An Update on Pharmacological and Phytochemical Aspects of Costus pictus D. Don - A Promising Anti-diabetic Plant

BACKGROUND

The genus Costus is the largest genus in the family Costaceae and encompasses about 150 known species. Among these, Costus pictus D. Don (Synonym: Costus mexicanus) is a traditional medicinal herb used to treat diabetes and other ailments. Currently, available treatment options in modern medicine have several adverse effects. Herbal medicines are gaining importance as they are cost-effective and display improved therapeutic effects with fewer side effects. Scientists have been seeking therapeutic compounds in plants, and various in vitro and in vivo studies report Costus pictus D. Don as a potential source in treating various diseases. Phytochemicals with various pharmacological properties of Costus pictus D. Don, viz. anti-cancer, anti-oxidant, diuretic, analgesic, and anti-microbial have been worked out and reported in the literature.

OBJECTIVE

The aim of the review is to categorize and summarize the available information on phytochemicals and pharmacological properties of Costus pictus D. Don and suggest outlooks for future research.

METHODS

This review combined scientific data regarding the use of Costus pictus D. Don plant for the management of diabetes and other ailments. A systematic search was performed on Costus pictus plant with anti-diabetic, anti-cancer, anti-microbial, anti-oxidant, and other pharmacological properties using several search engines such as Google Scholar, PubMed, Science Direct, Sci-Finder, other online journals and books for detailed analysis.

RESULTS

Research data compilation and critical review of the information would be beneficial for further exploration of its pharmacological and phytochemical aspects and, consequently, new drug development. Bioactivity-guided fractionation, isolation, and purification of new chemical entities from the plant as well as pharmacological evaluation of the same will lead to the search for safe and effective novel drugs for better healthcare.

CONCLUSION

This review critically summarizes the reports on natural compounds, and different extract of Costus pictus D. Don with their potent anti-diabetic activity along with other pharmacological activity. Since this review has been presented in a very interactive manner showing the geographical region of availability, parts of plant used, mechanism of action and phytoconstituents in different extracts of Costus pictus responsible for particular action, it will be of great importance to the interested readers to focus on the development of the new drug leads for the treatment of diseases.

Enhancement of Antioxidant Properties of the Medicinal Plant, Costus Pictus by Optimization of its Drying and Extraction Criteria

Antioxidants act as major protective factors against different infections and diseases. The search for natural antioxidants has gained significant momentum due to its associated health benefits. It prompted the investigation of the antioxidant properties of widely recognized medicinal plants, considering their prominent role in conventional medicine. The incorporation of natural antioxidants derived from medicinal plants into food products has the potential to enhance their health benefits. The present investigation is the first study on the optimization of drying and extraction techniques in Costus pictus leaves. C. pictus leaves were dried under varying conditions (40, 50 and 60 °C) and dried powders were subjected to various solvents, namely water, ethanol, methanol and ethyl acetate. The leaves dried at 60 °C and treated with ethanol showed improved activities and were subsequently selected for further extraction. Among the various extraction methods, ultrasound-assisted extraction demonstrated superior antioxidant properties and increased phytochemical contents, making it the optimal technique for our study. Fourier transform infrared spectroscopy (FTIR) reports also substantiated these quantitative results. The extraction process played a significant role in enhancing the desirable attributes and properties of the leaf extracts, surpassing the results obtained from both dried and fresh leaves. The application of liquid chromatography-mass spectrometry (LC-MS) analysis to the leaf extracts facilitated the identification of phenolic compounds and flavonoids, presenting a comprehensive insight into the composition of the extract. Exploration of antioxidant properties, phenolic compounds and flavonoids would validate the benefits and expand the applications of C. pictus in functional foods and nutraceuticals.

