Costus Pictus Research Articles

Assessment of genetic diversity in Costus pictus accessions based on RAPD and ISSR markers.

Costus pictus, belonging to the family Costaceae, is one of the valuable medicinal plants with its anti-diabetic property. Despite ever-increasing demand from the pharmaceutical industry, this species is being less exploited at molecular level. Hence, an effort has been made in the present study to characterize the 15 accessions of C. pictus collected from different geographical regions of India through random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) markers. A total of 25 RAPD and 20 ISSR primers were used in the present study. The RAPD analysis generated 343 loci, of which 124 were polymorphic with an average of 4.96 loci per primer. While, ISSR primers produced 177 loci, of which 77 were polymorphic with an average of 3.85 loci per primer. The similarity coefficients ranged from 0.86-0.99, 0.84-0.95 and 0.86-0.96 for RAPD, ISSR and combined RAPD-ISSR, respectively. The UPGMA dendrogram generated using these data showed low level of divergence among the accessions from South and West regions. Further, accession-specific bands were also revealed by RAPD and ISSR markers which might be contributed to specific trait. This investigation was an understanding of genetic variation within the C. pictus accessions. The present finding indicates that both the marker tools RAPD and ISSR combined or individually can be used in determining the genetic relationship between the accessions. It may be concluded that data of hereditary differences appeared among the C. pictus accessions could be utilized for their conservation and reproducing programs.

PHARMACOEPIDEMIOLOGICAL SURVEY ON THE USE OF COSTUS PICTUS (INSULIN PLANT) IN CENTRAL KERALA

Objective: Costus pictus commonly known as spiral ginger or insulin plant is grown in gardens as ornamental plant especially in Kerala and used to control sugar levels. The objective of the present survey was to collect information on the use of this plant as a control measure for diabetes mellitus in a community in central Kerala.Methods: The study was conducted with the help of a semi-structured questionnaire. The questionnaire broadly included questions about knowledge of insulin plant, its use, quantity and frequency of use, the relation of plant material consumption with food intake, effects related to blood sugar level and other symptoms, any discomfort or complications after use among diabetic and normal people. The data obtained was quantitatively transferred to an excel sheet and statistical analysis was carried out.Results: From the survey, it can be inferred that Costus pictus is widely used to normalise their sugar level. People who are using insulin plant have not done any species identification scientifically. Due to lack of knowledge and difficulty in identification (especially in the non-flowering season), many people are using Costus speciosus without knowing its adverse effects and allergic reactions.Conclusion: From the survey, it can be concluded that Costus pictus is widely used in some part of the community in Kerala, to normalize their sugar level. It is warranted to increase the awareness in the community about different species of Costus plant and adverse effects associated with similar species.

FREE RADICAL QUENCHING EFFICACY OF VARIOUS EXTRACTS OF C.PICTUS TO COMBAT OXIDATIVE DAMAGE/STRESS: AN IN VITRO STUDY

Objectives: The objectives of this research article are to elucidate the antioxidant activity of the sequentially extracted fractions using solvents with a varying range of polarity from the leaves of Costus pictus (Zingiberaceae). The antioxidant efficacy to combat the oxidative stress was evaluated based on their superoxide, hydrogen peroxide, and nitric oxide (NO) scavenging activity of the leaf extract.Methods: Extraction was performed by sequential extraction methods with low to high polar solvents. Using hexane as a low polar, dichloromethane as medium polar, and ethyl acetate and methanol as high polar, based on their individual boiling points extraction was carried out. The extracts were then evaporated using a rotary evaporator under vacuum and stored in the dry container. Then, antioxidant activity of each extract was evaluated for superoxide, hydrogen peroxide, and NO scavenging activity, ascorbic acid was used as a standard drug for the study of antioxidant activity. The output was statistically interpreted, and the most significant concentration of the best extract with good antioxidant activity was evaluated.Results: As the methanolic solvent is highly polar and able to retrieve the active lead components from the plant material, was very well correlated with the higher degree of free radical scavenging efficacy. It also exhibited the most and significant inhibition in superoxide radical scavenging, hydrogen peroxide scavenging, and NO scavenging which was about 86±1.23, 94±0.34, and 86±1.87 at 250 µg/ml of extract, respectively. The results from our experiments were in par with the positive control chosen.Conclusions: The above results help us to substantially conclude that bioactive components are extracted well in high polar solvents such as methanol, which mainly includes flavonoids and related polyphenols. These compounds present in C. pictus may be an active lead for potent antioxidant activities which would need further investigations in molecular level.Keywords: Costus pictus, Hexane, Dichloromethane, Ethyl acetate, Methanol, Ascorbic acid.

