The Effects of Morinda citrifolia L. Noni on High Blood Pressure : A Mechanistic Investigation and Case Study

Morinda citrifolia L. noni has been used in Polynesia for over 2,000 years. During that time, it has accumulated a myriad of reputed health benefits. Traditional healers have used different parts of the Noni tree to treat pain, inflammation, diabetes, gout, wounds, cancer, high blood pressure, and numerous other ailments. Most of the reputed benefits have been limited to published reports in the non-scientific literature. However, with the recent introduction and marketing of noni-based beverages and products, there is increased interest among members of the scientific community to better understand its basic chemistry and potential health benefits. The number of people reported to have successfully lowered their high blood pressure from drinking Noni fruit juice and TAHITIAN NONI® Juice has grown dramatically, but its mechanisms of action are largely unknown. Our focus is to elucidate the possible mechanisms involved in vitro, and to report a study on medicinally diagnosed high blood-pressure individuals, who were administered noni juice, while not taking prescribed blood-pressure medications. In vitro, TAHITIAN NONI® Juice (TNJ) in concentrations of 1 and 5% inhibited angiotensin converting enzymes (ACE) by 105 and 113%, respectively. TNJ also showed an IC 50 of 1.6 and 4.3% of the AT 1 and AT 2 receptors, respectively. Noni fruit juice concentrate (NFJC) showed an IC 50 of the AT 1 and AT 2 receptors of 1.97 and 2.29%, respectively. The test group consisted of 10 subjects (7 males, 3 females, ages 28-56 years) who were medically diagnosed with high blood pressure, but currently not taking any prescribed medications. Each subject consumed 2 ounces of TNJ twice a day, for 1 month. The group had average pre-test and post-test blood pressure of 144/83 and 132/76, respectively. The preliminary results suggest that NFJC and TNJ are able to lower high blood pressure by inhibiting ACE enzymes and AT receptors. The mechanisms elucidated warrant further clinical trials to assess the efficacy and dosage of TNJ on medically diagnosed high blood pressure patients.