Antidiabetic Phytochemicals From Medicinal Plants: Prospective Candidates for New Drug Discovery and Development

Diabetes, a chronic physiological dysfunction affecting people of different age groups and severely impairs the harmony of peoples' normal life worldwide. Despite the availability of insulin preparations and several synthetic oral antidiabetic drugs, there is a crucial need for the discovery and development of novel antidiabetic drugs because of the development of resistance and side effects of those drugs in long-term use. On the contrary, plants or herbal sources are getting popular day by day to the scientists, researchers, and pharmaceutical companies all over the world to search for potential bioactive compound(s) for the discovery and development of targeted novel antidiabetic drugs that may control diabetes with the least unwanted effects of conventional antidiabetic drugs. In this review, we have presented the prospective candidates comprised of either isolated phytochemical(s) and/or extract(s) containing bioactive phytoconstituents which have been reported in several in vitro, in vivo, and clinical studies possessing noteworthy antidiabetic potential. The mode of actions, attributed to antidiabetic activities of the reported phytochemicals and/or plant extracts have also been described to focus on the prospective phytochemicals and phytosources for further studies in the discovery and development of novel antidiabetic therapeutics.

Comparative Evaluation of BGR-34 and Sitagliptin in Diabetic Subjects-Open Labelled Randomised Parallel Clinical Study

This article is mainly concerned with the simultaneous open model clinical study of the drug named sitagliptin, a potent hyperglycaemic drug against a novel entity of the natural origin BGR- 34 in diabetic subjects. This was a 3-month randomized, parallel, comparative study. One hundred subjects were planned to be included in the study. The patients were randomly divided into two groups and according to the appropriate sample size analysis, both groups consisted of 100 patients, following the inclusion and exclusion criteria. A total of 90 patients (both male and female) of the mean patient age 30-65 years with the type 2 diabetes were enrolled in the phase 4 of this study and then the data were analyzed on the basis of the different test which included HbA1c (glycated haemoglobin), RBS (random blood sugar), FBS (fasting blood sugar) and PPG (postprandial glucose) values. After completion of the data calibration, the results were analyzed and as a result 10-20% decreased values of HBA1C values accompanied with the RBS, FBS and PPG values were seen in the patients undergoing a 12-week course with BGR-34. Based on the results obtained in the present study, it can be concluded that BGR-34 is effective in reducing high blood sugar levels and this reflects that the BGR-34 therapy is more effective drug in the treatment of diabetes suggesting that it is better in efficacy, and reliability with little or no adverse effects.

Bioactive Compounds in Anti-Diabetic Plants: From Herbal Medicine to Modern Drug Discovery

Natural products, including organisms (plants, animals, or microorganisms) have been shown to possess health benefits for animals and humans. According to the estimation of the World Health Organization, in developing countries, 80% of the population has still depended on traditional medicines or folk medicines which are mostly prepared from the plant for prevention or treatment diseases. Traditional medicine from plant extracts has proved to be more affordable, clinically effective and relatively less adverse effects than modern drugs. Literature shows that the attention on the application of phytochemical constituents of medicinal plants in the pharmaceutical industry has increased significantly. Plant-derived secondary metabolites are small molecules or macromolecules biosynthesized in plants including steroids, alkaloids, phenolic, lignans, carbohydrates and glycosides, etc. that possess a diversity of biological properties beneficial to humans, such as their antiallergic, anticancer, antimicrobial, anti-inflammatory, antidiabetic and antioxidant activities Diabetes mellitus is a chronic disease result of metabolic disorders in pancreas β-cells that have hyperglycemia. Hyperglycemia can be caused by a deficiency of insulin production by pancreatic (Type 1 diabetes mellitus) or insufficiency of insulin production in the face of insulin resistance (Type 2 diabetes mellitus). The current medications of diabetes mellitus focus on controlling and lowering blood glucose levels in the vessel to a normal level. However, most modern drugs have many side effects causing some serious medical problems during a period of treating. Therefore, traditional medicines have been used for a long time and play an important role as alternative medicines. Moreover, during the past few years, some of the new bioactive drugs isolated from plants showed antidiabetic activity with more efficacy than oral hypoglycemic agents used in clinical therapy. Traditional medicine performed a good clinical practice and is showing a bright future in the therapy of diabetes mellitus. World Health Organization has pointed out this prevention of diabetes and its complications is not only a major challenge for the future, but essential if health for all is to be attained. Therefore, this paper briefly reviews active compounds, and pharmacological effects of some popular plants which have been widely used in diabetic treatment. Morphological data from V-herb database of each species was also included for plant identification.

