Lithospermum erythrorhizon Siebold & Zucc. extract reduces the severity of endotoxin-induced uveitis.

BACKGROUND: Uveitis is an inflammatory eye condition that threatens vision, and effective anti-inflammatory treatments with minimal side effects are necessary to treat uveitis. PURPOSE: This study aimed to investigate the effects of Lithospermum erythrorhizon Siebold & Zucc. against endotoxin-induced uveitis in rat and mouse models. METHODS: Endotoxin-induced uveitis models of rats and mice were used to evaluate the effects of l. erythrorhizon treatment. Clinical inflammation scores and retinal thickness were assessed in the extract of l. erythrorhizon-treated rats. Histopathological examination revealed inflammatory cell infiltration into the ciliary body. Protein concentration, cellular infiltration, and prostaglandin-E2 levels were measured in the aqueous humor of the extract of l. erythrorhizon-treated rats. Protective effects of l. erythrorhizon on the anterior segment of the eye were examined in mice with endotoxin-induced uveitis. Additionally, we investigated the effect of l. erythrorhizon on the expression of pro-inflammatory cytokines [tumor necrosis factor alpha, interleukin-6, and interleukin-8] in lipopolysaccharide-stimulated THP1 human macrophages and examined the involvement of nuclear factor kappaB/activator protein 1 and interferon regulatory factor signaling pathways. Furthermore, three components of l. erythrorhizon were identified and assessed for their inhibitory effects on LPS-induced inflammation in RAW264.7 macrophage cells. RESULTS: Treatment of the extract of l. erythrorhizon significantly reduced clinical inflammation scores and retinal thickening in rats with endotoxin-induced uveitis. Histopathological examination revealed decreased inflammatory cell infiltration into the ciliary body. The extract of l. erythrorhizon effectively reduced the protein concentration, cellular infiltration, and PG-E2 levels in the aqueous humor of rats with endotoxin-induced uveitis. In mice with endotoxin-induced uveitis, the extract of l. erythrorhizon demonstrated a protective effect on the anterior segment of the eye by reducing inflammation and retinal thickening. The extract of l. erythrorhizon suppressed the expression of pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin-6, and interleukin-8) in lipopolysaccharide-induced inflammation in THP1 human macrophages, by modulating nuclear factor kappaB/activator protein 1 and interferon regulatory factor signaling pathways. Moreover, shikonin, acetylshikonin, and ß, ß-dimethylacryloylshikonin showed dose-dependent inhibition of nitric oxide, tumor necrosis factor alpha and interleukin-6 production in RAW264.7 macrophage cells. CONCLUSION: The extract of l. erythrorhizon is a potential therapeutic agent for uveitis management. Administration of the extract of l. erythrorhizon led to reduced inflammation, retinal thickening, and inflammatory cell infiltration in rat and mouse models of uveitis. The compounds (shikonin, acetylshikonin, and ß, ß-dimethylacryloylshikonin) identified in this study played crucial roles in mediating the anti-inflammatory effects of l. erythrorhizon. These findings indicate that the extract of l. erythrorhizon and its constituent compounds are promising candidates for further research and development of novel treatment modalities for uveitis.

Antiallergic Effects of N,N-dicoumaroylspermidine Isolated from Lithospermum erythrorhizon on Mast Cells and Ovalbumin-Induced Allergic Rhinitis.

In East Asia, the dried root of Lithospermum erythrorhizon has been utilized as an anti-inflammatory, antipyretic, detoxifying, and anti-inflammatory agent. Recently, we reported that L. erythrorhizon protects against allergic rhinitis; however, the component within L. erythrorhizon that exerts antiallergic activity remains unknown. The purpose of the current study was to isolate and characterize the antiallergic active components in an ethanolic extract of L. erythrorhizon roots. We examined the antiallergic effects of L. erythrorhizon reflux ethanol extracts in an ovalbumin (OVA)-induced allergic rhinitis mouse model, and compared the chemical compounds extracted using the hot reflux and cold extraction methods. Chromatographic separation identified two novel anthraquinones, erythrin A and B, one newly discovered compound from the Lithospermum genus, N1″,N3″-dicoumaroylspermidine, and nineteen other recognized compounds. Their chemical structures were elucidated by single (1D) and 2D analysis of nuclear magnetic resonance (NMR) spectroscopic data, as well as high resolution mass spectrometry. Among the identified compounds, N,N'-dicoumaroylspermidine strongly inhibited the release of ß-hexosaminidase, as well as the production of IL-3, IL-4, and IL-13 by IgE-sensitized and BSA-stimulated RBL-2H3 cells. Using the OVA-induced allergic rhinitis mouse model, we showed that N,N'-dicoumaroylspermidine reduced the production of serum OVA-specific IgE and the number of inflammatory cells in nasal lavage fluid. N,N'-dicoumaroylspermidine isolated from L. erythrorhizon exhibits antiallergic properties, making it potentially effective for allergic rhinitis.

Roots of Lithospermum erythrorhizon promotes retinal cell survival in optic nerve crush-induced retinal degeneration.

Lithospermum erythrorhizon (L. erythrorhizon), used in traditional medicine, is a potent wound healing, anti-inflammatory and antioxidant plant. However, the effects of L. erythrorhizon on retinal degenerative diseases remain unknown. Here, we explored the protective effects of L. erythrorhizon in in vitro and in vivo retinal degeneration. We found that ethanol extract of L. erythrorhizon (EELE) and the dichloromethane fraction of L. erythrorhizon (MCLE) significantly increased cell viability under glutamate/BSO-induced excitotoxicity/oxidative stress in R28 cells. Treatment with EELE and MCLE reduced the intracellular reactive oxygen species (ROS) and the levels of apoptotic proteins, such as cleaved PARP and cleaved caspase-3. Furthermore, oral administration of EELE and MCLE in an in vivo optic nerve crush mouse model decreased RGC cell death and increased retinal thickness. The major compound between EELE and MCLE was found to be lithospermic acid A (LAA), which has been shown to prevent the elevation of ROS in R28. Therefore, EELE and MCLE have protective effects against the death of retinal cells in vitro and in vivo, and the major compound, LAA, has an antioxidant effect on retinal cells, suggesting that EELE and MCLE could be beneficial agents for retinal degenerative diseases, including glaucoma.