Insulin Plant (Costus pictus) Extract Restores Thyroid Hormone Levels in Experimental Hypothyroidism.

Background:The aim of the present study was to investigate the preventive effect of Costus pictus leaf extract in experimental hypothyroidism.Materials and Methods:Forty male Wistar rats were randomly divided into four groups with ten rats in each group: Control (C), hypothyroid (H), control+extract (C+E), and hypothyroid+extract (H+E). Rats in C group did not receive any intervention throughout the experimental period. The rats in the C+E and H+E groups received pretreatment with C. pictus leaf extract for 4 weeks. Subsequently, for the next 6 weeks, rats in the H group received 0.05% propylthiouracil in drinking water while C+E group received C. pictus leaf extract and H+E group received propyl thiouracil and C. pictus leaf extract.Results:Hypothyroid group rats exhibited dramatic increase in thyroid-stimulating hormone (TSH) levels with concomitant depletion in the levels of thyroid hormones. Treatment with the extract resulted in remarkable improvement in thyroid profile. Extract produced 10.59-fold increase in plasma free T3, 8.65-fold increase in free T4, and 3.59-fold decrease in TSH levels in H+E group in comparison with H group. Treatment with the extract ameliorated hypercholesterolemia, decreased levels of plasma C-reactive protein and tumor necrosis factor alpha, suppressed tissue oxidative stress and prevented hepatic and renal damage caused due to thyroid hormone depletion in the H+E group. Pentacyclic triterpenes alpha and beta amyrins were identified and quantified in the extract.Conclusions:This is the first study to reveal that C. pictus extract has therapeutic potential to restore thyroid hormone levels and prevent the biochemical complications due to thyroid hormone insufficiency in the animal model of experimental hypothyroidism.SUMMARY The preventive effect of Costus pictus leaf extract in experimental hypothyroidism was evaluated in the present study.Hypothyroidism was induced in the experimental animals by giving 0.05% propylthiouracil in drinking water.Hypothyroid rats exhibited dramatic increase in thyroid-stimulating hormone (TSH) levels with concomitant depletion in the levels of thyroid hormones.Treatment with Costus pictus leaf extract in hypothyroid rats significantly improved the thyroid profile. It also ameliorated hypercholesterolemia, decreased the levels of plasma inflammatory markers, suppressed tissue oxidative stress and prevented hepatic and renal damage caused due to thyroid hormone depletion.The possible active principles alpha and beta amyrins were identified and quantified in the extract through LC-MS. Abbreviations Used: APCI: Atmospheric pressure chemical ionization; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; C group: Control group; C+E group: Control+extract group; C. pictus: Costus pictus; CRP: C-reactive protein; DPPH: 2,2-diphenyl-1-picrylhydrazyl; FRAP: Ferric reducing antioxidant power; HDL: High-density lipoprotein; H group: Hypothyroid group; H+E group: Hypothyroid+extract group; LDL: Low-density lipoprotein; LC-MS: Liquid chromatography-mass spectrometry; MDA: Malondialdehyde; PTU: 6-Propyl-2-thiouracil; SRM: Single reaction monitoring; TSH: Thyroid-stimulating hormone; TPTZ: 2,4,6-tri-(2-pyridyl)-5-triazine; TBA: 2-Thiobarbituric acid; TG: Triglyceride; TNFα: Tumor necrosis factor alpha; TAS: Total antioxidant status

Methanolic Extract of Costus pictus D. DON Induces Cytotoxicity in Liver Hepatocellular Carcinoma Cells Mediated by Histone Deacetylase Inhibition.

