Effects of Eurya japonica extracts on human corneal epithelial cells and experimental dry eye

Abstract

Eurya japonica (EJ) leaves have been indicated to exert anti-oxidative and anti-inflammatory effects. Dry eye disease (DED) is a chronic inflammatory disease and oxidative stress is closely associated with DED. The aim of the present study was to analyze the therapeutic efficacy of EJ in DED using human corneal epithelial (HCE) cells and a mouse model of experimental dry eye (EDE). EJ extracts (0.001, 0.01 and 0.1%) were used to treat HCE cells. Cell viability and mitochondrial function were detected using a EZ-Cytox cell viability assay kit and mitochondrial membrane potential assays. Dichlorofluorescein diacetate (DCF-DA) assay was used to measure cellular reactive oxygen species (ROS) levels. Subsequently, eye drops consisting of BSS or 0.001%, 0.01 and 0.1% EJ extracts were applied for treatment of EDE. At 7 days, conjunctival ROS production was measured using a DCF-DA assay. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, 10 kDa interferon gamma-induced protein 10 (IP-10) and monokine induced by interferon-γ (MIG) levels in the conjunctiva were analyzed using a multiplex immunobead assay. Tear film and ocular surface parameters were measured. Treatment with EJ extracts in HCE cells effectively improved cell viability, ROS levels and mitochondrial function. Mice treated with 0.01 and 0.1% EJ extracts indicated a significant decrease in ROS, TNF-α, IL-1β, IP-10 and MIG levels compared with the EDE or BSS groups. Furthermore, a significant improvement in all clinical parameters was observed in the 0.01 and 0.1% EJ extract groups. EJ extracts could decrease cytotoxicity and ROS production in HCE cells. Additionally, topical EJ extracts reduced oxidative damage and inflammation and improved clinical signs of EDE, suggesting that EJ extracts may be used as an adjunctive therapy for DED.

Alternative therapies for dry eye disease

“…This also applies to other anti-inflammatory natural products that have mostly been examined preclinically in animal models or in vitro. Other promising anti-inflammatory products for DED include Aster koraiensis extract [65], polydatin [66], Eurya japonica extract [67], L-carnitine [68], pterostilbene [69], alpha-lipoic acid [70], selenoprotein P [71], vitamin B12 [68,72], carotenoids [73], and anthocyanins [74].…”

Evaluation of Conventional and Hyaluronic Acid-Coated Thymoquinone Liposomes in an In Vitro Model of Dry Eye

“…Many studies suggested a key role of inflammatory and oxidative processes in the pathogenesis of DED [ 49 , 50 , 53 ]. In particular, the mitochondrial function was related to the progression of DED as well as the outcome of this disease to the modulation of mitochondrial homeostasis [ 54 ]. DED patients had high levels of reactive oxygen species (ROS) and increased inflammatory markers in the tear film [ 55 ].…”

Characteristics of Purified Horse Oil by Supercritical Fluid Extraction with Different Deodorants Agents

“…Subcutaneous fat was obtained from the necks of 27-month-old Jeju horses from a local slaughterhouse on Jeju Island, Korea. The collected horse fat was cut into dimensions of 0.5×0.5 cm and subjected to supercritical fluid extraction following the method described by Li et al (2020) , with slight modifications. Subsequently, a four-step purification process was performed.…”

“…This low-temperature approach preserves the appearance and nutritional content of the extracted oils. Supercritical fluid extraction has been widely used to extract bioactive compounds from various plant-based matrices, including green tea ( Kim et al, 2007 ), orange peel ( Lee et al, 2001 ), ginseng ( Woo et al, 2011 ), and leaves of Eurya japonica ( Li et al, 2020 ). However, the use of supercritical fluid extraction to extract oil from animal-based sources remains has not been explored in detail.…”