Effect in white shrimp Litopenaeus vannamei of Eleutherine bulbosa (Mill.) Urb. Powder on immune genes expression and resistance against Vibrio parahaemolyticus infection.

This study investigated the influence of Eleutherine bulbosa (Mill.) Urb. on the immune responses, bacterial population in the intestines, and resistance of white shrimp, Litopenaeus vannamei, against infection with Vibrio parahaemolyticus. Shrimp were fed with three dosages of powder, at 6.25 g kg-1 (P6.25), 12.5 g kg-1 (P12.5), and 25 g kg-1 (P25). One dosage of the crude extract was provided, 1.25 g kg-1 (E1.25), and the controls without administration of E. bulbosa consisted of a positive control (PC) and a negative control (NC). Feed supplementation was carried out for 30 days; then shrimp from all treatments were challenged by intramuscular injection with V. parahaemolyticus (106 cfu/mL), except for the NC. The results showed that supplementation with the powder and extract of E. bulbosa for 30 days resulted in significantly higher (P < 0.05) immune responses (total hemocyte count (THC), phenoloxidase activity (PO), respiratory bursts (RBs)), gene expression (prophenoloxidase (proPO), lipopolysaccharide- and ß-1,3-glucan-binding protein (LGBP)), and total bacterial count (TBC) compared to PC/NC. In post challenge testing, there were significantly higher levels for THC, PO, RBs, proPO, LGBP, and PE (peroxinetin), and the treatments were able to suppress V. parahaemolyticus in the intestines, hepatopancreas, and muscles and to reduce damage to the muscles and hepatopancreas. The survival rate with P12.5 was significantly higher compared to the other treatments. It was concluded that the shrimp receiving supplementation with the powder and extract of E. bulbosa had increased immunity and resistance against V. parahaemolyticus infection, with the best dosage being the P12.5 treatment.

Buton Forest Onion Extract (Eleutherine bulbosa (Mill.) Potential on Growth Performance of Vannamei Shrimp (Litopenaeus vannamei).

BACKGROUND AND OBJECTIVE: Vannamei shrimp Litopenaeus vannamei is an economically valuable aquaculture commodity but still faces problems due to disease and growth performance. Buton forest onion extract Eleutherine bulbosa (Mill.) Urbhas been shown can protect the shrimp from disease. This study aimed to evaluate the potential of the Buton forest onion extract on the growth of vannamei shrimp in tarpaulin pond. MATERIALS AND METHODS: The experiments were conducted for 90 days by adding Buton forest onion extract in feed at a dosage of 40 g kg-1. The Buton forest onion bulbs was extracted by maceration method using 96% ethanol. The test feed was made through the re-pelleting method. Treatment include supplementation of Buton forest onion extract diet supplemented with Buton forest onion extract diet at twice a week (treatment A) and control was without Buton forest onion extract(treatment K). Parameter measurement include final weight, average daily growth (ADG), feed conversion ratio (FCR), survival rate and water quality (temperature, salinity, turbidity and pH). RESULTS: This study was demonstrated the addition of Buton forest onion extract on feed with a frequency twice a week in significantly improve the growth performance of vannamei shrimp by improving the final weight and average daily growth at 65 and 90 days of maintenance. Water quality during the study was still within the optimum range for L. vannamei shrimp growth. CONCLUSION: This study showed that supplementation of Buton forest onion extract was able to improve the growth performance of shrimp in tarpaulin ponds.

Phytochemical analysis and antibacterial activities of Eleutherine bulbosa (Mill.) Urb. extract against Vibrio parahaemolyticus

To analyze compounds in Eleutherine bulbosa (E. bulbosa) (Mill.) Urb. extract and to determine its antibacterial capability against Vibrio parahaemolyticus (V. parahaemolyticus). Methods: E. bulbosa bulb extract was preprared using 96％ ethanol by the maceration method. Phytochemical investigation of E. bulbosa extract was analyzed using GC-MS, spectrophotometry and titrimetry methods. The zone of inhibition was identified by the diffusion agar method. The minimum inhibitory concentration and minimum bactericidal concentration were determined using the plate count method. The inhibitory rate against V. parahaemolyticus was determined by the microdilution method. Cellular leakage was evaluated by spectrophotometry and cellular damage was observed by scanning electron microscopy. Results: GC-MS analysis showed the high compound of the E. bulbosa extract was securixanthone E (7-hydroxy-1,2-dimethoxyxanthone). The compound groups also included fatty acid esters, isoquinolines, naphthalenes, and phenolics. The total phenolic content was (2.50 ± 0.00) mg/g, flavonoid (6.61 ± 0.00) mg/g, and tannin (0.03 ± 0.00)％. The greatest zone of inhibition and inhibitory rate were (11.83 ± 0.06) mm and (91.32 ± 2.76)％, respectively, at 10 mg/mL. The minimum inhibitory concentration was 0.156 mg/mL, while the minimum bactericidal concentration was 10 mg/mL. The E. bulbosa extract caused leakage and cellular damage to V. parahaemolyticus. Conclusions: The E. bulbosa extract possesses inhibitory activities against V. parahaemolyticus and causes cellular leakage and damage.