Vural Ayse, Polat Zubeyde Akin, Topalkara Aysen, Toker Mustafa Ilker, Erdogan Haydar, Arici Mustafa Kemal, Cetin Ali
Department of Ophthalmology, Cumhuriyet University School of Medicine, Sivas, Turkey.
Clin Exp Ophthalmol. 2007 Nov;35(8):749-54. doi: 10.1111/j.1442-9071.2007.01620.x.
To examine the effect of propolis in a rat model of Acanthamoeba keratitis and to determine its in vitro cytotoxicity in cultured corneal epithelial cells.
Eighteen Wistar albino rats were used. Cultured corneal epithelial cells obtained from two healthy rats for in vitro cytotoxicity of propolis. Corneal stromal inoculation was performed in 16 rats with amoebic culture containing 1 x 10(6) amoeba/mL. Rats with Acanthamoeba keratitis 5 days later after the inoculation were divided randomly into four groups, and eight eyes of each group were treated with study drugs. The propolis, chlorhexidine (CHX), propolis plus CHX and control eyes were treated with topical propolis, 0.002% CHX, propolis plus 0.002% CHX and lubricant eye drops, respectively. The study drugs were instilled every one hour for 10 days. All eyes were examined and keratitis graded by slit-lamp biomicroscopy on days 2, 5 and 10 during the administration of the study drugs. After the completion of keratitis grading, all the 16 rats were humanely killed and their corneas were excised and used for Acanthamoeba culture to evaluate presence of Acanthamoeba growth after treatment 14 days later.
Concentrations of propolis higher than 7.81 mg/mL cause damage to corneal epithelial cells in the experiment of in vitro cytotoxicity of propolis on corneal epithelial cells. The keratitis grade on day 2 in the CHX eyes was significantly lower than that in the control eyes (P < 0.05). The keratitis grades on days 5 and 10 in the propolis, CHX and propolis plus CHX eyes were significantly lower compared with those on days 5 and 10 in the control eyes (P < 0.05). In the propolis eyes, the keratitis grade on day 5 was significantly lower than that on day 2 (P < 0.05), and it was significantly lower on day 10 compared with that on day 5 (P < 0.05). In the CHX and propolis plus CHX eyes, the keratitis grade on day 10 was significantly lower compared with that on days 2 and 5 (P < 0.05). In the control eyes, there was no significant difference in the keratitis grades on days 2, 5 and 10 (P > 0.05). The culture positivity at Acanthamoeba growth after treatment experiment in the propolis, CHX and propolis plus CHX eyes was significantly lower than that in the control eyes (P < 0.05).
We suggest that propolis had amoebicidal properties in this rat model of Acanthamoeba keratitis. Further investigations to evaluate the antimicrobial activity of the individual fractions of the resin could yield more information about its mechanism of action in treating this disease.
研究蜂胶对棘阿米巴角膜炎大鼠模型的影响，并确定其对培养的角膜上皮细胞的体外细胞毒性。
使用18只Wistar白化大鼠。从两只健康大鼠获取培养的角膜上皮细胞用于蜂胶的体外细胞毒性实验。对16只大鼠进行角膜基质接种，接种含1×10(6)个阿米巴/毫升的阿米巴培养液。接种5天后患有棘阿米巴角膜炎的大鼠随机分为四组，每组8只眼，分别用研究药物治疗。蜂胶组、洗必泰（CHX）组、蜂胶加CHX组和对照组的眼睛分别局部给予蜂胶、0.002% CHX、蜂胶加0.002% CHX和润滑眼药水。研究药物每小时滴注1次，共10天。在给予研究药物的第2、5和10天，通过裂隙灯生物显微镜检查所有眼睛并对角膜炎进行分级。角膜炎分级完成后，对所有16只大鼠实施安乐死，切除其角膜用于棘阿米巴培养，以评估14天后治疗后棘阿米巴生长的情况。
在蜂胶对角膜上皮细胞的体外细胞毒性实验中，浓度高于7.81毫克/毫升的蜂胶会对角膜上皮细胞造成损伤。CHX组眼睛在第2天的角膜炎分级显著低于对照组（P < 0.05）。蜂胶组、CHX组和蜂胶加CHX组眼睛在第5天和第10天的角膜炎分级显著低于对照组在第5天和第10天的分级（P < 0.05）。在蜂胶组眼睛中，第5天的角膜炎分级显著低于第2天（P < 0.05），第10天显著低于第5天（P < 0.05）。在CHX组和蜂胶加CHX组眼睛中，第10天的角膜炎分级显著低于第2天和第5天（P < 0.05）。在对照组眼睛中，第2、5和10天的角膜炎分级无显著差异（P > 0.05）。在蜂胶组、CHX组和蜂胶加CHX组眼睛治疗后棘阿米巴生长的培养阳性率显著低于对照组（P < 0.05）。
我们认为在这个棘阿米巴角膜炎大鼠模型中蜂胶具有杀阿米巴特性。进一步研究评估树脂各组分的抗菌活性可能会获得更多关于其治疗该疾病作用机制的信息。
