Antidiabetic activity of ethanolic extract of tubers of Dioscorea alata in alloxan induced diabetic rats

Genome-Wide Identification and Evolutionary Analysis of Receptor-like Kinase Family Genes Provides Insights into Anthracnose Resistance of Dioscorea alata

Dioscorea alata, commonly known as "greater yam", is a vital crop in tropical and subtropical regions of the world, yet it faces significant threats from anthracnose disease, mainly caused by Colletotrichum gloeosporioides. However, exploring disease resistance genes in this species has been challenging due to the difficulty of genetic mapping resulting from the loss of the flowering trait in many varieties. The receptor-like kinase (RLK) gene family represents essential immune receptors in plants. In this study, genomic analysis revealed 467 RLK genes in D. alata. The identified RLKs were distributed unevenly across chromosomes, likely due to tandem duplication events. However, a considerable number of ancient whole-genome or segmental duplications dating back over 100 million years contributed to the diversity of RLK genes. Phylogenetic analysis unveiled at least 356 ancient RLK lineages in the common ancestor of Dioscoreaceae, which differentially inherited and expanded to form the current RLK profiles of D. alata and its relatives. The analysis of cis-regulatory elements indicated the involvement of RLK genes in diverse stress responses. Transcriptome analysis identified RLKs that were up-regulated in response to C. gloeosporioides infection, suggesting their potential role in resisting anthracnose disease. These findings provide novel insights into the evolution of RLK genes in D. alata and their potential contribution to disease resistance.

Modulation of Oxidative Stress and Glycemic Control in Diabetic Wistar Rats: The Therapeutic Potential of Theobroma cacao and Camellia sinensis Diets

  Background Diabetes mellitus is a complex metabolic disorder characterized by oxidative stress and impaired glycemic control. This study investigates the therapeutic potential of Theobroma cacao and Camellia sinensis diets in diabetic Wistar rats and assesses their impact on oxidative stress markers and blood glucose levels. Methods  In this experiment, eight groups of six male Wistar rats (n = 12.5%), aged 8 to 12 weeks, were carefully set up to see how different treatments for diabetes and oxidative stress affected the two conditions. The random selection process was implemented to minimize any potential bias and ensure that the results of the study would be representative of the general population of Wistar rats. The groups were as follows: a nondiabetic control group (NDC) served as the baseline, while diabetes was induced in the alloxan monohydrate group (150 mg/kg). Another group was given the standard drug metformin (M, 100 mg/kg), and two control groups that did not have diabetes were given extracts of Theobroma cacao (TC, 340 mg/kg) and Camellia sinensis (CS, 200 mg/kg). Three groups of diabetic rats were given a mix of these treatments. Theobroma cacao and Camellia sinensis extracts were given at set doses (TC, 340 mg/kg; CS, 200 mg/kg), along with 150 mg/kg of a drug that causes diabetes. Over a 21-day period, oxidative stress parameters such as glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione reductase (GSHrd) levels, and blood glucose were carefully measured to check for signs of oxidative stress and diabetes progression Results Considerable differences in GSH levels were noted across the groups, with the highest GSH concentration found in the group treated with the inducing drug, while the lowest GSH levels were observed in the diabetic group that was administered both Theobroma cacao and Camellia sinensis (p < 0.001). MDA levels also varied, with the diabetic group treated with Theobroma cacao having the highest MDA concentration (3.54 ± 0.29 μmol/L) and the nondiabetic control group treated with Camellia sinensis exhibiting the lowest MDA levels (1.66 ± 0.08 μmol/L; p < 0.001). SOD activity was highest in the standard drug group and lowest in the diabetic group treated with Theobroma cacao. GSH activity was notably higher in the diabetic groups that received dietary interventions (p < 0.001). Blood glucose levels showed diverse responses, with the standard drug group experiencing a substantial reduction, while the inducing drug group exhibited a consistent increase. Conclusion The study highlights the significant impact of dietary interventions with Theobroma cacao and Camellia sinensis on oxidative stress markers and blood glucose regulation in diabetic Wistar rats. These findings suggest a potential role for these dietary components in mitigating oxidative stress and improving glycemic control in diabetes, although further research is warranted to elucidate the underlying mechanisms and clinical implications.

