Monday, June 18, 2007
Golden Eagle Eyrie (Boise Centre on the Grove)

Detoxification activity of noni leaf water extract

Brett J. West, 'Afa K. Palu, and Chen X. Su. Tahitian Noni International, American Fork, UT

Noni leaves have been historically used among Pacific Islanders topically and internally to treat a number of health conditions, including those of the skin. To verify this traditional use, the detoxification potential of noni leaf hot-water extract was investigated in vivo and in vitro. For seven days prior to the trichlorfon treatment, the leaf extract was administered orally at a daily dose of 3.2 g/kg. The extract increased the survival time of Kunming mice receiving i.p. trichlorfon by 32.6% (P < 0.05), compared to the untreated control. Such results strongly suggest a detoxifying or mitigating effect. Mechanistically, the water extract induced Glutathione S-transferase activity in vitro by more than 2.5-fold at a concentration of 1.665 mg/mL, with induction being evident down to a concentration of 60 ėg/mL. Further, the antioxidant capacity of expressed juice from raw leaves was also evaluated in the oxygen radical absorbance capacity (ORAC) assay and found to be 84,724 ėmole trolox equivalents (TE)/L. This indicates very high potential for antioxidant activity. Free-radical damage is a significant component of trichlorfon toxicity and the observed antioxidant activity is likely another mechanism by which the water extract mitigates this toxicity. Glutathione S-tranferase is expressed in the skin, and previous research has indicated dietary sources of antioxidants can help protect the skin against free-radical mediated damage. With this in mind, the present investigation also indicates that the hot water extract of noni leaf may provide both systemic and skin–health benefits.