Protection of crocin dyes on the acute hepatic damage induced by aflatoxin B1 and dimethylnitrosamine in rats

Chemopreventive agents are compounds that inhibit carcinogenesis when administered prior or subsequent to a course of carcinogen administration. The effects of dietary administration of crocin dyes on the hepatic damage induced by aflatoxin B1 (AFB1) and dimethylnitrosamine (DMN) in rats were investigated. Female Sprague-Dawley rats were treated with different dosages of AFB1 (0.9 or 4.5 mg/kg) or DMN (8 or 20 mg/kg) by i.p. administration, and the different degrees of hepatic damage were revealed by the elevations of levels of serum marker enzymes such as aspartate amino-transferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase and lactic dehydrogenase. Pre-treatment of the animals with crocin dyes 50 mg/kg daily for three consecutive days, the enzyme elevations were significantly suppressed. This suggested that the crocin dyes possessed chemopreventive effects on the early acute hepatic damage induced by AFB1 or DMN. Feeding experiments demonstrated that crocin dyes at 0.1% in the diet could suppress partially the chronic hepatic damage induced by multiple dosages of AFB1 or DMN, but at a higher concentration of 1% crocin dye failed to do so because of their host toxicity. Crocin dyes are extracted from the fruits of Gardenia jasminoides and consist of carotenoids and geniposides as active principles. The protective mechanisms of crocin dyes may be attributed to their carotenoids which are converted metabolically to retinoids in rats.

Reversible hepatic black pigmentation and enzyme alteration induced by prolonged feeding of high dose of crocin dyes in rats

Crocin dyes, isolated from Gardenia jasminodes, did not affect hepatic function when they were orally administered to rats in a daily dose of 50 mg/kg for 8 days, but could induce acute hepatic discoloration. A high dosage of 100 mg/kg for 2 weeks could induce both hepatic damage and black pigmentation, but a lower dose of 100 mg/kg for 40 days did not. Rats fed on diet containing 1% of crocin dyes for four months were shown to have mild hepatic functional disorders and pigmentation. The black pigmentation of the liver and the acute hepatic damage associated with the discoloration were completely reversible. During the period of hepatic pigmentation caused by high dose of crocin dyes, the urine had abnormally increased porphyrin excretion and tended to display a blackish green color. The skin also appeared purplish black. The mechanism of black pigmentation seemed to correlate with the gradual accumulation of crocin dyes. In summary, the crocin dyes have a very low toxicity in rats even in high experimental dosage which would hardly happen in human practice. It is therefore suggested that the crocin dyes are safe for coloring foods.

Fluorescence polarization immunoassay. iii. an automated system for therapeutic drug determination

A fully automated system for performing fluorescence polarization immunoassay has been developed. Reagents for each assay are contained in coded reagent packs, and no reagent reconstitution is required. A common buffer is used for all assays, minimizing changeover and set-up times for each assay. A single sample may be assayed in 5 min, or 20 samples in 10 min. A single-tube blank subtraction for each sample results in highly precise polarization values and obviates sample interferences. We have used this method for assays of gentamicin, theophylline, phenytoin, and phenobarbital. CVs are 1-4%, and the results correlate well with those by other methods. Because of the instrument design and the stability of the reagents, daily calibration is not required; samples may therefore be run immediately upon receipt or batched as desired.

Fluorescence polarization immunoassay. iii. an automated system for therapeutic drug determination

A fully automated system for performing fluorescence polarization immunoassay has been developed. Reagents for each assay are contained in coded reagent packs, and no reagent reconstitution is required. A common buffer is used for all assays, minimizing changeover and set-up times for each assay. A single sample may be assayed in 5 min, or 20 samples in 10 min. A single-tube blank subtraction for each sample results in highly precise polarization values and obviates sample interferences. We have used this method for assays of gentamicin, theophylline, phenytoin, and phenobarbital. CVs are 1-4%, and the results correlate well with those by other methods. Because of the instrument design and the stability of the reagents, daily calibration is not required; samples may therefore be run immediately upon receipt or batched as desired.

Preparation and in vitro antifungal activities of some quinolizidine derived hemiaminals and beta-tert-amino sulfides

New alpha-thiohemiaminals, 7alpha-phenylthio-7-epideoxynupharidin-6-ol, the diasteriomeric 7beta-phenylthiodeoxy-nupharidin-6-ol, and 3-methyl-3-methylthio-4-hydroxyquinolizidine, were prepared and reduced to the corresponding beta-tert-amino sulfides. The configuration at C-7 of the beta-tert-amino sulfides was determined by observing the direction of the solvent-induced shift of the C-7 methyl proton resonance. The configuration at C-7 of the new alpha-thiohemiaminals was established by correlations with the beta-tert-amino sulfides and confirmed, in the case of the deoxynupharidine derivatives, by circular dichroism and ascertaining the sterochemistry of deuteride incorporation upon sodium borodeuteride reduction of the alpha-thiohemiaminal. The in vitro antifungal activities of six compounds possessing the quinolizidine skeleton, including all the newly synthesized compounds as well as some previously reported ones, and amphotericin B were tested against several human pathogenic fungi. Besides amphotericin B, only the two deoxynupharidine alpha-thiohemiaminals were active, especially against Histoplasma capsulatum and Blastomyces dermatitidis. The observations indicate activity is derived from the 3-furyl group and the functionality from which alpha-thioimmonium ions can be produced.

Preliminary studies of some physiological properties of Torula jeanselmei

The morphological characteristics of pathogenic and saprophytic strains of Torula jeanselmei (Fungi Imperfecti) are indistinguishable. Some basic physiological properties of T. jeanselmei were investigated in the hope of separating the human pathogenic strain from common saprophytes in a clinical laboratory. Nitrogen and carbon assimilation tests were not useful for distinguishing the pathogen, since all strains, pathogenic and saprophytic, were able to assimilate nitrogen from ammonium, nitrate, and nitrite sources, and all were able to utilize glucose, fructose, galactose, cellobiose, lactose, glycerol, and starch. It appeared that temperature range for growth might be useful in the identification of the pathogen. All pathogenic strains grew well at 37 C but poorly at 10 C; in contrast, all saprophytes could grow at 10 C but were unable to grow at 37 C (with two exceptions).