Abstract:

The extraction of ganoderma acid (GA) from Ganoderma lucidum spore was explored by the combined use of
cell wall disruption with laccase and ultrasonic-assisted extraction. Besides, this study also examined the antioxidant effect
of GA in subacute senile mice induced by D-galactose. Methods: The extraction process was optimized through orthogonal
array experiments. A subacute senile mouse model was established by continuous subcutaneous injection of D-galactose into
the nape of the neck. Using ascorbic acid as positive control group, the mice in the high, moderate and low dose groups were
given GA by gavage, while those in the blank and model control groups were given 0.5% CMC-Na by gavage. Body weights
of these mice were measured once a week for six weeks. After the experimental period, total superoxide dismutase (T-SOD),
the levels of malondialdehyde (MDA) in the serum, liver and brain of mice, the activities of glutathione peroxidase (GSHPx)
in the serum and brain, and total antioxidant capacity (T-AOC) in the serum and liver were determined. Results: The
optimal conditions for GA extraction were determined as follows: solid/liquid ratio, 1:60; enzyme concentration, 0.04 g/mL;
ultrasonic time, 3 h; and number of ultrasonic treatments, 3. Under these conditions, the maximum yield of GA of 1.69% was
obtained. Conclusions: The optimized extraction process is stable and feasible. The GA extracted from Ganoderma lucidum
spore could obviously improve T-SOD and GSH-Px activities as well as T-AOC capacity and reduce MDA content in mice.
Together, these results implied the obvious anti-aging effects of the GA on subacute senile mice induced by D-galactose.

Key words: laccase, ganoderic acid, D-galactose, aging, antioxidant effect