Colocasia Esculenta Tuber Research Articles

Safety profile of colocasia esculenta tuber extracts in benign prostate hyperplasia

IntroductionThis study was motivated by the increasing global incidence of benign prostatic hyperplasia (BPH) and the promising potential of nutraceuticals as complementary therapies in ameliorating its burden. We report the safety profile of C. esculenta tuber extracts, a novel nutraceutical in benign prostate hyperplasia in a rat model.MethodsIn this study, forty-five male albino rats were randomly assigned to 9 groups of 5 rats each. Group 1 (normal control) received olive oil and normal saline. Group 2 (BPH untreated group) received 3 mg/kg of testosterone propionate (TP) and normal saline, and group 3 (positive control) received 3 mg/kg of TP and 5 mg/kg of finasteride. Treatment groups 4, 5, 6, 7, 8, and 9 received 3 mg/kg of TP and a middle dose (200 mg/kg) of LD50 of ethanol crude tuber extract of C. esculenta (ECTECE) or hexane, dichloromethane, butanone, ethyl acetate and aqueous fractions of ECTECE respectively for a period of 28 days.ResultsThe negative controls showed a significant (p < 0.05) increase in mean relative prostate weight (approximately 5 times) as well as a reduction in relative testes weight (approximately 1.4 times less). There was no significant (p > 0.05) difference in the mean relative weights of most vital organs: liver, kidneys, and heart. This was also observed in hematological parameters: RBC, hemoglobin, HCT, MCV, MCH, MCHC, and platelets counts. In general, we note that the effects of the well-established drug finasteride on the biochemical parameters and histology of selected organs are comparable to those of C. esculenta fractions.ConclusionThis study demonstrates that C. esculenta tuber extracts provide potentially safe nutraceutical if applied in the management of benign prostate hyperplasia based on a rat model.

Physical-Chemical Crosslinked Electrospun Colocasia esculenta Tuber Protein-Chitosan-Poly(Ethylene Oxide) Nanofibers with Antibacterial Activity and Cytocompatibility.

BackgroundElectrospun nanofibers based on Colocasia esculenta tuber (CET) protein are considered as a promising material for wound dressing applications. However, the use of these nanofibers in aqueous conditions has poor stability. The present study was performed to obtain insights into the crosslinked electrospun CET’s protein–chitosan (CS)–poly(ethylene oxide) (PEO) nanofibers and to evaluate their potential for wound dressing applications.MethodsThe electrospun nanofibers were crosslinked with glutaraldehyde (GA) vapor and heat treatment (HT) to enhance their physicochemical stability. The crosslinked nanofibers were characterized by protein profiles, morphology structures, thermal behavior, mechanical properties, and degradation behavior. Furthermore, the antibacterial properties and cytocompatibility were analyzed by antibacterial assessment and cell proliferation.ResultsThe protein profiles of the electrospun CET’s protein–CS–PEO nanofibers before and after HT crosslinking contained one major bioactive protein with a molecular weight of 14.4 kDa. Scanning electron microscopy images of the crosslinked nanofibers indicated preservation of the structure after immersion in phosphate buffered saline. The crosslinked nanofibers resulted in higher ultimate tensile strength and lower ultimate strain compared to the non-crosslinked nanofibers. GA vapor crosslinking showed higher water stability compared to HT crosslinking. The in vitro antibacterial activity of the crosslinked nanofibers showed a stronger bacteriostatic effect on Staphylococcus aureus than on Escherichia coli. Human skin fibroblast cell proliferation on crosslinked GA vapor and HT nanofibers with 1% (w/v) CS and 2% (w/v) CET’s protein demonstrated the highest among all the other crosslinked nanofibers after seven days of cell culture. Cell proliferation and cell morphology results revealed that introducing higher CET’s protein concentration on crosslinked nanofibers could increase cell proliferation of the crosslinked nanofibers.ConclusionThese results are promising for the potential use of the crosslinked electrospun CET’s protein–CS–PEO nanofibers as bioactive wound dressing materials.