Dioscin: Therapeutic potential for diabetes and complications

Diabetes mellitus is a widespread metabolic disorder with increasing incidence worldwide, posing a considerable threat to human health because of its complications. Therefore, cost-effective antidiabetic drugs with minimal side effects are urgently needed. Dioscin, a naturally occurring compound, helps to reduce the complications of diabetes mellitus by regulating glucose and lipid metabolism, protecting islet β cells, improving insulin resistance, and inhibiting oxidative stress and inflammatory response. Plant-derived dioscin reduces the risk of toxicity and side effects associated with chemically synthesized drugs. It is a promising option for treating diabetes mellitus because of its preventive and therapeutic effects, which may be attributed to a variety of underlying mechanisms. However, data compiled by current studies are preliminary. Information about the molecular mechanism of dioscin remains limited, and no high-quality human experiments and clinical trials for testing its safety and efficacy have been conducted. As a resource for research in this area, this review is expected to provide a systematic framework for the application of dioscin in the treatment of diabetes mellitus and its complications.

Common Ayurvedic, Chinese traditional and Unani antidiabetic formulations- a review

Diabetes mellitus is the most widely recognized endocrine disorder which is influencing a bigger populace on the planet. There are various causes of diabetes, such as physical inactivity, obesity, family history, race, and age. Diabetes mellitus is associated with some life-threatening complications, such as neuropathy, nephropathy, various eye diseases or retinopathy, and cardiovascular disorders. Many synthetic antihyperglycemic agents are available in the market for the treatment of diabetes and its complications. But, due to some serious side effects of these synthetic agents, people are opting for herbal remedies and, therefore, they are now becoming popular. Herbal remedies have lesser side effects and higher affordability and therefore can be preferably used over synthetic agents for a long-term disorder like diabetes mellitus. In the present study, scientific research and review studies on the topic were collected from Science Direct, Scopus, PubMed, Google Scholar, and other relevant sources. The references of all the articles were screened manually for any additional information on popular polyherbal formulations in traditional Ayurvedic, Chinese, and Unani medicinal systems. It is found that these polyherbal formulations are studied for anti-diabetic potential. Furthermore, some are also investigated for mechanism of action of anti-diabetic effects. This review highlights various Ayurvedic, Chinese, and Unani polyherbal formulations commonly utilized in the management of diabetes mellitus along with their pre-clinical and clinical investigations, which will enhance the existing knowledge of the researchers.

Could consumption of yam (Dioscorea) or its extract be beneficial in controlling glycaemia: a systematic review

Yam (Dioscorea spp.) and its associated extracts have been shown to possess a variety of biological activities and identified as beneficial in the control of glycaemia in patients with type II diabetes mellitus (T2DM). The objective was to conduct a systematic search of the literature to investigate whether yam and its extract can improve glycaemia and whether the consumption of yam could be beneficial for managing T2DM. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Population, Invention, Comparison and Outcome framework, three databases (PubMed, Scopus and Web of Science) were searched using a key term strategy. Strict inclusion criteria were employed to identify all relevant and available studies. The quality of these studies was assessed using SYRCLE's Risk of Bias tool. Ten studies were included, and all studies consisted of findings from rodent models of diabetes, including animals consuming high fat diets or genetic models of diabetes. All ten studies showed that the consumption of yam and/or its extracts (containing dioscin, dioscorin, diosgenin, DA-9801/02 or Chinese yam polysaccharides) improved glycaemia. These included improvements in fasting blood glucose and reductions in glucose and increase in insulin levels following a glucose tolerance test. Furthermore, significant changes in body weight and adiposity were observed in nine studies, these included improvements in lipid biomarkers in four and reductions in inflammatory markers in one. The current work indicates that the consumption of yam or its extracts can be beneficial for improving blood glucose; however, the molecular mechanism for these effects remains largely unknown. Future trials on human subjects are warranted.

Ethnomedicinal study of medicinal plants used by Mizo tribes in Champhai district of Mizoram, India

BACKGROUND

Medicinal plants have been used countless times for curing diseases mainly in developing countries. They are easily available with little to no side effects when compared to modern medicine. This manuscript encompasses information on ethnomedicinal plants in Champhai district, located in the North East Region (NER) of India. The region lies within Indo-Burma biodiversity hotspot. This study will be the first quantitative report on the ethnomedicinal plants used by the local tribes of this region. Knowledge of medicinal plants is mostly acquired by word of mouth, and the knowledge is dying among the local youths with the prevalence of modern medicine. Hence, there is urgency in deciphering and recording such information.

