Cinnarizine (Stugeron) is a piperazine derivative having histamine H1-receptor and calcium-channel blocking activity with vasodilating and antiemetic properties but it induces PARKINSONIAN DISORDERS.

Cinnarizine inhibits melanogenesis in B16 cells by a dose-dependent manner at the non-cytotoxic concentrations and is a histamine receptor antagonists[3].

Cinnarizine has anticonvulsive properties in rats and mice. It could provide a direct neuroprotective effect against the damaging influx of calcium and also prevent neuronal damage as a result of MES- and PTZ-induced seizures[2]. Cinnarizine induces behavioural changes such as alopecia, bucolingual dyskinesia and reduction of motor activity in female parkin knock out (PK-KO) mice but not in wild-type (WT) controls.PK-KO mice have high striatal dopamine levels and increased dopamine metabolism in spite of low reduced tyrosine hydroxylase protein. Cinnarizine, which blocks dopamine receptors and increases dopamine release, further increased dopamine metabolism[3]. Its half-life is 4 hours.

MTT assay is performed to examine the viability of cells. Afterwards, the cells are incubated with the samples for 48 h, the culture medium is removed and replaced with 1 mg/mL MTT solution dissolved in phosphate-buffered saline (PBS) and incubated for an additional 2 h. The MTT solution is then removed and DMSO was added, following which the absorbance of the dissolved formazan crystals is determined at 570 nm by a spectrophotometer.(Only for Reference)