Genetic toxicity studies of glycolipids from Dacryopinax spathularia.

A series of in vitro studies were conducted to assess the genetic toxicity of jelly mushroom glycolipids from Dacryopinax spathularia (herein referred to as "AM-1"). In the bacterial reverse mutation assay (Ames test), there was no evidence of mutagenic activity in any Salmonella typhimurium strains tested or in Escherichia coli strain WP2uvrA, at dose levels up to 5000 µg/plate. In the micronucleus (MN) test using human lymphocytes, AM-1 did not show a statistically significant increase in the number of binucleated cells containing micronuclei when compared to concurrent control cultures at all time points and at any of the concentrations analyzed (up to 900 µg/ml of culture medium). No increase in mutation frequency or numbers of small and large colonies were noted for AM-1 (up to 800 µg/ml) compared to concurrent controls when tested in the mouse lymphoma thymidine kinase assay (MLA). Therefore, AM-1 was concluded to be negative in all three assays performed both in the absence and presence of Aroclor 1254- or phenobarbital/ß-naphthoflavone-induced rat liver (S9 mix) for metabolic activation. These results support the safety assessment of jelly mushroom glycolipids for potential use in food.

Developmental and reproduction toxicity studies of glycolipids from Dacryopinax spathularia.

The developmental and reproduction toxicity potential of jelly mushroom glycolipids from Dacryopinax spathularia was studied in Crl:CD (SD) rats by daily oral gavage administration at doses of 150, 500 or 1000 mg/kg/day. Pregnant female rats in the developmental study received the test article from Gestation Days 6-19. F0 and F1 parental animals in the 2-generation reproduction toxicity study were dosed for a minimum of 70 days prior to mating and throughout mating, gestation, and lactation, until the day prior to euthanasia (following weaning of litters on postnatal day 21). The offspring of the F0 and F1 generations were potentially exposed to the test article in utero and via the milk while nursing. In the developmental study, there were no adverse effects on intrauterine growth and survival, or fetal morphology. In the 2-generation reproduction toxicity study, there were no adverse effects on observed parameters including macroscopic or microscopic findings, or organ weights for F0 or F1 animals, no effects on reproductive performance, and no test article-related effects on F1 and F2 postnatal survival, development, or growth. Therefore, the no-observed-adverse-effect level (NOAEL) for parental systemic toxicity, parental reproductive toxicity, and developmental/neonatal toxicity, was considered to be 1000 mg/kg/day, the highest dosage tested.

Pharmacokinetics, excretion balance, and tissue distribution of [14C]-labeled glycolipids and long chain fatty acids from Dacryopinax spathularia in rats.

The pharmacokinetics, excretion balance, and tissue distribution of [14C]-labeled glycolipids from Dacryopinax spathularia (herein referred to as "AM-1") and [14C]-LCFA equivalents following single or repeated administration to Sprague Dawley rats were evaluated to support the safety assessment of these naturally derived jelly mushroom glycolipids for use as a food ingredient. Rats received equimolar doses of either [14C]-AM-1 or [14C]-LCFA via oral or intravenous administration followed by collection of biological samples at specified intervals. Approximately 88%-101% of the administered dose was recovered in expired air, urine, feces, and carcass following single or repeated oral administration of [14C]-AM-1 at 100 mg/kg or equimolar doses of [14C]-LCFA at 46 mg/kg. Cmax and AUClast for [14C]-AM-1- and [14C]-LCFA-equivalents-derived radioactivity detected by quantitative whole body autoradiography was highest in the tissues of the GI tract, as expected following oral administration. The remaining tissues had low concentrations of test article equivalents relative to the administered dose and no target tissues for residence or accumulation were identified. AM-1 and LCFA are poorly absorbed by the oral route and are primarily eliminated in the feces without absorption. Oral bioavailability of both AM-1 and LCFA including their metabolites is low at approximately 11%.

A 90-day oral toxicity study of glycolipids from Dacryopinax spathularia in CD® rats.

The subchronic toxicity of jelly mushroom glycolipids from Dacryopinax spathularia (herein referred to as "AM-1") was studied in Crl:CD(SD) rats. The test item was administered via the drinking water at concentrations of 1.5, 5.0 or 15 mg/mL for 90 days with an additional 4-week recovery period. No test article-related deaths, clinical observations or neurological effects were noted. Decreased drinking water consumption for mid- and high-dose groups was attributable to the reduced palatability of drinking water containing higher test article concentrations. Mean body weights of high-dose males were slightly reduced beginning study week 1 due to decreased food and drinking water intake, but were not statistically significant by week 7. No test article-related adverse effects were noted for hematological or clinical chemistry, or urinalysis parameters. Statistically significant changes in select parameters were within historical control data ranges, lacked histopathological correlates, and did not occur in a consistent pattern that would suggest biological significance. Microscopic examination did not reveal any test article-related morphological changes. The no-observed-adverse-effect level (NOAEL) was considered to be 15 mg/mL (1201 and 1423 mg AM-1/kg bw/day for male and female rats, respectively). These results support the safety assessment of jelly mushroom glycolipids for potential use in food.

A 90-day oral toxicity study of glycolipids from Dacryopinax spathularia in Beagle dogs.

The subchronic toxicity of glycolipids from Dacryopinax spathularia (herein referred to as "AM-1") was studied in male and female Beagle dogs administered AM-1 by oral capsule at doses of 150, 500 or 1000 mg/kg/day for 90 days. AM-1 was well tolerated at all dosages and there were no test article-related effects on survival, clinical observations, neurological screening (functional observational battery) parameters, clinical pathology parameters, organ weights, macroscopic or microscopic evaluations. Test article-related changes were limited to minimal effects on food consumption and body weight changes in the 1000 mg/kg/day group females. Therefore, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day, the highest dosage level tested. These results add to the safety database for these naturally derived jelly mushroom glycolipids with potential for use as a food ingredient.