Histopathological and biochemical assessments of Costus afer stem on alloxan-induced diabetic rats

BACKGROUND

In continuation of our study of the biological activity of the aqueous extract of Costus afer stem used in tradomedicare in Nigeria, this work has investigated the biochemical, nephroprotective, hepatoprotective and protective effects of aqueous extract of C. afer stem on alloxan-induced hyperglycaemic albino Wistar rats.

METHODS

Thirty male albino Wistar rats (150-200 g) were weight-matched into six groups of five rats each. Groups 1 and 2 were the normal (non-induced) and toxic (alloxan-induced) controls, respectively. Groups 3-6 were induced and treated with 1, 2 and 3 g/kg of the aqueous extract of C. afer stem and glibenclamide (5 mg/kg), respectively. Food and fluid intake, body weight, absolute and relative weight of organs (liver, pancreas, and kidneys) and biochemical parameters were measured.

RESULTS

There was a significant reduction in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin triglyceride, creatinine, urea and electrolyte when compared with toxic control group. The liver marker enzymes were restored in all the treated groups. The aqueous stem extract possessed hypoglycaemic effect and reversed the histopathological damage in alloxan-induced diabetic rats.

CONCLUSIONS

This study suggests that aqueous stem extract of C. afer possesses both hypoglycaemic and organ protective properties.

Antidiabetic activities of polysaccharides separated from Inonotus obliquus via the modulation of oxidative stress in mice with streptozotocin-induced diabetes

This study evaluated the effects of Inonotus obliquus polysaccharides (IOs) on diabetes and other underlying mechanisms related to inflammatory factors and oxidative stress in a mouse model of streptozotocin (STZ)-induced diabetes. Four weeks administration of metformin (120 mg/kg) and IO1-4 (50%-80% alcohol precipitation), or IO5 (total 80% alcohol precipitation) at doses of 50 mg/kg reverses the abnormal changes of bodyweights and fasting blood glucose levels of diabetic mice. IOs significantly increased the insulin and pyruvate kinase levels in serum, and improved the synthesis of glycogen, especially for IO5. IOs restored the disturbed serum levels of superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde. The down-regulation of interleukin-2 receptor, matrix metalloproteinase-9, and the enhancement of interleukin-2 in serum of diabetic mice were significantly attenuated by IOs. Histologic and morphology examinations showed that IOs repaired the damage on kidney tissues, inhibited inflammatory infiltrate and extracellular matrix deposit injuries in diabetic mice. Compared with untreated diabetic mice, IOs decreased the expression of phosphor-NF-κB in the kidneys. These results show that IOs treatment attenuated diabetic and renal injure in STZ-induced diabetic mice, possibly through the modulation of oxidative stress and inflammatory factors. These results provide valuable evidences to support the use of I. obliquus as a hypoglycemic functional food and/or medicine.

α-glucosidase and glycation inhibitory effects of costus speciosus leaves

BACKGROUND

Hyperglycaemia is a salient feature of poorly controlled diabetes mellitus. Rate of protein glycation is increased with hyperglycaemia leading to long term complications of diabetes. One approach of controlling blood glucose in diabetes targets at reducing the postprandial spikes of blood glucose. The objectives of this study were to assess the in vitro inhibitory effects of Costus speciosus (COS) leaves on α-amylase and α-glucosidase activities, fructosamine formation, protein glycation and glycation-induced protein cross-linking.

METHODS

Methanol extracts of COS leaves were used. Inhibitory effects on enzyme activities were measured using porcine pancreatic α-amylase and α-glucosidase from Saccharomyces cerevisiae in the presence of COS extract. Percentage inhibition of the enzymes and the IC50 values were determined. In vitro protein glycation inhibitory effect of COS leaves on early and late glycation products were measured using bovine serum albumin or chicken egg lysozyme with fructose. Nitroblue tetrazolium was used to assess the relative concentration of fructosamine and polyacrylamide gel electrophoresis was used to assess the degree of glycation and protein cross-linking in the reaction mixtures.

