Effect of acid treatment on allergenicity of peanut and egg.

BACKGROUND: Many food experts have studied various treatments or processing techniques in order to develop hypoallergenic foods. In a previous study, acid treatment dramatically mitigated the allergenicity of peanut, especially Ara h 2. RESULTS: Gel electrophoresis showed that most protein bands of acid-treated peanut were not detected, but protein bands of egg white became weaker and broader by acid treatment. In immunoblotting using a rabbit antibody, the antigenicity against ovalbumin or ovomucoid in acid-treated egg white was decreased but the antigenicity against Ara h 1 or Ara h 2 in peanut treated with pH 2 acetic acid was completely undetected. The allergenicity of ovalbumin and peanut fell significantly to 1/1022 and 1/5380, respectively, when measured as IC50 in the sample treated with pH 2.0 acetic acid. CONCLUSION: This study showed that acid treatment was more effective in peanut and barely effective in ovomucoid. This may contribute to the development of hypoallergenic food and clinical management of food allergy. © 2016 Society of Chemical Industry.

Sulforaphene suppresses growth of colon cancer-derived tumors via induction of glutathione depletion and microtubule depolymerization.

SCOPE: Cruciferous vegetables harbor a number of isothiocyanates that have been recognized for their cancer-related properties. Out of these, sulforaphene (a naturally occurring derivative of sulforaphane) has received little attention in studies of colon cancer and its mechanism of action remains to be elucidated. METHODS AND RESULTS: We observed that sulforaphene inhibited growth of human colon cancer cell lines HCT116, HT-29, KM12, SNU-1040, and DLD-1, while exhibiting negligible toxicity toward nonmalignant cells. Sulforaphene induced G2/M phase cell cycle arrest and apoptosis of colon cancer cells analyzed by flow cytometry, concomitant with phosphorylation of CDK1 and CDC25B at inhibitory sites, and upregulation of the p38 and JNK pathways. It was further determined that sulforaphene is a potent inhibitor of microtubule polymerization while generating reactive oxygen species via the depletion of glutathione. These observations further extended into inhibitory effects against colon tumor growth in a mouse xenograft model. CONCLUSION: These findings demonstrate that sulforaphene may contribute to the anti-tumor effects of cruciferous vegetables that contain sulforaphene and other isothiocyanates.

Erratum: Effects of enzymatic hydrolysis of buckwheat protein on antigenicity and allergenicity.

[This corrects the article on p. 278 in vol. 8, PMID: 24944772.].

Effects of enzymatic hydrolysis of buckwheat protein on antigenicity and allergenicity.

BACKGROUND/OBJECTIVES: Due to its beneficial health effects, use of buckwheat has shown a continuous increase, and concerns regarding the allergic property of buckwheat have also increased. This study was conducted for evaluation of the hydrolytic effects of seven commercial proteases on buckwheat allergens and its allergenicity. MATERIALS/METHODS: Extracted buckwheat protein was hydrolyzed by seven proteolytic enzymes at individual optimum temperature and pH for four hours. Analysis was then performed using SDS-PAGE, immunoblotting, and competitive inhibition ELISA (ciELISA) with rabbit antiserum to buckwheat protein, and direct ELISA with pooled serum of 21 buckwheat-sensitive patients. RESULTS: Alkaline protease, classified as serine peptidase, was most effective in reducing allergenicity of buckwheat protein. It caused decomposition of the whole buckwheat protein, as shown on SDS-PAGE, and results of immunoblotting showed that the rabbit antiserum to buckwheat protein no longer recognized it as an antigen. Allergenicity showed a decrease of more than 50% when pooled serum of patients was used in ELISA. Two proteolytic enzymes from Aspergillus sp. could not hydrolyze buckwheat allergens effectively, and the allergenicity even appeared to increase. CONCLUSIONS: Serine-type peptidases appeared to show a relatively effective reduction of buckwheat allergenicity. However, the antigenicity measured using rabbit antiserum did not correspond to the allergenicity measured using sera from human patients. Production of less allergenic buckwheat protein may be possible using enzymatic hydrolysis.

Allergenicity of an enzymatic hydrolysate of soybean 2S protein.

BACKGROUND: This study was performed to examine how the characteristics of soybean 2S protein influence allergenicity after enzymatic hydrolysis. Soybean 2S protein was extracted and enzymatic hydrolysis was performed using pepsin and chymotrypsin. Allergenicity was observed using soybean-sensitive patients' sera. RESULTS: Only 13.3% (6/45) of soybean-sensitive patients reacted to soybean Kunitz trypsin inhibitor (SKTI), known as the major allergen of soybean 2S protein. After peptic hydrolysis for 90 min at pH 1.2, the intensity of SKTI decreased to 25% but was still visible on SDS-PAGE. Chymotryptic hydrolysis following peptic hydrolysis at pH 8 for 60 min showed a limited hydrolytic effect on soybean 2S protein. Peptic hydrolysis of soybean 2S protein partially reduced the allergenicity of soybean 2S protein, while chymotryptic hydrolysis following peptic hydrolysis increased slightly the allergenicity. CONCLUSION: Food allergy caused by soybean 2S protein occurred in part of the soybean-sensitive patients. SKTI was partially digested after peptic hydrolysis for 90 min. The allergenicity was decreased with peptic hydrolysis, while subsequent treatment of chymotrypsin increased slightly the allergenicity.