Effects of aflatoxin B 1 on human skin lipids metabolism--a site of action on 1- 14 C-acetate incorporation

Examination of fungal growth and aflatoxin production on marihuana

Under favorable growth conditions, Aspergillus flavus and A. parasiticus produced aflatoxins on marihuana. Cultures of A. flavus ATCC 15548 produced both aflatoxin B1 (AFB1) and G1 (AFG1). The production of AFG1 was substantially greater than that of AFB1. Cultures of A. flavus NRRL 3251 and A. parasiticus NRRL 2999 produced only AFB1. All natural flora cultures tested negative for aflatoxins. No Aspergilli sporulations were observed in these cultures. In the cultures inoculated with known toxigenic fungi, the highest mean level for total aflatoxins was 8.7 microgram/g of medium. Marihuana appears not to yield large quantities of these mycotoxins but sufficient levels are present to be a potential health hazard for both the user and the forensic analyst who is in daily contact with such plant material. Careful processing, storage, and sanitation procedures should be maintained with marihuana. If these conditions are disregarded due to the illicit status of marihuana, the potential for mycotoxin contamination must be considered.

Incorporation of (2-14C)acetate into lipids of mink (Mustela vison) liver and intestine during in vitro and in vivo treatment with aflatoxin B1

The in vitro and in vivo incorporation of (2-14C)acetate into lipids of mink (Mustela vison) liver and intestines was studied. In vitro, a dose of aflatoxin B1 as small as 7.5 mug/ml of medium reduced by 20% the amount of (2-14C)acetate incorporated into lipids of mink liver slices, whereas 180 mug caused 76% reduction in the synthesis of lipids from the radioactive precusor. Similar inhibition of lipid synthesis by aflatoxin also was observed with tissues from mink intestines and fatty liver. The degree of inhibition (19 to 84% for tissue from intestines and 19 to 64% for tissue from fatty livers) depended on the amount of aflatoxin B1 (7.5 TO 180 MUG) present in the medium. In vivo, a substantially increased amount of 14C-labeled lipids was found in the livers of mink injected with 600 mug of aflatoxin B1 per kg of body weight 20, 28, and 40 h earlier. However, no appreciable difference in incorporation of (2-14C)acetate into lipids was observed between toxin-treated and control animals when these animals were sacrificed and examined for 14C-labeled lipids at 4 and 10 h after toxin was administered.