Dietary administration of Gynura bicolor (Roxb. Willd.) DC water extract enhances immune response and survival rate against Vibrio alginolyticus and white spot syndrome virus in white shrimp Litopeneaus vannamei.

Gynura bicolor (Roxb. & Willd.) DC., a perennial plant belonging to the Asteraceae family, is originated from the tropical area of Asia. The total hemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (RBs), superoxide dismutase (SOD) activity, and lysozyme activity were examined after white shrimp Litopenaeus vannamei had been fed diets containing the water extract of G. bicolor at 0 (control), 0.5, 1.0, and 2.0 g (kg diet)(-1) for 7-28 days. The results indicated that these parameters increased accordingly with the amount of extract and time. THCs of the shrimp fed the G. bicolor diets at 1.0 and 2.0 g (kg diet)(-1) were significantly higher than that fed the control diet for 14-28 days. For the shrimp fed the G. bicolor diets at 0.5, 1.0, and 2.0 g (kg diet)(-1), the PO, RBs, and lysozyme activities reached the highest levels after 7 days, whereas SOD activity reached the highest levels after 14 days. In a separate experiment, white shrimp L. vannamei fed the diets containing the G. bicolor extract for 28 days were challenged with Vibrio alginolyticus at 3 × 10(6) cfu shrimp(-1) and white spot syndrome virus (WSSV) at 1 × 10(3) copies shrimp(-1). The survival rate of the shrimp fed the G. bicolor diets was significantly higher than that of the shrimp fed the control diet at 48-144 h post challenge V. alginolyticus and WSSV. For the shrimp fed the G. bicolor diets at 0.5, 1 and 2 g (kg diet)(-1) under challenges of V. alginolyticus and WSSV, their LPS- and ß-1,3-glucan-binding protein (LGBP) and peroxinectin (PE) mRNA expressions were significantly higher than those of the challenged control shrimp at 12-96 and 24-144 h post-challenge, respectively. We concluded that dietary administration of a G. bicolor extract could enhance the innate immunity within 28 days as evidenced by the increases in immune parameters (PO, RBs, and lysozyme) and antioxidant enzyme (SOD) activities of shrimp to against V. alginolyticus and WSSV infections.

Dietary administration of zingerone to enhance growth, non-specific immune response, and resistance to Vibrio alginolyticus in Pacific white shrimp (Litopenaeus vannamei) juveniles.

Zingerone, one of the active components of ginger, is a phenolic alkanone with antioxidant and anti-inflammatory properties. The effects of zingerone supplementation on the growth, immunity, and disease resistance of Pacific white shrimp (Litopenaeus vannamei) juveniles were studied. Four experimental diets, including a control diet (without zingerone enrichment) and 1, 2.5, and 5 mg zingerone (kg diet)(-1) were used. After 56 days of culture, shrimp fed diets supplemented with 1, 2.5, and 5 mg zingerone (kg diet)(-1) had significantly greater weight gain and feed efficiency than the controls. Furthermore, after 56 days of culture, shrimp fed all doses of the zingerone diet had higher survival rates compared to the controls after 24-72 h of challenge by the pathogen, Vibrio alginolyticus. Significantly increased phenoloxidase levels were found in shrimp fed the zingerone diets at all doses, and respiratory bursts, lysozyme and phagocytic activities of shrimp fed 2.5 and 5 mg zingerone (kg diet)(-1) also significantly increased. Neither the total hemocyte count nor superoxide dismutase activity of the experimental and control groups revealed significant differences at any dose. The results indicate that zingerone can be recommended as a supplement to shrimp feed to increase growth, immunity, and disease resistance against the pathogen, V. alginolyticus. Use of zingerone as appetizer and immunostimulant in shrimp is promising.

Effects of hot-water extract of Toona sinensis on immune response and resistance to Aeromonas hydrophila in Oreochromis mossambicus.

Respiratory burst, lysozyme and phagocytic activities, and immunoglobulin levels in response to the pathogen Aeromonas hydrophila were examined in tilapia (Oreochromis mossanbicus, 10.65 +/- 2.5 g) injected individually with hot-water extract of Toona sinensis at 4 or 8 microg g(-1). Tilapia receiving the hot-water extract of T. sinensis at either dose had significantly increased respiratory burst, phagocytic activity and lysozyme activity towards A. hydrophila by 1 and 2 days post injection. No significant differences in total immunoglobulin levels were observed among the tilapia that received the two different doses of hot-water extract of T. sinensis at 4 and 8 microg g(-1). In another experiment, a Tilapia that had been injected with hot-water extract of T. sinensis was challenged with A. hydrophila at 5 x 10(7) colony-forming units (cfu) fish(-1). The survival of tilapia that received the hot-water extract of T. sinensis at 8 microg g(-1) was significantly higher than fish that received phosphate buffered saline and the control fish after 2 days, and at the termination of the experiment (7 days after the challenge). It was concluded that the hot-water extract of T. sinensis at 8 microg g(-1) or less had increased the immune response and resistance to A. hydrophila infection in tilapia.

