The study evaluates the effectiveness of 3-arylidene-2-oxindole in reducing intraocular pressure in old animals

Aim: To study the potential of the melatonin isostere, the compound K-165, to reduce intraocular pressure in old animals with elevated ophthalmotonus, and to evaluate its local irritant effect and cytotoxic properties. Materials and methods: The study was conducted in old rats over two years of age with intraocular pressure (IOP) above 16 mmHg. The level of ophthalmotonus was measured using a portable contact tonometer Tonovet ICare (Finland). The presence of IOP-lowering activity of the tested substance was assessed by the maximum reduction in ophthalmotonus compared to baseline pressure levels. The assessment of local irritant effects was conducted using a three-point scale after applying the substance to the eye tissues of the laboratory animal. Cytotoxicity was studied on HepG2 cell lines (human hepatocellular carcinoma) (CLS Cell Lines Service). Result: The compound K-165 reduces the level of intraocular pressure (IOP) in old animals, outperforming melatonin comparator. K-165 decreases ophthalmotonus by 21 % from baseline by the third hour and does not have a local irritating effect on the eye conjunctiva. It is shown that the mean cytotoxic concentration exceeds 100 μM for the compound K-165 (R² = 0.9), indicating low cytotoxicity. Conclusion: The compound K-165 significantly reduces IOP, does not have a local irritating effect, and is classified as a compound with low cytotoxicity.