Gelsemine alleviates both neuropathic pain and sleep disturbance in partial sciatic nerve ligation mice.

AIM: Gelsemine, an alkaloid from the Chinese herb Gelsemium elegans (Gardn & Champ) Benth., is effective in mitigating chronic pain in rats. In the present study we investigated whether the alkaloid improved sleep disturbance, the most common comorbid symptoms of chronic pain, in a mouse model of neuropathic pain. METHODS: Mice were subjected to partial sciatic nerve ligation (PSNL). After the mice were injected with gelsemine or pregabalin (the positive control) intraperitoneally, mechanical allodynia and thermal hyperalgesia were assessed, and electroencephalogram (EEG)/electromyogram (EMG) recording was performed. Motor performance of the mice was assessed using rota-rod test. c-Fos expression in the brain was analyzed with immunohistochemical staining. RESULTS: In PSNL mice, gelsemine (2 and 4 mg/kg) increased the mechanical threshold for 4 h and prolonged the thermal latencies for 3 h. Furthermore, gelsemine (4 mg/kg, administered at 6:30 AM) increased non-rapid eye movement (non-REM, NREM) sleep, decreased wakefulness, but did not affect REM sleep during the first 3 h in PSNL mice. Sleep architecture analysis showed that gelsemine decreased the mean duration of wakefulness and increased the total number of episodes of NREM sleep during the first 3 h after the dosing. Gelsemine (4 mg/kg) did not impair motor coordination in PSNL mice. Immunohistochemical study showed that PSNL increased c-Fos expression in the neurons of the anterior cingulate cortex, and gelsemine (4 mg/kg) decreased c-Fos expression by 58%. Gelsemine (4 mg/kg, administered at either 6:30 AM or 8:30 PM) did not produce hypnotic effect in normal mice. Pregabalin produced similar antinociceptive and hypnotic effects, but impaired motor coordination in PSNL mice. CONCLUSION: Gelsemine is an effective agent for treatment of both neuropathic pain and sleep disturbance in PSNL mice; anterior cingulate cortex might play a role in the hypnotic effects of gelsemine.

Excretion of berberine and its metabolites in oral administration in rats.

Berberine (BBR) has been confirmed to show extensive bioactivities for the treatments of diabetes and hypercholesterolemia in clinic. However, there are few pharmacokinetic studies to elucidate the excretions of BBR and its metabolites. Our research studied the excretions of BBR and its metabolites in rats after oral administration (200 mg/kg). Metabolites in bile, urine, and feces were detected by liquid chromatography coupled to ion trap time-of-flight mass spectrometry; meanwhile, a validated liquid chromatography coupled with tandem mass spectrometry method was developed for their quantifications. Sixteen metabolites, including 10 Phase I and six Phase II metabolites were identified and clarified after dosing in vivo. Total recovered rate of BBR was 22.83% (19.07% of prototype and 3.76% of its metabolites) with 9.2 × 10(-6) % in bile (24 h), 0.0939% in urine (48 h), and 22.74% in feces (48 h), respectively. 83% of BBR was excreted as thalifendine (M1) from bile, whereas thalifendine (M1) and berberrubine (M2) were the major metabolites occupying 78% of urine excretion. Most of BBR and its metabolites were found in feces containing 84% of prototype. In summary, we provided excretion profiles of BBR and its metabolites after oral administration in rats in vivo.