A preliminary report on oral glucose tolerance and antinociceptive activity tests conducted with methanol extract of Xanthosoma violaceum aerial parts
© Faisal et al.; licensee BioMed Central Ltd. 2014
Received: 31 May 2014
Accepted: 11 September 2014
Published: 13 September 2014
Xanthosoma violaceum is commonly observed in fallow areas of Bangladesh but almost no scientific studies exist on this plant. Rural people consume the plant on a frequent basis. The objective of this study was to scientifically analyze the antinociceptive property of methanol extract of aerial parts of the plant along with antihyperglycemic activity.
Antihyperglycemic activity was measured by oral glucose tolerance test (OGTT). Antinociceptive activity was determined by observed decreases in abdominal constrictions in intraperitoneally administered acetic acid-induced pain model in mice.
Administration of methanol extract of aerial parts led to dose-dependent and significant reductions in blood glucose levels in glucose-loaded mice. At doses of 50, 100, 200 and 400 mg per kg body weight, the extract reduced blood sugar levels by 19.3, 23.2, 31.8, and 47.1%, respectively compared to control animals. By comparison, a standard antihyperglycemic drug, glibenclamide, when administered at a dose of 10 mg per kg body weight, reduced blood glucose level by 48.9%. In antinociceptive activity tests, the extract at the above four doses reduced the number of abdominal constrictions by 41.4, 44.8, 48.3, and 55.2%, respectively. A standard pain relieving (antinociceptive) drug, aspirin, reduced the number of writhings by 31.0 and 51.7%, respectively, when administered at doses of 200 and 400 mg per kg body weight.
To our knowledge, this is the first report on oral glucose tolerance and antinociceptive activity evaluation of aerial parts of the plant. Since the plant is widely available in Bangladesh, the aerial parts can be a readily available source for particularly the rural population for lowering blood sugar in diabetic patients and for alleviating pain.
KeywordsAntihyperglycemic Xanthosoma violaceum OGTT Antinociceptive Araceae
Xanthosoma violaceum Schott (Araceae) is a common plant in Bangladesh and can be seen growing in fallow lands. In Bangladesh, it is known as ‘Dudh kochu’ and in English as “blue taro’. Aerial parts of the plant are consumed as vegetable by particularly the low income sections of the rural people, because it can be collected freely from the fallow lands. Until now, any scientific reports are practically non-existent on this plant. The only available report mentions that flavone-C-glycosides (apigenin 6-C-β-D-glucopyranosyl-8-C-β-D-apiofuranoside, as well as vitexin, isovitexin, isovitexin 4′-O-rhamnopyranoside, apigenin 6-C-[β-D-glucopyranosyl-(1-- > 6)-β-D-glucopyranoside], and apigenin 6,8-diC-β-D-glucopyranoside) with antioxidative properties are present in the leaves of the plant .
Antidiabetic, hypolipidemic and antioxidative effects have been noted with a related species of X. violaceum, namely, Xanthosoma sagittifolium corm extract . Apigenin derivatives, vitexin and isovitexin have been reported in X. violaceum. Apigenin has been reported to be able to regulate diabetes mellitus, as well as diabetes-induced thyroid dysfunction and lipid peroxidation in alloxan-induced diabetic mice . Streptozotocin (STZ)-treated islets were observed to release more insulin in the presence of apigenin, isolated from Teucrium polium, than apigenin-non-treated islets . Apigenin reportedly attenuated 2-deoxy-D-ribose-induced oxidative cell damage in HIT-T15 pancreatic β-cells . Vitexin and isovitexin, isolated from leaves of Ficus deltoidea, has been reported to in vivo inhibit α-glucosidase activity .
Methanol extract of Jatropha gossypifolia aerial parts has been reported to exhibit analgesic and anti-inflammatory activity; apigenin, vitexin and isovitexin are known to be present in the leaves of this plant . Methanol extract of aerial parts of Ficus pumila has also been reported to show analgesic and anti-inflammatory activities; apigenin was identified as one of the active ingredients .
Diabetes and pain are afflictions suffered by people throughout the world. Although medications are available, the rural people of Bangladesh often do not have access to or can afford these medications. As such, we had been screening various common Bangladeshi plants for their antihyperglycemic and antinociceptive properties [9–12]. Considering the presence of antidiabetic and analgesic components (apigenin, vitexin, isovitexin) present in X. violaceum, and considering that the corms of a related species X. sagittifolium have been reported to give antidiabetic effects, the objective of the present study was to conduct oral glucose tolerance test (OGTT) and acetic acid-induced gastric pain model test with methanol extract of aerial parts of X. violaceum towards evaluating the antihyperglycemic and antinociceptive potential of the extract.
Plant material collection
Aerial parts (leaves and stems) of X. violaceum were collected during September 2013 from Kawlar in Dhaka district, Bangladesh and taxonomically identified at the Bangladesh National Herbarium (Accession Number 38,592).
