In vitro and in silico assessment of antidiabetic and antioxidant potencies of secondary metabolites from Gymnema sylvestre.

This study investigated the chemical constituents, antioxidant potential, and in vitro and in silico antidiabetic activity of Gymnema sylvestre. Column chromatography and spectroscopic techniques identified twelve compounds from the methanol extract, including 4 sterols (1-4), 5 triterpenoids (5-9), and 3 flavonoids (10-12). The chemophenetic significance of all compounds was also investigated. The antioxidant capacity of the extract and compounds (1-4) was evaluated using FRAP and DPPH assays. The extract exhibited strong free radical scavenging activity (IC50 = 48.34 µg/mL), while compounds (1-4) displayed varying degrees of efficacy (IC50 = 98.30-286.13 µg/mL). The FRAP assay indicated significant reducing power for both extract and compounds (58.54, 47.61, 56.61, and 49.11 mg Eq.VitC/g for extract and compounds 1 & 2, 3, and 4, respectively). The antidiabetic potential was assessed through α-amylase and α-glucosidase enzyme inhibition assays. The crude extract demonstrated the most potent inhibition (IC50 = 218.46 and 57.42 µg/mL for α-glucosidase and α-amylase respectively) suggesting its potential for managing postprandial hyperglycaemia. In silico studies employed molecular docking and dynamics simulations to elucidate the interactions between identified compounds and α-amylase/α-glucosidase enzymes. The results revealed promising binding affinities between the compounds and target enzymes, with compound 6 demonstrating the highest predicted inhibitory activity with -10 kcal/mol and -9.1 kcal/mol for α-amylase and α-glucosidase, respectively. This study highlights the presence of diverse bioactive compounds in Gymnema sylvestre. The extract exhibits antioxidant properties and inhibits carbohydrate-digesting enzymes, suggesting its potential as a complementary therapeutic approach for managing hyperglycaemia associated with type 2 diabetes.

Phytochemical Profiling and Assessment of Antidiabetic Activity of Curcuma Angustifolia Rhizome Methanolic Extract: An In Vitro and In Silico Analysis.

Curcuma angustifolia Roxb. is a plant with medicinal potential, traditionally used to treat different diseases. The present study aimed to determine the antidiabetic activity of C. angustifolia rhizome in vitro and in silico. The methanolic extract of C. angustifolia rhizome was analyzed by FTIR and GC-MS to determine the phytochemicals present. The antidiabetic potential of the extract was evaluated by different assays in vitro. The extract inhibited both α-amylase and α-glucosidase enzymes and the glucose diffusion through the dialysis membrane in a concentration-dependent manner with IC50 values of 530.39±0.09, 293.75±0.11, and 551.74±0.3 µg/ml respectively. The methanolic extract also improved yeast cell's ability to take up glucose across plasma membranes and the adsorption of glucose. The findings were supported by molecular docking studies. The results showed that the methanol extract of C. angustifolia rhizome has significant antidiabetic activity and thus can be also studied to isolate the potential compound with antidiabetic activities.

Recent developments made in the assessment of the antidiabetic potential of gymnema species - From 2016 to 2020.

