Title: Anti-mTOR activity of aqueous extract from roots of Acanthopanax senticosus
Biography: Kyeong Mee Park
The mammalian target of rapamycin (mTOR) signaling pathway couples energy and nutrient abundance to the expression of cell growth and division. mTOR is crucially involved in the onset and progression of diabetes, cancer and ageing. The screening of >2,800 natural plant products used for traditional medicine has selected an aqueous extract from roots of Acanthopanax senticosus (A. senticosus) as a natural product that modulates mTORC1 pathway. The plant extract inhibits mTORC1 activity, but presents low cytotoxicity in HeLa human cancer cells. Treatment of the root extract of A. senticosus resulted in the inhibition of mTORC1 activity as measured by the phosphorylation status of p70 S6 kinase (S6K) in HeLa cells and the induction of autophagy as assessed by the conversion of cytoplasmic LCI into lipidated LCII in HeLa GFP-LC3 cells stably expressing GFP-LC3. The treatment of HeLa cells with this plant extract also induces cell cycle arrest at G2/M phase. A strong therapeutic potential of A. senticosus extract that inactivates mTORC1 pathway has been suggested by showing the reduced level of phosphorylated S6K in tissues of 15-week-old diabetic obese db/db mice intraperitoneally injected with A. senticosus extract (100 µg/g body weight/day) for a week. Taken together, these results suggest that the aqueous extract of A. senticosus is a promising candidate for prevention of cancer, diabetes, and ageing by inhibiting mTOR signaling.