Lowering the Intraocular Pressure in Rats and Rabbits by Cordyceps cicadae Extract and Its Active Compounds

Cordyceps cicadae (CC), an entomogenous fungus that has been reported to have therapeutic glaucoma, is a major cause of blindness worldwide and is characterized by progressive retinal ganglion cell (RGC) death, mostly due to elevated intraocular pressure (TOP). Here, an ethanolic extract of C. cicadae mycelium (CCME), a traditional medicinal mushroom, was studied for its potential in lowering TOP in rat and rabbit models. Data showed that CCME could significantly (60.5%) reduce the TOP induced by microbead occlusion after 56 days of oral administration. The apoptosis of retinal ganglion cells (RGCs) in rats decreased by 77.2%. CCME was also shown to lower the TOP of normal and dextrose-infusion-induced rabbits within 60 min after oral feeding. There were dose effects, and the effect was repeatable. The active ingredient, N6-(2-hydroxyethyl)-adenosine (HEA), was also shown to alleviate 29.6% TOP at 0.2 mg/kg body weight in this rabbit model. CCME was confirmed with only minor inhibition in the phosphorylated myosin light chain 2 (pMLC2) pathway.

Automated summary

The ethanolic extract of Cordyceps cicadae mycelium (CCME) was found to lower intraocular pressure caused by glaucoma and reduce apoptosis of retinal ganglion cells. The active ingredient HEA also had the same effect in a rabbit model.