In vivo antioxidative activity of a quantified Pueraria lobata root extract.

AIM OF THE STUDY: Oxidative stress has been associated with many pathological disorders such as atherosclerosis, diabetes and cancer. Supplementation with exogenous antioxidants, including phenolic compounds from plant sources, may help to restore the pro-oxidative/antioxidative balance. To take into account effects of absorption, metabolisation, plasma protein binding, distribution, and elimination, antioxidative research should not be limited to in vitro assays but be extended to in vivo models. MATERIALS AND METHODS: In the present work a quantified 50% EtOH root extract of Pueraria lobata (Willd.) Ohwi (Fabaceae) was selected to determine its in vivo antioxidative activity in a diabetic rat model, where diabetes and the accompanying oxidative stress were induced by intraperitoneal administration of streptozotocin. This root extract was found to contain 10.42+/-0.15% puerarin as the main constituent and smaller amounts of the related isoflavonoids 3'-hydroxypuerarin, 3'-methoxypuerarin, 6''-xylosylpuerarin, daidzin, genistin, daidzein and genistein, as determined by a validated HPLC method. This extract was administered orally at a daily dose of 500 mg/kg root extract, corresponding to 50mg/kg puerarin, during 3 weeks. In addition the effect on the plasma concentration of some fat-soluble antioxidants (co-enzyme Q(9), alpha- and gamma-tocopherol) was evaluated. RESULTS AND CONCLUSIONS: The level of malondialdehyde (MDA) in plasma, used as a marker of oxidative damage to lipids, was reduced to the same level as in healthy control animals, and as in the positive control group treated daily with 50mg/kg alpha-tocopherol acetate. No obvious signs of toxicity were observed by administration of 10x the treatment dose.

Antiplasmodial and other constituents from four Indonesian Garcinia spp.

Phytochemical investigations of four Garcinia spp. from Indonesia, i.e. Garcinia griffithii T. Anderson, Garcinia celebica L., Garcinia cornea L. and Garcinia cymosa K. Schum (Clusiaceae), have resulted in the isolation of a xanthone, 1,5-dihydroxy-3,6-dimethoxy-2,7-diprenylxanthone, 1,7-dihydroxyxanthone, isoxanthochymol, beta-sitosterol-3-O-beta-D-glucoside and stigmasterol-3-O-beta-D-glucoside from the stem bark of G. griffithii; friedelin and 3beta-hydroxy-23-oxo-9,16-lanostadien-26-oic acid or garcihombronane D from leaves of G. celebica; 23-hydroxy-3-oxo-cycloart-24-en-26-oic acid and epicatechin from stem bark of G. cornea; (+/-)-morelloflavone, morelloflavone-7-O-beta-D-glucoside or fukugiside, the triterpene 3beta-hydroxy-5-glutinen-28-oic acid and canophyllol from stem bark of G. cymosa. The xanthone and garcihombronane D displayed a selective activity against Plasmodium falciparum; isoxanthochymol and the triterpene beta-hydroxy-5-glutinen-28-oic acid a broad but non-selective antiprotozoal activity.

New furanoditerpenoids from Croton jatrophoides.

Four furanoditerpenoids were isolated from roots of Croton jatrophoides (Euphorbiaceae) collected in Tanzania. In addition to the known compounds penduliflaworosin and teucvin (mallotucin A), a new teucvin isomer, which was named isoteucvin, and a furanoditerpenoid with a new skeleton, for which the name jatrophoidin was adopted, were isolated. Their structures were elucidated by spectroscopic methods such as ESI-MS and NMR, including (1)H-, (13)C-, and two-dimensional NMR. The crystal structures of isoteucvin and jatrophoidin were solved using single-crystal X-ray diffraction, by which we also established the absolute configuration of jatrophoidin. The refined crystal structure of isoteucvin has the same (absolute) configuration as jatrophoidin, although the X-ray diffraction data of isoteucvin were not conclusive with respect to the absolute configuration.