Different metabolomic responses of grass carp (Ctenopharyngodon idellus) to dietary tannin and rapeseed meal

Effects of Tannic Acid Supplementation of a High-Carbohydrate Diet on the Growth, Serum Biochemical Parameters, Antioxidant Capacity, Digestive Enzyme Activity, and Liver and Intestinal Health of Largemouth Bass, Micropterus salmoides

We investigated the effects of dietary tannic acid (TA) supplementation of a high-carbohydrate diet on growth, feed utilization, whole-body proximate composition, serum biochemical indicators, antioxidant capacity, digestive enzyme activity, and liver and intestinal health of juvenile largemouth bass, Micropterus salmoides (initial mean weight: 8.08 ± 0.08 g). Five diets were prepared, including a positive control (dietary carbohydrate level, 16%, LC0), a negative control (dietary carbohydrate level, 21%, HC0), and three TA-supplementation diets based on the negative control diet with TA addition at 200, 400, and 800 mg/kg, respectively. After 8 weeks of feeding, the results showed that compared with the LC0 diet, 400-800 mg/kg dietary TA significantly improved the survival rate of largemouth bass (P < 0.05) while significantly reducing its weight-gain rate and specific growth rate (P < 0.05). Compared with the HC0 diet, 400 mg/kg dietary TA significantly increased serum catalase activity (P < 0.05), and significantly decreased serum malondialdehyde, liver glycogen, lightness (L ∗), and yellowness (b ∗) (P < 0.05). Moreover, compared with the HC0 diet, 200-400 mg/kg dietary TA effectively improved the vacuolation of hepatocytes caused by the high-carbohydrate diet and reduced the occurrence of intestinal epithelial cell vacuolation and necrosis. In turn, 800 mg/kg dietary TA significantly inhibited protease activity in the pyloric caecum and intestine (P < 0.05). In conclusion, dietary supplementation with TA inhibited protease activity, which resulted in decreased growth performance in largemouth bass. However, it was also found that 200-400 mg/kg TA enhanced the antioxidant capacity of largemouth bass in the case of the high-carbohydrate diet, reduced liver glycogen levels, and improved liver and intestinal health. Finally, it should be noted that, when the dietary TA level exceeded 800 mg/kg, TA appeared to play a pro-oxidation role in the liver, which may cause oxidative stress in the liver.

Dietary Supplementation with a Blend of Hydrolyzable and Condensed Tannins Ameliorates Diet-Induced Intestinal Inflammation in Zebrafish (Danio rerio)

The current study evaluated the effects of hydrolyzable and condensed tannins from chestnut and quebracho wood, respectively (TSP, Silvafeed^®), on zebrafish with intestinal inflammation induced by a plant-based diet (basal diet). Four experimental diets were prepared as follows: the basal diet + 0 TSP, the basal diet + TSP at 0.9 g/kg of feed, the basal diet + TSP at 1.7 g/kg of feed, and the basal diet + TSP at 3.4 g/kg of feed. Eighty-four zebrafish (Danio rerio) were fed for 12 days with the experimental diets. In zebrafish fed the basal diet, intestine integrity appeared to be altered, with damaged intestinal villi, high immunoexpression of tumor necrosis factor-α (TNFα) and cyclooxygenase 2 (COX2), and high expression of the cox2, interleukin 1 (il-1b), interleukin 8 (cxcl8-l1), and tnfα genes. The tannin treatment partially restored intestinal morphology and downregulated the expression of cytokines. The best activity was detected with 1.7 and 3.4 g/kg of feed. In the guts of all groups, Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes were the most represented phyla. The most represented genera were Plesiomonas and Sphingomonas, belonging to the Proteobacteria phylum; Cetobacterium, belonging to the Fusobacteria phylum; and Lactobacillus, belonging to the Firmicutes phylum. No significant differences were detected among groups, except for a slight decrease in the Fusobacteria phylum and slight increases in the Shewanella and Bacteroides genera with TSP. In conclusion, these results suggest that tannins can improve the zebrafish intestinal inflammation caused by a terrestrial-plant-based diet in a dose-dependent manner.