METHODS

Information was gathered through interviews with 200 informants across 15 villages of the Champhai district. From the data obtained, we evaluate indices such as used report (UR), frequency of citation (FC), informant consensus factor (Fic), cultural values (CVs) and relative importance (RI) for all the plant species. Secondary data were obtained from scientific databases such as Pubmed, Sci Finder and Science Direct. The scientific name of the plants was matched and arranged in consultation with the working list of all plant species ( http://www.theplantlist.org ).

RESULTS

Totally, 93 plant species from 53 families and 85 genera were recorded. The most common families are Euphorbiaceae and Asteraceae with six and five species representatives, respectively. Leaves were the most frequently used part of a plant and were usually used in the form of decoction. Curcuma longa has the most cultural value (27.28 CVs) with the highest used report (136 FC), and the highest RI value was Phyllanthus emblica. The main illness categories as per Frequency of citation were muscle/bone problem (0.962 Fic), gastro-intestinal disease (0.956 Fic) and skin care (0.953 Fic).

CONCLUSION

The people of Mizoram living in the Champhai district have an immense knowledge of ethnomedicinal plants. There were no side effects recorded for consuming ethnomedicinal plants. We observed that there is a scope of scientific validation of 10 plant species for their pharmacological activity and 13 species for the phytochemical characterisation or isolation of the phytochemicals. This might pave the path for developing a scientifically validated botanical or lead to semisyntheic derivatives intended for modern medicine.

A Family of [Zn6] Complexes from the Carboxylate-Bridge-Supported Assembly of [Zn2] Building Units: Synthetic, Structural, Spectroscopic, and Systematic Biological Studies

The three discrete [Zn₆] complexes [Na₃Zn₆(cpdp)₃(μ-Bz)₃(CH₃OH)₆][ZnCl₄][ZnCl₃(H₂O)]·3CH₃OH·1.5H₂O (1), [Na₃Zn₆(cpdp)₃(μ-p-OBz)₃(CH₃OH)₆]·2H₂O (2), and [Na₃Zn₆(cpdp)₃(μ-p-NO₂Bz)₃(CH₃OH)₆]Cl₃·2H₂O (3), supported by the carboxylate-based multidentate ligand N,N'-bis[2-carboxybenzomethyl]-N,N'-bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol (H₃cpdp), have been successfully synthesized and fully characterized (Bz = benzoate; p-OBz = dianion of p-hydroxybenzoic acid; p-NO₂Bz = p-nitrobenzoate). The complexes have been characterized by elemental analysis, FTIR, UV-vis, NMR spectroscopy, PXRD, and thermal analysis, including single-crystal X-ray crystallography of 1 and 2. The molecular architectures of 1-3 are built from the self-assembly of their corresponding [Zn₂] units, which are interconnected to the central [Na₃(CH₃OH)₆]³⁺ core by six endogenous benzoate groups, with each linking one Zn(II) and one Na(I) ion in a μ₂:η¹:η¹-syn-anti bidentate fashion. The composition of the (cpdp^3-)₃/(Zn²⁺)₆ complexes in 1-3 has been observed to be 1:2, on the basis of the UV-vis titration and NMR spectroscopic results, which is further supported by X-ray crystallography. Systematic biological studies performed with a mice model suggested possible antidiabetic efficacy as well as anticancer activities of the complexes. When complexes 1-3 were administered intraperitoneally in mice, 1 showed a lowering in the blood glucose level, overall maintenance of the pancreatic tissue mass, restriction of DNA damage in pancreatic cells, and retention of lipid droplet (LD) frequency, whereas 2 and 3 showed hepatic tissue mass consistency by inhibiting the DNA damage in hepatic cells, prior to the exposure to a potent diabetic inducer, alloxan (ALX). Similar trends of results were observed in inhibiting the generation of reactive oxygen species (ROS) in the pancreatic and hepatic cells, as examined by spectrofluorometric methods. Thus, 1 seems to be a better compound for overall diabetic management and control, whereas 2 and 3 seem to be promising compounds for designing chemopreventive drugs against hepatic carcinoma.

