Isatis tinctoria L.-derived Petroleum Ether Extract Mediates Anti-inflammatory Effects via Inhibition of Interleukin-6, Interleukin-33 and Mast Cell Degranulation

Abstract

The medicinal herb Isatis tinctoria (woad), which has been used in medicine for centuries, has demonstrated antiinflammatory effects in recent studies. However, to date, no defined extracts with precise characterization of their active substance content have been developed. This study aimed to develop novel well-characterized extracts of woad, and to determine their anti-inflammatory properties in animal and human skin tissues. The production and precise characterization of such extracts will enable evaluation of their potential dermatological use in the treatment of irritated, pruritic skin. Isatis tinctoria L. (woad) has been used in medicine for centuries and has demonstrated anti-inflammatory effects. However, to date, no well-defined extracts with precise analysis of active substances have been developed. The aim of this study was to develop novel extracts of Isatis tinctoria L., and to characterize their active ingredients and anti-inflammatory properties. Various extracts of Isatis tinctoria L. were analysed for their active ingredients, and screened for anti-inflammatory effects using cyclooxygenase-2 activity assays. A petroleum ether extract was found to have the best effects, and was tested in a mouse model of acute allergic contact dermatitis. In the mouse model the petroleum ether extract resulted in significantly reduced ear swelling, oedema and inflammatory cell density. In mouse skin and human keratinocyte cultures, petroleum ether extract inhibited pro-inflammatory cytokine expression. Furthermore, human mast cell degranulation was significantly inhibited in LAD2 cell cultures. In conclusion, novel woad extracts were developed and shown to have anti-inflammatory properties in a contact hypersensitivity animal model and human keratinocytes. The production of such extracts and further characterization of their specific properties will enable determination of their potential dermatological effects in the treatment of inflamed and irritated skin.

A focused natural compound screen reveals senolytic and senostatic effects ofIsatis tinctoria

“…The best-characterized medicinal activities of woad extracts are anti-viral, anti-microbial, and anti-inflammatory activities (Lotts et al 2020 ). As those processes are closely related to the SASP, we reasoned that woad extracts could impact SASP expression in senescent skin fibroblasts.…”

“…Biological activities of woad are mainly attributed to its anti-inflammatory, anti-viral, and anti-oxidant characteristics. No single compound has been isolated for such diverse bioactivities of woad yet; however, more defined extracts of woad were recently reported to have anti-inflammatory properties in a mouse model of dermatitis and human keratinocytes (Lotts et al 2020 ), suggesting the possibility that woad extracts may be effective for skin inflammation associated with senescence as well.…”

Hydroalcoholic Leaf Extract of Isatis tinctoria L. via Antioxidative and Anti-Inflammatory Effects Reduces Stress-Induced Behavioral and Cellular Disorders in Mice

“…Depending on the extraction and separation methods, particular groups of metabolites are dominant [19,20]. In in vitro and in vivo studies both the root and leaf extracts from I. tinctoria show anti-inflammatory properties by inhibiting proinflammatory cytokines [21,22] and suppression of nitric oxide (NO) production, which at least in part explain its impact on inflammatory and oxidative pathways [23][24][25]. Isatis tinctoria antioxidants' effects against free radicals are further supported by many in vitro assays revealing its strong scavenging activity as well as its good reducing power [16].…”

Chinese herbal prescriptions for COVID-19 management: Special reference to Taiwan Chingguan Yihau (NRICM101)

“…Indigo, sinigrin, aloe emodin and hesperetin have all demonstrated anti-influenza virus effects by blocking 3CL pro cleavage ( Lin et al, 2005 ). Petroleum ether extract of I. indigotica reportedly inhibits the levels of IL-6 and IL-33 expression and mast cell degranulation ( Lotts et al, 2020 ).…”