Preparation of methanolic extract of aerial parts
Aerial parts were cut into small pieces, air-dried in the shade, and 100 g of dried and powdered leaves and stems was extracted with methanol (w:v ratio of 1:6, final weight of the extract 10.05 g). 100 g of dried and powdered leaves and stems were stirred continuously in 600 ml methanol for 70 minutes. The mixture was left overnight followed by fresh stirring for 70 minutes the following morning. The mixture was again left overnight followed by filtration. All procedures were conducted at ambient temperature (25°C). The filtrate was collected and evaporated at 40°C [9–12].
Chemicals and drugs
Glibenclamide, aspirin, and glucose were obtained from Square Pharmaceuticals Ltd., Bangladesh. All other chemicals were of analytical grade.
Swiss albino mice (male), which weighed between 14–19 g were used in the present study. The animals were obtained from International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B). The animals were acclimatized for three days prior to actual experiments. The study was conducted following approval by the Institutional Animal Ethical Committee of University of Development Alternative, Dhaka, Bangladesh (Approval No. 48/EC/2013/UODA).
Oral glucose tolerance tests for evaluation of antihyperglycemic activity
where We and Wc represents the blood glucose concentration in glibenclamide or MEXV administered mice (Groups 2–6), and control mice (Group 1), respectively.
Antinociceptive activity evaluation through abdominal writhing test
where We and Wc represents the number of writhings in aspirin or MEXV administered mice (Groups 2–7), and control mice (Group 1), respectively.
Acute toxicity test
Acute toxicity test was conducted as previously described . Mice were divided into nine groups, each group consisting of six animals. Group 1 was given 1% Tween 80 in normal saline (2 ml per kg body weight). The other eight groups (Groups 2–9) were administered, respectively, 100, 200, 300, 600, 800, 1000, 2000 and 3000 mg of MEXV per kg body weight. All animals were closely observed for the next 8 hours to notice any behavioral changes or mortality and were kept under close observation for the next two weeks.
Experimental values are expressed as mean ± SEM. Independent Sample t-test was carried out for statistical comparison. Statistical significance was considered to be indicated by a p value < 0.05 in all cases .
Preliminary phytochemical screening
Preliminary phytochemical analysis of MEXV for presence of saponins, tannins, alkaloids, and flavonoids were conducted as described before .
Preliminary screening of phytochemicals
Various tests conducted for presence of phytochemicals in MEXV indicated the presence of tannins, alkaloids, and flavonoids.
The crude extract did not show any toxicity in mice even at the highest dose tested.
Antihyperglycemic activity evaluation results
Effect of crude methanol extract of X. violaceum aerial parts (MEXV) on blood glucose level in hyperglycemic mice following 120 minutes of glucose loading
Dose (mg/kg body weight)
Blood glucose level (mmol/l)
% lowering of blood glucose level
5.60 ± 0.27
2.86 ± 0.26
4.52 ± 0.16
4.30 ± 0.18
3.82 ± 0.27
2.96 ± 0.19
Antinociceptive activity evaluation results
Antinociceptive effect of crude methanol extract of X. violaceum aerial parts (MEXV) in acetic acid-induced pain model mice
Dose (mg/kg body weight)
Mean number of abdominal constrictions
5.8 ± 0.37
4.0 ± 0.84
2.8 ± 0.37
3.4 ± 0.24
3.2 ± 0.58
3.0 ± 0.63
2.6 ± 0.60
To our knowledge, this is the first reported instance of oral glucose tolerance and antinociceptive activity tests conducted with aerial parts of X. violaceum. The plant belongs to the Araceae family. Plant parts from other Araceae family plants have been previously reported for antihyperglycemic and antinociceptive activities, although the reports are few. Oligosaccharides isolated from Amorphophallus konjac have previously been shown to give hypoglycemic effect in streptozotocin (STZ)-induced diabetic model of isolated islets, and which has been hypothesized to be related with free radical attenuation and lower risks of islets damage from nitric oxide NO(*) radical . The ameliorative potential of Colocasia esculenta tubers have been reported in STZ-induced diabetic nephropathy in rats . Methanol extract of leaves of C. esculenta also reportedly demonstrated antihyperglycemic and antinociceptive potential .
Antinociceptive and antiinflammatory effect of Anchomanes difformis extract has been reported in rats against formalin-induced pain and egg albumin-induced inflammation . The analgesic activity of methanol leaf extract of Culcasia scandens has been reported against acetic acid-induced writhings and formalin-induced paw licking in mice . The analgesic activity of methanol extract of Amorphophallus campanulatus tubers has also been reported .