In Vitro & In Vivo Anti-Hyperglycemic Potential of Saponins Cake and Argan Oil from Argania spinosa

The Argan tree (Argania spinosa. L) is an evergreen tree endemic of southwestern Morocco. For centuries, various formulations have been used to treat several illnesses including diabetes. However, scientific results supporting these actions are needed. Hence, Argan fruit products (i.e., cake byproducts (saponins extract) and hand pressed Argan oil) were tested for their in-vitro anti-hyperglycemic activity, using α-glucosidase and α-amylase assays. The in-vivo anti-hyperglycemic activity was evaluated in a model of alloxan-induced diabetic mice. The diabetic animals were orally administered 100 mg/kg body weight of aqueous saponins cake extract and 3 mL/kg of Argan oil, respectively, to evaluate the anti-hyperglycemic effect. The blood glucose concentration and body weight of the experimental animals were monitored for 30 days. The chemical properties and composition of the Argan oil were assessed including acidity, peroxides, K232, K270, fatty acids, sterols, tocopherols, total polyphenols, and phenolic compounds. The saponins cake extract produced a significant reduction in blood glucose concentration in diabetic mice, which was better than the Argan oil. This decrease was equivalent to that detected in mice treated with metformin after 2–4 weeks. Moreover, the saponins cake extract showed a strong inhibitory action on α-amylase and α-glucosidase, which is also higher than that of Argan oil.

Characterization of an Endemic Plant Origanum grosii from Morocco: Trace Element Concentration and Antihyperglycemic Activities

Origanum genus is one of the most widely used herbs in folk medicine for its biological properties. The present investigation aims to characterize, for the first time, endemic Origanum grosii collected from the Taounate region, Morocco. This characterization was realized by determining the concentration of metals in different parts of the plant (flowers, leaves, and stems) by ICP-MS, and the results were studied statistically by Principal Component Analysis (PCA). Phytochemical screening with the dosage of polyphenols and flavonoids has been conducted. To know more about this species, antihyperglycemic tests have been performed to highlight the presence or absence of the antidiabetic effect for this plant. An Oral Glucose Tolerance Test (OGTT) has been performed on normal mice which were divided into two groups of six mice each. Group 1 (control group) was treated with distilled water, and group 2 was treated with an aqueous extract of O. grosii by gavage at 150 mg/kg. Digestive enzyme α-amylase inhibition assay has also been evaluated to study the inhibition effect of the studied extract using acarbose as a control. The results showed that the leaves exhibited a high concentration of trace elements (Ca, Mg, and K) and total absence of heavy metals, which were found in small quantities (Cr, Ni, and B) on the stems, and this makes the plant safe to use. On the other hand, tannins, flavonoids, triterpenes, and steroids were the major families strongly present in this species. The antidiabetic results showed that O. grosii have significantly reduced postprandial hyperglycemia after glucose loading in normal rats. It showed also that this species has a significant antihyperglycemic activity reflected by the inhibition of α-amylase. The one responsible for this property could be the synergy between the trace elements and the nature of the chemical families of O. grosii species, which can make this plant useful in the management of postprandial hyperglycemia.

Antidiabetic profiling, cytotoxicity and acute toxicity evaluation of aerial parts of Phragmites karka (Retz.)

ETHNOPHARMACOLOGICAL RELEVANCE

Phragmites karka (Retz.) of family Poaceae is a pristine tropical plant that is well known to the local healers for ailments of diabetes, fever, diarrhea and CNS depression but lacks the scientific evidence behind its traditional usage. Hence, we explicated this plant to find the scientific basis of its traditional utilization.

AIM OF THE STUDY

The current study aims to find out the antidiabetic potential, toxicity after oral administration and in vitro cytotoxic activity of aerial parts of the plant on HeLa cells.

METHODS

The plant was extracted with methanol by maceration and the crude extract was then subjected to solvent partitioning with modified Kupchan method for preparing several fractions. Phytochemical screening and total phenolic content of the plant was first determined through established procedures. Acute toxicity of the plant was studied by orally administering a single high dose (5000 mg/kg) of drug. Cytotoxicity of the methanolic plant extract was determined by measuring the percentage of cell viability on human cervical cancer cell lines, HeLa. In vitro antidiabetic activity was determined through iodine starch and DNSA (3,5-dinitrosalicylic acid) method of α-amylase inhibition. Finally, in vivo oral glucose tolerance test and alloxan induced antidiabetic activity test was performed at 150 and 300 mg/kg body weight doses of plant extract to confirm the in vivo antidiabetic activity.