BACKGROUND: In traditional herbal medicine, the Gymnema species has been well known for various therapeutic activities such as anti-diabetic, anti-inflammatory, anti-bacterial, anti-arthritic, anti-hyperlipidemic, cytotoxic, and immunostimulatory activities. This review is an effort to analyse all the recent studies done to explore the anti-diabetic potential of traditional Gymnema species. Gymnema sylvestre (Retz.) R.Br. ex Sm. is an important member of the Apocynaceae family that has been used to treat a variety of diseases, the most studied of which is diabetes. This action is mostly due to the pharmacologically active phytoconstituents present in its extract, which include gymnemic acids, triterpenoid saponin glycosides, and so on. Numerous other Gymnema species have also demonstrated a similar pharmacological action. INTRODUCTION: The goal of this study is to give a critical overview of the available data on Gymnema species that are used to treat diabetes. The major goal of this study is to give up-to-date knowledge on ethnopharmacology, botany, pharmacology, and structure-activity relationships of Gymnemaspecies from 2016 to 2020, as well as potential future research. The potential of using medicinal plants for alleviating symptoms of diabetes is recently being recognized. This review aims to summarize the available data and highlight both the potential and shortcomings of using Gymnema therapeutically. This knowledge can further be used to develop more therapeutically effective drugs derived from Gymnema. MATERIALS AND METHODS: Data for Gymnema species was obtained using a mix of several search terms from online databases such as PubMed, SCOPUS, and Europe PMC. Other literature surveys relevant to traditional knowledge, phytochemistry, pharmacology, or structure-activity relationship activity were also used as reference. Several methods by which Gymnema species extracts exert their effects have been investigated, and a summary of the newly discovered chemicals isolated from the plant in the previous five years has been provided. RESULTS: SAR based evaluation has been carried out for a total of 27 pharmacologically active compounds belonging to three species of Gymnema genus (Gymnema sylvestre, Gymnema latifolium, and Gymnema inodorum).These compounds demonstrated the critical significance of plant medicines for diabetes management. Numerous heterocyclic compounds have anti-diabetic action and may serve as a starting point for the design and identification of new diabetes inhibitors. CONCLUSIONS: This study aims to provide researchers with a better understanding of the antidiabetic potential Gymnema species, as well as an outline of prospective future developments. It was concluded after studying the evaluation done in the last 5 years that although extracts of Gymnema have shown good antidiabetic potential, further modifications in the structures could result in the development of more potent and safer compounds.

Identification of C21 Steroidal Glycosides from Gymnema sylvestre (Retz.) and Evaluation of Their Glucose Uptake Activities.

Gymnema sylvestre (Retz.) Schult is a multi-purpose traditional medicine that has long been used for the treatment of various diseases. To discover the potential bioactive composition of G. sylvestre, a chemical investigation was thus performed. In this research, four new C21 steroidal glycosides sylvepregosides A-D (1-4) were isolated along with four known compounds, gymnepregoside H (5), deacetylkidjoladinin (6), gymnepregoside G (7) and gymnepregoside I (8), from the ethyl acetate fraction of G. sylvestre. The structures of the new compounds were established by extensive 1D and 2D nuclear magnetic resonance (NMR) spectra with mass spectroscopy data. Compounds 1-6 promoted glucose uptake by the range of 1.10- to 2.37-fold, respectively. Compound 1 showed the most potent glucose uptake, with 1.37-fold enhancement. Further study showed that compounds 1 and 5 could promote GLUT-4 fusion with the plasma membrane in L6 cells. The result attained in this study indicated that the separation and characterization of these compounds play an important role in the research and development of new anti-diabetic drugs and pharmaceutical industry.

Assessment of Cota altissima (L.) J. Gay for phytochemical composition and antioxidant, anti-inflammatory, antidiabetic and antimicrobial activities.

Phytochemical profiles of essential oil (EO), fatty acids, and n-hexane (CAH), diethyl ether (CAD), ethyl acetate (CAE) and methanol extracts (CAM) of Cota altissima L. J. Gay (syn. Anthemis altissima L.) were investigated as well as their antioxidant, anti-inflammatory, antidiabetic and antimicrobial activites. The essential oil was characterized by the content of acetophenone (35.8%) and ß-caryophyllene (10.3%) by GC-MS/FID. Linoleic and oleic acid were found as main fatty acids. The major constituents of the extracts were found to be 5-caffeoylquinic acid, 3,5-dicaffeoylquinic acid, isorhamnetin glucoside, quercetin and quercetin glucoside by LC-MS/MS. Antioxidant activities of the extracts were determined by scavenging of DPPH and ABTS free radicals. Also, the inhibitory effects on lipoxygenase and α-glucosidase enzymes were determined. Antimicrobial activity was evaluated against Gram positive, Gram negative bacteria and yeast pathogens. CAM showed the highest antioxidant activity against DPPH and ABTS radicals with IC50 values of 126.60 and 144.40 µg/mL, respectively. In the anti-inflammatory activity, CAE demonstrated the highest antilipoxygenase activity with an IC50 value of 105.40 µg/mL, whereas, CAD showed the best inhibition of α-glucosidase with an IC50 value of 396.40 µg/mL in the antidiabetic activity. CAH was effective against Staphylococcus aureus at MIC = 312.5 µg/mL. This is the first report on antidiabetic, anti-inflammatory and antimicrobial activities of different extracts of C. altissima.

