Protective Effect of Holothurian Intestine Against Indomethacin Induced Gastric Mucosal Damage in Rats

Our study aimed to investigate the protective effects of Holothurian intestines(HI) on NSAIDs-induced gastric mucosal damage and the possible mechanism. At first, 60 male Wistar rats were induced of gastric lesions with indomethacin(IDM, 30 mg kg^(-1)). The rats were pretreated for 15 consecutive days with saline, sucralfate, or HI(0.4g kg^(-1) d-1, 0.8 g kg^(-1) d^(-1) and 1.6 g kg^(-1) d^(-1)) prior to IDM treatment, followed by evaluations of macroscopic damage and microscopic features; and investigation of the levels of inflammatory cytokines, oxidative stress parameters, gastric mucosal prostaglandin E2(PGE2) and total hexosamine in tissues. The expression of COX-1 and COX-2 m RNA in the gastric tissue were determined by quantitative polymerase chain reaction(q PCR). Pathological gastric ulcer indexes, levels of pro-inflammatory cytokines(IL-1β, IL-17, TNF-α) and lipid peroxidation were significantly decreased in HI-treated groups, whereas the levels of protective factors(TGF-β, GSH, SOD activity and PGE2) were significantly elevated especially in the group with HI 1.61 g kg^(-1) d^(-1)(P < 0.05). Furthermore, the expression of COX-2 mRNA decreased significantly in HI groups(P < 0.05). The study investigates that holothurian intestines may act as a kind of marine medicine which have protective effect on IDM-induced gastric ulcer, which could be a dietary preventive agent for the prevention of gastric damage.

Generation of Reactive Oxygen Species in Different Fractions of the Coelomocytes of Holothurian Eupentacta fraudatrix in Response to the Thermostable Toxin of Yersinia pseudotuberculosis in Vitro

Pure fraction (92%-95%) of phagocytes (FP) and a mixture of amoebocytes(62%) and morula cells (38 %) FPMC of the holothurian Eupentacta fraudatrix (Holothuroidea, Dendrochirota) were obtained by using ficoll verographine step gradient. Basal production of reactive oxygen species (ROS) in FP quantified by using reduction of nitroblue tetrazolium (NBT) was more than twice that in FPMC. Thermostable toxin of Yersinia pseudotuberculosis (TST) at different concentrations ( 0.2; 0.5; 2.5 μg/ml, but not 0.1 μg/ml) stimulated NBT reduction in FPMC after 24 h incubation. In FP, TST at concentrations of 0.1 and 0.2 μg/ml inhibited and at concentrations of 0.5 and 2.5 μg/ml stimulated NBT reduction after 24 h incubation. Maximal effect was observed in FP and FPMC at TST concentrations of 0.5 and 0.2 μg/ml, respectively. Addition of catalase (0.7 μg/ml) to the cells treated with TST (2.5 μg/ml) was followed by a decrease in NBT reduction compared to that under toxin treatment alone. TST stimulated superoxide dismutase activity in concentration dependent manner (maximum at 0.5 μg/ml concentration in FP) after 24 h treatment, and this stimulation was prevented by a commercial catalase. Plant lectin concanavalin A stimulated NBT reduction more than 5 fold in FPMC compared to the control. With addition of TST, lectin stimulated ROS to lesser extent than that with lectin alone. When catalase, TST, and lectin were added into the FPMC simultaneously, ROS increase was similar to that under lectin treatment alone. On the whole, data obtained indicated that ROS generation in holothurian coelomocytes especially occurs in both stimulated and not stimulated phagocytes, and that changes in ROS production by these cells may be one of the mechanisms of antibacterial protection of holothurians.

Rediscovery of the abyssal species Peniagone leander Pawson and Foell,1986(Holothuroidea:Elasipodida:Elpidiidae):the first record from the Mariana Trench area

The elpidiid holothurian Peniagone leander Pawson and Foell,1986 is recorded for the first time from the Mariana Trench area at a depth of 5571 m.The type description of this species was based on only in-situ photographs.P.leander is re-described and illustrated based on a preserved material and in-situ photographs taken on the seabed.The 16S rRNA was also obtained from the specimen and submitted to GenBank.This is the fourth discovery of this species,extending its bathymetric range in the western Pacific Ocean.