Determination of Antioxidant Activity of Ethanol Extract of Gölevez [(Colocasia esculenta (L.)] Tubers

In this study, the antioxidant activity of the ethanolic extract of Colocasia esculenta tubers were determined by four different antioxidant tests including DPPH and ABTS radicals scavenging activities, metal chelating activity and reducing power. The scavenging effect of extract of C. esculenta tubers and standards on DPPH radical at the highest concentration (600 µg mL-1) decreased in the following order: Vitamin C˃Trolox˃C. esculenta˃BHA and were found as 95.4, 93.6, 83.8 and 78.8 %, respectively. The scavenging effect of C. esculenta tuber extract and standards on ABTS radical at the highest concentration (100 µg mL-1) decreased in the order: Trolox = BHA˃C. esculenta and were found as 100, 100, 94.6%, respectively. The metal chelating capacity of extract of C. esculenta tubers and standards decreased in the order of C. esculenta˃BHA˃Trolox at lowest concentration (100 µg mL-1) and was found to be 78.0, 76.0, 63.5 %, respectively. Reducing power of extract of C. esculenta tubers and standards at the highest concentration (600 µg mL-1) followed the order: BHA˃Trolox˃C. esculenta. Total phenolic compound and flavonoid amounts of C. esculenta tubers were designated as 2400 mg GAE/kg extract and 2050 mg QE/kg extract, respectively.

Stabilization of chitosan-polyethylene oxide electrospun nanofibrous containing Colocasia esculenta tuber protein

In this study, protein in Colocasia esculenta tuber (CET) combined with polyethylene oxide (PEO) and chitosan were fabricated by electrospinning, which could be further stabilized by heat treatment and compared with glutaraldehyde vapor. CET’s protein containing 6.6% protein with molecular weight 53.5, 42, 24.4, 11.8, and 9.8 kDa shows no cytotoxicity and has the potential growth-stimulatory activities on NIH-3T3 fibroblast cell. The 10% (v/v) acetic acid was found as an appropriate solvent to electrospun the CET’s protein-chitosan-PEO solution. The influence of conductivity, surface tension, and viscosity in the solution of CET’s protein, chitosan, and PEO on nanofibers morphology was successfully demonstrated. The scanning electron microscope shows that the average diameter of the CET’s protein-chitosan-PEO nanofibers decreased with the increased of chitosan and CET’s protein content. The chemical and physical stabilization of nanofibers exhibits an increase in the fiber diameter up to 157%. The presence of 1% (w/v) chitosan resulted in a better preservative of the nanofibrous structure after the stabilization process. By the confirmation using Fourier transform infrared spectroscopic data, it is concluded that stabilization techniques applied in this study are promising to improve the value of CET’s protein-chitosan-PEO nanofiber in medical purposes.

Expression of Colocasia esculenta tuber agglutinin in Indian mustard provides resistance against Lipaphis erysimi and the expressed protein is non-allergenic.