Any phytochemical constituent(s) responsible for the observed antihyperglycemic and antinociceptive effects were not isolated and identified in this preliminary study. However, phytochemical analysis of the crude extract showed presence of tannins, alkaloids and flavonoids. Also as discussed earlier, some reported constituents of the plant like apigenin, vitexin and isovitexin have reported antidiabetic and analgesic activities [1, 3–8]. Antidiabetic and antihyperlipidemic effects of ethanolic extract of whole plant of Tridax procumbens have been shown in STZ-induced diabetic rats. The crude extract was found to contain tannins, alkaloids, and flavonoids . Hypoglycemic and tissue-protective effects have been seen with aqueous extract of Persea americana seeds in alloxan-induced diabetic rats ; the extract was also found to contain tannins, alkaloids, and flavonoids. Antinociceptive and antioxidant activities have been observed with ethanolic crude extract of leaves of Ageratum conyzoides from Bangladesh; phytochemical analysis of the crude extract revealed the presence of tannins, alkaloids, and flavonoids . Thus these group of compounds, either singly or in combination may be responsible for the observed antihyperglycemic and antinociceptive effects in the present study.
The results suggest that the extract merits further scientific attention for further isolation and identification of the bioactive component(s) responsible for the observed antihyperglycemic and antinociceptive effects.
This work was funded through internal funding of the University of Development Alternative.
- Picerno P, Mencherini T, Lauro MR, Barbato F, Aquino R: Phenolic constituents and antioxidant properties of Xanthosoma violac eum leaves. J Agric Food Chem. 2003, 51: 6423-6428. 10.1021/jf030284h.View ArticlePubMedGoogle Scholar
- Shajeela PS, Kalpanadevi V, Mohan VR: Potential antidiabetic, hypolipidaemic and antioxidant effects of Xanthosoma sagittifolium extract in alloxan induced diabetic rats. Int J Pharm Pharmacol Sci. 2013, 5: 27-31.Google Scholar
- Panda S, Kar A: Apigenin (4′, 5,7-trihydroxyflavone) regulates hyperglycaemia, thyroid dysfunction and lipid peroxidation in alloxan-induced diabetic mice. J Pharm Pharmacol. 2007, 59: 1543-1548. 10.1211/jpp.59.11.0012.View ArticlePubMedGoogle Scholar
- Esmaeili MA, Zohari F, Sadeghi H: Antioxidant and protective effects of major flavonoids from Teucrium polium on β-cell destruction in a model of streptozotocin-induced diabetes. Planta Med. 2009, 75: 1418-1420. 10.1055/s-0029-1185704.View ArticlePubMedGoogle Scholar
- Suh KS, Oh S, Woo JT, Kim SW, Kim YS, Chon S: Apigenin attenuates 2-deoxy-D-ribose-induced oxidative cell damage in HIT-T15 pancreatic β-cells. Biol Pharm Bull. 2012, 35: 121-126. 10.1248/bpb.35.121.View ArticlePubMedGoogle Scholar
- Choo CY, Sulong NY, Man F, Wong TW: Vitexin and isovitexin from the leaves of Ficus deltoidea with in-vivo α-glucosidase inhibition. J Ethnopharmacol. 2012, 142: 776-781. 10.1016/j.jep.2012.05.062.View ArticlePubMedGoogle Scholar
- Panda BB, Gaur K, Kori ML, Tyagi LK, Nema RK, Sharma CS, Jain AK: Anti-inflammatory and analgesic activity of Jatropha gossypifolia in experimental animal models. Global J Pharmacol. 2009, 3: 1-5.Google Scholar
- Liao CR, Kao CP, Peng WH, Chang YS, Lai SC, Ho YL: Analgesic and anti-inflammatory activities of methanol extract of Ficus pumila L. in mice. Evid Based Complement Alternat Med. 2012, 2012: 340141-doi:10.1155/2012/340141PubMedPubMed CentralGoogle Scholar
- Rahmatullah M, Hossain M, Mahmud A, Sultana N, Rahman SM, Islam MR, Khatoon MS, Jahan S, Islam F: Antihyperglycemic and antinociceptive activity evaluation of ‘khoyer’ prepared from boiling the wood of Acacia catechu in water. Afr J Tradit Complement Altern Med. 2013, 10: 1-5. 10.1625/jcam.10.1.PubMedPubMed CentralGoogle Scholar
- Haque ME, Rahman S, Rahmatullah M, Jahan R: Evaluation of antihyperglycemic and antinociceptive activity of Xanthium indicum stem extract in Swiss albino mice. BMC Complement Altern Med. 2013, 13: 296-10.1186/1472-6882-13-296. doi:10.1186/1472-6882-13-296View ArticlePubMedPubMed CentralGoogle Scholar
