TY - JOUR
T1 - Evaluation of gut modulatory and bronchodilator activities of Amaranthus spinosus Linn.
AU - Chaudhary, Mueen A.
AU - Imran, Imran
AU - Bashir, Samra
AU - Mehmood, Malik H.
AU - Rehman, Najeeb ur
AU - Gilani, Anwarul Hassan
N1 - Funding Information:
This study was supported partly by Pakistan Science Foundation and the University Research Council of the Aga Khan University, Karachi, Pakistan.
PY - 2012/10/1
Y1 - 2012/10/1
N2 - Background: The aqueous-methanolic extract of Amaranthus spinosus (A. spinosus Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses.Methods: The crude extract of A. spinosus was studied in-vivo for bronchodilator and laxative activities and in-vitro using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms.Results: In the in-vivo experiments in mice, the administration of A. spinosus increased fecal output at doses of 100 and 300 mg/kg showing laxative activity. It also inhibited carbachol-induced bronchospasm in anesthetized rats at 1, 3, 10 and 30 mg/kg indicative of bronchodilator activity. When tested on isolated gut preparations, the plant extract showed a concentration-dependent (0.01-10.0 mg/ml) spasmogenic effect in spontaneously contracting rabbit jejunum and guinea-pig ileum. The spasmogenic effect was partially blocked in tissues pretreated with atropine (0.1 μM). When tested on K+ (80 mM)-induced sustained contractions in isolated rabbit jejunum, the plant extract caused complete relaxation and also produced a shift in the Ca++ concentration-response curves (CRCs) towards right, similar to diltiazem. In rabbit trachea, the plant extract completely inhibited K+ (80 mM) and carbachol (CCh, 1 μM)-induced contractions at 1 mg/ml but pretreatment of tissue with propranolol (1 μM), caused around 10 fold shift in the inhibitory CRCs of the plant extract constructed against CCh-induced contraction. The plant extract (up to 0.3 mg/ml) also increased both force and rate of spontaneous contractions of isolated guinea-pig atria, followed by relaxation at higher concentration (1.0-5.0 mg/ml). The cardio-stimulant effect was abolished in the presence of propranolol, similar to that of isoprenaline. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the organic fraction, whereas the spasmogenic component was concentrated in the aqueous fraction.Conclusion: These results indicate that A. spinosus possesses laxative activity partially mediated through cholinergic action. The spasmolytic effect was mediated through calcium channel blocking (CCB), while bronchodilator activity through a combination of β-adrenergic and CCB pathways, which may explain the traditional uses of A. spinosus in gut and airways disorders.
AB - Background: The aqueous-methanolic extract of Amaranthus spinosus (A. spinosus Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses.Methods: The crude extract of A. spinosus was studied in-vivo for bronchodilator and laxative activities and in-vitro using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms.Results: In the in-vivo experiments in mice, the administration of A. spinosus increased fecal output at doses of 100 and 300 mg/kg showing laxative activity. It also inhibited carbachol-induced bronchospasm in anesthetized rats at 1, 3, 10 and 30 mg/kg indicative of bronchodilator activity. When tested on isolated gut preparations, the plant extract showed a concentration-dependent (0.01-10.0 mg/ml) spasmogenic effect in spontaneously contracting rabbit jejunum and guinea-pig ileum. The spasmogenic effect was partially blocked in tissues pretreated with atropine (0.1 μM). When tested on K+ (80 mM)-induced sustained contractions in isolated rabbit jejunum, the plant extract caused complete relaxation and also produced a shift in the Ca++ concentration-response curves (CRCs) towards right, similar to diltiazem. In rabbit trachea, the plant extract completely inhibited K+ (80 mM) and carbachol (CCh, 1 μM)-induced contractions at 1 mg/ml but pretreatment of tissue with propranolol (1 μM), caused around 10 fold shift in the inhibitory CRCs of the plant extract constructed against CCh-induced contraction. The plant extract (up to 0.3 mg/ml) also increased both force and rate of spontaneous contractions of isolated guinea-pig atria, followed by relaxation at higher concentration (1.0-5.0 mg/ml). The cardio-stimulant effect was abolished in the presence of propranolol, similar to that of isoprenaline. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the organic fraction, whereas the spasmogenic component was concentrated in the aqueous fraction.Conclusion: These results indicate that A. spinosus possesses laxative activity partially mediated through cholinergic action. The spasmolytic effect was mediated through calcium channel blocking (CCB), while bronchodilator activity through a combination of β-adrenergic and CCB pathways, which may explain the traditional uses of A. spinosus in gut and airways disorders.
KW - Amaranthus spinosus
KW - Bronchodilator
KW - Cholinergic
KW - Laxative
KW - Spasmolytic
UR - http://www.scopus.com/inward/record.url?scp=84866786248&partnerID=8YFLogxK
U2 - 10.1186/1472-6882-12-166
DO - 10.1186/1472-6882-12-166
M3 - Article
C2 - 23025418
AN - SCOPUS:84866786248
SN - 1472-6882
VL - 12
JO - BMC Complementary and Alternative Medicine
JF - BMC Complementary and Alternative Medicine
M1 - 1217
ER -