Antispasmodic and vasodilator activities of Morinda citrifolia root extract are mediated through blockade of voltage dependent calcium channels

Abstract

BackgroundMorinda citrifolia (Noni) is an edible plant with wide range of medicinal uses. It occurs exclusively in tropical climate zone from India through Southeast Asia and Australia to Eastern Polynesia and Hawaii. The objective of this study was to explore the possible mode(s) of action for its antispasmodic, vasodilator and cardio-suppressant effects to rationalize its medicinal use in gut and cardiovascular disorders.MethodsIsolated tissue preparations such as, rabbit jejunum, rat and rabbit aorta and guinea pig atria were used to test the antispasmodic and cardiovascular relaxant effects and the possible mode of action(s) of the 70% aqueous-ethanolic extract of Morinda citrifolia roots (Mc.Cr).ResultsThe Mc.Cr produced a concentration-dependent relaxation of spontaneous and high K+ induced contractions in isolated rabbit jejunum preparations. It also caused right ward shift in the concentration response curves of Ca++, similar to that of verapamil. In guinea-pig right atria, Mc.Cr caused inhibition of both atrial force and rate of spontaneous contractions. In rabbit thoracic aortic preparations, Mc.Cr also suppressed contractions induced by phenylephrine (1.0 μM) in normal- Ca++ and Ca++-free Kerb's solutions and by high K+, similar to that of verapamil. In rat thoracic aortic preparations, Mc.Cr also relaxed the phenylephrine (1.0 μM)-induced contractions. The vasodilatory responses were not altered in the presence of L-NAME (0.1 mM) or atropine (1.0 μM) and removal of endothelium.ConclusionsThese results suggest that the spasmolytic and vasodilator effects of Mc.Cr root extract are mediated possibly through blockade of voltage-dependent calcium channels and release of intracellular calcium, which may explain the medicinal use of Morinda citrifolia in diarrhea and hypertension. However, more detailed studies are required to assess the safety and efficacy of this plant.

The Effect of ethanol Psidium Guava leaf extract on KCl Induced Contracted Aortic tissues of Guinea Pigs

“…As reported [12] smooth muscle relaxation can be achieved by various mechanisms such as potassium channel opening, calcium channel blocking and receptor antagonism. So plant chemicals may have role in either of these mechanisms.…”

“…Blood pressure can be reduced when smooth muscle are relaxed. Potassium channel opening, calcium channel blocking and receptor antagonism are mechanisms that contribute Smooth muscle relaxations [12]. Annona leaf extract in normotensive Sprague Dawley rats was reported to lower elevated BP due to presence of essential oils present in the plant exhibiting vasodilator activities [27].…”

A Note on Anti-leishmanial, Spasmolytic and Spasmogenic, Antioxidant and Antimicrobial Activities of Fruits, Leaves and Stem of Morinda citrifolia Linn – an Important Medicinal and Food Supplement Plant

“…Hence in the present preliminary studies three parts namely fruits, leaves and stem were separately evaluated for different biological activities namely, anti-leishmanial, spasmolytic and spasmogenic, antioxidant and antimicrobial activities. It may be noted that in earlier studies the parts of the plant mainly used for these activities were roots [8], fruits and roots [9,10] and fruit juice [11]. The present results provide a direction regarding the selection of particular part for studying any specific biological activity referred to above in future.…”

Health Benefits of Morinda citrifolia (Noni): A Review

“…76 Anti-osteoporotic activity Isolated seven anthraquinones from an ethanolic extract of the roots of M. citrifolia. Reported all the isolated components were found to inhibit osteoclast tartrate resistant acid phosphatase (TRAP) activity and bone resorption including the inhibitory effects on osteoclastic bone resorption in osteoporotic rats.…”