Assessment of Antihyperglycemic Effect and Acute Toxicity of the Aqueous Scorzonera undulata Extract in Rats.

AIM: The current study was carried out in order to assess the antihyperglycemic effect of Scorzonera undulata (S. undulata). Backgroud: Scorzonera undulata subsp. deliciosa (DC.) Maire is used in the Moroccan pharmacopeia for managing diabetes. OBJECTIVE: The objective of the study was to evaluate the anithyperglycemic activity in normal and streptozotocin (STZ)-induced diabetic rats as well as the acute toxicity of the aqueous extract of the roots of Scorzonera undulata (S. undulata). METHODS: This study investigated the effects of the root aqueous extract of Scorzonera undulata (AERSU) at a dose of 20 mg/kg on blood glucose levels in normal and streptozotocin(STZ)-induced diabetic rats and the acute toxicity of AERSU was examined. Histopathological examination, preliminary phytochemical investigation, determination of glycogen content and evaluation of α-amylase were also performed. RESULTS: Both single and repeated oral doses of AERSU (20 mg/kg) produced a significant reduction in blood glucose levels in normal and diabetic rats. Furthermore, repeated oral administration of AERSU during 15 days increased the glycogen content in the liver in both normal and diabetic rats, inhibited α- amylase activity and improved the histological architecture of the liver and pancreas in treated diabetic rats and ameliorated some biochemical parameters such as ALT and AST. In addition, the preliminary phytochemical investigation showed the richness of the roots of S. undulata in certain phytochemicals particularly in polyphenols. CONCLUSION: AERSU exhibits an evident antihyperglycemic activity. This pharmacological effect may be due to the protection of surviving pancreatic ß cells and hepatocytes, effect of α-amylase and the improvement of glycogen storage in the liver. The dose used in this study seems to be free of any toxicity.

Development of a new low-cost adsorbent functionalized with iron nanoparticles for removal of metformin from contaminated water.

An adsorbent was developed from the residues of Moringa oleifera Lam. seed husks functionalized with iron nanoparticles for subsequent application to the removal of metformin from contaminated water. The material, MOM-Fe3O4, was characterized using TEM, SEM imaging, and EDX analysis, which revealed that iron nanoparticles were retained in the pores. The application of MOM-Fe3O4 to waste water resulted in a 93.9% reduction in the metformin content, demonstrating the efficacy of the material. Kinetic and equilibrium data were fitted to the pseudo-first-order and Langmuir models, respectively. The thermodynamic parameters indicated an exothermic and reversible process. A high adsorption capacity, 65.01 mg g-1 at 298 K, demonstrated the potential of using the new material as a low-cost adsorbent for the removal of pharmaceuticals such as metformin.

Assessment of 28-day oral toxicity and antipyretic activity of the saline extract from Pilosocereus gounellei (Cactaceae) stem in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Pilosocereus gounellei is a plant found in the Brazilian Caatinga and is popular due to its traditional uses in the treatment of inflammation. The present study was conducted to investigate the sub-acute toxicity of the saline extract from the stem of P. gounellei. AIM OF THE STUDY: To evaluate the 28-day oral toxicity (through behavioral, biochemical, hematological, and morphological analysis) and the antipyretic activity of the extract in mice. MATERIALS AND METHODS: A single oral dose (250, 500, and 1000 mg/kg) was administered daily over 28 consecutive days to male and female mice. Body weight, food and water intake, blood biochemical and hematological parameters, and urine composition were recorded. Histopathological examinations of the liver, kidney, spleen, lungs, and heart were performed and oxidative stress in the organs was evaluated by lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), and nitrite analysis. The antipyretic effect of the 500 mg/kg dose was assessed using a yeast-induced pyrexia model. RESULTS: Oral administration of the extract over 28 days did not affect body weight gain, food and water consumption, body temperature, and hematological parameters in male and female mice. Blood glucose, total cholesterol, and triglyceride levels in male and female mice were reduced. Protein in the urine and histological alterations in both the liver and lungs were detected in male and female mice treated with the highest dose of the extract. SOD levels in the liver and the spleen increased significantly in both sexes, whereas lipid peroxidation decreased in the spleen of male mice. The extract also exerted an antipyretic effect after the first 60 min of the evaluation until the end of the observation duration (180 min). CONCLUSION: The saline extract from the stem of P. gounellei did not present significant toxic effects over 28 consecutive days and demonstrated antipyretic activity when administered orally. Moreover, the results suggest that the extract has potential hypoglycemic and hypolipidemic effects. Future studies are needed to investigate its pharmacological potential.