RESULTS

No mortality was demonstrated by Phragmites karka in the acute toxicity test. However, signs of cellular toxicity was observed and histopathological studies on major organs exhibited necrosis in liver and kidney. In vitro cytotoxicity assay revealed the death of HeLa cells by DCM (dichloromethane) and n-hexane fractions of plant extract at 100 and 10 μg/mL concentrations. The IC50 value of the fractions were later evaluated by MTT assay (316.1 and 96.7 μg/mL for n-hexane and DCM fractions, respectively). In the iodine starch and DNSA method of α-amylase enzyme inhibitory activity test, substantial inhibition of enzyme was observed with the IC50 values of 2.05 and 2.08 mg/mL, respectively. In the in vivo antidiabetic activity test, considerable reduction in blood glucose level of diabetic mice was detected in both oral glucose tolerance test and alloxan induced antidiabetic activity test. In addition, the microscopic examination of pancreas showed noticeable recovery of pancreatic β cells and the blood lipid profile analysis represented a significant (p < 0.05) reduction of total cholesterol, LDL (low density lipoprotein) and triglyceride level in plant extract treated mice.

CONCLUSION

Results of this study reveals that the Phragmites karka extract is toxic at cellular level after oral administration and cytotoxic when tested on HeLa cells. The plant also evidenced hypoglycemic property, possibly through the inhibition of α-amylase enzyme and recovered the pancreatic beta cells along with the improvement of lipid profile of diabetic mice. However, robust studies on this plant is required to isolate the bioactive compounds, elucidate structures and evaluate their mechanism of actions in support of our findings.

CLASSIFICATION

Toxicology and Safety, Quality Traditional Medicine.

Hypoglycemic and Antihyperglycemic Activities of 80% Methanol Root Extract of Acanthus polystachyus Delile (Acanthaceae) in Type 2 Diabetic Rats

Background

The morbidity and mortality rate from diabetic mellitus are increasing in the world especially in low- and middle-income countries; hence, it is necessary to evaluate the efficacy and safety of medicinal plants to support existing drugs in treating diabetes mellitus. Therefore, the aim of this study was to evaluate the hypoglycemic effect of 80% methanol root extract of Acanthus polystachyus in normoglycemic, hyperglycemic, and streptozotocin–nicotinamide induced diabetic rats.

Methods

Male albino Wistar rats were divided into five groups (n=6) in all three models. In all models, group one rats served as a negative control and were received vehicle (10mL/kg distilled water), whereas group two (APRE100), three (APRE200), and four (APRE400) were treated with 100, 200, and 400mg/kg of extract, respectively, and group five were treated with glibenclamide (5mg/kg) and served as a positive control. Blood glucose levels were measured at different time points by taking blood from their tails. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test to carry out comparisons between and within-group and P < 0.05 was considered as statistically significant.

Results

The root of Acanthus polystachyus reduces peak blood sugar levels significantly after the loading of oral glucose at all tested doses. In streptozotocin–nicotinamide-induced type 2 diabetic rats, the daily oral administration of the crude extracts showed a significant reduction of blood glucose level at all tested doses compared to the negative control group. However, the extract did not reduce blood glucose levels in normoglycemic rats at all tested doses compared to both negative and positive control.

Conclusion

From this study, it can be concluded that the root extract of Acanthus polystachyus showed an antihyperglycemic effect in hyperglycemic and diabetic rats but lack hypoglycemic effect in normoglycemic rats. Hence, the plant root may be a good candidate for the development of new antidiabetic drugs.

The Dioscorea Genus (Yam)-An Appraisal of Nutritional and Therapeutic Potentials

The quest for a food secure and safe world has led to continuous effort toward improvements of global food and health systems. While the developed countries seem to have these systems stabilized, some parts of the world still face enormous challenges. Yam (Dioscorea species) is an orphan crop, widely distributed globally; and has contributed enormously to food security especially in sub-Saharan Africa because of its role in providing nutritional benefits and income. Additionally, yam has non-nutritional components called bioactive compounds, which offer numerous health benefits ranging from prevention to treatment of degenerative diseases. Pharmaceutical application of diosgenin and dioscorin, among other compounds isolated from yam, has shown more prospects recently. Despite the benefits embedded in yam, reports on the nutritional and therapeutic potentials of yam have been fragmented and the diversity within the genus has led to much confusion. An overview of the nutritional and health importance of yam will harness the crop to meet its potential towards combating hunger and malnutrition, while improving global health. This review makes a conscious attempt to provide an overview regarding the nutritional, bioactive compositions and therapeutic potentials of yam diversity. Insights on how to increase its utilization for a greater impact are elucidated.

