mg/kgBW); (4) High Fat Diet (HFD); (5) High Fat Diet and 175 mg/kgBW of EECCL (HFD + 175 mg/kgBW); (6) High Fat Diet and 350 mg/kgBW of EECCL (HFD + 350 mg/kgBW). The anti-obesity potential was evaluated through analyses of changes in body weight, visceral fat weight, and blood biochemicals including total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), leptin, insulin, adiponectin, ghrelin and fecal fat content. In addition, metabolite profiling of EECCL was carried out using NMR spectroscopy.

Results

Rats receiving EECCL together with HFD showed significant (p < 0.05) reduction in body weight gain compared to rats receiving HFD only. At the end of study, the body weight gain of EECCL treated rats was not significantly (p > 0.05) different with those of ND rats. Other related obesity biomarkers including plasma lipid profiles, insulin, leptin, ghrelin and adiponectin levels also showed significant improvement (p < 0.05). Administration of EECCL caused significant (p < 0.05) increase in fecal fat excretion, which validates the hypothesis of lipase inhibition, an anti-obesity mechanism similar to standard drug of Orlistat. The ¹H-NMR spectra of EECCL ascertained the presence of catechin, quercetin, rutin, kaempherol and chlorogenic acid in the extract.

Conclusion

Conclusively, EECCL showed anti-obesity properties by inhibition of intestinal lipid absorption and modulation of adipocytes markers.

Mangiferin modulation of metabolism and metabolic syndrome

The recent emergence of a worldwide epidemic of metabolic disorders, such as obesity and diabetes, demands effective strategy to develop nutraceuticals or pharmaceuticals to halt this trend. Natural products have long been and continue to be an attractive source of nutritional and pharmacological therapeutics. One such natural product is mangiferin (MGF), the predominant constituent of extracts of the mango plant Mangifera indica L. Reports on biological and pharmacological effects of MGF increased exponentially in recent years. MGF has documented antioxidant and anti-inflammatory effects. Recent studies indicate that it modulates multiple biological processes involved in metabolism of carbohydrates and lipids. MGF has been shown to improve metabolic abnormalities and disorders in animal models and humans. This review focuses on the recently reported biological and pharmacological effects of MGF on metabolism and metabolic disorders. © 2016 BioFactors, 42(5):492-503, 2016.

Antidiabetic and antihyperlipidemic activities of a novel polyherbal formulation in high fat diet/streptozotocin induced diabetic rat model

Objective:

To investigate the antidiabetic and antihyperlipidemic activities of polyherbal formulation (PHF) containing hydroalcoholic extracts of four plants namely Salacia oblonga, Salacia roxbhurgii, Garcinia indica and Lagerstroemia parviflora in streptozotocin (STZ)-induced diabetic rats by administering oral doses (200 and 400 mg/kg body weight).

Materials and Methods:

Animals were divided into diabetic and nondiabetic groups. Rats were fed with a high-fat diet (HFD) and induced with a single low dose of STZ (35 mg/kg) i.p. Diabetic rats were treated with formulation (200 and 400 mg/kg) and metformin 250 mg/kg. Blood glucose levels were measured using blood glucose test strips with ACCU CHEK glucometer. Lipid profile and gluconeogenic enzymes were determined in normal and STZ-induced diabetic rats after oral administration of the PHF for 28 days. Histopathological changes in diabetic rat organs (pancreas, liver, and kidney) were also observed after PHF treatment.

Results:

Treatment of diabetic rats with PHF and metformin decreased plasma glucose and lipid profile levels. Blood glucose level showed significant reduction after 28 days of treatment with formulation at 200 and 400 mg/kg and in metformin. Formulation treated rats showed significant (P < 0.001) decrease in the activities of gluconeogenic enzymes. Histological examination of various organ tissues of normal control, diabetic control, and drug-treated rats revealed significant results. Treatment with PHF reverses the most blood and tissue changes toward the normal level.

Conclusion:

These findings suggested the antihyperglycemic and antihyperlipidemic properties of the PHF and thus help in preventing future complications of diabetes.

