Timolol hemimaleate ((S)-L-714,465; MK 950), a β-blocker, is formulated for both systemic and topical use. It is commonly applied topically to decrease intraocular pressure in cases of open-angle glaucoma and ocular hypertension. Additionally, it is utilized in research for the treatment of infantile hemangiomas, hypertension, myocardial infarction, migraine prophylaxis, and atrial fibrillation. Moreover, Timolol has been recognized for its cardioprotective effects [1] [2].

Timolol hemimaleate significantly prevents increased lipid peroxidation in the hearts of diabetic rats, induces a balanced ratio between oxidative stress and antioxidant defense, and provides important cardioprotection against diabetes-induced ERS and associated apoptotic effects [3].

Timolol hemimaleate exhibits cardioprotective effects in diabetic rats by inhibiting the ERS response [3]. Animal model: 3-month-old male Wistar rats [3]. Dosage: 5 mg/kg. Administration: 5 mg/kg daily for 12 weeks. Result: Demonstrated cardioprotective effects.