• Korean Journal of Food Science and Technology
• /
• v.34 no.6
• /
• pp.1098-1102
• /
• 2002

Antioxidative activities of ethanol extracts of seed, branch, leaves, and aerial part of Crotalaria sessiflora L. were compared using in vitro experimental model. Solid contents of each extracts were 12.68, 16.28, 13.04, and 18.59 g/ 100 mL, and phenolic acid contents were $0.082{\pm}0.003,\;0.099{\pm}0.010,\;0.071{\pm}0.002,\;and\;0.094{\pm}0.011\;mg/mL$ in branch, aerial part, seed, and leaves, respectively. Extracts prepared from leaves showed highest electron-donating ability toward DPPH. SOD-liked activities were 78.95, 70.85, 74.65, and 87.49% in aerial part, branch, seed, an leaves respectively. Extracts prepared from leaves showed 59.39% inhibitory effect on peroxidation of egg yolk lecithin.

• Fisheries and Aquatic Sciences
• /
• v.26 no.3
• /
• pp.204-215
• /
• 2023

The thermolabile haemolysin (tlh) of Vibrio parahaemolyticus (Vptlh) from V. parahaemolyticus is a multiple-function enzyme, initially describes as a haemolytic factor activated by lecithin and phospholipase A2 enzymatic activity (Shinoda, 1991; Vazquez-Morado, 2021; Yanagase et al., 1970). Until now, the tlh structure has hypothesized including N-terminal and C-terminal domain, but what domain of the Vptlh structure does the haemolytic activity has not been refined yet. In this study, a 450-bp VpTLH nucleotide sequence of the entire Vptlh gene encoded the C-terminal domain cloned firstly to examine its responsibility in the activity of the Vptlh. The C-terminal domain fused with a 6-His-tag named the His-tag-VpC-terminal domain was expressed successfully in soluble form in the BL21 (DE3) PlysS cell. Remarkably, both expression and purification results confirmed a high agreement in the molecular weight of the His-tag-VpC-terminal domain was 47 kDa. This work showed the His-tag-VpC-terminal domain lysed the erythrocyte membranes in the blood agar and the phosphate buffered saline (0.9%) media without adding the lecithin substrate of the phospholipase enzyme. Haemolysis occurred at all tested diluted concentrations of His-tag-VpC-terminal domain (p < 0.05), providing evidence for the independent haemolytic activity of the His-tag-VpC-terminal domain. The content of 100 ㎍ of the His-tag-VpC-terminal domain brought the highest haemolytic activity of 80% compared to that in the three remaining contents. Significantly, the His-tag-VpC-terminal domain demonstrated not to involve the phospholipase activity in Luria-Bertani agar supplemented with 1% (vol/vol) egg yolk emulsion. All results proved the vital responsibility of the His-tag-VpC-terminal domain in causing the haemolytic activity without the required activation by the phospholipase enzyme. Raw extracts of Phellinus igniarus and Phellinus pipi at 10^-1 mg/mL inhibited the haemolytic activity of the His-tag-VpC-terminal domain from 67.7% to 87.42%, respectively. Hence applying the His-tag-VpC-terminal domain as a simple biological material to evaluate quickly potential derivatives against the Vptlh in vivo conditions will accessible and more advantageous than using the whole of the Vptlh.