Ocular non-P450 oxidative, reductive, hydrolytic, and conjugative drug metabolizing enzymes

Abstract

Metabolism in the eye for any species, laboratory animals or human, is gaining rapid interest as pharmaceutical scientists aim to treat a wide range of so-called incurable ocular diseases. Over a period of decades, reports of metabolic activity toward various drugs and biochemical markers have emerged in select ocular tissues of animals and humans. Ocular cytochrome P450 (P450) enzymes and transporters have been recently reviewed. However, there is a dearth of collated information on non-P450 drug metabolizing enzymes in eyes of various preclinical species and humans in health and disease. In an effort to complement ocular P450s and transporters, which have been well reviewed in the literature, this review is aimed at presenting collective information on non-P450 oxidative, hydrolytic, and conjugative ocular drug metabolizing enzymes. Herein, we also present a list of xenobiotics or drugs that have been reported to be metabolized in the eye.

Keywords:

• Ocular metabolism
• drug metabolizing enzymes
• eye
• ocular disposition
• ophthalmic barriers
• ophthalmic drugs
• extrahepatic metabolism

Acknowledgements

The authors thank Bindi Sohal, Stephen A. Martin, Valerie M. Kramlinger, Mithat Gunduz, and Amanda L. Cirello for valuable discussions on application of ocular metabolism and for providing a perspective on extrahepatic metabolism and drug metabolizing enzymes.

Disclosure statement

No potential conflict of interest was reported by the authors.