Abstract: Objective To investigate the effects of different extracts of pericarpium citri reticulatae (PCR) and pogostemon cablin benth (PCB) on the contraction of gastrointestinal smooth muscle and the level of gastrointestinal hormones in rat model of gastrointestinal motility disorder. Methods Seventy Wistar rats were randomly divided into groups of control, model, water extractive of PCR, hesperidin, water extractive of PCB, water extractive of PCB plus volatile oil and patchouli alcohol, ten rats in each group. Except the control group, the rest groups were established gastrointestinal motor disorder model via limb ischemia-reperfusion (LIR). After modeling rats of groups were intervened with corresponding extracts. The effects of different extracts on contraction amplitude of corpora ventriculi and small intestine smooth muscle were observed. The levels of gastrointestinal hormones including motilin (MOT), gastrin (GAS), cholecystokinin (CCK) and somatostatin (SS) were detected by radioimmunoassay. Results The contraction amplitudes of corpora ventriculi and small intestine smooth muscle were decreased (P < 0.05), the serum level of GAS and plasma level of MOT were also significantly decreased, while CCK and SS levels in the gastric antrum were significantly increased in model group than those of the control group (P < 0.05). Water extractive of PCR, hesperidin, water extractive of PCB and water extractive of PCB +patchouli oil can increase the contraction amplitudes of corpora ventriculi and small intestine smooth muscle, increase the serum level of GAS and reduce levels of CCK and SS in the gastric antrum (P < 0.05), whereas showed no influence in the plasma level of MOT (P > 0.05)]. Compared with model group, patchouli alcohol showed no influence in the contraction of gastrointestinal smooth muscle and levels of MOT, GAS, CCK and SS (P > 0.05). In the aspect of regulating the contraction of gastrointestinal smooth muscle and the level of GAS, CCK and SS, the pharmacological effect of PCR water extract was better than that of hesperidin (P < 0.05), while water extractive of PCB + volatile oil was better than that of water extractive of PCB(P < 0.05). Conclusion The active ingredients of PCR and PCB have variant regulative effects on the contraction of
gastrointestinal smooth muscle and the serum level of GAS, CCK and SS in the gastric antrum in rat model of gastrointestinal
motility disorder.

Key words: PERICARPIUM CITRUS RETICULATA, POGOSTEMON CABLIN, rats, Wistar, reperfusion injury, motilin, gastrins, cholecystokinin, somatostatin, gastrointestinal motor disorder