Toxicological evaluation of Alpinia oxyphylla-derived molecule (PD-00105): in vitro genotoxicity studies and 90-day oral toxicity study in rats.

Abstract

PD-00105 corresponds to a compound initially identified in the fruit of Alpinia oxyphylla Miq., obtained by chemical synthesis and proposed to be use in dietary supplements for its potential neuroprotective properties. The aim of this study was to perform a toxicological evaluation of PD-00105 in accordance with the testing strategy recommended by food regulatory authorities. All studies were conducted in accordance with Good Laboratory Practice (GLP), and followed the Organization for Economic Co-operation and Development (OECD) test guidelines for chemicals. Studies included a bacterial reverse mutation test, one in vitro micronucleus test in mammalian cells, and a repeated dose 90-day oral toxicity study. No sign of toxicity was observed in the two genotoxicity tests. The test item induced a significant liver and kidney toxicity at high doses (50 and 100mg/kg BW/day), highlighted by significant increases in liver and kidney absolute and relative weights, associated with histopathological findings and concomitant changes in hematology and clinical chemistry. Increases in alanine aminotransferase, alkaline phosphatase, total protein, albumin, globulin, cholesterol, LDL, and HDL have been measured in these two groups. However, findings observed in the low-dose group (10mg/kg BW/day) were considered as minimal and non-adverse, and were limited to an increase in liver weight in males and in kidneys weight in females, without concomitant changes in blood chemistry. The No Observed Adverse Effect Level (NOAEL) of PD-00105 was established as 10mg/kg BW/day under the conditions of this study. This study substantiates the use of PD-00105 in dietary supplements at doses of 10mg/day, taking into account a safety margin factor for dose conversion to humans.