ICAR-Directorate of Coldwater Fisheries Research, Anusandhan Bhawan, Bhimtal, Nainital, Uttarakhand, -263136, India.
Fish Physiol Biochem. 2024 Apr;50(2):589-603. doi: 10.1007/s10695-023-01292-4. Epub 2024 Jan 4.
Although the immuno-modulatory and stress-relieving properties of β-glucan is well elucidated in humans and other animal models, including fish, its role as a dietary supplement on reproduction is extremely scarce. Therefore, in this study, adult female fish were fed one of four test diets having 0 (control), 0.5, 1, and 1.5% β-D-glucan for 130 days and its effect on reproductive performance, ovarian and liver histology, sex hormones, and transcript abundance of selected reproduction-related genes was assessed. Low dietary intake of β-glucan improved fertilization and hatching rates (p<0.05). The relative fecundity and percentage of spawning females were higher (non-significant) in 0.5% β-glucan-fed groups. Surprisingly, even after 130 days, spawning did not occur in 1.5% β-glucan-fed individuals. Irrespective of β-glucan intake, all the brooders recorded similar plasma 17β-estradiol and maturation-inducing hormone (p>0.05). Higher intake of β-glucan (1.5%) upregulated aromatase genes without a parallel increase in 17β-estradiol. However, plasma vitellogenin increased with increasing β-glucan up to 1.0% then declined at 1.5% (p<0.05). The fish that received control, 0.5, and 1.5% β-glucan recorded similar vitellogenin levels in their plasma. Significantly higher plasma cortisol was evidenced in 1.5% β-glucan fed brooders (p<0.05). Histologically, higher follicular atresia and leaking of yolk material was evidenced in 1.5% β-glucan-fed group. Liver histology revealed the highest nutrient/lipid accumulation in fish that received 1.0% and 1.5% β-glucan. This study demonstrated the stimulatory effect of β-glucan intake at a lower dose (0.5%) on reproduction. However, higher intake (1.5%) could perturb normal reproductive function in a fish model and caused an increased number of atretic follicles leading to spawning/reproductive failure.
虽然β-葡聚糖在人类和其他动物模型（包括鱼类）中的免疫调节和缓解压力特性已经得到充分阐明，但作为膳食补充剂对繁殖的作用却极其有限。因此，在这项研究中，成年雌性鱼类被喂食四种测试饮食中的一种，分别含有 0（对照）、0.5、1 和 1.5%的β-D-葡聚糖，持续 130 天，并评估其对繁殖性能、卵巢和肝脏组织学、性激素以及选定的繁殖相关基因的转录丰度的影响。低水平的β-葡聚糖饮食可提高受精率和孵化率（p<0.05）。在 0.5%β-葡聚糖喂养组中，相对繁殖力和产卵雌鱼的比例更高（无显著差异）。令人惊讶的是，即使经过 130 天，1.5%β-葡聚糖喂养的个体也没有产卵。无论β-葡聚糖的摄入量如何，所有的亲鱼的血浆 17β-雌二醇和促成熟激素（Maturation-Inducing Hormone，MIH）水平都相似（p>0.05）。更高的β-葡聚糖（1.5%）摄入上调了芳香化酶基因，但没有相应增加 17β-雌二醇。然而，血浆卵黄蛋白原随着β-葡聚糖的增加而增加，达到 1.0%后在 1.5%时下降（p<0.05）。接受对照、0.5%和 1.5%β-葡聚糖的鱼类在血浆中记录到相似的卵黄蛋白原水平。在接受 1.5%β-葡聚糖喂养的亲鱼中，血浆皮质醇水平显著升高（p<0.05）。组织学上，在 1.5%β-葡聚糖喂养组中，发现更多的卵泡闭锁和卵黄物质泄漏。肝脏组织学显示，接受 1.0%和 1.5%β-葡聚糖的鱼类积累了最高的营养/脂质。本研究表明，较低剂量（0.5%）的β-葡聚糖摄入对繁殖有刺激作用。然而，更高的摄入量（1.5%）可能会扰乱鱼类模型的正常生殖功能，并导致更多的闭锁卵泡，从而导致产卵/繁殖失败。
