Increase in plasma total antioxidant capacity of grazing Japanese Black heifers and cows in forestland in Japan

Blood total antioxidant capacity (TAC) has become a key bio‐marker for animal health. Forest‐grazing cattle are known to forage various native plants that have high TAC. This study evaluated differences of plasma TAC between forest‐grazing (FG) and pasture‐grazing cattle (PG). Experiment 1 monitored the plasma TAC levels of 32 Japanese Black cattle. The level in PG did not change throughout the grazing period. However, that in FG, which increased from summer, was significantly higher than that in PG through fall (P < 0.05). In experiment 2, we used nine Japanese Black heifers and investigated their blood antioxidant parameters and the TAC in plants that the cattle consumed in late June and September. The plasma TAC levels in FG were significantly higher than those in PG in both periods (P < 0.05). Plasma levels of lipid peroxidation in FG tended to be lower than that in PG (P = 0.098). Furthermore, the TAC levels in various species of shrubs and trees consumed by FG were higher than those in pasture grasses. Results of this study show that plasma TAC of grazing Japanese Black cattle in forestland increase from summer through fall.     

Interaction of grammistins with lipids and their antibacterial activity

ABSTRACT: Grammistins are hemolytic and ichthyotoxic peptides in the skin secretion of soapfishes and are structurally characterized by their abundance in amphiphilic α-helicity. In the present study, their interaction with lipids and lipid vesicles as well as antibacterial activity were examined using four grammistins (Gs 1 and Gs 2 from Grammistes sexlineatus and Pp 1 and Pp 3 from Pogonoperca punctata ). The hemolytic activity of grammistins was inhibited by phospholipids but not by cholesterol. Moreover, grammistins released carboxyfluorescein entrapped within liposomes made of phosphatidylcholine. In contrast, grammistins were found to have antibacterial activity with a broad spectrum against nine species of bacteria, including both Gram-negative and Gram-positive groups. The potency of their antibacterial activity was not related to that of hemolytic activity, suggesting that grammistins bind to membrane phospholipids but lyse erythrocyte and bacterial membranes via different mechanisms. Conclusively, grammistins are new members of the family of cell non-selective membrane-lytic peptides with amphiphilic α-helices, being similar to pardaxins, which are secreted from the skin of soles, and to melittin, which is derived from bee venom.     

In vivo and in vitro effects of Rhizopus extract on body growth and steroid production in masu salmon, Oncorhynchus masou Brevoort

This study investigated the in vivo and in vitro effects of Rhizopus (filamentous fungus) extract (RU) in masu salmon Oncorhynchus masou Brevoort. Underyearling fish were fed with RU for 16 months. Monthly changes in body growth, gonadal maturation and serum levels of sex steroids were monitored. Gonads were also incubated at 0, 1, 10, 100 and 1000 μg RU mL⁻¹ Leibovitz's L‐15 medium for 18 h. The levels of steroids in serum and cultured medium were measured. It was determined that RU‐fed immature and mature males, when compared with control groups, showed significantly higher body growth during spring, summer and the spawning period. Similarly, immature RU‐fed females showed significantly higher fork length and body weight in autumn, spring and summer. Furthermore, RU‐fed males showed significantly higher levels of serum testosterone (T) and 11‐ketotestosterone (11‐KT) levels in the pre‐spawning season, and 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) in the spawning season. In vitro RU incubation of gonads showed a dose‐dependent and significant increase in T, 11‐KT, oestradiol‐17β and DHP release in the medium. It appears that the causes of enhanced body growth and increased steroid production herein observed in salmonids are the physiologically active substances that may be present in the mycelium of the fungus.