[Qingre Lidan Jiedu Recipe improves high copper load-induced cognitive dysfunction in rats by regulating mitophagy]

To explore the mechanisms of Qingre Lidan Jiedu Recipe (QLJR) for improving cognitive dysfunction in rats with high copper load.

Seventy-five male SD rats were randomized into normal control group, model group, QLJR group, penicillamine (PCA) group, and QLJR+ PCA group. Except for those in the control group, all the rats were fed a high-copper diet for 12 weeks. The effects of the treatments on cognitive function of the rats were assessed using the Barnes maze and passive avoidance tests. Hippocampal expressions of NIX, FUNDC1 and LC3 of the rats were detected using Western blotting and immunofluorescence staining, and changes in mitochondrial morphology were observed with transmission electron microscopy.

Behavioral tests showed prolonged target hole latency, shortened latency to enter the dark chamber, and increased error counts of the rats in the model group, which were significantly improved in QLJR+PCA group; the error counts were significantly lower in QLJR+PCA group than in either QLJR or PCA group. Among all the groups, the hippocampal expressions of NIX and FUNDC1 were the lowest and LC3 I/II expression the highest in the model group; NIX and FUNDC1 expressions were significantly higher and LC3 I expression was lower in QLJR+PCA group than in QLJR group and PCA group. Immunofluorescence staining revealed weakened NIX and FUNDC1 expressions and enhanced LC3 expression in the hippocampus of the rats in the model group as compared with those in the normal control and QLJR+PCA groups, but their expressions did not differ significantly between QLJR and PCA groups. The rats in the model group showed obvious structural disarray of the mitochondria, which were improved in all the treatment groups.

QLJR improves cognitive dysfunction in rats with high copper load possibly by regulating mitophagy.