Effects of extracts from Gynura bicolor (Roxb. & Willd.) DC. on iron bioavailability in rats.

Gynura bicolor (Roxb. & Willd.) DC. is widely distributed in certain areas of Asia and is very popular in vegetarian cuisine in Taiwan. This study investigates the effects of G. bicolor extracts with different polarities of 80 mg/kg body weight (BW) G. bicolor alcohol extract, 80 mg/kg BW G. bicolor water extract, and 80 mg/kg BW G. bicolor ether extract on Fe bioavailability using the hemoglobin repletion efficiency assay. Wistar rats were assigned to five groups: a group receiving an iron-deficient (ID) diet; a group receiving an ID diet supplemented with ferrous sulfate (20 mg Fe/kg BW); and three groups receiving ID diets supplemented with ferrous sulfate and one of G. bicolor alcohol extract, G. bicolor water extract, or G. bicolor water extract. The results indicated that the levels of hemoglobin, serum iron, serum ferritin, liver ferritin, hemoglobin regeneration efficiency, relative biological value, and hepcidin all were significantly higher than those of the ID diet group. Besides, the iron transporter divalent metal transporter-1 was significantly reduced, but iron release protein expression of ferroportin was significantly increased. It was concluded that G. bicolor extracts may promote iron bioavailability and regulate the expressions of divalent metal transporter-1 and ferroportin.

Anticancer effects on human pancreatic cancer cells of triterpenoids, polysaccharides and 1,3-ß-D-glucan derived from the fruiting body of Antrodia camphorata.

Antrodia camphorata is a fungus native to Taiwan, and it is considered a precious medicinal agent. We analyzed triterpenoids, polysaccharides and 1,3-ß-D-glucan, three major effective components in A. camphorata extracts (ACE). ACE exhibited a selective cytotoxic effect on BxPC-3 human pancreatic cancer cells. ACE markedly inhibited the migration ability of BxPC-3 cells. Treatment of BxPC-3 cells with ACE resulted in the increase of cells in the sub-G1 phase and G2/M phase arrest. Apoptosis was confirmed by validating phosphatidylserine externalization, the observation of characteristic chromatin condensation, and nuclear DNA fragmentation. ACE induced apoptosis in BxPC-3 cells through a mitochondria-dependent pathway by triggering an appropriate balance of bax/bcl-2, cytochrome c release, activation of caspase-9 and -3, and poly(ADP-ribose) polymerase cleavage. ACE shows great therapeutic potential due to its cytotoxic effects against BxPC-3 cells which include inhibiting cell migration and inducing mitochondria-mediated apoptosis.

Differential blood lipid-lowering effects of alkylsulfonated chitosan of different molecular weights in Syrian hamsters in vivo.

This study investigated the effects of alkylsulfonated chitosan of different molecular weights on intestinal lipid absorption, blood lipid profiles and circulating adhesion molecules. Syrian hamsters were fed an AIN-93G-based high­fat diet (HFD) and were orally administered 5 or 10 mg/kg BW of oligomer (6 kDa) chitosan (OC), low­molecular-weight (70 kDa) chitosan (LMC) or high­molecular-weight (200 kDa) chitosan (HMC) four times per week for 12 weeks. Animals receiving 2.5 mg/kg BW lovastatin (LOVA) served as a positive control. The blood lipid profiles of these control animals revealed that all chitosans and LOVA significantly decreased total triglyceride, total cholesterol, low­density lipoprotein (LDL)-cholesterol and very­low­density lipoprotein (VLDL)-cholesterol levels in a dose­dependent manner compared to the HFD-fed controls (P<0.05). The blood lipid lowering effectiveness of the three chitosans followed the order of LMC>OC>HMC. Hamsters receiving 5 and 10 mg/kg LMC (P<0.05) exhibited an increase in fecal fat content. Immunoblot assay revealed that acyl­coenzyme A:cholesterol acyltransferase-2 (ACAT-2) expression was suppressed in all chitosan-fed animals compared to the HFD-fed controls (P<0.05). These results suggest that chitosan effectively decreases blood lipid content, and its effectiveness depends on the molecular size of chitosan. The hypolipidemic effect of chitosan is partly attributed to its suppression of intestinal lipid absorption and hepatic ACAT-2 expression.