以紫外線B誘發小鼠乾眼症狀之動物模式探討蟬花菌絲體萃取物緩解乾眼症狀之功效與機制

由於電子產品的普及與現代生活型態上的改變，人們用眼的習慣相較於從前已有巨大改變，導致眼睛相關的文明病如雨後春筍般出現，乾眼症即是其中一種。目前，臨床上針對乾眼症的處置大多給予人工淚液或類固醇等藥物，但只能暫時緩解，並無長期護眼的效果。根據本草綱目記載，蟬花應用於治療眼疾具有良好的效果，且已有在臨床中醫使用紀錄。本研究以蟬花菌絲體萃取物為材料，測試其對以紫外線B照射眼表所誘導小鼠乾眼症模式之緩解功效。實驗組別共有十組，依溶劑不同分別為：oil-Blank、oil-Damage、Dose 1、Dose 2、Dose 3、Dose 4、saline-Blank、saline-Damage、Dose 5與Dose 6。實驗流程共計11天，自Day -2開始進行蟬花菌絲體萃取物餵食，於Day 1開始連續每天進行傷害組與實驗組紫外線B照射傷害，並於Day 0、4、7進行乾眼症淚液量(TV)與淚液膜破裂時間(TBUT)測試，於Day 8進行眼表攝影並犧牲取下相關組織進行後續病理切片分析。實驗結果顯示，給予蟬花菌絲體萃取物之組別，淚液分泌量落於1.7至1.8 mm，淚液膜破裂時間介於6至7秒，而傷害組淚液分泌量落於1.2至1.5之間，淚液膜破裂時間則位於4至6秒，因此實驗組皆較傷害組在淚液分泌量與淚膜穩定度上具有緩解效果，並且角膜表面之健康情形亦佳。組織病理分析發現給予蟬花菌絲體萃取物在角膜、淚腺與麥氏腺上均可緩解發炎反應，且亦可促進角膜上皮細胞修補，並且可維持結膜杯狀細胞之生成與分泌，使淚液中黏多醣層穩定。本研究之實驗結果支持蟬花菌絲體萃取物應用於緩解乾眼症狀之可行性，後續將可進行蟬花菌絲體之產品開發與應用，以期能成為新一代護眼產品。

With the increasing popularity of electronic devices and the changes in modern life style, the habits of human vision use have been greatly changed, resulting in burgeoning of many eye diseases. Dry eye represents one of such diseases due to heavy eye use. To date, the dry eye status is mostly relieved by artificial tears or steroid treatment, only to sooth the situation temporarily without long term protective effects. However, according to Compendium of Materia Medica, Cordyceps cicadae may be effective in many eye diseases and has been used clinically in Chinese medicine. It is reported that Cordyceps cicadae contains anti-oxidative ingredients and therefore may be helpful for dry eye relief. This study examined the efficacy Cordyceps cicadae mycelium extract using the mouse dry eye model induced by UVB irradiation. Ten study groups were included: oil-Blank, oil-Damage, Dose 1, Dose 2, Dose 3, Dose 4, saline-Blank, saline-Damage, Dose 5, and Dose 6. The entire protocol lasted for 11 days. The mice fed daily with the extract from Day -2, and UVB damage was performed from Day 1until Day 7. Tear volume (TV) and Tear Break Up Time (TBUT) were assessed on Days 0 , 4, and 7. On Day 8, all mice were sacrificed after ocular surface photography, with eyes and accessory tissues collected for pathological analyses. The results showed that all TVs in mice fed with Cordyceps cicadae mycelium extracts fell between 1.7-1.8 mm, and TBUTs were between 6 – 7 seconds, outperforming those without treatments. Furthermore, less ocular surface damages were seen in mice fed with the extracts. Histopathological analyses showed mitigated inflammatory activities in cornea, extra-orbital lacrimal gland, and Meibomian glands, with enhancement of cornea repair and maintenance of conjunctival goblet cells and secretion. The results of this study support the use of Cordyceps cicadae mycelium extracts for dry eye mitigation and warrant subsequent development of related products for dry eye relief.