Yohimbine

Yohimbine is a natural, orally active α2-adrenergic receptor antagonist. Yohimbine can promote norepinephrine release and dilate peripheral blood vessels by blocking α2-adrenergic receptors, while also increasing blood flow to the corpus cavernosum to facilitate erection. Yohimbine can be used in research related to erectile dysfunction, pain, and antiepileptic effects^[1-4].

In vitro, Yohimbine (10-100μM) was used to treat KB-ChR-8-5 cells for 24 hours. Yohimbine significantly induced apoptosis, increased reactive oxygen species generation, and reduced mitochondrial membrane potential^[5]. Yohimbine (10-100μM) was used to treat MOVAS-1 cells for 24 hours. Yohimbine significantly inhibited cell proliferation and migration, downregulated MMP-2 and MMP-9 expression, and caused cell cycle arrest in the G0/G1 phase^[6].

In vivo, Yohimbine (25μg; subcutaneous injection) was administered to male Balb/c mice 4 hours before LPS (100μg; intraperitoneal injection) treatment. Yohimbine significantly improved gastric emptying delay and gastrointestinal transit inhibition in endotoxemic mice and downregulated LPS-induced iNOS expression in the small intestine^[7]. Yohimbine (10mM; 10μL) was locally injected into the left TMJ region once a week for 4 weeks in an 8-week-old male BalB/C mouse model of temporomandibular joint osteoarthritis. Yohimbine significantly improved cartilage destruction in the temporomandibular joint^[8].

References:
[1] Docherty JR. Yohimbine antagonises α1A- and α1D-adrenoceptor mediated components in addition to the α2A-adrenoceptor component to pressor responses in the pithed rat. Eur J Pharmacol. 2012 Mar 15;679(1-3):90-4.
[2] Damase-Michel C, Tran MA, Llau ME, et al. The effect of yohimbine on sympathetic responsiveness in essential hypertension. Eur J Clin Pharmacol. 1993;44(2):199-201.
[3] Musso NR, Vergassola C, Pende A, et al. Yohimbine effects on blood pressure and plasma catecholamines in human hypertension. Am J Hypertens. 1995 Jun;8(6):565-71.
[4] Sáiz J, Pazos A, Del Olmo E, Sáiz V, et al. Yohimbine-induced alterations in alpha(2)-adrenoceptors in kidney regions of the spontaneously hypertensive rats: an autoradiographic analysis. Pharmacol Rep. 2008 May-Jun;60(3):391-8.
[5] Chiu CW, Hsieh CY, Yang CH, et al. Yohimbine, an α2-Adrenoceptor Antagonist, Suppresses PDGF-BB-Stimulated Vascular Smooth Muscle Cell Proliferation by Downregulating the PLCγ1 Signaling Pathway. Int J Mol Sci. 2022 Jul 21;23(14):8049.
[6] Jabir NR, Khan MS, Alafaleq NO, et al. Anticancer potential of yohimbine in drug-resistant oral cancer KB-ChR-8-5 cells. Mol Biol Rep. 2022 Oct;49(10):9565-9573.
[7] Hamano N, Inada T, Iwata R, et al. The alpha2-adrenergic receptor antagonist yohimbine improves endotoxin-induced inhibition of gastrointestinal motility in mice. Br J Anaesth. 2007 Apr;98(4):484-90.
[8] Ou F, Huang Y, Sun J, et al. Yohimbine Ameliorates Temporomandibular Joint Chondrocyte Inflammation with Suppression of NF-κB Pathway. Inflammation. 2021 Feb;44(1):80-90.

Yohimbine是一种天然的、具有口服活性的α2-肾上腺素能受体拮抗剂。Yohimbine可通过阻断α2-肾上腺素能受体来促进去甲肾上腺素释放和扩张外周血管。Yohimbine通过增加阴茎海绵体血流量以促进勃起。Yohimbine可用于勃起功能障碍、疼痛和抗癫痫的相关研究^[1-4]。

在体外，Yohimbine（10-100μM）处理KB-ChR-8-5细胞24小时。Yohimbine显著诱导细胞凋亡，同时增加活性氧生成并降低线粒体膜电位^[5]。Yohimbine（10-100μM）处理MOVAS-1细胞24小时。Yohimbine显著抑制细胞增殖和迁移，同时下调MMP-2和MMP-9表达并引起G0/G1期细胞周期停滞^[6]。

在体内，在LPS（100μg；腹腔注射）处理前4小时，Yohimbine（25μg；皮下注射）处理雄性Balb/c小鼠。Yohimbine显著改善了内毒素血症小鼠的胃排空延迟和胃肠道传输抑制，并下调了LPS诱导的小肠iNOS表达^[7]。Yohimbine（10mM；10μL）每周一次局部注射到左侧TMJ区域，用于处理8周龄雄性BalB/C小鼠的颞下颌关节骨关节炎模型，持续4周。Yohimbine显著改善了颞下颌关节的软骨破坏^[8]。