Shi Meijun, Gao Mingfu, Sun Hao, Yang Weichao, Zhao Hongxia, Zhang Lixin, Xu Hui
CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Animals (Basel). 2023 Aug 3;13(15):2502. doi: 10.3390/ani13152502.
L-ascorbic acid (ASA) is a micronutrient that is essential for reproduction, growth, and immunity in animals. Due to the loss of enzyme L-gulono-1,4-lactone oxidase (GLO), most aquatic animals lack the capacity for ASA biosynthesis and therefore require supplementation with exogenous ASA. Recent studies have shown that 2-keto-L-gulonic acid (2KGA), a novel potential precursor of ASA, can enhance plant growth and improve stress resistance by promoting the synthesis and accumulation of ASA. Our hypothesis is that 2-keto-L-gulonic acid (2KGA) plays a similar role in aquatic animals. To investigate this, we conducted an in vivo trial to examine the effects of exogenous 2KGA supplementation on ASA metabolism and growth of zebrafish (). Zebrafish were categorized into groups based on their dietary intake, including a basal diet (CK group), a basal diet supplemented with 800 mg/kg ASA (ASA group), and 800 mg/kg 2KGA-Na (2KGA group) for a duration of three weeks. The results demonstrated a significant increase in ASA content in zebrafish treated with 2KGA (34.82% increase, < 0.05) compared to the CK group, reaching a consistent level with the ASA group (39.61% increase, < 0.05). Furthermore, the supplementation of 2KGA significantly improved growth parameters relevant to zebrafish (specific growth rate increased by 129.04%, < 0.05) and enhanced feed utilization (feed intake increased by 15.65%, < 0.05). Positive correlations were observed between growth parameters, feed utilization, whole-body chemical composition, and ASA content. Our findings suggest that supplementation with exogenous 2KGA can serve as a novel approach for elevating ASA synthesis in aquatic animals, and further investigation of its underlying mechanism is required.
L-抗坏血酸（ASA）是一种对动物繁殖、生长和免疫至关重要的微量营养素。由于缺乏L-古洛糖酸-1,4-内酯氧化酶（GLO），大多数水生动物缺乏合成ASA的能力，因此需要补充外源ASA。最近的研究表明，2-酮基-L-古龙酸（2KGA）是一种新的潜在ASA前体，它可以通过促进ASA的合成和积累来促进植物生长并提高抗逆性。我们的假设是2-酮基-L-古龙酸（2KGA）在水生动物中发挥类似作用。为了研究这一点，我们进行了一项体内试验，以研究外源补充2KGA对斑马鱼ASA代谢和生长的影响。斑马鱼根据饮食摄入量分为几组，包括基础饲料组（CK组）、添加800 mg/kg ASA的基础饲料组（ASA组）和添加800 mg/kg 2KGA-Na的组（2KGA组），持续三周。结果表明，与CK组相比，用2KGA处理的斑马鱼体内ASA含量显著增加（增加34.82%，P<0.05），达到与ASA组一致的水平（增加39.61%，P<0.05）。此外，补充2KGA显著改善了与斑马鱼相关的生长参数（特定生长率提高了129.04%，P<0.05）并提高了饲料利用率（采食量增加了15.65%，P<0.05）。在生长参数、饲料利用率、鱼体化学成分和ASA含量之间观察到正相关。我们的研究结果表明，外源补充2KGA可以作为提高水生动物ASA合成的一种新方法，需要进一步研究其潜在机制。