Potential of Neglected and Underutilized Yams (Dioscorea spp.) for Improving Nutritional Security and Health Benefits

Food and nutritional security are the major concerns in many countries of the world and may have potential to contribute to sustainable food systems under climate change. To address the food and nutritional insecurity, it has become extremely important to diversify the present-day agricultural system as well as to search for alternative food and feed ingredients. Some wild root and tuber crops occupy a remarkable position toward food security of the developing world due to their high calorific value and superior carbohydrate content. Yam (Dioscorea spp.) provides food and medicines to millions of people in the world especially in the tropics and sub tropics. It is recognized as the fourth most important tuber crop after potatoes, cassava, and sweet potatoes. It contributes about 10% of the total root and tubers production around the world. Yams also considered as famine food and plays a prime role in the food habit of small and marginal rural families and forest-dwelling communities during the food scarcity periods. These species are unique for their food, medicinal and economic values but their wider utilization is limited due to the presence of anti-nutritional compositions. This paper describes the ethnobotany of yam species in relation to their nutritional, anti-nutritional and pharmacological properties and highlights the potentiality for food and nutritional security for combating the “hidden hunger” caused by micronutrient deficiencies.

Antidiabetic and protective effects of the aqueous extract of Arbutus unedo L. in streptozotocin-nicotinamide-induced diabetic mice

Background

Diabetes mellitus (DM) is currently a major health problem and the most common chronic disease worldwide. Traditional medicinal plants remedies remain a potential adjunct therapy to maintain better glycemic control while also imparting few side-effects. Arbutus unedo L. has been traditionally used to manage several diseases including diabetes. This study was undertaken to contribute the validation of the traditional use of Arbutus unedoL. (Ericaceae) in the treatment of diabetes.

Methods

In-vitro antidiabetic effect of the A. unedo roots aqueous extract was conducted using α-glucosidase and α-amylase assays. While in-vivo antidiabetic activity was conducted using streptozotocin-nicotinamide (STZ-NA) induced diabetic mice. Diabetic animals were orally administered the aqueous extract in 500 mg/kg of body weight to assess the antidiabetic effect. The blood glucose level and body weight of the experimental animals were monitored for 4 weeks. In addition, the histopathological examination of the treated mice pancreas was also conducted to observe the changes of β-cells during the treatment process.

Results

The extract produced a significant decrease in blood glucose level in diabetic mice. This decrease was equivalent to that which observed in mice treated with a standard after 2–4 weeks. In addition, the plant extract exhibited a potent inhibitory effect on α-amylase and α-glucosidase activity with IC50 values of 730.15±0.25 μg/mL and 94.81±5.99 μg/mL, respectively. Moreover, the histopathologic examination of the pancreas showed a restoration of normal pancreatic islet cell architecture which observed in the diabetic mice treated with plant extract.

Conclusions

The aqueous A. unedo roots extract has a significant in vitro and in vivo antidiabetic effects and improves metabolic alterations. The revealed results justify its traditional medicinal use.

Evaluation of anti-inflammatory activity and standardisation of hydro-methanol extract of underground tuber of Dioscorea alata

Context The underground edible tuber of Dioscorea alata L. (Dioscoreaceae) is a functional food with high nutritive value and therapeutic potential. The tuber is known to possess anti-inflammatory properties in traditional medicine. Objective The present study explores the anti-inflammatory activity and standardisation of D. alata tuber hydromethanol extract. Materials and methods Hydromethanol extract (70%) of D. alata tuber was chemically characterised using HPLC and GC-MS techniques. Murine lymphocytes were cultured for 48 h with six different concentrations (0-80 μg/mL) of the extract. The expression of nitric oxide (NO), TNF-α, COX-1, COX-2, and PGE2 were evaluated using colorimetric and ELISA methods. Results Dioscorea alata extract inhibited the expression of NO and TNF-α with an IC50 value of 134.51 ± 6.75 and 113.30 ± 7.44 μg/mL, respectively. The IC50 values for inhibition of total COX, COX-1, COX-2 activities and PGE2 level were 41.96 ± 3.07, 141.41 ± 8.99, 32.50 ± 1.69, and 186.34 ± 15.36 μg/mL, respectively. Inhibition of PGE2 level and COX-2 activity was positively correlated (R(2) = 0.9393). Gallic acid (GA), 4-hydroxy benzoic acid (4HBA), syringic acid (SYA), p-coumaric acid (PCA), and myricetin (MY) were identified and quantified using HPLC. GC-MS analysis revealed the presence of 13 different phytocompounds such as hexadecanoic acid, methyl stearate, cinnamyl cinnamate, and squalene. Conclusion The D. alata extract significantly down-regulated the pro-inflammatory signals in a gradual manner compared with control (0 μg/mL). Different bioactive phytocompounds individually possessing anti-inflammatory activities contributed to the overall bioactivity of the D. alata tuber extract.