Background:Leaves of Costus pictus D. Don, (insulin plant) are used as dietary supplement for the treatment of diabetes.Objective:The antidiabetic activity of this plant is well documented, but its activity on different cell types and mechanism remains unknown. Thus, the present study evaluates the cytotoxicity of C. pictus methanolic extract (CPME) against various cancer and normal cells.Materials and Methods:Dried leaves of C. pictus were extracted using methanol and were subjected to histone deacetylase (HDAC) inhibition and toxicity studies.Results:The CPME displayed a selective toxicity toward tested cancer cells in a dose- and time-dependent manner. CPME exhibited significant cytotoxicity on Liver hepatocellular carcinoma cells (Hep G2) (half maximal inhibitory concentration IC50 = 6.7 mg/ml). Since CPME demonstrates both antidiabetic, anticancer activity, and HDAC enzyme play a detrimental role in both the complications, we have evaluated the CPME-induced HDAC regulation on Hep G2 cell lines. CPME showed a notable HDAC inhibition (55%). Furthermore, CPME did not show any genotoxicity or membrane instability at the tested concentrations.Conclusion:CPME demonstrates selective cytotoxicity toward tumor cells at a lower concentration through HDAC inhibition.SUMMARY C. pictus is used as munching supplementary food for the treatment of diabetesCPME selectively induces cytotoxicity in cancer cells leaving normal cells healthySelective toxicity to cancer cells are attributed by the inhibition of HDAC enzymeCPME did not show any genotoxicity and membrane instability in blood cellsCPME could be potential source of HDAC inhibitor. Abbreviations used: A549: Human lung carcinoma cells, CPME: Costus pictus methanolic extract, DMEM: Dulbecco's modified eagle's medium, DMSO: Dimethyl sulfoxide, ELISA: Enzyme-linked immunosorbent assay, 5-FU: 5-Fluorouracil, Hep G2: Liver hepatocellular carcinoma cells, HEK-293: Human embryonic kidney cells, Hela: Human cervical carcinoma cells, HT-29: Human colorectal adenocarcinoma cells, HDAC: Histone deacetylase, IC50: Half maximal inhibitory concentration, MCF-7: Human breast adenocarcinoma cells, MDA-MB-435S: Human breast cancer cells, MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide, NFF: Neonatal foreskin fibroblasts, PHA: Phytohemagglutinin, PBS: Phosphate buffer saline, RPMI-1640: Roswell Park Memorial Institute Medium.

Antibacterial Activity and Screening of Antibacterial Compounds of Costus pictus D.Don Using GC-MS

Antibacterial Activity and Screening of Antibacterial Compounds of Costus pictus D.Don Using GC-MS

Comparative in-vitro evaluation of anthelmintic property of leaves and rhizome of Costus pictus D. Don against albendazole

Background: In developing countries, helminthic infections pose a great threat to public health. Traditional medical remedies using plant products as antiparasitic agents have been in trail throughout the world accounting to limited availability and affordability of modern medicine. More recently, the medicinal plant Costus pict us D. Don has been extensively studied by researchers because of its diverse biochemical properties. Objective: This study was designed to analyze the plant for its primary constituents and to evaluate the anthelmintic property of methanolic and aqueous extract of leaves and rhizomes of C. pictus D. Don in different concentrations and compare it against the standard drug albendazole using earthworm Pheretima posthuma as an animal model. Materials and Methods: Anthelmintic property was tested by exposing the worms (18 groups with 3 worms each) one after another to different concentrations (25 mg/ml, 50 mg/ml, 75 mg/ml, and 100 mg/ml) of methanolic and aqueous extracts of leaves and rhizomes of C. pictus D. Don. The absence of movement even after dipping the worm in warm water was noted as time of paralysis, and death was noted when its body color became pale. Results: The results of our study showed both the methanolic and aqueous extract of leaves and rhizomes in all concentrations were toxic to the worms. However, methanolic extract of rhizomes at a concentration of 100 mg/ml showed more potency when compared to albendazole (20 mg/ml). Conclusions: Methanolic extracts of leaves and rhizomes of C. pictus D. Don have potent dose-dependent anthelmintic effect when compared to their aqueous extract.

Computational Identification, Target Prediction, and Validation of Conserved miRNAs in Insulin Plant (Costus pictus D. Don).

