Submitted to: Phytotherapy Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2007
Publication Date: 1/29/2008
Citation: Remsberg, C.M., Yanez, J.A., Ohgami, Y., Vega-Villa, K.R., Rimando, A.M., Davies, N.M. 2008. Pharmacometrics of Pterostilbene: Pre-Clinical Pharmacokinetics and Metabolism, Anti-Cancer, Anti-Inflammatory, Anti-Oxidant, and Analgesic Activity. Phytotherapy Research. 22(2):169-179. Interpretive Summary: The metabolic fate of the phytochemical pterostilbene was investigated. Pterostilbene, at a dose of 20 mg/kg body weight, was administered intravenously to Male Sprague-Dawley rats. Analysis of serum and urine samples by HPLC showed the presence of a pterostilbene-glucoside metabolite. Further studies were conducted to determine the anti-cancer, anti-inflammatory, anti-oxidant, and analgesic activities of pterostilbene. Pterostilbene demonstrated concentration - dependent (1-100 ug/mL) inhibitory activity in the five cancer cell lines (malignant melanoma, colorectal carcinoma, hepatocellular carcinoma, breast adenocarcinoma, and prostate adenocarcinoma) examined. Its anti-inflammatory activity was studies in vitro by inducing inflammation in chondrocytes with interleukin-1B (IL-1B) followed by treatment with pterostilbene (1-100 ug/mL). Pterostilbene showed decreased levels of various mediators released during inflammatory events (MMP-3, sGAG, and TNF-a) compared to controls. Pterostilbene demonstrated a concentration-dependent anti-oxidant capacity, measured using the ABTS method. Analgesic activity was demonstrated using hot-plate and tail-flick tests in mice after administration of pterostilbene (50 mg/kg body weight). This study is the first, to our knowledge, to delineate the metabolism of pterostilbene.
Technical Abstract: Purpose: To evaluate the pre-clinical pharmacokinetics and pharmacodynamics of pterostilbene. Methods: Rat liver microsomes were used to evaluate in vitro phase I and II metabolism. Right jugular vein cannulated male Sprague-Dawley rats were dosed intravenously with 20 mg/kg of pterostilbene and samples were analyzed via reverse phase HPLC method. Anti-cancer activity was assessed in malignant melanoma (A-375), colorectal carcinoma (HCT-116), hepatocellular carcinoma (Hep-G2), breast adenocarcinoma (MDA-MB-231), and prostate adenocarcinoma (PC-3) cell lines by measuring cell viability after treatment with pterostilbene (1-100 ug/mL). Inflammation was induced in an in vitro colitis model by the addition of tumor necrosis factor-a (TNF-a) into the cell medium of HT-29 cells followed by treatment with pterostilbene (1-100 ug/mL). Anti-inflammatory activity of pterostilbene was examined by inducing inflammation in canine chondrocytes with interleukin-1B (IL-1B) followed by treatment with pterostilbene (1-100 ug/mL). Anti-oxidant capacity was measured using the ABTS method. Analgesic activity was assessed by hot-plate and tail-flick tests in mice after administration of pterostilbene (50 mg/kg). Results: After an acute IV dose of pterostilbene, serum AUC, serum t1/2, urine t1/2, Cltotal, and VdB were 17.5 ± 6.6 ug.h/mL, 1.73 ± 0.78 h, 17.3 ± 5.6 h, 0.960 ± 0.025 L/h/kg, and 2.41 ± 1.13 L/kg (mean ± SEM), respectively. A pterostilbene glucuronidated metabolite was detected in both serum and urine. In vitro metabolism suggests that pterostilbene undergoes both phase I and II metabolism. Pterostilbene demonstrated concentration-dependent activity in all the cancer cell lines examined. Pterostilbene reduced PGE2 levels dose-dependently in the media of colorectal adenocarcinoma (HT-29) cells. In canine chondrocytes, pterostilbene showed decreased levels of MMP-3, sGAG, and TNF-a compared to IL-1B positive controls. Pterostilbene demonstrated a concentration-dependent anti-oxidant capacity. Pterostilbene significantly increased the latency period to response in both analgesic tests. Conclusions: This study is the first, to our knowledge, to delineate the pharmacokinetics and metabolism of pterostilbene. Pharmacodynamic models revealed pterostilbene possesses anti-cancer, anti-inflammatory, anti-oxidant, and analgesic activities.