Abstract:

The aim of this study is to explore the protective effects of royal jelly (RJ) harvested at different time points on
bromobenzene-induced oxidative damage in mice. The 48 h RJ and 72 h RJ were fed to Kunming mice by gavage, each of
which was used to set up a high dose group at 9 g/(kg·d) (48 h RJ-H and 72 h RJ-H), a moderate dose group at 3 g/(kg·d)
(48 h RJ-M and 72 h RJ-M) and a low dose group at 1 g/(kg·d) (48 h RJ-L and 72 h RJ-L), respectively. At the same time, a
control group was set up. Each mouse in the experimental groups was given RJ at a dose of 10 mL/kg, while the control group
mice were given the same amount of distilled water. The mice were fed royal jelly daily by oral gavage for 45 days, and then
given bromobenzene oil at a dose of 0.3 mg/kg (10 mL/kg) by gavage. After 22 h, liver weight and malondialdehyde (MDA)
content, superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity and total antioxidant capacity
(T-AOC) in blood and liver tissue of each mouse were detected. Results showed that preventive administration of RJ had no
significant effect on body weight, liver weight or liver coefficient in bromobenzene-challenged mice (P > 0.05). The level of
serum MDA in the mice from all groups except the 48 h RJ-L group was significantly reduced compared to that in the blank
control group (P < 0.05). Administration of moderate and high-dose RJ caused a significant elevation in the levels of serum
SOD activity and GSH-Px content, and the mice from all groups administered with RJ showed significantly increased levels
of serum T-AOC than the blank control group (P < 0.05). In addition, oral gavage of RJ resulted in a significant reduction in
the levels of MDA, GSH-Px and T-AOC in liver tissue (P < 0.05). The level of SOD activity in liver tissue of the mice from
all groups except the 48 h RJ-L group exhibited a significant increase compared with those from the blank control group
(P < 0.05). Therefore, both 48 h RJ and 72 h RJ have protective effects on bromobenzene-induced oxidative damage in mice.

Key words: royal jelly, harvesting time, oxidative damage