Insulin plant (Costus pictus D. Don) is an economically important medicinal plant for the content of its high value secondary metabolites, bioactive compounds, and remarkable flowering features. MicroRNAs are a class of short (∼21 nucleotides), endogenous, noncoding RNA molecules that play a vital role in regulating gene expression. Here, we used a computer-based homology approach to identify conserved miRNAs in Transcribed Sequence Assemblies (TSA) of C. pictus. It led us to identify 42 miRNAs of 13 different families in C. pictus for the first time. Using quantitative polymerase chain reaction (qPCR) assays, we further confirmed the expression of 8 miRNAs (miR394, miR159b, miR166k, miR172, miR159f, miR166, miR144, and miR858) in young and mature leaf tissues. A total of 109 potential target genes of the identified miRNAs were subsequently predicted in rice (Oryza sativa L.) genome. The target genes encode transcription factors, enzymes, and various functional proteins involved in the regulation of several metabolic pathways. The findings in the present study lay the foundation for further research on miRNAs and miRNA-mediated gene regulation in this important medicinal plant.

Comparative Study of Antioxidant and Catalytic Activity of Silver and Gold Nanoparticles Synthesized From Costus pictus Leaf Extract

Biological synthesis of silver and gold nanoparticles using Costus pictus leaf extract (CPLE) and their potential in vitro antioxidant and catalytic activities were reported here. Formation of Costus pictus silver (CPAgNPs) and gold (CPAuNPs) nanoparticles was confirmed by UV-visible spectroscopy and their spherical shape by scanning electron microscopy. The synthesized nanoparticles gave strong signals for silver and gold in energy dispersive X-ray spectroscopy. The CPAgNPs and CPAuNPs had an average size of 46.7 and 37.2 nm, respectively, as determined by dynamic light scattering particle size analyzer. Fourier transform infrared spectroscopy (FTIR) analysis indicated involvement of amine and carbonyl groups in the formation of CPAgNPs and CPAuNPs. Thermal stability of synthesized nanoparticles was assessed by thermogravimetric analysis-differential scanning calorimetry. CPAgNPs, CPAuNPs and CPLE exhibited tremendous antioxidant activity when being assessed by various in vitro assays, and their activity was comparable to standard antioxidants. CPAgNPs, CPAuNPs and CPLE also caused degradation of dyes like methylene blue and methyl red. While CPAgNPs, CPAuNPs and CPLE caused respective 85%, 42% and 30% degradation of methylene blue, they showed less activity against methyl red. These observations signify that such green methods open up new avenues in nanobiotechnology for the synthesis of nanoparticles with extensive industrial and biomedical applications.

Insulin plant (Costus pictus) extract improves insulin sensitivity and ameliorates atherogenic dyslipidaemia in fructose induced insulin resistant rats: Molecular mechanism

The preventative effect of insulin plant (Costus pictus) leaf extract on hyperglycaemia, insulin sensitivity and dyslipidaemia in fructose-fed insulin resistant rats was investigated in the present study, further the possible underlying mechanism was also explored. It was observed that under insulin resistant condition this plant extract decreases hyperinsulinaemia by improving insulin sensitivity at the peripheral level through its antioxidant and anti-inflammatory effects. At molecular level decreased activation of molecules involved in stress sensitive signalling cascade and down regulation of pro-inflammatory cytokines were noticed. Furthermore the effects of this plant extract on adipokine profile and plasma homocysteine were evaluated. The possible active components responsible for the beneficial effect exerted by this plant extract have also been identified and quantified. To the best of our knowledge this is the first study on insulin plant extract on the aforementioned animal model.

Synthesis and Characterization of Silver Nanoparticles of Insulin Plant (Costus pictus D. Don) leaves

