Skullcap (Scutellaria baicalensis) Extract and Its Active Compound, Wogonin, Inhibit Ovalbumin-Induced Th2-Mediated Response

Abstract

Skullcap (Scutellaria baicalensis) has been widely used as a dietary ingredient and traditional herbal medicine owing to its anti-inflammatory and anticancer properties. In this study, we investigated the anti-allergic effects of skullcap and its active compounds, focusing on T cell-mediated responses ex vivo and in vivo. Splenocytes from mice sensitized with ovalbumin (OVA) were isolated for analyses of cytokine production and cell viability. Mice sensitized with OVA were orally administered skullcap or wogonin for 16 days, and then immunoglobulin (Ig) and cytokine levels were measured by enzyme-linked immunosorbent assays. Treatment with skullcap significantly inhibited interleukin (IL)-4 production without reduction of cell viability. Moreover, wogonin, but not baicalin and baicalein, suppressed IL-4 and interferon-gamma production. In vivo, skullcap and wogonin downregulated OVA-induced Th2 immune responses, especially IgE and IL-5 prediction. Wogonin as an active component of skullcap may be applied as a therapeutic agent for IgE-and IL-5-mediated allergic disorders.

Scutellaria baicalensisGeorgi. (Lamiaceae): a review of its traditional uses, botany, phytochemistry, pharmacology and toxicology

“…[51] Moreover, many previous works have demonstrated that Scutellaria baicalensis has significant antiallergic effects, but the detailed functions and mechanisms have not been elucidated so far. Shin et al [52] demonstrated that wogonin, an active ingredient of Scutellaria baicalensis, could downregulate the OVA-induced Th2 immune response, strongly inhibit the production of IL-5 and indirectly reduce IgE levels without reduction in cell viability. This finding might suggest that wogonin can be used as a therapeutic agent for IgE and IL-5-mediated allergic diseases.…”

“…Meanwhile, they had an interesting finding that oral administration of 1 mg/kg BW of wogonin was equivalent to the administration of Scutellaria baicalensis extract at 25 mg/kg BW. [52] In 2017, Bui et al showed that the EESB (100, 200 and 400 mg/kg, p.o. ), baicalein (10 mg/kg, p.o.)…”

High‐dose wogonin exacerbates DSS‐induced colitis by up‐regulating effector T cell function and inhibiting Treg cell

“…Activation‐induced IL‐4, IL‐5 and IL‐10 secretions were lower in wogonin‐fed mice compared with control mice with DSS‐induced colitis 23. In addition, relative low dose of wogonin (50 μM) suppressed IL‐4 production of murine splenocytes in vitro and down‐regulated OVA‐induced Th2 immune responses, particularly IgE and IL‐5 secretion in vivo 24. Although Th2 cell‐associated cytokines were not observed, our results confirmed that relatively high‐dose wogonin treatment (50–100 μg/ml equivalent to 176–352 μM) promoted IFN‐ɣ production of CD4 + and CD8 + cells in the presence of IL‐2 ex vivo .…”

“…immune responses, particularly IgE and IL-5 prediction [24]. However, IFN-c and IL-2 production of T cells co-stimulated by concanavalin A and wogonin has been shown to be significantly enhanced [23].…”

Research Progress of Antitumor Activity by Baicalin and Baicalein

“…At present, more than 40 kinds of flavonoids have been found in Astragalus, among which Baicalein, Wogonin and Baicalin (Baicalin) and Wogonoside are high in Astragalus and have obvious pharmacological effects. Previous phytochemical studies showed that the major flavonoids in Scutellaria baicalensis are baicalin (baicalein-7-O-gluc-uronide), baicalein (5,6,7-trihydoxyflavone) [5], wogonoside and wogonin, the glycoside (baicalin) [6] can be transformed into its aglycon (baicalein) [7,8]. Both of them possess significant pharmacological activities [9], and have great potency with less toxicity in inhibiting hypertension, inflammation, allergies and hepatitis, as well as cancer [10] including lung, colorectal, prostate and breast carcinomas [10][11][12][13][14].…”