OBJECTIVETo investigate and compare the effects of Compound Chaihu Shugan Decoction (CHSGD, "treatment from Gan") and Dingxian Pill (DXP, "treatment from the sputum") on the metabolism path of glutamate in the pentylenetetrazol-kindled seizure rats' hippocampus, thus exploring the molecular mechanism of "heterotherapy for homopathy".

METHODSA chronic kindling seizures rat model was established by intraperitoneal injecting pentylenetetrazol (PTZ). Totally 24 fully kindled seizure rats were randomized into four groups, i.e., the model control group, the Sodium Valproate (VPA) group, the DXP group, and the CHSGD group. They were respectively treated with normal saline, VPA, CHSGD, and DXP, respectively. Rats in the control group were treated with normal saline by peritoneal injection and by gastrogavage. After intragastric administration for 4 successive weeks, the glutamate (Glu) levels in the hippocampus were detected by high performance liquid chromatography (HPLC). The expressions of glutamate transporter-1 (GLT-1) proteins were detected by Western blot. The activity of glutamine synthetase (GS) was detected by using GS detection kit.

RESULTSCompared with the control group, the content of Glu in the model group significantly increased, and the expression of GLT-1 and the activity of GS significantly decreased (P < 0.01). Compared with the model group, the content of Glu in each medication group significantly decreased, and the protein expression of GLT-1 as well as the activity of GS significantly increased (P < 0.01). But when compared between the CHSGD group and the DXP group, the content of Glu was lower and the activity of GS was higher in the CHSGD group than in the DXP group (P < 0.01), while there was no statistical difference in the expression of GLT-1 between the two groups (P > 0.05).

CONCLUSIONSCHSGD ("treatment from Gan") and DXP ("treatment from the sputum") could both decrease the level of Glu and raise the expression of GLT-1 and the activity of GS, indicating that CHSGD and DXP both could regulate the metabolism path of Glu to affect the level of the Glu in the brain. But the effects of CHSGD were superior to those of DXP in decreasing the content of Glu and up-regulating the activity of GS, suggesting that there were some different effects targets between the two compounds on the metabolism path of Glu, which may be one of possible molecular mechanisms for treating epilepsy by heterotherapy for homopathy.