Drug Res (Stuttg) 2020; 70(02/03): 107-111
DOI: 10.1055/a-1076-0703
Original Article
© Georg Thieme Verlag KG Stuttgart · New York

Persea Americana Seeds Cause Ileal Smooth Muscle Relaxation Via Stimulation of α-1 Adrenoceptors

1  Departments of Veterinary Pharmacology and Toxicology, University of Ibadan, Ibadan, Nigeria
,
Adedunke Omobolanle Oshinloye
2  Departments of Pharmacology and Therapeutics, University of Ibadan, Ibadan, Nigeria
,
Ayobami Deborah Obisesan
1  Departments of Veterinary Pharmacology and Toxicology, University of Ibadan, Ibadan, Nigeria
,
Opeyemi Mordiyah Olateju
1  Departments of Veterinary Pharmacology and Toxicology, University of Ibadan, Ibadan, Nigeria
,
Victor Adedotun Adenuga
1  Departments of Veterinary Pharmacology and Toxicology, University of Ibadan, Ibadan, Nigeria
› Author Affiliations
Further Information

Publication History

received 31 October 2019

accepted 02 December 2019

Publication Date:
02 January 2020 (online)

Abstract

The effect of methanol extract of P. americana seeds on isolated ileal smooth muscle was studied for isometric response using 10 adult rabbits of both sexes. Reactivity and agonist-antagonist responses of rabbit ileum to the extract were determined in this study. The affinity, effective concentration to give 50% response (EC50) and maximum response were calculated from the concentration response curves (CRC) obtained. The result for the reactivity study showed the seed extract of P. americana caused concentration dependent relaxation of isolated rabbit ileum with threshold responses at concentration of 1×10−9 mg/ml and 120 mg/ml respectively. The extract-antagonist study showed an upward and right shift in CRC in the presence of phenoxybenzamine, a non-selective adrenergic antagonist, with the EC50 increased from 5.01 mg/ml to 12.59 mg/ml and affinity decreased from 0.20 to 0.08. Extract-antagonist study also showed a right and upward shift in the CRC with a greater magnitude in the presence of prazosin, an α1-adrenergic antagonist, with EC50 increased from 0.32 mg/ml to 25.12 mg/ml and a consequential decrease in the affinity from 3.13 to 0.04. In the presence of propranolol, a β-adrenergic antagonist, a downward and left shift in the CRC was observed with the EC50 and PA2 remaining constant at 0.1 mg/ml and 10 respectively. P. americana concentration-dependently reduced or inhibited gastric motility, increasing transit time which is important for food absorption, thus a pro-nutritive and antispasmodic effect. The interaction with α1-adrenoceptors is beneficially in heart failure management. The plant can be developed as a drug candidate for management of hypertension.