RESULTS

α-Glucosidase inhibitory activity was detected in COS leaves with a IC50 of 67.5 μg/ml which was significantly lower than the IC50 value of Acarbose (p < 0.01). Amylase inhibitory effects occurred at a comparatively higher concentration of extract with a IC50 of 5.88 mg/ml which was significantly higher than the IC50 value of Acarbose (p < 0.01). COS (250 μg/ml) demonstrated inhibitory effects on fructosamine formation and glycation induced protein cross-linking which were in par with 1 mg/ml aminoguanidine were detected.

CONCLUSION

Methanol extracts of COS leaves demonstrated in vitro inhibitory activities on α-glucosidase, fructosamine formation, glycation and glycation induced protein cross-linking. These findings provide scientific evidence to support the use of COS leaves for hypoglycemic effects with an added advantage in slowing down protein glycation.

Chemical profile and in vivo hypoglycemic effects of Syzygium jambos, Costus speciosus and Tapeinochilos ananassae plant extracts used as diabetes adjuvants in Puerto Rico

BACKGROUND

The increasing numbers of people who use plant-based remedies as alternative or complementary medicine call for the validation of less known herbal formulations used to treat their ailments. Since Puerto Rico has the highest rate of Type 2 diabetes within all the states and territories of the United States, and Puerto Ricans commonly use plants as diabetes adjuvants, it is important to study the plants' physiological effects, and identify their bioactive compounds to understand their role in modulation of blood glucose levels. We present the phytochemical profiles and hypoglycemic effects of Tapeinochilus ananassae, Costus speciosus and Syzygium jambos.

METHODS

Phytochemicals in methanolic and aqueous extracts were analyzed by thin layer chromatography (TLC). Alkaloids (Bromocresol green, λ=470 nm), flavonoids (AlCl3, λ=415 nm), saponins (DNS, λ=760 nm), tannins (FeCl3/K4Fe(CN)6, λ=395 nm) and phenolics (Folin-Ciocalteau, λ=765 nm) were quantified. Male C57BLKS/J (db/db) and C57BL/J (ob/ob) genetically obese mice were orally gavaged with aqueous extracts of lyophilized plant decoctions for 10 wks.

RESULTS

Our results show that T. ananassae had significantly greater amounts of flavonoids and tannins, while S. jambos showed the greatest concentration of phenolics and C. speciosus exhibited higher amounts of alkaloids. C57BLKS/J db/db treated with plant extracts show better glucose modulation when the extracts are administered in complement with an insulin injection. Finally, C57BL/J ob/ob mice on T. ananassae and S. jambos treatments show better blood glucose modulation over time.

CONCLUSION

These results document for the first time the chemical profile of T. ananassae and provide evidence for a potential anti-diabetic efficacy of T. ananassae and S. jambos.

Next generation sequencing and de novo transcriptome analysis of Costus pictus D. Don, a non-model plant with potent anti-diabetic properties

Background

Phyto-remedies for diabetic control are popular among patients with Type II Diabetes mellitus (DM), in addition to other diabetic control measures. A number of plant species are known to possess diabetic control properties. Costus pictus D. Don is popularly known as “Insulin Plant” in Southern India whose leaves have been reported to increase insulin pools in blood plasma. Next Generation Sequencing is employed as a powerful tool for identifying molecular signatures in the transcriptome related to physiological functions of plant tissues. We sequenced the leaf transcriptome of C. pictus using Illumina reversible dye terminator sequencing technology and used combination of bioinformatics tools for identifying transcripts related to anti-diabetic properties of C. pictus.

