The enhancement effect of low-dose dietary lipopolysaccharide on the growth and immunity of Litopenaeus vannamei, and transcriptome analysis.

In this study, the effects of dietary lipopolysaccharide (LPS) on Litopenaeus vannamei were investigated to determine whether LPS could play a role as a potential immunostimulant in shrimp. L. vannamei with an initial body weight of 0.30 ± 0.02 g were fed a diet containing LPS at doses of 0, 0.2, 1, 5, 25 or 125 mg kg-1 for eight weeks (groups LPS0, LPS0.2, LPS1, LPS5, LPS25 and LPS125, respectively). After eight weeks of feeding, the growth performance, immunity and transcriptome response of L. vannamei were analysed. Only dietary LPS at 0.2 and 1 mg kg-1 resulted in a significant increase in the growth of L. vannamei (P < 0.05). According to the weight gain rate (WGR) and specific growth rate (SGR), the optimum dietary LPS level was 2.462 and 2.455 mg kg-1, respectively. When compared with the control group, the survival rate (SR) of L. vannamei in the LPS0.2 group was significantly increased after white spot syndrome virus (WSSV) infection and the SR of L. vannamei in the LPS1 group was significantly increased after Vibrio parahaemolyticus infection (both P < 0.05). Compared with the LPS0 group, immune enzyme activity in the serum of L. vannamei could be significantly increased and the content of maleic dialdehyde (MDA) significantly decreased by dietary LPS. Transcriptome analysis of the haemocytes of L. vannamei identified 399 up-regulated differentially expressed genes (DEGs) and 5000 down-regulated DEGs in the LPS0.2 compared to the control group. Most of the DEGs were significantly enriched in the following pathways: phosphatidylinositol signalling, Wnt signalling, Jak-STAT signalling and inositol phosphate metabolism. In conclusion, this study revealed that diets supplemented with low-dose LPS had positive effects on the growth and immunity of L. vannamei.

Effects of replacing fish meal with cottonseed protein concentrate on the growth, immune responses, digestive ability and intestinal microbial flora in Litopenaeus vannamei.

The effects of cottonseed protein concentrate (CPC) in place of fishmeal on the growth performance, immune response, digestive ability and intestinal microbiota of Litopenaeus vannamei were investigated in this study. L. vannamei (initial body weight: 0.42 ± 0.01g) was fed for 8 weeks by four isonitrogenous and isolipid feeds with CPC replacing fishmeal (FM) at 0% (control), 15% (CPC15), 30% (CPC30) and 45% (CPC45), respectively. At the end of the study, the final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR) and protein efficiency ratio (PER) of L. vannamei in CPC15 and CPC30 groups were significantly increased, while the feed conversion ratio (FCR) of L. vannamei in the CPC30 group was significantly reduced when compared with the FM group (P < 0.05). After Vibrio parahaemolyticus infection, the cumulative mortality of L. vannamei in CPC15 within 24 hpi was significantly lower than that of the control group (P < 0.05). When compared with the control group, the activities and expression of the immunity-related enzymes in the hepatopancreas had almost the same obvious change trend in the CPC-containing groups, which indicated that the replacement for fishmeal by CPC led to significant immune response in L. vannamei. Besides, significant up-regulation of the digestive enzyme activities were observed in the CPC-containing groups. Analysis of intestinal microbiota showed that significant difference in alpha diversity existed between the CPC-containing groups and the control group. The relative abundances of several top 10 dominated species at the phylum and genus levels were significantly changed in the CPC-containing groups compared with the control group (P < 0.05). Functional prediction of the microbiota indicated that the pathway of protein digestion and absorption was significantly more abundant while the pathways of nitrotoluene degradation, aminobenzoate degradation, atrazine degradation, dioxin degradation and xylene degradation were significantly less abundant in the CPC-containing groups than the FM group (P < 0.05). In summary, optimal dietary CPC replacement of FM could improve the growth, immunity, digestive capacity and the diversities of the intestinal microbial flora of L. vannamei. However, parts of the functions of the intestinal microbial flora were decline.

An updated review on the potential antineoplastic actions of oleuropein.

Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.