Conessine

Conessine is a steroidal alkaloid that has been found in H. antidysenterica and has diverse biological activities.^1,2,3,4,5 It is active against a variety of Gram-positive and Gram-negative bacteria, including B. subtilis, S. aureus, M. luteus, and E. coli (MICs = 15.6-1,000 µg/disc in agar diffusion assays), the amoeba E. histolytica, as well as P. falciparum schizonts (IC₅₀ = 1.9 µg/ml).^1,2,3 Conessine inhibits replication of the coronaviruses HCoV-OC43, HCoV-NL63, MERS-CoV, and MHV-A59 in infected cells with EC₅₀ values of 2.34, 10.75, 4.98, and 11.46 µM, respectively.⁴ It is also a histamine H₃ receptor antagonist (K_is = 5.37 and 12.3 nM for the human and rat receptors, respectively).⁵ Conessine (10 mg/kg) reduces parasitemia in a mouse model of P. berghei infection.³

WARNING This product is not for human or veterinary use.

1. Siddiqui, B.S., Ali, S.T., Rizwani, G.H., et al. Antimicrobial activity of the methanolic bark extract of Holarrhena pubescens (Buch. Ham), its fractions and the pure compound conessine. Nat. Prod. Res. 26(11), 987-992 (2012).

2. Jayaswal, S.B. Amoebicidal activity of steroidal alkaloids of Wrightia tomentosa in vitro. Indian J. Pharm. 38(4), 112-113 (1976).

3. Dua, V.K., Verma, G., Singh, B., et al. Anti-malarial property of steroidal alkaloid conessine isolated from the bark of Holarrhena antidysenterica. Malar. J. 12, 194 (2013).

4. Shen, L., Niu, J., Wang, C., et al. High-throughput screening and identification of potent broad-spectrum inhibitors of coronaviruses. J. Virol. 93(12), e00023-00019 (2019).

5. Zhao, C., Sun, M., Bennani, Y.L., et al. The alkaloid conessine and analogues as potent histamine H3 receptor antagonists. J. Med. Chem. 51(17), 5423-5430 (2008).