Health effects of Morinda citrifolia (noni) on lipid and glucose metabolism

Abstract

The relationship between metabolic abnormalities including obesity, insulin resistance, hypertension, and dyslipidemia is growing at an alarming rate in the United States. Although there are many conventional treatments for these metabolic disorders, many people are turning to complementary and alternative medicine. Morinda citrifolia (noni) has been used as a folk remedy for centuries by Polynesian healers. Recently there has been a dramatic increase in the interest and use of this plant Despite the purported health benefits of consuming noni juice, there have been very few scientific studies validating or refuting these claims. The aim of our study was to investigate the mechanism underlying the beneficial effects of noni juice in vitro and in vivo with focus on glucose and lipid metabolism. Human hepatoma cell (HepG2) treated with 1.5% and 3% (v/v) noni juice was shown to reduce apolipoprotein (apoB) secretion, cellular triglyceride,• and cholesterol mass. However, when murine pre-adipocytes (3T3-Ll) were treated with noni during differentiation (I, 2, and 3% v/v), there was an increase in lipid accumulation and lipolysis. Short term (5 weeks) treatment with noni (1.5 /µ1g body weight, twice daily) in male C57BU6J mice fed a control diet or high fat diet exhibited significant improvements in glucose regulation and reduced weight gain. However, there were no significant changes in lipid metabolism and adiponectin secretion. Long term (12 weeks) treatment with noni also showed significant improvement in glucose regulation, and slight modifications in lipid metabolism. On the other band, there were no significant changes in adipokine and apolipoprotein secretion, as well as peroxisome proliferator activated receptor gamma (PPARɣ) expression. Based on the data obtained from these studies, it is evident that the noni juice may be beneficially modulating glucose metabolism. However, the molecular mechanism on which noni juice is acting must still be elucidated. Also, there are some indications that noni juice may affect lipid metabolism in vitro and in vivo but further studies must be conducted to conclusively determine the effects.