- Khatun F, Zaman F, Mosaiab T, Mostafa F, Zaman M, Rehana F, Nasrin D, Jamal F, Nahar N, Rahmatullah M: Evaluation of antinociceptive and antihyperglycemic activities in methanol extracts of whole plants of Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) in mice. Pak J Pharm Sci. 2012, 25: 583-587.PubMedGoogle Scholar
- Hossain AI, Faisal M, Rahman S, Jahan R, Rahmatullah M: A preliminary evaluation of antihyperglycemic and analgesic activity of Alternanthera sessilis aerial parts. BMC Complement Altern Med. 2014, 14: 169-10.1186/1472-6882-14-169. doi:10.1186/1472-6882-14-169View ArticlePubMedPubMed CentralGoogle Scholar
- Joy KL, Kuttan RJ: Anti-diabetic activity of Picrorrhiza kurroa extract. J Ethnopharmacol. 1999, 67: 143-148. 10.1016/S0378-8741(98)00243-8.View ArticlePubMedGoogle Scholar
- Venkatesh S, Reddy GD, Reddy YSR, Sathyavathy D, Reddy B: Effect of Helicteres isora root extracts on glucose tolerance in glucose-induced hyperglycemic rats. Fitoterapia. 2004, 75: 364-367. 10.1016/j.fitote.2003.12.025.View ArticlePubMedGoogle Scholar
- Shanmugasundaram P, Venkataraman S: Anti-nociceptive activity of Hygrophilous auriculata (Schum) Heine. Afr J Tradit Complement Altern Med. 2005, 2: 62-69.Google Scholar
- Ganapaty S, Dash GK, Subburaju T, Suresh P: Diuretic, laxative and toxicity studies of Cocculus hirsutus aerial parts. Fitoterapia. 2002, 71: 28-31.View ArticleGoogle Scholar
- Kumar C, Kumar R, Nehar S: Phytochemical properties, total antioxidant status of acetone and methanol extract of Terminalia arjuna Roxb. bark and its hypoglycemic effect on Type-II diabetic albino rats. J Pharmacogn Phytochem. 2013, 2: 199-208.Google Scholar
- Lu XJ, Chen XM, Fu DX, Cong W, Ouyang F: Effect of Amorphophallus Konjac oligosaccharides on STZ-induced diabetes model of isolated islets. Life Sci. 2002, 72: 711-719. 10.1016/S0024-3205(02)02303-2.View ArticlePubMedGoogle Scholar
- Eleazu CO, Iroaganachi M, Eleazu KC: Ameliorative potentials of cocoyam (Colocasia esculenta L.) and unripe plantain (Musa paradisiaca L.) on the relative tissue weights of streptozotocin-induced diabetic rats. J Diabetes Res. 2013, 2013: 160964-View ArticlePubMedPubMed CentralGoogle Scholar
- Akter A, Rahman S, Morshed MT, Hossain S, Jahan S, Swarna A, Rahmatullah M: Evaluation of antihyperglycemic and antinociceptive potential of Colocasia esculenta (L.) Schott (Araceae) leaves. Adv Nat Appl Sci. 2013, 7: 143-148.Google Scholar
- Adebayo AH, John-Africa LB, Agbafor AG, Omotosho OE, Mosaku TO: Anti-nociceptive and anti-inflammatory activities of extract of Anchomanes difformis in rats. Pak J Pharm Sci. 2014, 27: 265-270.PubMedGoogle Scholar
- Okoli CO, Akah PA, Egbuniwe ON: Analgesic activity of leaf extracts of Culcasia scandens P. Beauv. Indian J Exp Biol. 2006, 44: 422-424.PubMedGoogle Scholar
- Shilpi JA, Ray PK, Sarder MM, Uddin SJ: Analgesic activity of Amorphophallus campanulatus tuber. Fitoterapia. 2005, 76: 367-369. 10.1016/j.fitote.2005.03.024.View ArticlePubMedGoogle Scholar
- Petchi RR, Parasuraman S, Vijaya C: Antidiabetic and antihyperlipidemic effects of an ethanolic extract of the whole plant of Tridax procumbens (Linn.) in streptozotocin-induced diabetic rats. J Basic Clin Pharmcol. 2013, 4: 88-92. 10.4103/0976-0105.121655.View ArticleGoogle Scholar
- Ezejiofor AN, Okorie A, Orisakwe OE: Hypoglycaemic and tissue-protective effects of the aqueous extract of Persea americana seeds on alloxan-induced albino rats. Malays J Med Sci. 2013, 20: 31-39.PubMedPubMed CentralGoogle Scholar
- Hossain H, Karmakar UK, Biswas SK, Shahid-Ud-Daula AF, Jahan IA, Adnan T, Chowdhury A: Antinociceptive and antioxidant potential of the crude ethanol extract of the leaves of Ageratum conyzoides grown in Bangladesh. Pharm Biol. 2013, 51: 893-898. 10.3109/13880209.2013.770535.View ArticlePubMedGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6882/14/335/prepub
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