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An aquatic nutrition expert studying the mechanism by which Eucommia regulates fish flesh quality.

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Leng Xiangjun is a professor at the College of Fisheries and Life Science, Shanghai Ocean University, and an expert of the Key Laboratory of Freshwater Aquatic Germplasm Resources of the Ministry of Agriculture. He systematically studied the regulation of grass carp growth and muscle quality by Eucommia and its active components. A classic 2008 trial showed that adding 2% and 4% Eucommia leaf powder or 0.1% and 0.15% Eucommia leaf extract to the basal diet of grass carp for 60 days significantly increased weight-gain rate, significantly reduced the feed conversion ratio, and significantly increased serum SOD activity in all test groups.

He further revealed the mechanism at the cellular and molecular levels: Eucommia extract and its chlorogenic acid, quercetin and aucubin activate the TGF-beta/Smads/CTGF signaling pathway to upregulate the expression of collagen synthesis genes, increasing the content of total muscle collagen and alkali-insoluble collagen and improving muscle hardness, chewiness and water-holding capacity. This series of studies provides solid scientific support for the large-scale application of Eucommia leaf feed additives in aquaculture.

Milestones

• In 2018 and 2020, research results on Eucommia regulation of grass carp quality were successively published in the Journal of Fisheries of China and the Chinese Journal of Animal Nutrition
• His Eucommia feed research is widely cited by feed industry media as a classic basis for the aquaculture application of Eucommia leaf extract

Key Contributions

• In 2008, demonstrated that adding 2% and 4% Eucommia leaf powder and Eucommia leaf extract to feed significantly increases the weight-gain rate of grass carp, reduces the feed conversion ratio and improves muscle quality
• Led the National Natural Science Foundation of China project 'Mechanism by which Eucommia regulates collagen formation in grass carp and its correlation with flesh quality'
• Elucidated the mechanism by which Eucommia promotes collagen metabolism in intramuscular fibroblasts of grass carp through the TGF-beta/Smads/CTGF signaling pathway, identifying chlorogenic acid, quercetin and aucubin as the main active components
• Published a series of papers in the Journal of Fisheries of China and the Chinese Journal of Animal Nutrition on the effects of Eucommia on growth, muscle quality and collagen gene expression in grass carp
• Preliminarily established a fish muscle quality evaluation system and quality-improvement strategies, promoting the shift of aquaculture from quantity-oriented to quality-oriented