21655-84-5

Harmane hydrochloride is a benzodiazepine receptor inhibitor (IC50=7 μM), with IC50 values for mACh, Opioid Receptor, MAO-A/B, and α2-adrenergic receptor of 24 μM, 2.8 μM, 0.5 μM, 5 μM, and 18 μM, respectively. Harmane hydrochloride inhibits the I1 imidazoline receptor (IC50 = 30 nM) to reduce blood pressure and has antidepressant, anti-anxiety, anticonvulsant, and analgesic effects. Harmane hydrochloride inhibits dopamine biosynthesis by decreasing tyrosine hydroxylase (TH) activity and enhancing L-DOPA-induced cytotoxicity in PC12 cells. Additionally, Harmane hydrochloride can increase the mutagenic effect induced by 2-acetylaminofluorene (AAF)[1][2][3][4][5][6].

hMAO-A: 0.5 μM (IC₅₀); MAO-B: 5 μM (IC₅₀); α2-adrenergic receptor: 18 μM (IC₅₀); I1-Imidazoline receptor: 30 nM (IC₅₀); nAChR: 24 μM (IC₅₀); benzodiazepine receptor: 7 nM (IC₅₀); Opioid receptor: 2.8 μM (IC₅₀); Loperamide: 163 μM (IC₅₀); Serotonin: 101 μM (IC₅₀)

[1] W E Müller, et al. On the neuropharmacology of harmane and other beta-carbolines. Pharmacol Biochem Behav. 1981 May;14(5):693-9. DOI:10.1016/0091-3057(81)90133-7
[2] Musgrave IF, et, al. Harmane produces hypotension following microinjection into the RVLM: possible role of I(1)-imidazoline receptors. Br J Pharmacol. 2000 Mar;129(6):1057-9. DOI:10.1038/sj.bjp.0703142
[3] Glover V, et, al. β-Carbolines as selective monoamine oxidase inhibitors:In vivo implications DOI:10.1007/BF01254930
[4] https://pubmed.ncbi.nlm.nih.gov/345280/
[5] E D Louis, et al. Harmane induces anxiolysis and antidepressant-like effects in rats. Ann N Y Acad Sci. 2005 Aug 9;65(3):391-6. DOI:10.1196/annals.1304.024
[6] Yoo Jung Yang, et al. Effects of harman and norharman on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells. Eur J Pharmacol. 2008 Jun 10;587(1-3):57-64. DOI:10.1016/j.ejphar.2008.03.050