Orally Administered Salacia reticulata Extract Reduces H1N1 Influenza Clinical Symptoms in Murine Lung Tissues Putatively Due to Enhanced Natural Killer Cell Activity

Influenza is a major cause of respiratory tract infection. Although most cases do not require further hospitalization, influenza periodically causes epidemics in humans that can potentially infect and kill millions of people. To countermeasure this threat, new vaccines need to be developed annually to match emerging influenza viral strains with increased resistance to existing vaccines. Thus, there is a need for finding and developing new anti-influenza viral agents as alternatives to current treatments. Here, we tested the antiviral effects of an extract from the stems and roots of Salacia reticulata (SSRE), a plant rich in phytochemicals, such as salacinol, kotalanol, and catechins, on H1N1 influenza virus-infected mice. Following oral administration of 0.6 mg/day of SSRE, the incidence of coughing decreased in 80% of mice, and only one case of severe pulmonary inflammation was detected. Moreover, when compared with mice given Lactobacillus casei JCM1134, a strain previously shown to help increase in vitro natural killer (NK) cell activity, SSRE-administered mice showed greater and equal NK cell activity in splenocytes and pulmonary cells, respectively, at high effector cell:target cell ratios. Next, to test whether or not SSRE would exert protective effects against influenza in the absence of gut microbiota, mice were given antibiotics before being inoculated influenza virus and subsequently administered SSRE. SSRE administration induced an increase in NK cell activity in splenocytes and pulmonary cells at levels similar to those detected in mice not treated with antibiotics. Based on our results, it can be concluded that phytochemicals in the SSRE exerted protective effects against influenza infection putatively via modulation of the immune response, including enhancement of NK cell activity, although some protective effects were not necessarily through modulation of gut microbiota. Further investigation is necessary to elucidate the molecular mechanisms underlying the protective effects of SSRE against influenza infection.

Salacia - The new multi-targeted approach in diabetics

Salacia species plant has been used traditionally as an Ayurvedic medicine for diabetes mellitus. Studies over the past decades have shown its multi-targeted role in diabetics. In the present review article, various mechanisms of action of Salacia on diabetics are discussed in detail. Apart from the well-known action of decreasing postprandial glucose sugar by inhibiting α-glucosidase and α-pancreatic amylase, it also inhibits aldose reductase which otherwise results in microvascular complications. Importantly, its peroxisome proliferator-activated receptor (PPAR)-γ agonist (such as thiazolidinediones, the insulin sensitizers) action increases the uptake of free fatty acid (FFA) and facilitates their storage in subcutaneous fat rather than the visceral fat. This reduces plasma FFA and insulin resistance. Furthermore, it increases the expression of and translocation to the cell surface of glucose transporter 1 and 4 receptors which result in glucose uptake by the liver and skeletal muscle and decreases plasma glucose levels. It also decreases inflammatory cytokines and increases adiponectin expression. Salacia as PPAR-α agonist (such as fibrates) has a role in the management of dyslipidemia. The activation of PPAR-α leads to the increased expression of lipoprotein lipase and apolipoprotein (Apo) A-V and decrease in hepatic Apo-C-III. These actions lower plasma triglycerides in chylomicrons and very low-density lipoprotein particles, thus liberating fatty acids, which are taken up and stored as fat in adipocytes. Salacia has been shown to suppress the overexpression of cardiac PPAR-α (similar to angiotensin-converting enzyme inhibitors/angiotensin receptor blockers) and thereby preventing diabetic cardiomyopathy. It also suppresses the cardiac angiotensin II Type 1 receptors resulting in antihypertrophic and antifibrogenic effect.

Salacia Extract Improves Postprandial Glucose and Insulin Response: A Randomized Double-Blind, Placebo Controlled, Crossover Study in Healthy Volunteers

Thirty-five healthy subjects were randomly assigned to different doses of Salacia chinensis extract (200 mg, 300 mg, and 500 mg SCE) capsules and compared with placebo. It is a placebo controlled randomized crossover design study. Subjects were given oral sucrose solution along with capsules and plasma glucose and insulin responses were analyzed. Blood samples were collected at 0, 30, 60, 90, 120, and 180 minutes after administration. AUC insulin significantly lowered after ingestion of SCE. No significant adverse events were observed. Reducing glucose and insulin is very important in reducing postprandial hyperglycemia.

