The effect of supplementation with Scutellaria baicalensis on hepatic function

Abstract

The dried root of the angiosperm Scutellaria baicalensis, also known as Chinese skullcap or Baikal skullcap, is widely used in traditional Chinese medicine, Korean traditional medicine and as a nutritional supplement; several studies have indicated that both the supplement and some of its ingredients may have clinically beneficial actions. However, the National Institutes of Health official guidance states that the use of Scutellaria "has been implicated in rare instances of clinically apparent liver injury" and that "the onset of symptoms and jaundice occurred within 6-24 weeks of starting skullcap, and the serum enzyme pattern was typically hepatocellular", with marked increases in serum alanine transaminase, aspartate transaminase, alkaline phosphatase and bilirubin levels. Careful perusal of all such published case reports showed that in each case the patient was concurrently taking at least one other supplement which had an established association with hepatic dysfunction. The authors hypothesised that long-term supplementation with Scutellaria baicalensis does not lead to hepatic dysfunction. The aim of this study was to test this hypothesis by assessing liver function before and after starting supplementation with Scutellaria baicalensis. Pre- and post-supplementation serum assays of alanine transaminase, aspartate transaminase, alkaline phosphatase and bilirubin were carried out in 17 patients (16 female) of average age 38.6 (standard error 4.4) years who had each taken 1335 mg dried root daily for an average of 444 (71) days. The mean baseline versus follow-up values for each liver function test were: alanine transaminase: 25.7 (2.6) IU/L v. 25.1 (1.7) IU/L; aspartate transaminase: 22.1 (1.1) IU/L v. 23.5 (1.3) IU/L; alkaline phosphatase: 63.7 (4.6) IU/L v. 63.3 (3.9) IU/L; and bilirubin: 6.1 (0.6) μM v. 6.0 (0.7) μM. None of these changes was statistically significant; indeed, three of the four parameters showed a non-significant decrease over time. Furthermore, none manifested clinical symptoms or signs of hepatic dysfunction during Scutellaria supplementation. These results suggest that daily intake of a relatively high level of Scutellaria baicalensis for over a year is not associated with any biochemical or clinical evidence of hepatic dysfunction. Indeed, Scutellaria baicalensis has been shown in murine experiments to have hepatoprotective actions.