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

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 100 mg/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 (10 mg/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 10 mg/kg BW/day under the conditions of this study. This study substantiates the use of PD-00105 in dietary supplements at doses of 10 mg/day, taking into account a safety margin factor for dose conversion to humans.

Olive juice dry extract containing hydroxytyrosol, as a nontoxic and safe substance: Results from pre-clinical studies and review of toxicological studies.

Products derived from olives, such as the raw fruit and oils, are widely consumed due to their taste, and purported nutritional/health benefits. Phenolic compounds, especially hydroxytyrosol (HT), have been proposed as one of the key substances involved in these effects. An olive juice extract, standardized to contain 20% HT ("OE20HT"), was produced to investigate its health benefits. The aim of this study was to demonstrate the genotoxic safety of this ingredient based on in vitro Ames assay and in vitro micronucleus assay. Results indicated that OE20HT was not mutagenic at concentrations of up to 5000 µg/plate, with or without metabolic activation, and was neither aneugenic nor clastogenic after 3-hour exposure at concentrations of up to 60 µg/mL with or without metabolic activation, or after 24-hour exposure at concentrations of up to 40 µg/mL. To further substantiate the safety of OE20HT following ingestion without conducting additional animal studies, a comprehensive literature review was conducted. No safety concerns were identified based on acute or sub-chronic studies in animals, including reproductive and developmental studies. These results were supported by clinical studies demonstrating the absence of adverse effects after oral supplementation with olive extracts or HT. Based on in vitro data and the literature review, the OE20HT extract is therefore considered as safe for human consumption at doses up to 2.5 mg/kg body weight/day.

Perinatal undernutrition-induced obesity is independent of the developmental programming of feeding.

Protein or calorie restriction during gestation and/or suckling induces hyperphagia and increases the susceptibility to develop obesity, glucose intolerance and hypertension in adulthood. The mechanisms by which early nutrient restriction affects the normal physiological regulation of feeding as well as to what extent the metabolic programming of hyperphagia contributes to the long-term risk of obesity and insulin resistance remain, however, to be determined. Here the temporal pattern of food intake and the behavioural satiety sequence were investigated in the offspring of Sprague-Dawley rats fed a control (C) or a low-protein (LP) diet throughout pregnancy and lactation. During the first two months of their post-natal life, protein-restricted animals exhibited hyperphagia characterized by a delayed appearance of satiety, an increase in meal size and reduced latency to eat. Protein-restricted pups also exhibited an enhanced expression of the orexigenic peptides Agouti-related protein and neuropeptide Y and decreased hypothalamic levels of the anorexigenic peptide pro-opiomelanocortin. At 8 months, LP rats still consumed larger meals than their control counterparts but they ingested daily the same amount of food as control offspring and exhibited enhanced abdominal fat and increased levels of triglycerides and fatty acids in serum. These observations indicate that the hyperphagia observed in young LP rats results from a decreased action of negative feedback signals critical to meal termination and an enhanced function of the positive signals that initiate and maintain eating. These results also suggest that perinatal malnutrition programmes obesity through a mechanism independent of its effects on feeding behaviour.