IC50: 8.55 μM for BACE1

Epiberberine is a natural bioactive protoberberine alkaloid from Coptidis Rhizoma. Coptidis Rhizoma and its isolated alkaloids are found to possess a variety of activities including antioxidant and neuroprotective activities.

In vitro: Among six protoberberine alkaloids from Coptidis Rhizoma exhibiting predominant cholinesterases (ChEs) inhibitory effects, only epiberberine and groenlandicine exerted good, non-competitive BACE1 inhibitory activities with IC50 values of 8.55 and 19.68 μM, respectively, as compared with a positive control, quercetin. In addition, epiberberine also showed potent AChE and BChE inhibitory effects [1].

In vivo: In rats, epiberberine could parallelly shift the dose-response curves of Clo and BHT-920 to the normal without changing the maximal effect. The pA2 values of epiberberine were found to be 6.5 and 6.8 respectively. Epiberberine was also found to antagonize the contractile response of isolated rabbit aortic strips to Meth competitively. Epiberberine given to anesthetized rats intravenously was shown to be able to temporarily decrease blood pressure and gradually accelerate heart rate. The heart rate persistently and constantly increased in spite of blood pressure restoration. These results suggested epiberberine possessed poor α-blocking action [2].

Clinical trial: N/A

References:
[1] Jung HA,Min BS,Yokozawa T,Lee JH,Kim YS,Choi JS. Anti-Alzheimer and antioxidant activities of Coptidis Rhizoma alkaloids. Biol Pharm Bull.2009 Aug;32(8):1433-8.
[2] Wang JL,Fang DC.  Effect of epiberberine on alpha-adrenoceptors. Yao Xue Xue Bao.1990;25(4):289-92.