Results

A total of 55,006 transcripts were identified, of which 69.15% transcripts could be annotated. We identified transcripts related to pathways of bixin biosynthesis and geraniol and geranial biosynthesis as major transcripts from the class of isoprenoid secondary metabolites and validated the presence of putative norbixin methyltransferase, a precursor of Bixin. The transcripts encoding these terpenoids are known to be Peroxisome Proliferator-Activated Receptor (PPAR) agonists and anti-glycation agents. Sequential extraction and High Performance Liquid Chromatography (HPLC) confirmed the presence of bixin in C. pictus methanolic extracts. Another significant transcript identified in relation to anti-diabetic, anti-obesity and immuno-modulation is of Abscisic Acid biosynthetic pathway. We also report many other transcripts for the biosynthesis of antitumor, anti-oxidant and antimicrobial metabolites of C. pictus leaves.

Conclusion

Solid molecular signatures (transcripts related to bixin, abscisic acid, and geranial and geraniol biosynthesis) for the anti-diabetic properties of C. pictus leaves and vital clues related to the other phytochemical functions like antitumor, anti-oxidant, immuno-modulatory, anti-microbial and anti-malarial properties through the secondary metabolite pathway annotations are reported. The data provided will be of immense help to researchers working in the treatment of DM using herbal therapies.

Management of diabetes in Guinean traditional medicine: an ethnobotanical investigation in the coastal lowlands

ETHNOPHARMACOLOGICAL RELEVANCE

This survey was carried out in the coastal lowlands of Guinea-Conakry in order to make an inventory of plants used by traditional healers, herbalists and diabetic patients for the management of diabetes mellitus.

MATERIALS AND METHODS

Frequent ethnomedical and ethnobotanical investigations were conducted from June 2008 to December 2009 in Conakry, Kindia, Forécariah, Dubréka, Boke, Fria and Boffa. It is a cross-sectional survey and data collection is based on the interactive method. During this period a total of 112 people aged from 39 to 76 years old were interviewed.

RESULTS

During this investigation 146 plant species belonging to 55 families were collected. The most cited plants were Anacardium occidentale L. and Ficus spp., while the Fabaceae family was the most represented, followed by the Euphorbiaceae and Rubiaceae. The most frequently plant parts used by the traditional healers and the herbalists were the stem-bark and decoctions the most common preparation mode.

CONCLUSIONS

It is clear that a variety of plants is used in the management and treatment of diabetes. Due to the increasing prevalence of type 2 diabetes, there is an urgent need for scientific investigations to rationalise the use of these traditional remedies, which could represent accessible alternative medicines for the Guinean populations.

Preventive effect of phycocyanin from Spirulina platensis on alloxan-injured mice

The preventive effect of phycocyanin (obtained from Spirulina platensis) on alloxan-injured mice is investigated. Oral administration of phycocyanin was started two weeks before an alloxan injury and continued until four weeks later. Tests resulted in the following positive results of oral phycocyanin administration on alloxan-injured mice: decrease fasting blood glucose and glycosylated serum protein (GSP); maintain total antioxidative capability (T-AOC); avert malondialdehyde (MDA) formation in the liver, kidney, and pancreas; decrease total cholesterol (TC) level and triglycerides (TG) level in serum and liver; increase the levels of hepatic glycogen level; maintain glucokinase (GK) expression in the liver and decrease p53 expression in the pancreas at mRNA level. The histological observations also supported the above results. Acute toxicity study further shows that phycocyanin is relatively safe. These results led to the conclusion that phycocyanin has significant preventive effect on alloxan-injured mice. The inhibition of p53 pathway could be one of the mechanisms that led to the protection of pancreatic islets from alloxan injury. We also proposed that GK expression that functions to promote liver glycogen synthesis could be the reason for reduced blood glucose level. The encouraging results are the first step in studying the potential of phycocyanin as a clinical measure in preventing diabetes.

