The effect of supplementation with Scutellaria baicalensis on hepatic function.

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.

The Influence of Compatibility of Rhubarb and Radix Scutellariae on the Pharmacokinetics of Anthraquinones and Flavonoids in Rat Plasma.

BACKGROUND AND OBJECTIVES: Rhubarb-Radix scutellariae is a classic herb pair, which is commonly used to clear away heat and toxin in clinic. The aim of this study was to investigate the influence of compatibility of Rhubarb and Radix scutellariae on the pharmacokinetic behaviors of anthraquinones and flavonoids in rat plasma. METHODS: Eighteen rats were randomly divided into three groups, and were orally administered Rhubarb and/or Radix scutellariae extracts. A sensitive and rapid UPLC-MS/MS method was developed and validated to determine the concentrations of baicalin, baicalein, wogonside, wogonin, rhein, and emodin in rat plasma. The concentrations of phase II conjugates of flavonoid aglycones and anthraquinone aglycones were also determined after hydrolyzing the plasma with sulfatase. RESULTS: Compared with administration of Radix scutellariae alone, co-administration of Rhubarb significantly decreased the first maximum plasma concentration (C max1) of baicalin, wogonside, and the phase II conjugates of baicalein, wogonin to 46.40, 61.27, 41.49, and 20.50%, respectively. The area under the plasma concentration-time curve from time zero to infinity (AUC0-∞) was significantly decreased from 82.60 ± 20.22 to 51.91 ± 7.46 µM·h for rhein and 276.83 ± 98.02 to 175.42 ± 86.82 µM·h for the phase II conjugates of wogonin after compatibility. The time to reach the first maximum plasma concentration (T max1) of anthraquinones was shortened and the second peak of anthraquinones disappeared after compatibility. CONCLUSIONS: Compatibility of Rhubarb and Radix scutellariae can significantly affect the pharmacokinetic behaviors of characteristic constituents of the two herbs. The cause of these pharmacokinetic differences was further discussed combined with the in vivo ADME (absorption, disposition, metabolism, and excretion) processes of anthraquinones and flavonoids.