Effects of Dietary Andrographolide Levels on Growth Performance, Antioxidant Capacity, Intestinal Immune Function and Microbioma of Rice Field Eel (Monopterus Albus)
ANIMALS
Authors: Shi, Yong; Zhong, Lei; Liu, Yanli; Zhang, Junzhi; Lv, Zhao; Li, Yao; Hu, Yi
Abstract
Simple Summary This study investigated the effects of dietary andrographolide on the growth performance, antioxidant capacity, intestinal immune function and microbioma of rice field eel. This study indicated that the diets supplemented with low-dose andrographolide (75 and 150 mg/kg) significantly improved growth performance, enhanced antioxidant capacity and regulated the intestinal physical barrier and microbiota of M. albus. In addition, dietary supplementation of andrographolide upregulated of anti-inflammatory cytokines and downregulated of proinflammatory cytokines. The anti-inflammatory function of andrographolide may be related to the suppression of the toll-like receptor signaling pathway. These results can provide the valuable data for future rice field eel feeds. An eight-week feeding trial was conducted to investigate the effects of dietary andrographolide on the growth performance, antioxidant capacity in the liver, intestinal inflammatory response and microbiota of Monopterus albus. A total of 900 health fish (25.00 +/- 0.15 g) were randomly divided into five groups: AD1 (the basal diet) as the control, and AD2, AD3, AD4 and AD5 groups, which were fed the basal diet supplemented with 75, 150, 225 and 300 mg/kg andrographolide, respectively. The results showed that compared with the control group, dietary andrographolide supplementation (1) significantly increased trypsin and lipase activities in the intestine, and increased the weight gain rate but not significantly; (2) significantly increased the levels of glutathione reductase (GR), glutathione (GSH) and glutathione peroxidase (GPx) and the content of in the liver; significantly decreased the contents of reactive oxygen species (ROS) and malondialdehyde (MDA); remarkably upregulated the Nrf2, SOD1, GSTK and GSTO mRNA levels in the liver; downregulated the Keap1 mRNA level; (3) significantly increased the villi length and goblet cell numbers in the intestine, remarkably upregulated the Occludin mRNA level in the intestine, downregulated the Claudin-15 mRNA level; (4) remarkably upregulated the IL-10, TGF-beta 1 and TGF-beta 3 mRNA levels in the intestine; downregulated the IL-12 beta and TLR-3 mRNA levels; (5) significantly decreased the richness and diversity of the intestinal microbioma, increased the percentages of Fusobacteria and Firmicutes and significantly decreased the percentages of Cyanobacteria and Proteobacteria. In conclusion, these results showed that dietary low-dose andrographolide (75 and 150 mg/kg) promoted growth and antioxidant capacity, regulated the intestinal microbioma, enhanced intestinal physical and immune barrier function in rice field eel.
Epibenthic Harmful Marine Dinoflagellates from Fuerteventura (Canary Islands), with Special Reference to the Ciguatoxin-Producing Gambierdiscus
JOURNAL OF MARINE SCIENCE AND ENGINEERING
Authors: Bravo, Isabel; Rodriguez, Francisco; Ramilo, Isabel; Afonso-Carrillo, Julio
Abstract
The relationship between the ciguatoxin-producer benthic dinoflagellate Gambierdiscus and other epibenthic dinoflagellates in the Canary Islands was examined in macrophyte samples obtained from two locations of Fuerteventura Island in September 2016. The genera examined included Coolia, Gambierdiscus, Ostreopsis, Prorocentrum, Scrippsiella, Sinophysis, and Vulcanodinium. Distinct assemblages among these benthic dinoflagellates and preferential macroalgal communities were observed. Vulcanodinium showed the highest cell concentrations (81.6 x 10(3) cells gr(-1) wet weight macrophyte), followed by Ostreopsis (25.2 x 10(3) cells gr(-1) wet weight macrophyte). These two species were most represented at a station (Playitas) characterized by turfy Rhodophytes. In turn, Gambierdiscus (3.8 x 10(3) cells gr(-1) wet weight macrophyte) and Sinophysis (2.6 x 10(3) cells gr(-1) wet weight macrophyte) were mostly found in a second station (Cotillo) dominated by Rhodophytes and Phaeophytes. The influence of macrophyte's thallus architecture on the abundance of dinoflagellates was observed. Filamentous morphotypes followed by macroalgae arranged in entangled clumps presented more richness of epiphytic dinoflagellates. Morphometric analysis was applied to Gambierdiscus specimens. By large, G. excentricus was the most abundant species and G. australes occupied the second place. The toxigenic potential of some of the genera/species distributed in the benthic habitats of the Canary coasts, together with the already known presence of ciguatera in the region, merits future studies on possible transmission of their toxins in the marine food chain.