Antidiabetic Naphthoquinones and Their Plant Resources in Thailand.

Diabetes mellitus is the seventh leading cause of death globally. Ninety percent of the diabetic population suffers from type-2 diabetes, which still needs an effective, safe and economical oral hypoglycemic therapy. Plants are rich sources of various therapeutic molecules. More than 400 medicinal plants of interesting phytochemical diversity have been reported for their antidiabetic potential. Naphthoquinones are a group of phytochemicals, which have a wide range of pharmacological potential, including antidiabetic activity. Naphthoquinones exert their antidiabetic effects through various mechanisms such as the inhibition of α-glucosidase and protein tyrosine phosphatase 1B, increased glucose uptake in myocytes and adipocytes via glucose transporter type 4 (GLUT4) and GLUT2 translocations, enhanced peroxisome proliferator-activated receptor gamma (PPARγ) ligand activity, and by normalizing carbohydrate metabolizing enzymes in the liver. Moreover, naphthoquinone inhibits adipogenesis by both upstream and downstream regulation to control obesity, which is one of the important risk factors for diabetes. Naturally occurring naphthoquinones, as well as their plant sources, are therefore of interest for exploring their antidiabetic potential. The present review aims to overview the antidiabetic potential of naphthoquinones and their plant resources in Thailand.

Broad bean (Vicia faba L.) pods: a rich source of bioactive ingredients with antimicrobial, antioxidant, enzyme inhibitory, anti-diabetic and health-promoting properties.

This study was aimed at investigating the chemical composition (proximate, minerals, fatty acids and phenolic compounds) and the in vitro (antimicrobial, radical scavenging, anti-acetylcholinesterase and protein denaturing activities) and in vivo (anti-diabetic and histo-protective effects in alloxan-induced diabetic mice) biological activities of broad bean pods (BBPs), a food waste by-product material. The results showed that BBPs have high dietary fiber (57.46%), carbohydrate (18.93%) and protein (13.81%) content versus low fat content (<1%) contributing to a low energy value of 139.24 kcal per 100 g. Profiling of fatty acids showed an abundance of the essential polyunsaturated α-linolenic and linoleic acids, exhibiting an excellent nutritional quality as revealed by their low atherogenic and thrombogenic indices and their hypocholesterolemic properties. The methanol extract which exhibited the highest total phenolic, flavonoid and tannin contents was found to be the most active extract in terms of antimicrobial and anti-radical activities. In alloxan-induced diabetic mice, the oral administration of a methanol extract (500 mg per kg bw) attenuated the elevated levels of serum alanine aminotransferase (ALA), aspartate aminotransferase (AST), and alkaline phosphatase activities, and urea, uric acid, and creatinine. It effectively normalized the status of lipid profiles, mitigated oxidative stress through the activation of antioxidant enzymes (CAT, GPx and SOD), and alleviated oxidative stress-mediated histopathological changes in the pancreas, liver, kidney and testis. Compositional analysis by HPLC-PDA-ESI-MS/MS revealed the presence of flavan-3-ols (catechin, epicatechin and their derivatives), flavones (apigenin derivatives) and flavonols (glycosides of quercetin and kaempferol), among others. These findings suggest that BBPs may be an effective functional food for the management of diabetes and its complications.

Plants used to treat diabetes in Sri Lankan Siddha Medicine - An ethnopharmacological review of historical and modern sources.