Objectives: Cost effective and eco-friendly technique for green synthesis of silver nanoparticles from the methanolic extract of Costus pictus leaf and characterization of synthesized silver nanoparticles was carried out in this study. Methods: Synthesis of silver nanoparticles of Insulin plant (Costus pictus) leaves was done by using 1mM AgNO3 solution and incubates 5hr at room temperature. Characterization of synthesized nanoparticles was done by UV–Vis absorption spectroscopy, SEM, polydispersity index and zeta value. Results: The biological synthesis of silver nanoparticles using Costus pictus extract was shown to be rapid and produced particles of fairly uniform size and shape. As the methanolic leaf extracts of Costus pictus D. Don were mixed with the aqueous solution of silver nitrate, it changed into brown colour due to the excitation of surface Plasmon vibrations, which indicated the formation of methanolic extract of Costus pictus silver nanoparticles (MECPAgNPs). UV-Visible spectroscopy analysis of nanoparticles showed the broadening of the peak indicated the particles are poly dispersed. The surface Plasmon band in the silver nanoparticles in the solution remains close to 420nm. Throughout the reaction period indicating the particles are dispersed in the aqueous solution of silver nitrate, with no evidence for aggregation. The average particle size (z-average) was found to be 132.6nm, its polydispersity index was 0.248 and zeta values were measured and it was found to be -25.1mV with the peak area of 100% intensity. This indicates that the formed silver nanoparticle is stable. A SEM images showed that the silver nanoparticles formed were spherical in shape, with an average size of around 100nm. SEM showed uniformly distributed silver nanoparticles on the surface of the cells was observed. Conclusion: The Biomedical application of silver nanoparticles can be rendered more effective by using biologically synthesized nanoparticles that are found to be exceptionally stable, and also minimize toxicity and cost.

A review on Insulin plant (Costus igneus Nak)

Costus igneus Nak and Costus pictus D. Don, commonly known as Spiral flag, is a member of Costaceae and a newly introduced plant in India from South and Central America. It is a perennial, upright, spreading plant reaching about two feet tall, with spirally arranged leaves and attractive flowers. In southern India, it usually grows as an ornamental plant and its leaves are used as a dietary supplement in the treatment of diabetes mellitus. Recently, a number of researches have been carried out to evaluate the anti-diabetic potential of this plant. Besides, it has been proven to possess various pharmacological activities like hypolipidemic, diuretic, antioxidant, anti-microbial, anti-cancerous. Further, various phytochemical investigations reveal the presence of carbohydrates, triterpenoids, proteins, alkaloids, tannins, saponins, flavonoids, steroid, and appreciable amounts of trace elements. This work is an attempt to compile and explore the different pharmacological and phytochemical studies reported till date.

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

BackgroundPhyto-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.ResultsA 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.ConclusionSolid 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.

Micropropagation and Microrhizome Induction in Costus pictus D. Don Using In Vitro and Ex Vitro Nodal Segments as Explant

Costus pictus D. Don is a potent anti-diabetic plant used in folk, ayurvedic and homeopathic system of medicine. Gene and protein expression of key targets in insulin signaling pathway have revealed that methyl tetracosonoate, a bio-active molecule from Costus pictus extract has anti-diabetic activity. The axillary buds of Costus pictus are dormant. The dormancy of axillary buds were broken when cultured in Murashige and Skoog (MS) medium supplemented with 3-4 μM 6-benzylaminopurine (BAP) in combination with 0.21 μM naphthalene acetic acid (NAA). The highest bud-break percentage was achieved in those supplemented with 0.6 μM NAA and 3 μM BAP. The sprouted axillary buds were transferred onto medium supplemented with 0.6 μM NAA and 6-10 μM BAP for shoot multiplication. The maximum average number of shoot was achieved in medium supplemented with 0.6 μM NAA and 8 μM BAP. The shoots were successfully rooted when transferred onto media supplemented with 1-12 μM NAA or indole-3-acetic acid (IAA) and 3 μM BAP. The maximum number of roots was found in 8 μM NAA and 3 μM BAP. The dormancy of in vitro axillary buds were also successfully broken in stems from which shoot apex were decapitated and cultured in MS medium with 0.6 μM NAA, 7 μM BAP and 5-13% sucrose. These sprouted in vitro axillary buds could be used as secondary explants for shoot multiplication. The maximum was in medium supplemented with 9% sucrose. Rhizomes were successfully induced when 4-month old plantlets were cultured on 1⁄2 strength MS medium supplemented with 2.4 μM NAA, 32 μM BAP and 5-13% sucrose. Microrhizomes formed in 9% sucrose was largest in size with highest average fresh weight.

