Levobunolol  (Synonyms: l-Bunolol)

Levobunolol (l-Bunolol) is a non-selective β-adrenergic antagonist and vasodilator. By blocking calcium ion influx and reducing the sensitivity of vascular smooth muscle to calcium, Levobunolol effectively dilates the ciliary arteries and increases ocular blood flow, so it is widely used in research on glaucoma and ocular hypertension. Levobunolol inhibits the β-receptor signaling pathway and the expression of related proliferation markers (such as CK3, CK14, CK19, Ki67) in corneal cells. In rabbit models, Levobunolol not only does not inhibit corneal epithelial regeneration, but also accelerates the healing of mechanical injury without adverse effects. Levobunolol also inhibits histamine-induced vasoconstriction and intracellular calcium elevation, exhibiting unique vascular regulatory activity. Levobunolol protects ocular blood flow and promotes corneal repair^[1][2][3].

Levobunolol (50 μM; 24 h) significantly inhibits the migration and proliferation of corneal epithelial stem/progenitor cells in TKE2 mice^[1].
Levobunolol (50 μM; 7 d) reduces the clone size of corneal epithelial stem/progenitor cells in TKE2 mice without affecting the number of clones^[1].
Levobunolol (10 μM-0.3 mM; 10-30 min) induces concentration-dependent relaxation in isolated rabbit ciliary arterial rings precontracted by various stimuli, with the strongest inhibitory potency against histamine-induced contraction (EC₅₀=20.7 μM). This relaxation effect is independent of endothelial nitric oxide synthase activity and vascular endothelium^[3].
Levobunolol (10 μM) does not bind to recombinant human histamine H₁ receptors, but exhibits partial inhibitory effects on the binding of [³H]tiotidine to histamine H₂ receptors^[3].
Levobunolol (3 μM) significantly inhibits histamine-induced elevation of [Ca²⁺]_i in human aortic smooth muscle cells cultured in calcium-containing medium, but exerts no effect on this response in calcium-free medium^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Levobunolol (5 mg/mL; topical; 4 times daily) marginally impairs corneal epithelial wound healing and reduces expression of corneal differentiation and stem cell markers in Mus musculus with 2.5 mm central corneal epithelial scrapes^[1].
Levobunolol (0.25%; topical; every 12 hours) accelerates rabbit corneal epithelial wound healing, with a mean wound radius of 1.58 mm at 50% closure, a healing rate of 5.00 μm/h, and projected closure before 60 hours^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

291.39

C₁₇H₂₅NO₃

47141-42-4

O=C1CCCC2=C1C=CC=C2OC[C@@H](O)CNC(C)(C)C

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• [1]. Yuan X, et al. β-blocker eye drops affect ocular surface through β2 adrenoceptor of corneal limbal stem cells[J]. BMC ophthalmology, 2021, 21(1): 419.

  [2]. Reidy J J, et al. Effect of topical beta blockers on corneal epithelial wound healing in the rabbit[J]. British journal of ophthalmology, 1994, 78(5): 377-380.

  [3]. Dong Y, et al. Vasodilatory mechanism of levobunolol on vascular smooth muscle cells. Exp Eye Res. 2007;84(6):1039-1046.  [Content Brief]