Antidiarrhoeal Activity of Hydroethanolic Leaf Extract of Bryophyllum pinnatum Lam. Kurtz (Crassulaceae).
BACKGROUND
Bryophyllum pinnatum Lam. Kurtz (Crassulaceae) is used in traditional African medicine in the treatment of diarrhoea.


OBJECTIVE
To investigate the antidiarrhoeal action of the hydroethanolic leaf extract of Bryophyllum pinnatum (BP).


METHODS
Normal intestinal transit, castor oil-induced intestinal transit, castor oil-induced diarrhoea, gastric emptying and enteropooling models in rodents were used to investigate antidiarrhoeal effect. The possible mechanism of antidiarrhoeal activity was investigated using prazosin (1 mg/kg, s.c; α1, adrenoceptor antagonist), yohimbine (1 mg/kg, s.c; α2 adrenoceptor antagonist), propranolol (1 mg/kg, i.p; α- adrenoceptor non-selective antagonist), atropine (1 mg/kg, s.c; muscarinic cholinergic antagonist), pilocarpine (1 mg/kg, s.c; muscarinic cholinergic agonist), and isosorbide dinitrate (IDN) (150 mg/kg, p.o; nitric oxide donor).


RESULTS
BP (25-100 mg/kg, p.o) produced dose-dependent and significant (P < 0.001) decrease in intestinal propulsion in normal and castor oil-induced intestinal transit models in comparison to distilled water (10 ml/kg, p.o.) treated control. This antidiarrhoeal effect was inhibited by propranolol pretreatment but yohimbine, prazosin, or atropine pretreatment failed to block this effect. BP treatment reduced the increased peristaltic activity induced by pilocarpine, however, co-treatment with IDN significantly (P < 0.001) enhanced the antidiarrhoeal effect of the extract. In castor oil-induced diarrhoea test, the extract produced a dose-dependent and significant (P < 0.001) increase in onset of diarrhoea, decreased diarrhoea score, the number and weight of wet stools when compared to control. The in vivo antidiarrhoeal index (ADI(in) vivo)) of 53.52 produced by the extract (50 mg/kg, p.o.) was similar to 76.28 ADI(in vivo) produced by morphine (10 mg/kg, s.c.). The extract produced dose- dependent and significant (P < 0.05; P < 0.001) decrease in the weight and volume of intestinal content in the intestinal fluid accumulation model. In gastric emptying test, BP treatment reduced the quantity of test meal emptied in 1 h but not significant.


CONCLUSIONS
The results showed that the hydroethanolic leaf extract of Bryophyllum pinnatum possesses antidiarrhoeal activity possibly mediated by interaction with β adrenoceptor, muscarinic cholinergic receptor and nitric oxide pathway.
Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos State, Nigeria. ooadey@yahoo.com
Olufunmilayo O
OO
Adeyemi
Ismail O
IO
Ishola
Uzodinma
U
Okoro
D000818:Animals; D000930:Antidiarrheals / Q000494:pharmacology*; D002368:Castor Oil; D029627:Crassulaceae; D003967:Diarrhea / Q000188:drug therapy*; D005746:Gastric Emptying / Q000187:drug effects; D005772:Gastrointestinal Transit / Q000187:drug effects; D016488:Medicine, African Traditional; D051379:Mice; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*
D000930:Antidiarrheals; D010936:Plant Extracts; D002368:Castor Oil