No abstract

A phytochemical study of the fruits of noni (Morinda citrifolia) collected in Tahiti led to the isolation of two new lignans, (+)-3,4,3',4'-tetrahydroxy-9,7'alpha-epoxylignano-7 alpha,9'-lactone (1) and (+)-3,3'-bisdemethyltanegool (2), as well as seven known compounds, (-)-pinoresinol (3), (-)-3,3'-bisdemethylpinoresinol (4), quercetin (5), kaempferol (6), scopoletin (7), isoscopoletin (8), and vanillin. The structures of 1 and 2 were determined by spectroscopic techniques. Compounds 3, 6, and 8 were isolated for the first time from noni fruit. Compounds 1-8 were shown to inhibit 5- and/or 15-lipoxygenase, with IC50 values ranging from 0.43 to 16.5 microM. Compound 5 exhibited weak inhibitory activity toward cyclooxygenase-2.

Iridoids DAA and AA are found to be present in leaf, root, seed and flower of noni plants, and were identified as the major components in noni fruit. Given the great variation of iridoid contents in noni fruit grown in different tropical areas worldwide, geographical factors appear to have significant effects on fruit composition. The iridoids in noni fruit were stable at the temperatures used during pasteurisation and, therefore, may be useful marker compounds for identity and quality testing of commercial noni products.

Summary The antioxidant activity, potential toxicity, and iridoid content of processed Cornelian cherry products were assessed. Cornus officinalis L. juice and Cornus mas L. fruit puree possessed antioxidant activity in the 2,2‐diphenylpicrylhydrazyl radical scavenging, reducing power and oxygen radical absorbance capacity assays. Both products were non‐genotoxic in reverse mutation tests in Salmonella typhimurium. Both C. officinalis juice and C. mas puree were non‐toxic in acute oral toxicity tests, with respective LD50 values >5100 mg kg−1 body weight (b.w.) and >5200 mg kg−1 b.w. The major iridoid identified in C. mas puree was loganic acid, while the major iridoid in C. officinalis juice was found to be morroniside. The presence of iridoids in C. mas is reported for the first time.

Morinda citrifolia L. (Rubiaceae) commonly known as noni, has been used in Polynesia by traditional healers for the treatment of cuts, bruises and wounds. Our objective was to investigate the wound-healing mechanisms of the noni leaf. The investigations of its wound-healing mechanisms were carried out using fresh noni leaf juice (NLJ), noni leaf ethanol extract (NLEE) and its methanol (MFEE) and hexane (HFEE) fractions on the PDGF and A(2A) receptors in vitro and topically in mice. Fresh noni leaf juice showed significant affinity to PDGF receptors, and displayed 166% binding inhibition of the ligand binding to its receptors, while at the same concentration, it only had 7% inhibition of the ligand binding to the A(2A) receptors. NLEE, HFEE and MFEE showed significant affinity to A(2A) receptors, concentration dependently, with IC(50) values of 34.1, 42.9 and 86.7 μg/mL, respectively. However, MFEE significantly increased wound closure and reduced the half closure time in mice with a CT(50) of 5.4 ± 0.2 days compared with control (p < 0.05). These results suggest that noni leaf significantly accelerated wound healing in mice via its ligand binding to the PDGF and A(2A) receptors as its probable mechanisms of wound-healing and also support its traditional usage for wound-healing in Polynesia.