Activation of alpha-7 nicotinic acetylcholine receptor by tropisetron mitigates 3-nitropropionic acid-induced Huntington's disease in rats: Role of PI3K/Akt and JAK2/NF-κB signaling pathways.

Huntington's disease (HD) is an inheritable autosomal-dominant disorder that targets mainly the striatum. 3-Nitropropionic acid (3-NP) induces obvious deleterious behavioral, neurochemical, and histological effects similar to the symptoms of HD. Our study aimed to examine the neuroprotective activity of tropisetron, an alpha-7 neuronal nicotinic acetylcholine receptor (α-7nAChR) agonist, against neurotoxic events associated with 3-NP-induced HD in rats. Forty-eight rats were randomly allocated into four groups. Group I received normal saline, while Groups II, III and IV received 3-NP for 2 weeks. In addition, Group III and IV were treated with tropisetron 1 h after 3-NP administration. Meanwhile, Group IV received methyllycaconitine (MLA), an α-7nAChR antagonist, 30 min before tropisetron administration. Treatment with tropisetron improved motor deficits as confirmed by the behavioral tests and restored normal histopathological features of the striatum. Moreover, tropisetron showed an anti-oxidant activity via increasing the activities of SDH and HO-1 as well as Nrf2 expression along with reducing MDA level. Tropisetron also markedly upregulated the protein expression of p-PI3K and p-Akt which in turn hampered JAK2/NF-κB inflammatory cascade. In addition, tropisetron showed an anti-apoptotic activity through boosting the expression of Bcl-2 and reducing Bax expression and caspase-3 level. Interestingly, all the aforementioned effects of tropisetron were blocked by pre-administration of MLA, which confirms that such neuroprotective effects are mediated via activating of α-7nAChR. In conclusion, tropisetron showed a neuroprotective activity against 3-NP-induced HD via activating PI3K/Akt signaling and suppressing JAK2/NF-κB inflammatory axis. Thus, repositioning of tropisetron could represent a promising therapeutic strategy in management of HD.

[Heat-sensitive moxibustion combined with tropisetron hydrochloride for chemotherapy-induced nausea and vomiting: a randomized controlled trial].

OBJECTIVE: To compare the clinical efficacy of heat-sensitive moxibustion combined with tropisetron hydrochloride and tropisetron hydrochloride alone in the treatment of chemotherapy-induced nausea and vomiting (CINV). METHODS: Sixty CINV patients were randomly divided into an observation group and a control group, 30 cases in each group.The control group was treated with tropisetron hydrochloride. On the basis of the treatment in the control group, heat-sensitive acupoints were explored at Zhongwan (CV 12), Shenque (CV 8), Qihai (CV 6), Guanyuan (CV 4), Shangwan (CV 13), Xiawan (CV 10), Jianli (CV 11) and bilateral Zusanli (ST 36), Neiguan (PC 6), Tianshu (ST 25), Liangmen (ST 21) areas in the observation group，and heat-sensitive moxibustion was applied at heat-sensitive acupoints. The treatment started from the day of chemotherapy in both groups, once a day for 7 days. The occurrence and severity of nausea and vomiting after chemotherapy were recorded after each treatment on the 1st to 7th days of chemotherapy in the two groups, the complete remission rate was evaluated. The KPS score, quality of life scale score before and after treatment and incidence of myelosuppression were compared between the two groups. RESULTS: On the 2nd to 4th days of chemotherapy, the incidence and severity of nausea and vomiting in the observation group were lower than those in the control group (P<0.05), the complete remission rates of nausea and vomiting were higher than those in the control group (P<0.05). After treatment, the KPS score in the observation group was higher than those before treatment and in the control group (P<0.05). After treatment, the scores of emotional function and overall health status in the observation group were higher than those before treatment and in the control group (P<0.05), the scores of fatigue, pain, insomnia, loss of appetite and diarrhea were lower than those before treatment and in the control group (P<0.05). The incidence of myelosuppression in the observation group was 20.0% (6/30), which was lower than 46.7% (14/30) in the control group (P<0.05). CONCLUSION: Heat-sensitive moxibustion combined with tropisetron hydrochloride can effectively reduce nausea and vomiting after chemotherapy in patients with malignant tumor, improve the quality of life, relieve the myelosuppression caused by chemotherapy drugs.