INTRODUCTION AND BACKGROUND: In recent decades diabetes mellitus has become a considerable health problem in countries like Sri Lanka and results in an increasing economic burden hampering the social and economic development of these countries. About 60% to 70% of the rural population in Sri Lanka rely on indigenous medicinal systems as their main source for primary health care. Siddha (Tamil) Medicine is one of the four Sri Lankan traditional medicinal systems and it is practised mostly in the eastern and northern provinces of Sri Lanka where the majority of Tamils reside. AIM: The foundation of this study is a documentation of plant species recorded in historical and modern Sri Lankan Siddha Medical documents used to treat diabetes. Based on the systematic documentation and analysis of Siddha concepts about diabetes and its signs and preparations used to treat diabetes in Sri Lankan Siddha Medicine, the plant species included in these preparations (excluding globally or very widely used, very well studied species) were evaluated in terms of the current state-of-the-art about these species' pharmacology and effectiveness in order to lay a foundation for their further development. METHOD: Historic and modern Sri Lankan university texts books in Tamil were used as sources for information on diabetes Siddha concepts and antidiabetic Sri Lankan Siddha Medicine preparations. Information on the known antidiabetic effects of extracts and compounds obtained from these species were used in order to assess the current state of the art of these species. RESULTS AND DISCUSSION: Information of ingredients, preparation methods, amount of ingredients used, and dosages of 60 antidiabetic Sri Lankan Siddha Medicine preparations were obtained. Animal parts including marine organisms, inorganic substances, and plants are the three types of ingredients used. Overall 171 plant species in 73 families were documented. Senna auriculata (L.) Roxb. (Fabaceae) was identified as the most frequently cited species. Globally distributed and very well studied plants were excluded in the pharmacological and clinical literature review which includes 123 plant species. The majority (48%) of the plant species reviewed were studied up to in vivo level as the current maximum level of scientific evidence available. Followed by 41% of species have not been studied for antidiabetic activities or did not show antidiabetic activity. Moreover, 6% and 5% were studied up to in vitro and in clinical levels, respectively. The majority of the species were studied only in the models that represent type 1 diabetes. CONCLUSION: This is the first study systematically assessing the importance of preparations and plants used in antidiabetic Sri Lankan Siddha Medicine preparations. Antidiabetic plants are a crucial health care resource in Sri Lankan Siddha Medicine. This study also identified a wide range of methodological problems in the studies conducted so far. More and better type 2 diabetes models should be employed in future studies. This comprehensive review creates the basis for a more systematic study of these local resources.

Knowledge and demand for medicinal plants used in the treatment and management of diabetes in Nyeri County, Kenya.

ETHNOPHARMACOLOGICAL RELEVANCE: Non communicable diseases are currently a major health challenge facing humanity. Nyeri County has one of the highest diabetes prevalence in Kenya (12.6%), compared to the country's prevalence of 5.6%. The purpose of the study was to document; diabetes knowledge, medicinal plants and demand for the services of traditional medicine practitioners, in the management and treatment of diabetes. METHODS: A cross-sectional study was carried out in the six constituencies in Nyeri, using pre-tested semi-structured questionnaires. Thirty practicing traditional medicine practitioners were purposively selected for the study. Field observation and identification was carried out on all plants that were cited during the interview. Plant samples were collected and voucher specimen deposited in the University of Nairobi Herbarium in the - School of Biological Sciences. RESULTS: The study revealed 30 plant species in 28 genera and 23 families that are used by the traditional medicine practitioners to treat and manage diabetes. Demand for traditional medicine practitioners' services in the treatment of diabetes is low and often occurs when conventional drugs fail. CONCLUSION: Interaction with the TMPs unveiled significant diversity of potential anti diabetic medicinal plants and in-depth ethnobotanical knowledge that they possessed. Preference for traditional herbal medicine was low despite wide ethnobotanical knowledge in the face of high prevalence of diabetes in the locality. The findings form the basis of pharmacological studies for standardization of the documented ethnomedicine used in the treatment and management of diabetes in the study area.

Phytochemical Comparison of the Water and Ethanol Leaf Extracts of the Cree medicinal plant, Sarracenia purpurea L. (Sarraceniaceae).

PURPOSE: The Cree of Eeyou Istchee in Northern Quebec identified Sarracenia purpurea L. as an important plant for the treatment of Type 2 diabetes. Traditionally the plant is used as a decoction (boiling water extract) of the leaf, however, in order to study the extract in a laboratory setting, an 80% ethanol extract was used. In this study, the phytochemistry of both extracts of the leaves was compared and quantified. METHODS: Two S. purpurea leaf extracts were prepared, one a traditional hot water extract and the other an 80% ethanol extract. Using UPLC-ESI-MS, the extracts were phytochemically compared for 2 triterpenes, betulinic acid and ursolic acid, using one gradient method and for 10 additional substances, including the actives quercetin-3-O-galactoside and morroniside, using a different method. RESULTS: The concentrations of the nine phenolic substances present, as well as an active principle, the iridoid glycoside morroniside, were very similar between the two extracts, with generally slightly higher concentrations of phenolics in the ethanol extract as expected. However, two triterpenes, betulinic acid and ursolic acid, were 107 and 93 times more concentrated, respectively, in the ethanol extract compared to the water extract. CONCLUSION: The main phytochemical markers and most importantly the antidiabetic active principles, quercetin-3-O-galactoside and morroniside, were present in similar amounts in the two extracts, which predicts similar bioactivity.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Evaluation by microarray of the potential safety of Sarracenia purpurea L. (Sarraceniaceae) a traditional medicine used by the Cree of Eeyou Istchee.

