Protective effects of traditional food on cadmium toxicity

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19700
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 58:Society medicine, nursing, and related fields
• Research Institution: Kitasato University
• Principal Investigator: Horiguchi Hyogo 北里大学, 医学部, 教授 (90254002)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: カドミウム / 大豆 / 味噌 / ラット / 肝障害 / 尿細管障害

Outline of Final Research Achievements

We examined the possibility that soy, a representative of traditional Japanese foodstuffs, would mitigate the toxicity of cadmium (Cd) in rats that were kept with diets containing soy or miso, fermented soybean paste. Rats were injected with Cd at 10 mg/kg sc and observed for 24 hours. The mortality rates of rats tended to be lower in rats kept with soy-miso diets. The increase levels of plasma GOT and GPT after injection of Cd at 6 mg/kg tended to be lower in rats kept with soy-miso diets. On the other hand, rats were injected with Cd at 2 mg/kg once a week for 5 months. The mortality rates of rats kept were higher in rats kept with soy-miso diets. The increase levels of urinary NAG in Cd-injected rats kept with soy-miso diets tended to be lower.
These results suggest the possibility that soy would mitigate and enhance the acute and chronic toxicity of Cd, respectively, and suppress its acute hepatic injury and chronic renal tubular dysfunction, although only slightly.

Free Research Field

重金属の毒性学

Academic Significance and Societal Importance of the Research Achievements

日本人のCd曝露レベルが国際的に見て高いのは日本の伝統的な食品のCd含量が高いためであり、従ってそのような食品にはCdに対する解毒作用を持つ何らかの物質が多く含まれているかもしれないという本研究の発想は非常に独創的である。そして、実際に本研究の成果として大豆や味噌がCdの毒性に対して種々の作用を持つことの一端が見出されたことは意義深く、大豆や味噌を含めてもっと幅広く日本の伝統的な食品のCdの毒性に対する作用を解明し、社会に応用するための今後の大きな研究の一分野の基となる可能性があると考えられる。