Scientists may have found an effective all-natural treatment for glaucoma, according to new research presented today at the 2015 Annual Meeting of the Association for Research in Vision and Ophthalmology, in Denver, Colo.

In a study of adult mice, baicalein—a non-toxic, natural flavonoid derived from the root of Scutellaria baicalensis—reduced intraocular pressure (IOP) by improving the rate at which fluid drained from the eye.

"Baicalein showed a consistent ocular hypotensive response and was able to reduce IOP during both daytime and nighttime in normal animals," says Hoi-lam Li, of the Hong Kong Polytechnic University School of Optometry in Hong Kong. "It remains to be determined whether baicalein has any IOP-lowering effect in ocular hypertensive rats."

Li and his colleagues applied 10 mM of topical baicalein to the treatment eye twice, separated by 10-minute intervals, while using phosphate-buffered saline as a control in the fellow eye. They saw a significant reduction in IOP within 6 hours of drug treatment as well as significantly enhanced outflow facility.

Elevated IOP is widely recognized as an important risk factor for glaucoma and perhaps the only treatable risk factor. Like other chronic diseases, glaucoma therapy requires lifelong adherence and patient compliance to achieve positive treatment outcomes.

"Given the fact that many anti-glaucoma agents have substantial contraindications or long-term side effects, a potent, long-lasting drug with fewer side effects would be highly desirable. Baicalein is a natural compound that has no reported toxicity," Li says. "It appears to be a good candidate for glaucoma therapy in view of its effects on both aqueous humor secretion and outflow facility."

The team is now trying to figure out the mechanistic actions of baicalein in regulating drainage. "Our goal is to better understand how baicalein affects aqueous humor secretion and outflow facility, and their relationship to IOP," Li says.

He and his colleagues have adopted an integrated approach to study the effects of baicalein on aqueous humor inflow and outflow using isolated single cells, excised ciliary epithelium, arterially-perfused eyes, and whole-eye perfusion systems.

"The results of these studies can provide insight into the physiological mechanism for regulating aqueous humor dynamics and thereby IOP," Li says. "More importantly, the outcome of these studies may have a direct translational biomedical significance for the future development of novel anti-glaucoma agents."


Li HL, Ashpole NE, Navarro ID, Lam TC, Chan HL, To CH, et al. Baicalein lowers intraocular pressure and increases outflow facility in mouse eye. 2015 Annual Meeting of the Association for Research in Vision and Ophthalmology, Denver, Colo. May 6, 2015; 4853-A0006.