Effects of pirenoxine: Using an in vitro and in vivo cataract animal model as assay systems

• Main Authors: Ming-Hsuan Tsai, 蔡明璇
• Other Authors: 吳姿樺
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/64837793119251829761

碩士 === 臺北醫學大學 === 藥學研究所 === 96 === Pirenoxine (Catalin®; Px) was first introduced in 1958 in Japan as an anti-cataractogenic agent. In spite of insufficient evidence, it is still widely used for cataract treatment in Taiwan now. To elucidate the pharmacology and effects of Px, in vitro and in vivo cataract animal model were used to analyze the effects of Px in current study. In in vitro screening system, excess calcium (50mM) or sodium selenite (10, 30, 50mM)-induced lens protein turbidity were established. The possible protective effects of Px in inhibiting or delaying the turbidity formation were determined by daily measurements of the optical density (OD) at 405 nm for 5 consecutive days. All endpoint results showed that various concentrations of Px (1.6μM, 16μM, 32 μM, 80 μM) possesses dose-dependent effect in protecting lens proteins. In calcium-induced lens turbidity system, the changes of OD for of Px (0, 32, 80 μM) treatments, compared to the day 0, were 2.9 ± 0.3, 1.9 ± 0.2, 0.9 ± 0.1 in fold, respectively. As to selenite (10mM)-induced groups, the changes of OD (fold) for Px (0, 16, 32, 80 μM) treatments were 8.8 ± 1.4、4.5 ± 1.1、2.2 ± 0.7、0.1 ± 0.3, respectively. In selenite (30mM)-induced groups, the changes of OD (fold) for test groups of Px (0, 16, 32, 80 μM) were 4.5 ± 0.6, 2.7 ± 0.2, 1.9 ± 0.2, 1.2 ± 0.1, respectively. In selenite (50mM)-induced groups, the changes of OD (fold) for test groups of Px (0, 16, 32, 80 μM) were 5.7 ± 0.5 versus 3.6 ± 0.4, 2.7 ± 0.3, 1.5 ± 0.1 respectively. All above treatment groups showed significant statistically differences compared to the controls without Px incubations (p<0.05). The incubated lens proteins of each group were then analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. There was no difference between control and the Px-treated groups in calcium-induced turbidity system; however, patterns of lens proteins in groups with higher Px resulted in more similar to the normal ones in selenite-induced turbidity system and suggested Px tends to protect lens proteins against conformation changes induced by selenite. The in vivo study was designed to test the preventive use of Px from cataractogenesis. Postnatal day 9 rat pups (Sprague-Dawley) were pretreated with Px (5 mg/kg, subcutaneously) for three days and continuously for the next seven days. After giving overdoses of sodium selenite (19 µmole/kg, subcutaneously) to induce cataract formation at postnatal day 12, the degrees of cataract formation were scored daily until the eye lenses were collected at postnatal day 19 for protein analyzing by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that there was no significant difference in opacity score among the groups at endpoint; however, Px （5 mg/ kg） delayed the progression of cataract formation during the development. SDS-PAGE showed fewer degraded proteins in the rats treated with higher dose of Px. Intravitreal injections of Px (10μl, 1 mg/ml) for 3 consecutive days were then followed to test therapeutic effects of Px against cataract but no curative effect was observed. In conclusion, our in vitro experimental results suggest that Px delays turbidity. Even Px can delay cataract progression at first; nevertheless, the dose used for animal model has no protecting effects. Clinical uses of Px for cataract prevention or treatment still require further investigations.