Transgenic Brassica juncea plants expressing Colocasia esculenta tuber agglutinin (CEA) shows the non-allergenic nature of the expressed protein leading to enhanced mortality and reduced fecundity of mustard aphid-Lipaphis erysimi. Lipaphis erysimi (common name: mustard aphid) is the most devastating sucking insect pest of Indian mustard (Brassica juncea L.). Colocasia esculenta tuber agglutinin (CEA), a GNA (Galanthus nivalis agglutinin)-related lectin has previously been reported by the present group to be effective against a wide array of hemipteran insects in artificial diet-based bioassays. In the present study, efficacy of CEA in controlling L. erysimi has been established through the development of transgenic B. juncea expressing this novel lectin. Southern hybridization of the transgenic plants confirmed stable integration of cea gene. Expression of CEA in T0, T1 and T2 transgenic plants was confirmed through western blot analysis. Level of expression of CEA in the T2 transgenic B. juncea ranged from 0.2 to 0.47% of the total soluble protein. In the in planta insect bioassays, the CEA expressing B. juncea lines exhibited enhanced insect mortality of 70-81.67%, whereas fecundity of L. erysimi was reduced by 49.35-62.11% compared to the control plants. Biosafety assessment of the transgenic B. juncea protein containing CEA was carried out by weight of evidence approach following the recommendations by FAO/WHO (Evaluation of the allergenicity of genetically modified foods: report of a joint FAO/WHO expert consultation, 22-25 Jan, Rome, http://www.fao.org/docrep/007/y0820e/y0820e00.HTM , 2001), Codex (Codex principles and guidelines on foods derived from biotechnology, Food and Agriculture Organization of the United Nations, Rome; Codex, Codex principles and guidelines on foods derived from biotechnology, Food and Agriculture Organization of the United Nations, Rome, 2003) and ICMR (Indian Council of Medical Research, guidelines for safety assessment of food derived from genetically engineered plants, http://www.icmr.nic.in/guide/Guidelines%20for%20Genetically%20Engineered%20Plants.pdf , 2008). Bioinformatics analysis, pepsin digestibility, thermal stability assay, immuno-screening and allergenicity assessment in BALB/c mice model demonstrated that the expressed CEA protein from transgenic B. juncea does not incite any allergenic response. The present study establishes CEA as an efficient insecticidal and non-allergenic protein to be utilized for controlling mustard aphid and similar hemipteran insects through the development of genetically modified plants.

Production, physicochemical and sensory characterization of cocoyam mixed flours and pastes (achu)

Colocasia esculenta L. Schott and Xanthosoma sagittifolium L. Schott are two tropical tubers species commonly referred as cocoyams. Colocasia esculenta tuber is usually used for the preparation of achu (smooth paste food), but not always available. This work is aimed at evaluating the effect of mixing two cocoyam flours on the physicochemical and sensory characteristics of precooked composite flours and achu. In this respect, a factorial design was realized. This factorial design was 2 varieties of Xanthosoma sagittifolium (white-flesh and red-flesh) coded as WX and RX and 5 levels of substitutions (0, 25, 50, 75 and 100%) in the Colocasia esculenta (Ibo coco) coded as IC. Precooked flours showed significant (p < 0.05) differences in the contents of ash (2.09 ± 0.33 to 4.21 ± 0.03%), fiber (1.33 ± 0.04 to 1.57 ± 0.43%), total sugar (71.12 ± 0.85 to 74.02 ± 1.42%), starch (47.26 ± 0.95 to 66.59 ± 1.09%), proteins (3.20 ± 0.14 to 4.35 ± 0.07%) and total oxalate (0.41 ± 0.16 to 0.82 ± 0.11%). The water absorption capacity and water solubility index also shown a significant difference (p < 0.05). The highest gelatinization temperature, final viscosity, setback, and consistency during the heating time were recorded for Xanthosoma sagittifolium flours, meanwhile the peak viscosity and breakdown indexes were higher in Colocasia esculenta flour. It was also observed that there was least difference (p < 0.05) in the overall acceptability (4.54 ± 1.96 to 5.74 ± 1.40) of the sensory attributes of reconstituted achu by the participants. Elsewhere, the results revealed that more than 35% of the participants like very much the achu made from cocoyam flour mixtures while 44.65% of them just like it. These results indicate the potential of Xanthosoma sagittifolium precooked flours for substituting Colocasia esculenta flour at varying proportions in achu making.

Mannose in Complex with Colocasia esculenta Tuber Agglutinin

The major tuber storage protein of Colocasia esculenta is a monocot mannose-binding, widely used, dietarylectin, for which a crystal structure was previously shown to consist of four β-prism II domains or two αβheterodimers, each forming a α2β2 heterotetramer with a symmetry related unit. In the present study, the same lectincrystallized in the presence of a 50 molar excess of free mannose, persists in forming such α2β2 heterotetramers.Lectin crystals apparently complexed to mannose were obtained by hanging-drop, vapor-diffusion method at roomtemperature and high-resolution X-ray diffraction data were collected using a home X-ray source. Using the crystalstructure of the Remusatia vivipara lectin, the structure of the complex has been solved by molecular replacementand subsequent crystallographic refinement. Five different mannose binding sites per heterodimer with partialoccupancy have been found, among which only one appears to bind close to a classical carbohydrate recognitionsite characterized earlier for these lectins. Mannose binding at these five sites is described.