Roots and Tuber Crops as Functional Foods: A Review on Phytochemical Constituents and Their Potential Health Benefits

Starchy roots and tuber crops play a pivotal role in the human diet. There are number of roots and tubers which make an extensive biodiversity even within the same geographical location. Thus, they add variety to the diet in addition to offering numerous desirable nutritional and health benefits such as antioxidative, hypoglycemic, hypocholesterolemic, antimicrobial, and immunomodulatory activities. A number of bioactive constituents such as phenolic compounds, saponins, bioactive proteins, glycoalkaloids, and phytic acids are responsible for the observed effects. Many starchy tuber crops, except the common potatoes, sweet potatoes, and cassava, are not yet fully explored for their nutritional and health benefits. In Asian countries, some edible tubers are also used as traditional medicinal. A variety of foods can be prepared using tubers and they may also be used in industrial applications. Processing may affect the bioactivities of constituent compounds. Tubers have an immense potential as functional foods and nutraceutical ingredients to be explored in disease risk reduction and wellness.

Assessment of In Vivo Antidiabetic Properties of Umbelliferone and Lupeol Constituents of Banana (Musa sp. var. Nanjangud Rasa Bale) Flower in Hyperglycaemic Rodent Model

Banana is an extensively cultivated plant worldwide, mainly for its fruit, while its ancillary product, the banana flower is consumed as a vegetable and is highly recommended for diabetics in the traditional Indian medicine system. This study is based on an investigation of the in vivo antihyperglycaemic activity of Umbelliferone (C1) and Lupeol (C2) isolated from the ethanol extract of banana flower (EF) in alloxan induced diabetic rat model. Diabetic rats which were administered with C1, C2 and EF (100 and 200 mg/kg b. wt.) for 4 weeks showed deterioration in fasting hyperglycaemia and reversal of abnormalities in serum/urine protein, urea and creatinine, when compared to the diabetic control group of rats. The diabetic group of rats fed with EF, C1 and C2 (100 mg/kg b. wt.) once daily, for a period of 28 days resulted in a significant reduction of diabetic symptoms viz., polyphagia, polydipsia, polyuria and urine sugar together with an improved body weight. HbA1c extent was reduced whereas levels of insulin and Hb were increased. Both the extract and compounds wielded positive impacts in diabetic rats by reversal of altered activities of hepatic marker enzymes viz., aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP); glycolytic enzyme (hexokinase); shunt enzyme (glucose-6-phosphate dehydrogenase); gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase, lactate dehydrogenase) and pyruvate kinase. The characteristic diabetic complications such as hypercholesterolemia and hypertriacylglycerolemia also significantly reverted to normal in the serum/liver of diabetic rats. Besides these, the treatment increased the activities of enzymatic and non-enzymatic antioxidants in the serum and liver. The histological observations revealed a marked regeneration of the β-cells in the drug treated diabetic rats. In conclusion, the present study illustrates that EF, C1 and C2 enhances the glycolytic activities, besides increasing the hepatic glucose utilization in diabetic rats by stimulating insulin secretion from the remnant β-cells along with potential enzymatic and non-enzymatic antioxidant activities.

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.

Antidiabetic plants used among the ethnic communities of Unakoti district of Tripura, India

ETHNOPHARMACOLOGICAL RELEVANCE

A large group of ethnic communities living in Unakoti district of Tripura, India is still dependent on traditional herbal remedies for treatment of diabetes. Valuable information collected from these communities in the present investigation is important in maintaining their indigenous knowledge of folklore medicine.

