Anti-Inflammatory and Antioxidative Stress Effects of Oryzanol in Glaucomatous Rabbits

Abstract

Purpose. γ-Oryzanol works by anti-inflammatory and radical scavenging activity as a neuroprotective, anticancer, antiulcer, and immunosuppressive agent. The present study was conducted to investigate effect of oryzanol in acute and chronic experimental glaucoma in rabbits. Methods. Effect of oryzanol was evaluated in 5% dextrose induced acute model of ocular hypertension in rabbit eye. Chronic model of glaucoma was induced with subconjunctival injection of 5% of 0.3 ml phenol. Treatment with oryzanol was given for next two weeks after induction of glaucoma. From anterior chamber of rabbit eye aqueous humor was collected to assess various oxidative stress parameters like malondialdehyde, superoxide dismutase, glutathione peroxidase, catalase, nitric oxide, and inflammatory parameters like TNF-α and IL-6. Structural damage in eye was examined by histopathological studies. Results. In acute model of ocular hypertension oryzanol did not alter raised intraocular pressure. In chronic model of glaucoma oryzanol exhibited significant reduction in oxidative stress followed by reduction in intraocular pressure. Oryzanol treatment reduced level of TNF-α and IL-6. Histopathological studies revealed decreased structural damage of trabecular meshwork, lamina cribrosa, and retina with oryzanol treatment. Conclusions. Oryzanol showed protective effect against glaucoma by its antioxidative stress and anti-inflammatory property. Treatment with oryzanol can reduce optic nerve damage.

Figure 1

Effect of OZ on IOP. (a) Acute glaucomatous rabbits. (b) Chronic glaucomatous rabbits. Data are expressed as mean ± SEM. (n = 6). Values are statistically significant at ^∗p < 0.05 versus normal control; ^#p < 0.05 versus chronic control.

Figure 2

Effect of OZ on total protein concentration in AH of chronic glaucomatous rabbits. Data are expressed as mean ± SEM. (n = 6). Values are statistically significant at ^∗p < 0.05 versus normal control; ^#p < 0.05 versus chronic control.

Figure 3

Effect of OZ on various oxidative stress markers. (a) Malondialdehyde (MDA) level, (b) nitrite (NO) level, (c) superoxide dismutase (SOD) level, (d) catalase (CAT) level, and (e) glutathione peroxidase GPx level. Data are expressed as mean ± SEM. (n = 6). Values are statistically significant at ^∗p < 0.05 versus normal control; ^#p < 0.05 versus chronic control.

Figure 4

Effect of OZ on inflammatory mediators. (a) TNF-α level and (b) IL-6 level. Data are expressed as mean ± SEM. (n = 6). Values are statistically significant at ^∗p < 0.05 versus normal control; ^#p < 0.05 versus chronic control.

Figure 5

Histopathological sections of various tissues of rabbit's eye. Trabecular meshwork of (a) normal control, (b) chronic control, and (c) OZ treatment; optic nerve head (lamina cribrosa) of (d) normal control, (e) chronic control, and (f) OZ treatment; retina of (g) normal control, (h) chronic control, and (i) OZ treatment animals. (Magnification: 250x, scale: 150 μm).