1) M-cholinomimetics of plant origin for the treatment of glaucoma

The main plant-derived M-cholinomimetic used in the treatment of glaucoma is pilocarpine.

Pilocarpine is a natural alkaloid obtained from plants of the genus Pilocarpus.

Mechanism of action: Pilocarpine directly stimulates muscarinic cholinergic receptors (primarily M3), causing contraction of the iris sphincter and ciliary muscles. This produces miosis (pupil constriction) and increases aqueous humor outflow through the trabecular meshwork, reducing intraocular pressure.

Clinical use: Pilocarpine is used in selected cases of open-angle glaucoma and, after initial pressure reduction, in certain cases of angle-closure glaucoma. It is not generally a first-line treatment for chronic glaucoma.

Adverse effects: Blurred vision, brow pain, headache, reduced night vision, and rarely retinal detachment.