Protective Effects of Vitamin E Forms (Alpha-tocopherol, Gamma-tocopherol and d-alpha-tocopherol Polyethylene Glycol 1000 Succinate) on Retinal Edema During Ischemia–reperfusion Injury in the Guinea Pig Retina

Aydemir, Orhan; Çelebi, Serdal; Yılmaz, Turgut; Yekeler, Hayrettin; Kükner, Aysel

doi:10.1007/s10792-005-2034-z

Cited by 19 publications

(15 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Aqueous solubility of the molecule is an important determinant for its transport across sclera but also for its ability to evade the conjunctival blood and lymph vesselmediated washout (44). Scleral aqueous pore diameter varies between 20 and 80 nm (38), which facilitates the diffusion of small hydrophilic molecules.…”

Section: In Vivo Posterior Ocular Tissue Rapamycin Distribution Studiesmentioning

confidence: 99%

Nanomicellar Topical Aqueous Drop Formulation of Rapamycin for Back-of-the-Eye Delivery

et al. 2014

View full text Add to dashboard Cite

Abstract. The objective of this study was to develop a clear, aqueous rapamycin-loaded mixed nanomicellar formulations (MNFs) for the back-of-the-eye delivery. MNF of rapamycin (0.2%) was prepared with vitamin E tocopherol polyethylene glycol succinate (TPGS) (Vit E TPGS) and octoxynol-40 (Oc-40) as polymeric matrix. MNF was characterized by various parameters such as size, charge, shape, and viscosity. Proton nuclear magnetic resonance ( 1 H NMR) was used to identify unentrapped rapamycin in MNF. Cytotoxicity was evaluated in human retinal pigment epithelial (D407) and rabbit primary corneal epithelial cells (rPCECs). In vivo posterior ocular rapamycin distribution studies were conducted in male New Zealand white rabbits. The optimized MNF has excellent rapamycin entrapment and loading efficiency. The average size of MNF was 10.98±0.089 and 10.84±0.11 nm for blank and rapamycin-loaded MNF, respectively. TEM analysis revealed that nanomicelles are spherical in shape. Absence of free rapamycin in the MNF was confirmed by 1 H NMR studies. Neither placebo nor rapamycin-loaded MNF produced cytotoxicity on D407 and rPCECs indicating formulations are tolerable. In vivo studies demonstrated a very high rapamycin concentration in retina-choroid (362.35±56.17 ng/g tissue). No drug was identified in the vitreous humor indicating the sequestration of rapamycin in lipoidal retinal tissues. In summary, a clear, aqueous MNF comprising of Vit E TPGS and Oc-40 loaded with rapamycin was successfully developed. Back-of-the-eye tissue distribution studies demonstrated a very high rapamycin levels in retina-choroid (place of drug action) with a negligible drug partitioning into vitreous humor.

show abstract

Section: In Vivo Posterior Ocular Tissue Rapamycin Distribution Studiesmentioning

confidence: 99%

Nanomicellar Topical Aqueous Drop Formulation of Rapamycin for Back-of-the-Eye Delivery

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Reperfusion following ischemia results in oxidative stress, which also plays a role in RGC damage [4,5]. Investigations have been carried out to study the neuroprotection of RGCs using carotenoids [6]. …”

Section: Introductionmentioning

confidence: 99%

Lutein Protects RGC-5 Cells Against Hypoxia and Oxidative Stress

2010

IJMS

View full text Add to dashboard Cite

Retinal ischemia and oxidative stress lead to neuronal death in many ocular pathologies. Recently, we found that lutein, an oxy-carotenoid, protected the inner retina from ischemia/reperfusion injury. However, it is uncertain whether lutein directly protects retinal ganglion cells (RGCs). Here, an in vitro model of hypoxia and oxidative stress was used to further investigate the neuroprotective role of lutein in RGCs. Cobalt chloride (CoCl2) and hydrogen peroxide (H2O2) were added to a transformed RGC cell line, RGC-5, to induce chemical hypoxia and oxidative stress, respectively. Either lutein or vehicle was added to cultured cells. A higher cell count was observed in the lutein-treated cells compared with the vehicle-treated cells. Our data from this in vitro model revealed that lutein might protect RGC-5 cells from damage when exposed to either CoCl2-induced chemical hypoxia or H2O2-induced oxidative stress. These results suggest that lutein may play a role as a neuroprotectant.

show abstract

“…However, several lines of evidence support the inference that uveitis and glaucoma may share some of the ethiopathogenic mechanisms, particularly oxidative damage and increased NO production. Indeed, there is experimental evidence supporting the value of antioxidant and antinitridergic compounds for treating both glaucoma and uveitis [97, 131]. As already mentioned, melatonin by itself exhibits both antioxidant and antinitridergic properties.…”

Section: Discussionmentioning

confidence: 95%

“…Oxidative stress has been proposed as a primary cause for retinopathy in preterm infants because it is associated with low levels of reduced glutathione [92] and vitamin E [93]. Additionally, several lines of evidence support that retinal oxidative damage also plays a significant role in other ophthalmic diseases such as diabetic retinopathy [94, 95], retinal ischemia [96, 97], glaucoma [21], and uveitis [98], among others.…”

Section: Oxidative and Nitrosative Stress In The Eye And The Role Of mentioning

confidence: 99%

Melatonin as a therapeutic tool in ophthalmology: implications for glaucoma and uveitis

Rosenstein

Pandi-Perumal²,

Srinivasan³

et al. 2010

Journal of Pineal Research

View full text Add to dashboard Cite

: Several lines of evidence support the view that increased free radical generation and altered nitric oxide (NO) metabolism play a role in the pathogenesis of highly prevalent ocular diseases, such as glaucoma and uveitis. Data are discussed indicating that melatonin, being an efficient antioxidant that displays antinitridergic properties, has a promising role in the treatment of these ocular dysfunctions. Melatonin synthesis occurs in the eye of most species, and melatonin receptors are localized in different ocular structures. In view of the fact that melatonin lacks significant adverse collateral effects even at high doses, the application of melatonin could potentially protect ocular tissues by effectively scavenging free radicals and excessive amounts of NO generated in the glaucomatous or uveitic eye.

show abstract

Protective Effects of Vitamin E Forms (Alpha-tocopherol, Gamma-tocopherol and d-alpha-tocopherol Polyethylene Glycol 1000 Succinate) on Retinal Edema During Ischemia–reperfusion Injury in the Guinea Pig Retina

Abstract: The results from these experiments indicate that vitamin E forms have protective effects on the retina during retinal ischemia-reperfusion injury, but, the effects of alpha-tocopherol and TPGS appear to be much greater than that of gamma-tocopherol.

Cited by 19 publications

References 29 publications

Nanomicellar Topical Aqueous Drop Formulation of Rapamycin for Back-of-the-Eye Delivery

Nanomicellar Topical Aqueous Drop Formulation of Rapamycin for Back-of-the-Eye Delivery

Lutein Protects RGC-5 Cells Against Hypoxia and Oxidative Stress

Melatonin as a therapeutic tool in ophthalmology: implications for glaucoma and uveitis

Contact Info

Product

Resources

About