Pulmonary anti-inflammatory effects and spasmolytic properties of Costa Rican noni juice (Morinda citrifolia L.).

ETHNOPHARMACOLOGICAL RELEVANCE: Morinda citrifolia L. (Noni) is a medicinal plant used in Polynesia for many properties such as anti-inflammatory, anti-diabetic and antineoplastic effects. Recent studies showed that noni juice have anti-oxidant and acute anti-inflammatory activities likely due to polyphenols, iridoids and vitamin C content. The present study was undertaken to evaluate chronic anti-inflammatory and spasmolytic effects of noni juice.

MATERIALS AND METHODS: Therefore, we evaluated the effect of oral or intraperitoneal administrations of noni juice in vivo on the lung inflammation in ovalbumin (OVA) sensitized Brown Norway rat (with prednisolone 10mg/kg intraperitoneously as reference compound) and the ex vivo effect of noni juice on BaCl2 (calcium signal) or methacholine (cholinergic signal) induced spasms in jejunum segments.

RESULTS: We found that noni juice (intraperitoneously 2.17mL/kg and orally 4.55mL/kg) reduced the inflammation in OVA-sensitized Brown Norway rat with regard to the decreased number of inflammatory cells in lung (macrophages minus 20-26%, lymphocytes minus 58-34%, eosinophils minus 53-30%, neutrophils minus 70-28% respectively). Noni juice demonstrated a dose-dependent NO scavenging effect up to 8.1nmol of nitrites for 50µL of noni juice. In addition noni juice inhibited (up to 90%) calcium and cholinergic induced spasms on the jejunum segments model with a rightward shift of the concentration response curve.

CONCLUSION: We describe for the first time that noni juice demonstrate (1) a chronic anti-inflammatory activity on sensitized lungs along with (2) a spasmolytic effect integrating a calcium channel blocker activity component.