An Updated Review on the Phytochemistry, Pharmacology, and Clinical Trials of Salacia oblonga

Salacia oblonga (S. oblonga), a perennial herb, has been used for thousands of years in ayurvedic medicine and is closely associated with prevention, treatment, and cure of various human ailments such as obesity and diabetes. A vast and wide range of chemical compounds such as polyphenols, friedelane-type triterpenes, norfriedelane-type triterpenes, eudesmane-type sesquiterpenes including various glycosides had been isolated from this plant. This review is aimed to survey the literature covering the phytochemistry and pharmacology of S. oblonga and to review the scientific data including active components and their multi-targeted mechanisms of action against various metabolic syndromes. We also included clinical trials related to this plant in this review. The overview would assist researchers to gather scientific information related to S. oblonga in future.

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

Dioscorea oppositifolia is a well-known edible and traditional medicine for the treatment of gastrointestinal diseases. In our previous study, D. oppositifolia exhibited both pancreatic lipase inhibition and an anti-adipogenesis effect in vitro. This study was performed to investigate the anti-obesity effect of D. oppositifolia on high-fat diet-induced obese mice. Female ICR mice were fed a high-fat diet with the 100 mg/kg of D. oppositifolia n-BuOH extract for 8 weeks. The high-fat diet mice received the 15 mg/kg Orlistat orally as a positive control. The body weight, parametrial adipose tissue weight, and the levels of triglyceride (TG), total cholesterol (TC), and low density lipoprotein (LDL)-cholesterol in blood serum of female ICR mice were significantly decreased by feeding a high-fat diet with the n-BuOH extract of D. oppositifolia. An inhibitory effect of D. oppositifolia extract on dietary fat absorption was also clearly shown. The D. oppositifolia sample was found to contain 3,5-dimethoxy-2,7-phenanthrenediol and (3R,5R)-3,5-dihydroxy-1,7-bis(4-hydroxyphenyl)-3,5-heptanediol as main components based on its phytochemical analysis. The present study is the first report of the anti-obesity effect by D. oppositifolia n-BuOH extract using an established disease model. The increase in fecal fat excretion by treatment of D. oppositifolia may be an effective approach for treating obesity and related diseases.

Medicinal Plants and Their Inhibitory Activities against Pancreatic Lipase: A Review

Obesity is recognized as a major life style disorder especially in developing countries and it is prevailing at an alarming speed in new world countries due to fast food intake, industrialization, and reduction of physical activity. Furthermore, it is associated with a vast number of chronic diseases and disabilities. To date, relatively effective drugs, from either natural or synthetic sources, are generally associated with serious side effects, often leading to cessation of clinical trials or even withdrawal from the market. In order to find new compounds which are more effective or with less adverse effects compared to orlistat, the drug that has been approved for obesity, new compounds isolated from natural products are being identified and screened for antiobesity effects, in particular, for their pancreatic lipase inhibitory effect. Pancreatic lipase inhibitory activity has been extensively used for the determination of potential efficacy of natural products as antiobesity agents. In attempts to identify natural products for overcoming obesity, more researches have been focused on the identification of newer pancreatic lipase inhibitors with less unpleasant adverse effects. In this review, we consider the potential role of plants that have been investigated for their pancreatic lipase inhibitory activity.

A subchronic oral toxicity study of Salacia reticulata extract powder in rats

The safety of Salacia plant (Salacia reticulata) extract powder, which is used in Ayurvedic medical practices, was studied in a dose range-finding subchronic toxicity study in Crl:CD Sprague-Dawley rats. Male and female rats were randomly assigned to 4 treatment groups and were treated by oral gavage with 0, 10, 65, and 400 mg/kg body weight/day of the powder for 91 days. Body weight, food consumption, and clinical signs were assessed during the treatment period. Urinalysis, hematology, blood chemistry, and organ weights were determined one day after the final treatment. The animals were euthanized at the end of the treatment and were examined for necropsy and histopathological purposes. No adverse toxicity was observed in the Salacia powder-treated groups with a No Observed Adverse Effect Level of ≧400 mg/kg body weight/day in both male and female SD rats.

