Also known as Asian or Chinese lizard’s tail (or Sam-baekcho in Korea), Saururus chinensis is an East Asian plant used in traditional medicine for various indications including edema, gonorrhea, jaundice, hypertension, leproma, pneumonia, and rheumatoid arthritis.1,2 Specifically, Korean traditional medicine practitioners as well as Native Americans and early colonists in what is now the United States used the botanical to treat cancer, edema, rheumatoid arthritis, and other inflammatory conditions.2-4 Modern research has produced evidence supporting the use of this plant in the dermatologic realm. This column focuses on the relevant bench science and possible applications.
Various beneficial effects
In 2008, Yoo et al. found that the ethanol extract of the dried aerial parts of S. chinensis exhibit anti-inflammatory, antiangiogenic, and antinociceptive properties, which they suggested may partially account for the established therapeutic effects of the plant.2 Also, Lee et al. reported in 2012 on the antiproliferative effects against human cancer cell lines of neolignans found in S. chinensis.5
Antioxidant properties have been associated with S. chinensis. In 2014, Kim et al. reported that S. chinensis extract attenuated the lipopolysaccharide (LPS)-stimulated neuroinflammatory response in BV-2 microglia cells, a result that the authors partly ascribed to the antioxidant constituents (particularly quercetin) of the plant.3
Atopic dermatitis
In 2008, Choi et al. determined that the leaves of S. chinensis impeded the formation of atopic dermatitis–like skin lesions in NC/Nga mice caused by repeated application of picryl chloride, potentially by stimulating the Th1 cell response, thus modulating Th1/Th2 imbalance. They concluded that S. chinensis has potential as an adjunct treatment option for atopic dermatitis.6
Anti-inflammatory activity
In 2010, Bae et al. studied the anti-inflammatory properties of sauchinone, a lignan derived from S. chinensis reputed to exert antioxidant, anti-inflammatory, and hepatoprotective activity,7 using LPS-stimulated RAW264.7 cells. They found that the lignan lowered tumor necrosis factor (TNF)–alpha synthesis by inhibiting the c-Raf-MEK1/2-ERK1/2 phosphorylation pathway, accounting for the anti-inflammatory effects of the S. chinensis constituent.8
More recently, Zhang et al. determined that the ethanol extract of S. chinensis leaves impaired proinflammatory gene expression by blocking the TAK1/AP-1 pathway in LPS-treated RAW264.7 macrophages. They suggested that such suppression is a significant step in the anti-inflammatory function exhibited by the plant.1
Photoprotection
Park et al. investigated in 2013 the beneficial effects of sauchinone. Specifically, they studied potential photoprotective effects of the lignan against UVB in HaCaT human epidermal keratinocytes. They found that sauchinone (5-40 mcm) conferred significant protection as evaluated by cell viability and a toxicity assay. At 20-40 mcm, sauchinone blocked the upregulation of matrix metalloproteinase (MMP)–1 proteins and decrease of type 1 collagen engendered by UVB exposure. The investigators further discovered that sauchinone diminished the synthesis of reactive oxygen species. Overall, they determined that sauchinone imparted protection by suppressing extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 MAPK signaling through the activation of oxidative defense enzymes.7