PURPOSE: The purpose of this study was to assess safety of the traditional antidiabetic extracts of either S. purpurea or its lead active principle, morroniside at the transcriptional level. The overarching objective was to profile and validate transcriptional changes in the cytochrome P450 family of genes, in response to treatment with S. purpurea ethanolic extract or its lead active, morroniside. METHODS: Transcriptional activity was profiled using a 19K human cDNA microarray in C2BBe1 cells, clone of Caco-2 intestinal cells, which are a model of first-pass metabolism (1, 2). Cells were treated with S. purpurea extract for 4 and 24 hrs, as well as the pure compound morroniside for 4 hrs, to determine their effects. RESULTS: No evidence of cytochrome P450 transcriptome regulation or of transcriptional activation of other diabetes relevant mRNA was detected after rigorous quantitative-PCR validation of microarray results. CONCLUSION: Our data do not support a transcriptional mechanism of action for either S. purpurea extract or its lead active, morroniside. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

BAY 41-2272 activates host defence against local and disseminated Candida albicans infections

In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272), a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation. .

Anti-diabetic effect of dietary mango (Mangifera indica L.) peel in streptozotocin-induced diabetic rats.

BACKGROUND: In the present study, the composition of mango peel powder (MPP) collected from the mango pulp industry was determined and the effect of MPP on ameliorating diabetes and its associated complications was studied. RESULTS: Mango peel was rich in polyphenols, carotenoids and dietary fibre. Peel extract contained various bioactive compounds and was found to be rich in soluble dietary fibre. Peel extract exhibited antioxidant properties and protected against DNA damage. Therefore, the effect of peel on ameliorating diabetes was investigated in a rat model of diabetes. A significant increase in urine sugar, urine volume, fasting blood glucose, total cholesterol, triglycerides and low density lipoprotein, and decrease in high density lipoprotein were observed in the rats; however, these parameters were ameliorated in diabetic rats fed with diet supplemented with mango peel at 5% and 10% levels in basal diet. Treatment of diabetic rats with MPP increased antioxidant enzyme activities and decreased lipid peroxidation in plasma, kidney and liver compared to untreated diabetic rats. Glomerular filtration rate and microalbuminuria levels were ameliorated in MPP treated diabetic group. CONCLUSIONS: Mango peel, a by-product, can be used as an ingredient in functional and therapeutic foods.

An in vitro study reveals nutraceutical properties of Ananas comosus (L.) Merr. var. Mauritius fruit residue beneficial to diabetes.

BACKGROUND: Rapid urbanisation and nutritional transition is fuelling the increased global incidence of type 2 diabetes. Pineapple fruit residue was explored for its nutraceutical properties as an alternative or adjunct to currently available treatment regime. Ethyl acetate and methanolic extracts of pineapple fruit residue were evaluated for anti-diabetic activity in cell free and cell based systems. Specifically, we assessed: (1) antioxidant potential, (2) anti-glycation potential, (3) carbohydrate digestive enzyme inhibition, and (4) lipid accumulation and glycerol-3-phosphate dehydrogenase activity in differentiating 3T3-L1 cells. RESULTS: The active components in the ethyl acetate and methanolic extracts were identified as sinapic acid, daucosterol, 2-methylpropanoate, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, methyl 2-methylbutanoate and triterpenoid ergosterol using DART/HRMS and ESI/HRMS. Micronutrient analysis revealed the presence of magnesium, potassium and calcium. Adipogenic potential, anti-glycation property of the ethyl acetate extract, and DNA damage protection capacity of the methanolic extract are promising. CONCLUSION: Results from this study clearly indicate that pineapple fruit residue could be utilised as a nutraceutical against diabetes and related complications.

