Cimetidine (SKF-92334) hydrochloride is an orally active inverse histamine H2 receptor antagonist with a Ki of 0.6 μM, demonstrating anti-cancer and anti-inflammatory activity, and is a gastric acid reducer useful in the research of duodenal and gastric ulcers [1] [2] [5].

Cimetidine (SKF-92334) hydrochloride, distinguished as a partial H2R agonist, exhibits a unique pharmacological profile compared to ranitidine and famotidine, which may underlie its anticancer effects on gastrointestinal malignancies [1]. In ovarian cancer cells expressing high OCT2 mRNA levels (IGROV-1 cells), cimetidine hydrochloride does not affect cisplatin's uptake or cytotoxicity [3]. Additionally, it does not influence the proliferation, survival, migration, or invasion of 3LL cells. However, cimetidine hydrochloride can counteract MDSC-mediated T-cell suppression and enhance IFN-γ production [4]. Its mechanism includes the suppression of NCAM gene expression through inhibiting NF-kappaB nuclear translocation, a key activator of NCAM [5].

Cimetidine (SKF-92334) hydrochloride effectively diminishes the accumulation of CD11b(+)Gr-1(+) myeloid derived-suppressive cells (MDSC) in the spleen, blood, and tumor tissues of mice with tumors [4]. Additionally, this compound positively influences periodontal disease in rats by lowering the RANKL/OPG ratio in gingival connective tissue and mitigating alveolar bone resorption [6].