Hepatopancreas-Intestinal Health in Grass Carp (Ctenopharyngodon idella) Fed with Hydrolyzable Tannin or Rapeseed Meal

This study evaluated the effect of dietary rapeseed meal (RM) and hydrolyzable tannin on grass carp (Ctenopharyngodon idella) and determined the possible role of tannin on health when RM was added to the diet. Eight diets were formulated. Four were semipurified-diets with 0, 0.75, 1.25, and 1.75% hydrolyzable tannin (T0, T1, T2, and T3), and the other four were practical diets containing 0, 30, 50, and 70% RM (R0, R30, R50, and R70), which had similar tannin contents as semipurified-diets. After the 56 d feeding trial, the antioxidative enzymes and relative biochemical indexes showed a similar tendency in practical and semipurified groups. In hepatopancreas, superoxide dismutase (SOD) and catalase (CAT) activities increased with RM and tannin levels, respectively, while glutathione (GSH) content and glutathione peroxidase (GPx) activity increased. Malondialdehyde (MDA) content increased and decreased in T3 and R70, respectively. In the intestine, MDA content and SOD activity increased with RM and tannin levels, while GSH content and GPx activity decreased. The expression levels of interleukin 8 (IL-8) and interleukin 10 (IL-10) were upregulated with RM and tannin levels, and the Kelch-like ECH-associated protein 1 (Keap1) expression was upregulated in T3, whereas it was downregulated in R50. This study demonstrated that 50% of RM and 0.75% of tannin induced oxidative stress, injured hepatic antioxidant ability, and resulted in intestinal inflammation in grass carp. Therefore, the tannin in rapeseed meal cannot be neglected in aquatic feeding.

Metabolomics approach to assess the effect of siphonal autotomy on metabolic characteristics of razor clam Solen grandis

Autotomy appendages are fundamental evolutionary adaptations to escape predation. The siphon is an important foraging organ for bivalves. Here, we report the first demonstration of autotomy of the siphon in marine bivalves (razor clam Solen grandis) and the effect of siphonal autotomy in S. grandis on foraging and metabolic characteristics. In this study, the feeding rate and digestive enzyme activities upon siphonal autotomy in razor clams were investigated. Moreover, endogenous metabolites pre/post-autotomy of the siphon were investigated using liquid chromatography tandem-mass spectrometry (LC–MS). The feeding rate and digestive enzyme activities decreased significantly after siphonal autotomy in S. grandis (P < 0.05), suggesting that autotomy of the siphon negatively affected its foraging. These results might be related to the reduction in the foraging radius. Additionally, the effect of autotomy was investigated on a total of 34 differentially abundant metabolites, and pathway analysis indicated that 32 differentially enriched metabolic pathways were worthy of attention. Further integrated key metabolic pathway analysis showed that glycine, serine and threonine metabolism; taurine and hypotaurine metabolism; biotin metabolism; vitamin B6 and thiamine metabolism were significantly relevant pathways in S. grandis pre/post-autotomy of the siphon. The downregulation of glycine, taurine, and hypotaurine is expected to indicate a shortage of intermediate compounds and energy in S. grandis. Therefore, to provide the required energy and materials for siphon regeneration in S. grandis, we anticipated that it would be necessary to supplement these as exogenous metabolites from the daily diet.

Medicinal Importance, Pharmacological Activities, and Analytical Aspects of Strictinin: A Mini-Review

BACKGROUND

Plants and their derived products have been used in history as food and medicine. Plant materials are rich sources of fiber, minerals, vitamins, and bioactive phytochemicals, which are useful for human beings. Strictinin is an important phytoconstituent of green tea.

METHODS

Present work mainly focuses on the biological importance, therapeutic potential, and pharmacological activities of strictinin in medicine. Numerous scientific data have been collected from various literature databases such as Google Scholar, Science Direct, PubMed, and Scopus database in order to realize the health beneficial potential of strictinin. Pharmacological data has been collected and analyzed in the present work to find the effectiveness of strictinin against human disorders and complications. Analytical data of strictinin has been also collected and analyzed in the present work.

RESULTS

Scientific data analysis revealed the biological importance of strictinin in medicine. Scientific data analysis signified the therapeutic benefit of strictinin mainly due to its anticancer, antimicrobial, antibacterial, antiviral, and antioxidant activity. However, enzymatic activities, cytotoxicity, effectiveness on skin disorders, and osteogenic potential of strictinin have also been discussed. Analytical data revealed the importance of modern analytical techniques in medicine for the separation, identification, and isolation of strictinin.

CONCLUSION

Present work signified the biological importance and therapeutic benefits of strictinin in medicine and other allied health sectors.