Safety assessment of aqueous extract from leaf Smallanthus sonchifolius and its main active lactone, enhydrin.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves of Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson (yacon) have been used since pre-Columbian times in the Andean region to prepare medicinal herbal tea with beneficial health properties. However, there are still disagreements about the safe use. This work was carried out to evaluate the toxicity profile of both, 10% decoction of yacon leaves and their major active lactone, enhydrin. MATERIALS AND METHODS: In vitro cytotoxicity assays were performed with Hep-G2, COS1, CHO-K1 and Vero cell lines using a test of metabolic competence based upon assessment of mitochondrial performance. In vivo toxicity study was performed in adult Wistar rats. In the acute oral toxicity each group of rats was orally given a single dose of 10% decoction or enhydrin. General condition, behavior and mortality were recorded for up to 14 days post treatment. In subchronic toxicity studies, both products were given orally for 90 days to rats. Body weight and food intakes were observed weekly. Hematological, clinical chemistry parameters and organ weight were determined in all animals at the end of the experimental period. RESULTS: Cell viability decreased in a concentration dependent fashion when cells were incubated with 2-200 µg of 10% decoction and 0.015-7.5 µg of enhydrin. In acute study in rats, there were no deaths or signs of toxicity observed after oral administration of single doses of 10% decoction or enhydrin at any dose level up to the highest dose tested (14.0 g/kg and 0.32 g/kg, respectively). In subchronic studies in rats, both products administered orally for 90 days at daily doses of 0.07, 0.14 and 0.28 g 10% decoction/kg and 0.4, 0.8 and 8.0 mg enhydrin/kg, did not caused haematological, biochemical and histological alterations. CONCLUSIONS: The results presented in this paper lead us to the conclusion that the use of 10% decoction and enhydrin is safe in rat at doses in which it is demonstrated the hypoglycaemic effect.

Effect of flaxseed gum on reduction of blood glucose and cholesterol in type 2 diabetic patients.

The effects of ingestion of flaxseed gum on blood glucose and cholesterol, particularly low-density lipoprotein cholesterol, in type 2 diabetes were evaluated. Flaxseed gum was incorporated in wheat flour chapattis. Sixty patients of type 2 diabetes were fed a daily diet for 3 months, along with six wheat flour chapattis containing flaxseed gum (5 g), as per the recommendations of the American Diabetic Association. The control group (60 individuals) consumed an identical diet but the chapattis were without gum. The blood biochemistry profiles monitored before starting the study and at monthly intervals showed fasting blood sugar in the experimental group decreased from 154 ± 8 mg/dl to 136 ± 7 mg/dl (P=0.03) while the total cholesterol reduced from 182 ± 11 mg/dl to 163 ± 9 mg/dl (P=0.03). Results showed a decrease in low-density lipoprotein cholesterol from 110 ± 8 mg/dl to 92 ± 9 mg/dl (P=0.02). The study demonstrated the efficacy of flax gum in the blood biochemistry profiles of type 2 diabetes.

In-vivo assessment of antidiabetic and antioxidant activities of grapevine leaves (Vitis vinifera) in diabetic rats.

The acute and the subacute (15 days) hypoglycaemic and antihyperglycaemic effect of the two different doses (250, 500 mg/kg) of the aqueous extract from the leaves of Vitis vinifera L. were evaluated in this study. The aqueous extract was further fractionated through successive solvent extractions and the acute effect of different doses of its subfractions, 25 mg/kg for ethylacetate fraction, 80 mg/kg for n-butanol fraction and 375 mg/kg for remaining aqueous fraction were investigated using normal, glucose-hyperglycaemic and streptozotocin-induced diabetic rats. Blood glucose levels were measured according to the glucose oxidase method. Tolbutamide was used as a reference drug at a dose of 100 mg/kg. The antioxidant activity of the test samples was studied in the liver, kidney and heart tissues of diabetic rats by measuring malondialdehyde (MDA) and glutathion (GSH) levels. All results were compared to the diabetic control groups. The results showed that EtOAc Fr. was rich in polyphenolics and possessed a significant antihyperglycaemic and antioxidant activity equipotent with the reference hypoglycaemic agent (tolbutamide), when evaluated in diabetic rats.