Fructus lycii: A Natural Dietary Supplement for Amelioration of Retinal Diseases

Fructus lycii (F. lycii) is an exotic “berry-type” fruit of the plant Lycium barbarum that is characterized by a complex mixture of bioactive compounds distinguished by their high antioxidant potential. F. lycii is used in traditional Chinese home cooking and in the Chinese Pharmacopeia as an aid to vision and longevity as well as a remedy for diabetes to balance “yin” and “yang” in the body for about two centuries. Although a myriad of bioactive compounds have been isolated from F. lycii, polysaccharides, carotenoids, flavonoids, and phenolics represent the key functional components of F. lycii. F. lycii has been shown to exhibit a wide range of biological activities in experimental settings including antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects. Despite its medicinal role dating back to the eighteenth century in the Far East and robust evidence of beneficial effects on ocular health and retinal diseases originating mainly from studies in animal models, the role of F. lycii in the clinical management of retinal diseases is yet to be established. This article comprehensively reviews the literature germane to F. lycii and retinal diseases with particular emphasis on age-related macular degeneration, diabetic retinopathy, and retinitis pigmentosa, which are commonly seen in clinical practice.

Investigations of metallic elements and phenolics in Chinese medicinal plants

Traditional Chinese Medicines (TCM) can be contaminated with heavy metals, and therefore, the aim of this study is to analyze the Fe, Mn, Zn, Cu, Cd, Pb, Cr, and phenolic compounds contents in TCM plants used against civilization diseases. Metals were determined by flame atomic absorption spectroscopy (FAAS) for Fe, Mn, Zn, and Cu and inductively coupled plasma-optical emission spectroscopy (ICP-OES) for Pb, Cd, and Cr. The total phenolic, flavonoid, and phenolic acid contents were determined by HPLC and UV/vis spectrometry. The contents of the studied elements were highest in Radix Rehmanniae, whereas lowest in Fructus Lycii and Fructus Crataegi. The studied metals were assayed in the decreasing order: Fe, Zn, Mn, Cu, Cr, Pb, and Cd. Radix Rehmanniae Glutinosae Preparata showed the lowest phenolic composition, while Fructus Lycii showed the richest content. Principal component analysis (PCA) revealed that the contents of ferulic acid, caffeic acid, rutin, and Cu, Cr, and Cd were among the most important factors responsible for the differentiation between the investigated medicinal plants. Cluster analysis (CA) showed that the TCM samples originating from the same botanical plant species were often found in the same cluster, which confirms the similar level of studied elements determined within the samples.

Study on Identification Method of Fructus Lycii Origin by Mineral Elements

In order to rapid discriminate the source of Fructus Lycii origin, Fructus Lycii from five different areas were collected, the content of K, Ca, Na, Mg, Fe, Zn ,Cu and Mn were analyzed with flame atomic absorption spectrometry,and the data was analyzed with Stepwise discriminant analysis method,and the discriminant function was established. The results showed that Fructus Lycii from five different areas was well clustering. The discriminant model was re-discriminated by using the method of mutual test; its discrimination accuracy was 94.4% for the original samples and the unknown samples. The recognition rates for Ningxia, Hebei, Qinghai cultivation regions were all 100%. In conclusion, mineral element combined with chemometrics method was a fast and accurate method to identify the origin source of Fructus Lycii.

Efficacy of Ethanol Extract ofFructus lyciiand Its Constituents Lutein/Zeaxanthin in Protecting Retinal Pigment Epithelium Cells against Oxidative Stress:In VivoandIn VitroModels of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a major cause of blindness worldwide. Oxidative stress plays a large role in the pathogenesis of AMD. The present study was to evaluate the effects ofFructus lyciiethanol extract on AMD in mice and to investigate whether combination of lutein and zeaxanthin, two carotenoid pigments inFructus lycii, could protect human retinal pigment epithelial ARPE-19 cells treated with hydrogen peroxide (H2O2)in vitro. We found that severe sediment beneath retinal pigment epithelium and thickened Bruch membrane occurred in AMD mice. However,Fructus lyciiethanol extract improved the histopathologic changes and decreased the thickness of Bruch membrane. Furthermore, the gene and protein expression of cathepsin B and cystatin C was upregulated in AMD mice but was eliminated byFructus lyciiethanol extract. Investigationsin vitroshowed that ARPE-19 cell proliferation was suppressed by H2O2. However, lutein/zeaxanthin not only stimulated cell proliferation but also abrogated the enhanced expression of MMP-2 and TIMP-1 in H2O2-treated ARPE-19 cells. These data collectively suggested thatFructus lyciiethanol extract and its active components lutein/zeaxanthin had protective effects on AMDin vivoandin vitro, providing novel insights into the beneficial role ofFructus lyciifor AMD therapy.