Pharmacological Screening of Indigenous Plants for Possible Gastrointestinal, Respiratory and Cardiovascular Activities.

Abstract

The present study was undertaken to explore therapeutic potential of selected plants to provide scientific basis for the ethno-pharmacological uses pertaining to gastrointestinal, respiratory and cardiovascular systems. The crude ethanolic extract of Brachychiton populneus (Bp.Cr) exhibited relaxation of periodic contractions in isolated preparations of rabbit jejunum. The relaxant effect of Bp.Cr was confirmed to be attributed to opening of K+ ATP channels, which is further confirmed significantly (P<0.005) by in vivo experiments (i.e. Charcoal meal and fecal mass count). In isolated preparation of rabbit trachea, the Bp.Cr exhibited relaxation of contractions induced by K+(25 mmol) and CCh (1 μmol), being more potent against K+ (25 mmol) suggested the opening of K+ATP channels as possible mechanism. In isolated aortic preparation (denuded), Bp.Cr exhibited relaxation of contractions induced by K+ (25 mmol) and phenylephrine (1 µmol). In isolated preparations of rabbit paired atria, the Bp.Cr exhibited cardio depressant effects may be attributed to the known K+ ATP channels opening activity. In in vivo studies, Bp.Cr caused a significant (p<0.05) fall in MABP which can be attributed to the proposed K+ channels opening potential. Furthermore, Bp.Cr also showed significant (p<0.01) anti-emetic (CuSO4 induced) activities. The K+ ATP channel opener activity was found to be concentrated in the dichloromethane fraction of Bp.Cr (Bp.Dcm). The K+ ATP channel opener activity of Bp.Cr was found to be comparable to that of cromakalim. The crude extract of Cenchrus ciliaris L. (Cc.Cr) exhibited relaxant effect on the spontaneous and spastic contractions induced by K+ (80 mmol) in isolated rabbit jejunum, similar to that of verapamil, suggested the involvement of Ca2+ channel blocking(CCB) activity as possible mechanism. The spasmolytic activity is further confirmed significantly (P<0.005) by in vivo experiments (i.e. Charcoal meal and fecal mass count). In isolated preparation of trachea, the contractions induced by CCh (1 µmol) and K+ (80 mmol) were relaxed completely by Cc.Cr, being more potent against CCh (1 µmol), explaining the dual mechanism of muscarinic receptors antagonism and CCB activity, similar to dicyclomine. The Cc.Dcm was found to have CCB; while aqueous fraction of Cc.Cr (Cc.Aq) showed antimuscarinic activity. In isolated rabbit aorta(denuded), Cc.Cr exhibited α1-adrenergic agonistic activity, angiotensin II agonistic activity as well as CCB. The angiotensin II agonistic and CCB activity was concentrated in Cc.Dcm while α1-adrenergic agonistic activity was found to be concentrated in Cc.Aq. In isolated paired atrial preparation, Cc.Cr exerted cardio-stimulation via β1adrenoceptors agonist activity, as well as, cardio depressant activity of Cc.Cr can be attributed to already mentioned CCB activity. In vivo experiments showed that Cc.Cr significantly (p<0.05) reduced the MABP and heart rate which may be outcome of CCB activities of Cc.Cr. The crude ethanolic extract of Cyperus niveus (Cn.Cr) underwent relaxation of the induced contractions of CCh (1 µmol) and K+ (80 mmol) in isolated preparations of rabbit jejunum and trachea, suggested the relaxation by dual mechanism of antimuscarinic and CCB activities, similar to dicyclomine. The CCB activity was concentrated in Cn.Dcm while antimuscarinic activity was concentrated in Cn.Aq. The observed anti-muscarinic activity was further confirmed in isolated preparations of rat ileum. Cn.Cr also exhibited significant (p<0.005) anti-diarrheal (Castor oil induced), anti-motility (transit test) and anti-emetic (CuSO4 induced) activities. In isolated preparations of rabbit aorta (denuded), Cn.Cr showed contractile response which was found to be due to α1 adrenergic and HT2A serotonergic agonistic activities along with CCB activities. In isolated preparation of rabbit paired atria, Cn.Cr initially showed partial β adrenergic agonistic activity, along with cardio depressant effect which may be outcome of some constituent(s) possessing CCB activity. In in vivo experiments, the MABP and heart rate in normotensive anaesthetized rats was reduced significantly subsequent to administration of Cn.Dcm, which may be outcome of CCB activities of Cn.Dcm. Conclusion: Brachychiton populneus is known to possess folkloric repute as a remedy for asthma, cough, cardiac ailments, constipation and diarrhea; however, pharmacological screening of the plant extract exhibited spasmolytic, spasmogenic, bronchodilator, vasorelaxant, cardio tonic, hypotensive, anti-diarrheal, anti-motility and anti-emetic activities. Thus, provided scientific basis for its folkloric uses in multiple ailments. Cenchrus ciliaris L. is a grass of high nutritive value and possesses a folkloric repute as diuretic, anti-diarrheal, anti-asthmatic, emollient, lactogogue, purgative, stomachic, in kidney pain, sores, tumors and wounds; however scientific investigation of the plant extract exhibited spasmolytic, bronchodilator, vasorelaxant, cardio tonic, hypotensive, anti-diarrheal, anti-motility and antiemetic activities. Thus, provided scientific evidences for its folkloric uses in multiple ailments. Cyperus niveus Retz. is used in traditional system of medicines to manage various diseases including cancers, colic, common colds, dysentery, diarrhea, emesis, inflammations, chest troubles, as cordial, desiccant, stimulant, sedative, and diuretic; pharmacological evaluation of the plant extract exhibited spasmolytic, bronchodilator, vasorelaxant, cardio tonic, hypotensive, anti-diarrheal, anti-motility and anti-emetic activities. Thus, provided scientific evidences for its folkloric uses in multiple disorders.