In vitro effect of phenolic antioxidants on germination, growth and aflatoxin B accumulation by peanut Aspergillus section Flavi.

AIMS: The effectiveness of the food-grade antioxidants butylated hydroxytoluene (BHT), trihydroxybutyrophenone (THB), propyl paraben (PP) and butylated hydroxyanisole (BHA) at 1, 10 and 20 mmol l(-1) concentrations on germination, growth, and aflatoxin B(1) (AFB(1)) production by Aspergillus section Flavi strains was determined. METHODS AND RESULTS: Assays on the lag phase of germination, germination percentage, germ tube elongation rate, lag phase, growth rate and AFB(1) production by three strains of Aspergillus flavus and three of Aspergillus parasiticus were carried out in vitro on peanut extract meal agar conditioned at different water activities (a(w): 0.982, 0.971, 0.955, 0.937). The antioxidants PP and BHA efficiently inhibited the germination of the two species tested at the doses 10 and 20 mmol(-1). The antioxidants PP and BHA at 1 mmol l(-1) and THB at 20 mmol l(-1) reduced the germ tube elongation rate most effectively, regardless of a(w) levels. An increase in the lag time and a reduction in the growth rate of 100% of the strains was observed, this was due to the action of BHT at the doses 10 and 20 mmol(-1) at 0.982, 0.971 and 0.955 a(w), although these treatments stimulated the AFB(1) accumulation in most of the fungi tested. The more effective antioxidants were PP and BHA, which increased the lag phase, reduced the growth rate and AFB(1) production in all of the strains at the four a(w) assayed. At concentrations 10 and 20 mmol l(-1), these antioxidants totally inhibited fungal development. CONCLUSIONS: The study shows that the antioxidants BHA and PP are effective fungal inhibitors to peanut Aspergillus section Flavi in wide range of water activity. SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggest that phenolic antioxidants, BHA and PP, can be effective fungitoxicants on aflatoxigenic strains in peanut at industrial level.

Neoadjuvant chemotherapy with cisplatin, ifosfamide and 5-fluorouracil in the treatment of locally advanced cervical cancer.

The objective of this study was to evaluate clinical and histological response, resectability, and survival in patients with cervical epidermoid carcinoma stage IB2 to IIIB with the use of neoadjuvant chemotherapy followed by radical surgery and/or radiation therapy. Between September 1989 and February 1996, 53 patients were admitted to this study. They were given three cycles of cisplatin 30 mg/m2/day, 5-fluorouracil 500 mg/m2/day, ifosfamide 2000 mg/m2/day i.v., and mesna 400 mg/m2/day i.v. at hour 0 and 400 mg/m2 at hours 4 and 8 during three days every 21-28 days. We evaluated 47 patients. Global clinical response obtained was 85% {95% (CI), 75-97%, CR in 14 patients (30%) and PR in 26 patients (55%)}. Twenty-three patients underwent surgery. Six patients (13%) had a complete histological response. Median follow-up was 42 months (5-96). In resected patients, with a median follow-up of 57 months (5-96), the estimated five-year disease-free survival was 78%. Global survival estimated to 60 months was 83% for stage IB2, 70% for IIB, and 20% for IIIB. This mode of therapy offers a new option to improve survival in locally advanced cervical cancer. Randomized trials are required in order to establish a definitive role for this therapeutic strategy.

Fumonisin production on irradiated corn kernels: effect of inoculum size.

Production of fumonisins B1, B2, and B3 by Fusarium moniliforme was evaluated on irradiated corn kernels inoculated with different spore concentrations (10, 10(2), 10(3), 10(5), and 10(6)), a water activity of 0.97, and a temperature of 25 degrees C. There was a direct relationship between the level of toxin produced and inoculum size. The highest levels of total fumonisin produced after 35 days of incubation were 5,028 and 9,063 ng/g at 10(5) and 10(6) spores per ml, respectively. The pattern of fumonisin production (FB1 > FB2 > FB3) in cultures growing from different inocula was not affected during the 35 days of incubation. The ratio between FB2 and FB1 varied from 0.15 to 0.42, whereas the ratio between FB3 and FB1 varied from 0.34 to 0.87.

Aflatoxin B1, zearalenone and deoxynivalenol production on irradiated corn kernels: Influence of inoculum size.

The influence of inoculum size on aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON) production was examined on irradiated corn kernels.Spore concentrations were determined in serial dilutions and adjusted to 10,10(2),10(3),10(5) and 10(6) spores/ml. Aflatoxin B1 production was dependent on the inoculum size. The high levels of aflatoxin B1 produced byA. parasiticus (21 and 30 mg/kg) were obtained with 10(2) and 10(3) spores/ml after 35 and 20 days incubation. There was no spore concentration influence on zearalenone and deoxynivalenol production after 10, 20 and 35 days incubation. At 28°C and 0.97 water activity (aw), the mean levels of zearalenone production were 382, 267 and 520 µg/kg and the mean levels on deoxynivalenol production were 697,465 and 782 µg/kg.