Costus pictus extracts stimulate insulin secretion from mouse and human islets of Langerhans in vitro

Plant-derived extracts have been used as folk remedies for Type 2 diabetes mellitus (T2DM) for many centuries, and offer the potential of cheap and readily available alternatives to conventional pharmaceuticals in developing countries. Extracts of Costus pictus (CP), a plant belonging to the Costaceae family, are reported to have antidiabetic activity in vivo. The exact molecular mode of action(s) of CP is unclear but the antihyperglycemic effect seen in animal studies was associated with dramatic increases in insulin secretion so in our study we have measured the effect of aqueous CP extract on insulin secretion in vitro from the MIN6 β-cell line and isolated mouse and human islets. Our data demonstrate that CP has a direct stimulatory effect on insulin secretion at basal but not stimulatory glucose concentrations which was not associated with compromised membrane integrity or decrease β-cell viability. Single cell calcium microfluorimetry measurements showed that CP caused elevations in β-cell intracellular Ca(2+) concentrations ([Ca(2+)](i)), an effect which was completely abolished by the removal of extracellular Ca(2+) or blockade of voltage-gated Ca(2+) channels (VGCC). These in vitro observations suggest that one mode of action of CP is through stimulating insulin secretion which may be mediated, in part, by the ability of CP to increase [Ca(2+)](i) levels through VGCC. CP extracts may provide an affordable and inexpensive alternative for treating patients with T2DM.

Antihyperglycemic and insulin secretory activity of Costus pictus leaf extract in streptozotocin induced diabetic rats and in in vitro pancreatic islet culture

AIM OF THE STUDY

The leaves of Costus pictus D. Don were used extensively for its antihyperglycemic activity by the people in Kerala, India. In the present study, the antihyperglycemic and insulin secretory activity of an aqueous extract of Costus pictus leaf extract was investigated in streptozotocin induced diabetic rats.

MATERIALS AND METHODS

Oral Glucose Tolerance Test was done to determine the effective dose of Costus pictus extract. Aqueous extract of Costus pictus leaves was given orally to the diabetic rats for 14 days. The insulin secretory action of the leaf extract was investigated using isolated pancreatic islets from rat. Liver glucose uptake activity was measured using D-[14C] glucose.

RESULTS

The oral administration of an aqueous extract of Costus pictus at a dose of 250 mg/kg body weight significantly decreased the blood glucose with significant increase in plasma insulin level in diabetic rats at the end of 14 days treatment. The Costus pictus leaf extract significantly increased glucose induced insulin secretion at both 4 mM and 20 mM glucose concentrations which represents normal physiological and diabetic condition respectively. The decreased glucose uptake activity of the liver of diabetic rats was reverted to near normal levels after the treatment with Costus pictus leaf extract.

CONCLUSION

Our results suggest the glucose lowering effect of Costus pictus to be associated with the potentiation of insulin release from pancreatic islets and enhancement of peripheral utilization of glucose.

Costus spicatus tea failed to improve diabetic progression in C57BLKS/J db/db mice, a model of type 2 diabetes mellitus

AIM OF THE STUDY

Costus spicatus Sw. (Costaceae) is a prominent medicinal herb used by Dominicans in the Dominican Republic and the United States for the treatment of diabetes, a growing epidemic in the Hispanic community. An ethnobotanical survey of the Dominican community in New York City revealed the popular use of a tea from the insulina plant to treat hyperglycemia. Insulina was identified as Costus spicatus. We tested the ability of a tea made from the leaves of Costus spicatus to alter glucose homeostasis in C57BLKS/J (KS) db/db mice, a model of obesity-induced hyperglycemia with progressive beta cell depletion.

MATERIALS AND METHODS

From 6 to 16 weeks of age, Experimental and Control animals (n=6/5) were given ad lib access to Costus spicatus tea or water, respectively.

RESULTS

Weight gain and progression of hyperglycemia and insulinopenia between the Experimental and Control groups were statistically indistinguishable. There was no difference between groups in average fed or fasting glucose and insulin concentrations. Intraperitoneal (IP) insulin tolerance testing after the 10-week study period showed that Costus spicatus tea consumption did not alter insulin sensitivity.

CONCLUSIONS

These data suggest that at the dose given, tea made from Costus spicatus leaves had no efficacy in the treatment of obesity-induced hyperglycemia. More investigation is needed to more fully explore dosages and the possible utility and biological activity of this common Dominican herbal remedy for the treatment of type 2 diabetes mellitus.