Anti-diabetic and Anti-hyperlipidemic Effects and Safety of Salacia reticulata and Related Species

Extracts of Salacia reticulata Wight (Hypocrataceae) roots, stems, and leaves have been used in Asia for hundreds of years for the folkloric treatment of diabetes and other health problems. Constituents that have been identified as exhibiting anti-diabetic effects include salacinol, kotalanol, ponkorinol, salaprinol, and their corresponding de-0-sulfonated compounds. Mangiferin, kotalagenin 16-acetate and various proanthocyanidin oligomers have also been isolated. Studies indicate that Salacia extracts modulate multiple targets that influence carbohydrate and lipid metabolism including α-glucosidase, aldose reductase, pancreatic lipase, peroxisomal proliferator-activated receptor-α, glucose transporter-4 mediated glucose uptake, and angiotensin II type 1 receptor. Furthermore, Salacia extracts exhibit free radical scavenging, antioxidant and hepatoprotectant activities. In human studies, Salacia extracts have been shown to decrease plasma glucose and insulin levels, decrease HbA1c, and modulate serum lipid levels with no adverse effects being reported. Similar results have been demonstrated in rat and mouse models as well as in vitro systems. Safety of S. reticulata and other Salacia species as S. oblonga and S. chinensis in rats and mice indicate that extracts are exceedingly safe. No clinical studies have examined the effects of Salacia extracts on human weight loss, although weight loss and decreases in weight gain have been demonstrated in animal models. Because of the large number of pharmacologically active compounds, it is difficult to establish standards for extracts.

Salacia reticulata (Kothala himbutu) revisited; a missed opportunity to treat diabetes and obesity?

Background

Nearly 50% of diabetic patients worldwide use complementary medicines to treat or supplement their conventional diabetes treatment. Salacia reticulata (Kothala himbutu) is a woody climber used widely in the Ayurvedic system to treat diabetes and obesity.

Objective

In this review I critically analyze the evidence for using Salacia reticulata for treating type 2 diabetes and obesity. The available evidence is described in terms of in-vitro studies, animal studies and clinical trials.

Results and conclusions

In vitro studies demonstrate the ability of Salacia to inhibit intestinal alpha glucosidase. In mouse mesenteric fat it enhances the mRNA expression for hormone sensitive lipase (HSL) and adiponectin; thus increasing lipolysis and reducing insulin resistance respectively. In 3 T3-L-1 adipocytes lipogenesis factors are down regulated and lipolysis factors are up regulated with Salacia reticulata treatment. Animal studies and clinical trials are consistent in demonstrating improvement of glucose concentrations in the fasted and sucrose and maltose loaded states. Clinically significant reductions of HbA1C and plasma Insulin are reported with treatment of 6 weeks to 3 months. One clinical trial reported significant reduction of weight and BMI when Salacia is used in combination with vitamin D.

Salacia reticulata effectively improves insulin resistance, glucose metabolism and reduces obesity. A larger evidence base is required from well-planned studies to confirm its efficacy and safety.

Flavonoid interactions during digestion, absorption, distribution and metabolism: a sequential structure-activity/property relationship-based approach in the study of bioavailability and bioactivity

Flavonoids are a group of polyphenols that provide health-promoting benefits upon consumption. However, poor bioavailability has been a major hurdle in their use as drugs or nutraceuticals. Low bioavailability has been associated with flavonoid interactions at various stages of the digestion, absorption and distribution process, which is strongly affected by their molecular structure. In this review, we use structure-activity/property relationship to discuss various flavonoid interactions with food matrices, digestive enzymes, intestinal transporters and blood proteins. This approach reveals specific bioactive properties of flavonoids in the gastrointestinal tract as well as various barriers for their bioavailability. In the last part of this review, we use these insights to determine the effect of different structural characteristics on the overall bioavailability of flavonoids. Such information is crucial when flavonoid or flavonoid derivatives are used as active ingredients in foods or drugs.