Oxidative stress and potential applications of free radical scavengers in glaucoma

Figures & data

Figure 1. The structures of the eye and formation of aqueous humor.

Figure 2. Intrinsic and extrinsic pathways for apoptosis. The extrinsic pathway can be induced by members of the TNF family receptors such as tumor necrosis factor receptor (TNFR) and FAS. The intrinsic pathway can be activated by release of cytochrome c from mitochondria. In the cytosol, cytochrome c binds and activates Apaf-1, allowing it to bind and activate caspase-9. Caspase-9 and -8 activate caspase-3. Apaf-1, apoptotic protease-activating factor-1; Cyt c, cytochrome c; JNK, c-Jun N-terminal kinase; p38 MAPK, p38 mitogen-activated protein kinase; FASL, FAS Ligand.

Table 1. Potential applications of free radical scavengers in glaucomatous neurodegeneration

Model	Treatment	Effect	REF.
Experimental rat model of elevated intraocular pressure	Astaxanthin	Reduced oxidant-induced protein oxidation, lipid peroxidation and apoptotic cell death	82
Primary porcine trabecular meshwork cells were submitted to chronic treatment with resveratrol every 3 days for 15 days and then incubated under oxidative stress conditions (40% oxygen)	Resveratrol	The level of endogenous reactive oxygen species was significantly decreased and the induction of mRNA expression of the inflammatory markers interleukin-1α, -6, -8 and endothelialleukocyte adhesion molecule after chronic oxidative stress was significantly inhibited by chronic treatment with resveratrol. The accumulation of carbonylated proteins induced by oxidative stress was significantly lower in resveratrol-treated samples. Resveratrol-treated cells showed protection against apoptosis after acute oxidative stress	86
Patients with glaucoma	Ginkgo biloba extract	Ginkgo biloba extract significantly increased end diastolic velocity in the opthalmic artery	87
Patients with normal tension glaucoma	Ginkgo biloba extract	A significant improvement in visual fields was recorded after Ginkgo biloba extract treatment	88
Patients with primary open-angle glaucoma	Dorzolamide	Oxidative activity, superoxide dismutase activity and total antioxidant status were significantly decreased after dorzolamide adminstration	95
Oxidative stress–induced primary cell cultures of human trabecular meshwork changes in primary open-angle glaucoma	Prostaglandin analogues (bimatoprost, travoprost, and latanoprost)	The typical glaucomatous trabecular meshwork changes, which were characterized by cell loss, increased accumulation of extracellular matrix and cellular senescence in vitro were reduced with pretreatment with prostaglandin analogs	96
Glaucomatous DBA/2J mice	Galavit (monosodium luminal)	Galavit prevents decreases in glutamate, glutathione, and glutamine synthetase in the retinas of glaucomatous DBA/2J mice	99
Experimental rat model of elevated intraocular pressure	Nitric oxide synthase inhibition and Mn (III) meso-tetrakis (N-n-hexylpyridinium-2-yl) porphyrin (MnTnHex-2-PyP^5+)	Latencies of all visual evoked potentials components (P(1), N(1), P(2), N(2), P(3)) were significantly prolonged in elevated intraocular pressure and returned to control levels following treatment. Retinal protein nitration, NOS-2 expression and nitrite/nitrate levels were significantly decreased after treatment	100

Figure 3. Scheme of retinal oxidative damage.

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