Hypoglycemic effect of Costus pictus D. Don on alloxan induced type 2 diabetes mellitus in albino rats

ObjectiveTo demonstrate the effect of aqueous extract of Costus pictus (C. pictus) leaves on blood glucose, lipid profile and liver antioxidant enzymes and lipid peroxidation in alloxan induced diabetic rats. MethodsAqueous extract of C. pictus (AECP) leaves was administered orally for 30 days and its effect on blood glucose, lipid profile, hepatic marker enzymes such as serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), serum urea, creatinine, protein and albumin content and liver antioxidant enzymes such as catalase, peroxidase, superoxide dismutase and lipid peroxidation in alloxan induced diabetic rats were examined. ResultsOral administration of aqueous extract of C. pictus leaves to diabetic rats for 30 days significantly reduced the levels of blood glucose, lipid profile, lipid peroxidation, liver marker enzymes, urea, creatinine and increased the levels of antioxidant enzymes. ConclusionsThe aqueous extract of C. pictus leaves controls the blood glucose level, improves lipid metabolism and prevents diabetic complications associated with lipid peroxidation and also maintains the antioxidant enzymes in experimental diabetic rats. Therefore, it can be recommeded for the prevention of diabetes mellitus.

Oxalic acid and oxalate oxidase enzyme in Costus pictus D. Don

The leaves of Costus pictus are sour in taste due to the presence of oxalic acid in the leaves. Different stages of leaves were collected and the samples were designated as stage one, stage two and stage three. It was found that oxalate content and oxalate oxidase activity were maximum in second leaf stage followed by first leaf stage and third leaf stage. Drying causes substantial loss of oxalate content and complete loss of oxalate oxidase activity. With various solvents water recovered more oxalate followed by methanol and ethanol while oxalate oxidase activity was maximum in ethanol followed by methanol and water. The ethanol or methanol extract of second leaf stage of C. pictus can be used for isolating active principles. The oxalate oxidase from C. pictus can be used as a cheap source of oxalate oxidase enzyme which is used in oxalate determination in biological fluids. Moreover, the sensitivity of oxalate determination employing oxalate oxidase from C. pictus will be more as oxalate oxidase in C. pictus has K m 20 times lesser than the oxalate oxidase enzyme from barley seedling.

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 Ca²⁺ concentrations ([Ca²⁺]_i), an effect which was completely abolished by the removal of extracellular Ca²⁺ or blockade of voltage-gated Ca²⁺ 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 [Ca²⁺]_i levels through VGCC. CP extracts may provide an affordable and inexpensive alternative for treating patients with T2DM.

Negative regulation of glucose uptake by Costus pictus in L6 myotube cell line

The leaf of Costus pictus D. Don is considered as an antidiabetic in folklore medicine and is known to reduce the blood sugar, similar to insulin. The aim of this study is to investigate the effect of ethanolic extract of C. pictus leaf on glucose uptake by L6 myotube cell line (skeletal muscle cells) involved in glucose utilization. Ethanolic extract of C. pictus leaf was analyzed to study GLUT4 translocation and glucose uptake activity, but it has no direct peripheral action at 300 μg/ml dose comparable with insulin and metformin. The glucose uptake was not enhanced by the extract of C. pictus leaf.

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.

Anti-diabetic effect of Costus pictus leaves in normal and streptozotocin-induced diabetic rats

Costus pictus D. Don, commonly known as ‘insulin plant’ is a member of Zingiberacea family and is used as a munching dietary supplement for the treatment of diabetes in Southern India. The present study was carried out to evaluate the antidiabetic effect of Costus pictus leaves in normal and streptozotocin-induced diabetic rats. The oral feeding of aqueous leaf solution of this plant in diabetic rats for 28 days at a dosage of 2gm/kg body weight exhibited a significant (p<0.001) reduction in fasting blood glucose level and a remarkable increase in serum insulin level. There was a significant reduction (p<0.001) in serum parameters like SGOT, SGPT, lipids, triglycerides, total cholesterol, urea, TBARS, and albumin in diabetic rats treated with leaf solution. The body weight of diabetic rats was restored to normal state when treated with the C. pictus. Morphometric analysis of C. pictus-treated rat pancreatic islets showed a significant (p<0.001) increase in the number and area of islets when compared with normal and diabetic control rats. Histopathology studies in liver and kidney of diabetic rats treated with aqueous solution did not show any marked difference from normal which revealed the non-toxic effect of this plant. Estimation of trace elements using particle induced X-ray emission analysis in the leaf was also determined to find the antidiabetic potential elements in this plant. Based on the above results it is evident that the leaves of C. pictus have antidiabetic effect and must be considered as a potential candidate for future studies on diabetes mellitus.