Enjie Diao

Ozonolysis efficiency and safety evaluation of aflatoxin B1 in peanuts.

Ozonolysis efficiency of aflatoxin-contaminated peanuts (ACPs) was investigated, and the safety of ACPs untreated/treated by ozone was evaluated after 28-day intragastrically administration in male and female Wistar rats. 89.40% of aflatoxin B1 (AFB1) in peanuts was decomposed by ozone with a concentration of 50mg/L, flow rate of 5L/min for 60h. After 60h, the ozonolysis efficiency of AFB1 was not further improved. In the subchronic toxicity experiment, all rats did not have unusual changes in behavior, and no signs of intoxication were observed except for several dead rats due to inappropriate gavage or anesthesia. The results of subchronic toxicity indicated that rats fed on ACPs alone had significantly decreased in body weight gain and feed conversion efficiency. Most serum biochemical indexes of rats had apparently changed compared with those in the negative control, and gender difference significantly affected most indexes of subchronic toxicity except for the ratios of organ to body weight and histopathological observation. Rats fed on ACPs treated by ozone showed significant beneficial health effects. All the results suggested that the deleterious effects of AFB1 could be highly reduced by ozone, and ozone itself did not show any toxic effects on animals in this processing.

Structures of the ozonolysis products and ozonolysis pathway of aflatoxin B1 in acetonitrile solution.

The ozonolysis of aflatoxin B(1) (400 μg/mL) in acetonitrile solution was conducted with an ozone concentration of 6.28 mg/L at the flow rate of 60 mL/min for different times. The results showed that ozone was an effective detoxification agent because of its powerful oxidative role. Thin-layer chromatography and liquid chromatography-quadrupole time-of-flight mass spectra were applied to confirm and identify the ozonolysis products of aflatoxin B(1). A total of 13 products were identified, and 6 of them were main products. The structural identification of these products provided effective information for understanding the ozonolysis pathway of aflatoxin B(1). Two ozonolysis pathways were proposed on the basis of the accurate mass and molecular formulas of these product ions. Nine ozonolysis products came from the first oxidative pathway based on the Criegee mechanism, and the other four products were produced from the second pathway based on the oxidative and electrophilic reactions of ozone. According to the toxicity mechanism of aflatoxin B(1) to animals, the toxicity of aflatoxin B(1) was significantly reduced because of the disappearance of the double bond on the terminal furan ring or the lactone moiety on the benzene ring.

Detoxification and safety evaluation of aflatoxin B1 in peanut oil using alkali refining.

BACKGROUND Aflatoxin B1 (AFB1 ) is often detected in peanut oil, which comes from contaminated peanuts. AFB1 in peanut oil seriously threatens the health of consumers. However, there are few methods to effectively remove AFB1 in peanut oil. This study aimed to use an alkali-refining method to degrade AFB1 in peanut oil efficiently without increasing the equipment of oil and fat refining. RESULTS The optimum detoxifying conditions of AFB1 in peanut oil with alkali refining were established using response surface methodology (RSM), and the safety of peanut oil after being refined with alkali was evaluated based on the Ames tests and HepG2 cell viability. The results showed that AFB1 in peanut oil was decreased from 34.78 to 0.37 µg kg(-1) (98.94% reduction) under the optimum detoxifying conditions, i.e. when the initial temperature of alkali refining was 43.51 °C, the amount of excess alkali was 0.30%, the content of alkali solution was 23.42% and the end temperature of alkali refining was 77.07 °C. The acid value and color of peanut oil refined by alkali were improved significantly, while the peroxide value was increased within an acceptable level. The safety of peanut oil contaminated by AFB1 was improved significantly after being refined with alkali. CONCLUSION These results indicate that alkali refining is an effective method for removing AFB1 in peanut oil. The optimum detoxifying conditions of AFB1 in peanut oil with alkali refining could be used to guide the production of oil companies for ensuring food safety.

Ozone detoxification of patulin in aqueous solution and cytotoxic evaluation using human hepatic carcinoma cells

Patulin often contaminates fruits and fruit-base products, which seriously threats the health of consumers. In this study, ozone was used to degrade patulin in aqueous solution, and investigated the cytotoxicity of patulin after ozone detoxification on human hepatic carcinoma cells (HepG2) using MTT assay and apoptosis assay. Patulin was rapidly degraded from 24.59 mg/L to 9.85 mg/L within 180 s by 10.60 mg/L of ozone at a flow rate of 90 mL/min, and reduced by 59.94%. The half maximal inhibitory concentration (IC50) of patulin on HepG2 cells was 9.32 μmol/L after 24 h of exposure, and it showed a dose dependent effect. After 90 s of ozone detoxification, the cell viability of HepG2 cells obviously increased from 42.31% to 93.96%, and the total apoptotic cells significantly reduced from 22.24% to 11.18% after 180 s of ozone treatment. The results clearly show the great potential of ozone in degrading patulin in liquid foods.

Enhanced cytotoxic and apoptotic potential in hepatic carcinoma cells of chitosan nanoparticles loaded with ginsenoside compound K

Ginsenoside compound K (CK) has been shown to exhibit anticancer properties. In this study, chitosan nanoparticles loaded with ginsenoside compound K (CK-NPs) were prepared as a delivery system using a self-assembly technique with amphipathic deoxycholic acid-O carboxymethyl chitosan as the carrier, which improved the water solubility of CK. By evaluating drug loading, entrapment efficiency, and in vitro release behavior, the feasibility of CK-NPs as a drug carrier nanoparticle for the treatment of human hepatic carcinoma cells (HepG2) was investigated. Result revealed that CK and CK-NPs showed a dose-dependent inhibitory effect on HepG2 cells with IC50 values of 23.33 and 16.58 μg/mL, respectively. Furthermore, fluorescence imaging demonstrated that CK-NPs promoted cellular uptake in vitro. Therefore, all results indicated that CK-NPs might be a novel drug delivery system to improve the solubility and enhance the cytotoxic and apoptotic potentials of CK for effective liver cancer chemotherapy.