OBJECTIVETo investigate the effect of Bushen Yanggan Recipe (BSYGR) on the function and morphology of nigrostriatal system in Parkinsonian model rats with long-term levodopa treatment.

METHODSUnilateral Parkinsonian rat models were established by injecting 6-hydroxydopamine (6-OHDA) into the substantia nigra pars compacta (SNpc) and ventral segmental area (VTA). Animals were randomly divided into four groups, the sham control group, model control group, levodopa group and levodopa plus BSYGR group. The content of striatal dopa (DA), digydroxy-phenyl acetic acid (DOPAC) and homovanilic acid (HVA) or the THmRNA expression level in the midbrain were measured.

RESULTS(1) Levels of striatal DA, DOPAC, HVA, DOPAC/DA, HVA/DA decreased in the model control group by about 90% as compared with those in sham control group (P < 0.05). These parameters in the levodopa group were higher than those in the sham control group, while in the levodopa plus BSYGR group, they were lower than those in the levodopa group (P < 0.01), approaching the levels in the sham control group (P > 0.05). (2) Striatal TH activity in the model group was lower than that in the sham control group significantly, but higher than that in the levodopa group, while in the levodopa plus BSYGR group, it showed a level obviously higher than that in the levodopa group (P < 0.05). (3) Levodopa plus BSYGR group had a higher midbrain THmRNA expression level than that in the levodopa group.

CONCLUSIONBSYGR could effectively reduce the side effects resulting from the long-term treatment of levodopa.