The dried root of the angiosperm Scutellaria baicalensis, also known as Chinese skullcap or Baikal skullcap, is widely used in traditional Chinese medicine, traditional Korean medicine and as a dietary supplement in the West.
Its main active ingredients (baicalein, baicalin, wogonin, wogonoside and oroxilin A) can directly act on immune cells such as lymphocytes, macrophages, mast cells, dendritic cells, monocytes and neutrophils, and inhibit the production of the inflammatory cytokines Il-1β, Il- 6, Il-8 and Tnf-α and other inflammatory mediators such as nitric oxide, prostaglandins, leukotrienes and reactive oxygen species.
Since, in addition to down-regulation of cytokine production, the active constituents of S. baicalensis also have antiviral and antibacterial effects, they may be promising therapeutic candidates for the prevention of infection-related cytokine storms compared with drugs that have only antimicrobial or antibacterial properties.
All of these activities give a rationale for traditional clinical applications: respiratory tract infections, pneumonia, colitis, hepatitis, and allergic diseases.
This plant also has a long history of use in the treatment of a variety of cancer-related symptoms. Over the past decade, its potential and that of its individual derived compounds as antitumor agents targeting various pathways has received extensive research attention. In particular, its properties in inhibiting cell proliferation and metastasis have been studied, but the underlying mechanisms remain unclear to this day.
A 2020 study evaluated the effects of this plant combined with metformin on the treatment of type 2 diabetes. Subjects who were already prescribed metformin were assigned to the group supplemented with Scutellaria (3.52 g/day) or the placebo group.
The initial treatment period was eight weeks, and after the washout period for four weeks they were transferred to the opposite treatment for another eight weeks. Glucose tolerance was lower in the supplemented group than in the placebo group.
Similarly, the relative RNA expression of Tnf-α was significantly reduced after supplemental treatment. Scutellaria treatment influenced the gut microbiota, particularly Lactobacillus and Akkermansia, which showed significant increases after phytotherapy supplementation.
Some subjects showed elevated levels of liver enzymes after supplementation, and their microbiota composition at baseline differed from that of subjects whose liver enzymes were not affected. These results suggest that the synergy between phytotherapy and metformin may improve glucose tolerance and inflammation, as well as affect the gut microbiota in type 2 diabetes.
With respect to liver function, it should be mentioned that official guidelines from the National institutes of health state that Scutellaria use “has been implicated in rare cases of clinically evident liver damage” and that “onset of symptoms and jaundice occurred within 6 to 24 weeks of initiation,” with marked increases in serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, and bilirubin.
A 2019 study re-read and re-evaluated the available literature on the topic, In the study, pre- and post-initiation serum assays of alanine transaminase, aspartate transaminase, alkaline phosphatase, and bilirubin were performed in 17 patients (16 female) with a mean age of 38.6 years who had each taken 1,335 mg of dried root daily for an average of 444 days. None of these changes were statistically significant, and none experienced clinical symptoms or signs of hepatic dysfunction while supplementing with Scutellaria.
Bibliography
The main bioactive compounds of Scutellaria baicalensis Georgi. for alleviation of inflammatory cytokines: a comprehensive review. Biomed Pharmacother. 2021 Jan;133:110917.
Combined effects of Scutellaria baicalensis with metformin on glucose tolerance of patients with type 2 diabetes via gut microbiota modulation. Am J Physiol Endocrinol Metab. 2020 Jan 1;318(1):E52-E61
The effect of supplementation with Scutellaria baicalensis on hepatic function. Med Hypotheses. 2019 Dec;133:109402.
A comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensis. Pharm Biol. 2018 Dec;56(1):465-484.
Scutellaria baicalensis and Cancer Treatment: Recent Progress and Perspectives in Biomedical and Clinical Studies. Am J Chin Med. 2018;46(1):25-54.
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