Thermal and chemical denaturation of Colocasia esculenta tuber agglutinin from α2β2 to unfolded state

The major tuber storage protein of Colocasia esculenta, is a monocot mannose-binding, widely used dietary lectin, containing two polypeptides of 12.0 and 12.4 kDa. By both gel filtration and dynamic light scattering at pH 7.2, the lectin has a α2β2 form of apparent molecular mass of 48.2 kDa and a hydrodynamic radius of 6.1 ± .2 nm; however, at pH 3, it migrates as αβ and has a reduced hydrodynamic radius of 4.6 ± .3 nm. Our circular dichroism spectroscopy studies show that the lectin retains approximately 100% of its secondary structure between pH 2–8, going down to ~90% for extreme acidic/alkaline conditions. The fluorescence emission maxima of 346 to 350 nm for pH 4 to 10 show that the tryptophan residues are relatively exposed. The unfolding is a simple two-state process, N4 ↔ 4U, as seen in our denaturation scan profiles. These denaturation profiles, monitored separately by fluorescence, far-UV CD, and near-UV CD, are completely super imposable. Analyses of these profiles provide an estimate of several thermodynamic parameters at each guanidinium chloride concentration, including the melting temperature Tg, which is 346.9 K in 0 M, but lowers to 321.8 K in 3.6 M. Dimeric and tetrameric interfaces observed in the crystal structure for the same protein are used to rationalize solution data in some detail.

Crystal Structure of Colocasia esculenta Tuber Agglutinin at 1.74 Å Resolution and Its Quaternary Interactions

Many members of the monocot mannose-binding lectin family, characterized by specificity towards mannose have been characterized and cloned. A majority of these lectins molecules contain 1-4 polypeptides of about 110 residues each. From the previously solved crystal structures of a few such lectins, mostly from non-edible plants, these lectins are thought to possess a common β-prism II fold structure. The major tuber storage protein of Colocasia esculenta is a monocot mannose-binding, widely used, dietary lectin. This tuber agglutinin contains two polypeptides of 12.0 and 12.4 kDa by matrix assisted laser desorption ionisation time-of-flight mass spectrometry. By gel filtration at pH 7.2, the purified lectin has a α2β2 form of apparent molecular mass of 48.2 kDa in solution but at pH 3, it has the heterodimeric αβ form. Lectin crystals were obtained by hanging-drop, vapor-diffusion method at room temperature and high-resolution X-ray diffraction data were collected using a home X-ray source. Among previously solved crystal structures of this family are garlic, Solomon’s seal, snowdrop, daffodil and Spanish blue-bell lectins, but the protein sequence of the Colocasia esculenta tuber agglutinin was found to be closest to that of the Remusatia vivipara lectin having no simple mannose-binding property. Using the previously solved 2.4A crystal structure of the Remusatia vivipara lectin, that of Colocasia esculenta has been solved by molecular replacement and subsequent crystallographic refinement and root mean square deviations between various lectins are tabulated and rationalized. The asymmetric unit in our lectin crystal structure contains four β-prism II domains or two αβ heterodimers, each forming a α2β2 heterotetramer with a symmetry related unit. The tetrameric interface obtained from our crystal structure is used to explain the conversion to dimers in acidic pH. Five ordered magnesium ions were located in the asymmetric unit and the presence of magnesium verified by atomic absorption spectroscopy.

