Cell experiment:

Briefly, MCF-7 cells (1×104 cells/well) are seeded in 96-well plates and treated with different concentrations of dehydrocorydaline (0-200 μM) for 24 h. The cell viability is determined. To explore the role of caspase-8 in dehydrocorydaline induced cytotoxicity, a caspase-8 inhibitor Z-IETD-FMK (10 μM) is co-incubated with 200 μM dehydrocorydaline.

Animal experiment:

Briefly, the mice are placed individually in glass beakers and are allowed to acclimate for 30 min before the test. The vehicle or Dehydrocorydaline (3.6, 6 or 10 mg/kg) are injected (10 ml/kg, i.p.) 15 min prior to the formalin injection. Morphine (10 mg/kg) or diclofenac sodium (20 mg/kg) are injected 15 and 30 min, respectively, prior to the formalin injection as positive controls. Then, 25 μL of a 5% formalin solution is injected into the plantar surface of the right hind paw of each mouse. Immediately after the formalin injection, the mice are placed individually in the beakers, and a mirror is placed under the beaker to allow clear observation of the paws of the animals. The time that the animals spent on biting/licking the injected paw is measured with a stopwatch every 5 min and considered as indication of nociception.

Dehydrocorydaline (13-Methylpalmatine) is an alkaloid isolated from traditional Chinese herb Corydalis yanhusuo W.T. Wang. Dehydrocorydaline regulates protein expression of Bax, Bcl-2; activates caspase-7, caspase-8, and inactivates PARP.

Dehydrocorydaline (0-200 μM) treatment significantly inhibits the growth of MCF-7 cells in a dose-dependent manner. The cell viability is decreased by approximate 40% after 24 h of 200 μM Dehydrocorydaline[1]. Dehydrocorydaline (0-200 μM)dose-dependently increases Bax protein expression and decreases Bcl-2 protein expression[1]. Dehydrocorydaline (0-200 μM)induces activation of caspase-7,-8 and the cleavage of PARP without affecting caspase-9[1].

Dehydrocorydaline manifests a low acute toxicity with an LD50 of about 277.5±19.0 mg/kg body weight in mice following oral administration and 21.1±1.4 mg/kg for intraperitoneal injection[2].

References:
[1]. Xu Z, et al. Dehydrocorydaline inhibits breast cancer cells proliferation by inducing apoptosis in MCF-7 cells. Am J Chin Med. 2012;40(1):177-85.
[2]. Yin ZY, et al. Antinociceptive effects of dehydrocorydaline in mouse models of inflammatory pain involve the opioid receptor and inflammatory cytokines. Sci Rep. 2016 Jun 7;6:27129.