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Abstract Bruton's tyrosine kinase (BTK) plays a central and pivotal role in controlling the pathways involved in the pathobiology of cancer, rheumatoid arthritis (RA), and other autoimmune disorders. ZYBT1 is a potent, irreversible, specific BTK inhibitor that inhibits the ibrutinib‐resistant C481S BTK with nanomolar potency. ZYBT1 is found to be a promising molecule to treat both cancer and RA. In the present report we profiled the molecule for in‐vitro, in‐vivo activity, and pharmacokinetic properties. ZYBT1 inhibits BTK and C481S BTK with an IC50 of 1 nmol/L and 14 nmol/L, respectively, inhibits the growth of various leukemic cell lines with IC50 of 1 nmol/L to 15 μmol/L, blocks the phosphorylation of BTK and PLCγ2, and inhibits secretion of TNF‐α, IL‐8 and IL‐6. It has favorable pharmacokinetic properties suitable for using as an oral anti‐cancer and anti‐arthritic drug. In accordance with the in‐vitro properties, it demonstrated robust efficacy in murine models of collagen‐induced arthritis (CIA) and streptococcal cell wall (SCW) induced arthritis. In both models, ZYBT1 alone could suppress the progression of the diseases. It also reduced the growth of TMD8 xenograft tumor. The results suggested that ZYBT1 has high potential for treating RA, and cancer.

T3 (3,5,3′-triiodothyronine) has drawn relatively little attention in relation to cardiovascular (CVS) diseases. The present study was designed to evaluate the cardioprotective action of T3 in isoproterenol-(ISO-) induced cardiac toxicity. Female Wistar rats were exposed with ISO (100 mg/kg, body weight, subcutaneously) for 2 days at the interval of 24 h followed by T3 (3 μg/kg, body weight, orally) treatment for 3 days. Positive control rats received only ISO (100 mg/kg, body weight, subcutaneously) for 2 days at the interval of 24 hrs. Control group animals received normal saline as a vehicle. As expected, ISO-induced significant changes were observed in low-density lipoprotein, total cholesterol, ALT, CK-MB to TCK ratio, and prolongation of QT interval in electrocardiogram, which is toward normalization after T3 treatment. Lower heart weight, upregulation of cardiac myosin heavy chain alpha (MHC-α), and reduced inflammatory cell infiltration, myonecrosis, vacuolar changes, and a trend toward normal cardiac muscle fiber architecture in microscopic examination of cardiac tissue further support the cardioprotective effect of T3.