Orally Disintegrating Tablet Using Colocasia esculenta Tuber Polysaccharide as a Disintegrant and its Comparision with Commercially Available Superdisintegrants

Background: Colocasia esculenta is a fast growing plant and is cultivated for consumption of leaf and tuber. Polysaccharide obtained from the tubers of Colocasia esculenta is known as Taro polymer. Chemically it is neutral heteropolysaccharide of galactose, galactose and arabinose. Objective: The present research work was aimed at the development and characterization of orally disintegrating tablet of Valsartan using natural disintegrant to produce rapid onset of action and patient compliance. Method: Polysaccharide from Colocasia esculenta tubers was isolated using solvent precipitation method. The isolated polysaccharide was investigated as disintegrant in orally disintegrating tablets. Valsartan, an antihypertensive drug, was selected as a model drug. The drug excipient interactions were characterized by FTIR studies. The tablets of Valsartan were prepared separately using different concentrations [2.5, 5, 7.5 and 10 % w/w] of isolated Colocasia esculenta polysaccharide and Kollidon®, Ac-Di-Sol® as synthetic superdisintegrants by using direct compression method. The tablets thus prepared were evaluated for various pre-compression and post-compression parameters. The disintegration time and in vitro drug release of the optimized formulation was compared with the available marketed formulation. The stability studies were performed on the optimised batch F12. Results: The formulation F12 containing 10 % of polysaccharide showed rapid wetting time and disintegration time and is comparable to formulations prepared using synthetic superdisintegrants at the same concentration level. Conclusion: Colocasia esculenta polysaccharide can be used as a disintegrant in the formulation of orally disintegrating tablets. Its disintegrating property was found to be comparable with that of the commercially available superdisintegrants. Keywords: Orally disintegrating tablet, polysaccharide, Colocasia esculenta, tubers, valsartan.

Molecular Mechanism Underlying the Entomotoxic Effect of Colocasia esculenta Tuber Agglutinin against Dysdercus cingulatus

Colocasia esculenta tuber agglutinin (CEA), a mannose binding lectin, exhibits insecticidal efficacy against different hemipteran pests. Dysdercus cingulatus, red cotton bug (RCB), has also shown significant susceptibility to CEA intoxication. However, the molecular basis behind such entomotoxicity of CEA has not been addressed adequately. The present study elucidates the mechanism of insecticidal efficacy of CEA against RCB. Confocal and scanning electron microscopic analyses documented CEA binding to insect midgut tissue, resulting in an alteration of perimicrovillar membrane (PMM) morphology. Internalization of CEA into insect haemolymph and ovary was documented by western blotting analyses. Ligand blot followed by mass spectrometric identification revealed the cognate binding partners of CEA as actin, ATPase and cytochrome P450. Deglycosylation and mannose inhibition assays indicated the interaction to probably be mannose mediated. Bioinformatic identification of putative glycosylation or mannosylation sites in the binding partners further supports the sugar mediated interaction. Correlating entomotoxicity of CEA with immune histological and binding assays to the insect gut contributes to a better understanding of the insecticidal potential of CEA and endorses its future biotechnological application.

Binding of insecticidal lectin Colocasia esculenta tuber agglutinin (CEA) to midgut receptors of Bemisia tabaci and Lipaphis erysimi provides clues to its insecticidal potential.

The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications.

Characterization of a Highly Potent Insecticidal Lectin from &amp;lt;i&amp;gt;Colocasia esculenta&amp;lt;/i&amp;gt; Tuber and Cloning of Its Coding Sequence

Hemipteran insects are the most devastating pest for different crops of high economic value. Colocasia esculenta tuber agglutinin (CEA), a mannose binding monocot lectin from araceae family was previously reported by the present group to be effective against some members of this class of pests. In the present study, efficacy of this potent lectin has been extended to cotton aphid (Aphis gossypii) which is becoming a highly damaging pest of cotton in recent days. Because, like other aphids, A. gossypii not only extracts the phloem fluid but also transmit disease causing viruses and add to the high degree of yield loss. Efficacy of the lectin on cotton aphid as well as other hemipteran insects prompted us further to clone the protein coding gene. Very little sequence information of this gene was available in the database. Hence, attempt had been made to study the protein through liquid chromatography-tandem mass spectrometry (LC-MS/MS) to have the detailed peptide information. On the basis of the peptide homology information obtained from LC-MS/MS the complete coding sequence of CEA was determined. The coding sequence corresponding to CEA was cloned further using primers designed on the basis of above information and genome walk technology for its potential utilisation in insect management programme.