METHODS

Systematic and extensive field surveys were conducted during 2011-2013 among the ethnic inhabitants of Unokati district, Tripura, India covering all the seasons to collect information on their traditional herbal medication system for treatment of diabetes. Obtained data were analysed through fidelity level (FL), use value (UV) and relative frequency of citation (RFC) to authenticate the uniqueness of the species being used for diabetes treatment.

RESULTS

In this current study a total of 39 medicinal plant species belonging to 37 genera and 28 families were presented, used by the traditional healers of Unakoti district, Tripura, India for diabetes treatment. FL, UV and RFC values of collected plants for the selected study area ranges between 06% and 100%, 0.07% and 2.64% and 0.02% and 0.51% respectively. Out of 39 collected plants, 11, 5 and 3 plant species have showed significant (<50%) FL, UV and RFC values respectively.

CONCLUSION

Like many other ethnic communities of the world, inhabitants of Unakoti district depend on a traditional medication system to treat diabetes. Documented floras are locally available and need proper further pharmacological validation to endorse their traditional use in a modern health care system. This will help in the development of effective herbal antidiabetic medicines in near future.

Rediscovering medicinal plants' potential with OMICS: microsatellite survey in expressed sequence tags of eleven traditional plants with potent antidiabetic properties

Herbal medicines and traditionally used medicinal plants present an untapped potential for novel molecular target discovery using systems science and OMICS biotechnology driven strategies. Since up to 40% of the world's poor people have no access to government health services, traditional and folk medicines are often the only therapeutics available to them. In this vein, North East (NE) India is recognized for its rich bioresources. As part of the Indo-Burma hotspot, it is regarded as an epicenter of biodiversity for several plants having myriad traditional uses, including medicinal use. However, the improvement of these valuable bioresources through molecular breeding strategies, for example, using genic microsatellites or Simple Sequence Repeats (SSRs) or Expressed Sequence Tags (ESTs)-derived SSRs has not been fully utilized in large scale to date. In this study, we identified a total of 47,700 microsatellites from 109,609 ESTs of 11 medicinal plants (pineapple, papaya, noyontara, bitter orange, bermuda brass, ratalu, barbados nut, mango, mulberry, lotus, and guduchi) having proven antidiabetic properties. A total of 58,159 primer pairs were designed for the non-redundant 8060 SSR-positive ESTs and putative functions were assigned to 4483 unique contigs. Among the identified microsatellites, excluding mononucleotide repeats, di-/trinucleotides are predominant, among which repeat motifs of AG/CT and AAG/CTT were most abundant. Similarity search of SSR containing ESTs and antidiabetic gene sequences revealed 11 microsatellites linked to antidiabetic genes in five plants. GO term enrichment analysis revealed a total of 80 enriched GO terms widely distributed in 53 biological processes, 17 molecular functions, and 10 cellular components associated with the 11 markers. The present study therefore provides concrete insights into the frequency and distribution of SSRs in important medicinal resources. The microsatellite markers reported here markedly add to the genetic stock for cross transferability in these plants and the literature on biomarkers and novel drug discovery for common chronic diseases such as diabetes.

Dioscorea Extract (DA-9801) Modulates Markers of Peripheral Neuropathy in Type 2 Diabetic db/db Mice

The purpose of this study was to investigate the therapeutic effects of DA-9801, an optimized extract of Dioscorea species, on diabetic peripheral neuropathy in a type 2 diabetic animal model. In this study, db/db mice were treated with DA-9801 (30 and 100 mg/kg, daily, p.o.) for 12 weeks. DA-9801 reduced the blood glucose levels and increased the withdrawal latencies in hot plate tests. Moreover, it prevented nerve damage based on increased nerve conduction velocity and ultrastructural changes. Decrease of nerve growth factor (NGF) may have a detrimental effect on diabetic neuropathy. We previously reported NGF regulatory properties of the Dioscorea genus. In this study, DA-9801 induced NGF production in rat primary astrocytes. In addition, it increased NGF levels in the sciatic nerve and the plasma of type 2 diabetic animals. DA-9801 also increased neurite outgrowth and mRNA expression of Tieg1/Klf10, an NGF target gene, in PC12 cells. These results demonstrated the attenuation of diabetic peripheral neuropathy by oral treatment with DA-9801 via NGF regulation. DA-9801 is currently being evaluated in a phase II clinical study.