Does Skullcap Have Health Benefits? A Scientist Explains

Introduction

Scutellaria baicalensis, also known as Chinese skullcap or Huang Qin, is a root extract that has been used in both Traditional Chinese and Traditional Japanese medicine for centuries.  

Skullcap is also widely used as a backbone in herbal formulas in the western world where it is often referred to as ‘scute’.

Skullcap is believed to have cardio-protective, relaxant, anti-anxiety, anti-inflammatory, antioxidant and antibacterial properties and is purported to relieve menstrual cramping and tension headaches.

It is generally thought that skullcap is poorly researched but let’s look at what research there is on this commonly used herbal medicine.

What Is Skullcap?

Skullcap is a plant of the Lamiaceae or mint family. Related but different forms of Scutellaria are used in different healing traditions. Scutellaria baicalensis is used in Chinese medicine while Scutellaria lateriflora is used in western herbalism.

Scutellaria contains bioactive compounds including flavanoids and phenols. Two key related bioactive compounds in skullcap are baicalen and baicalein which are generally considered to be potent anti-inflammatories.

Skullap is frequently used in formulations for respiratory conditions in both traditional eastern medicine and western herbal medicine.

Skullcap is a key component in a Japanese and Chinese herbal formation known as Kampo (Tsumara saiboku or TJ-96). Kampo is often used as a steroid sparing agent.

In general, skullcap is poorly water soluble and for this reason skullcap tinctures are preferred to teas.

Is There Any Research?

There are over 1700 papers on skullcap including 25 clinical trials. To put this into context, there are over 200 published clinical trials on lavender.

Does Skullcap Fight Cancer Cells?

There are three clinical studies looking at the effect of skullcap in cancer. Two of these studies were done in the laboratory, but were based on patient-derived cancer cells, while just one study was done in patients.

The first study looked at cancer cells from children with acute lymphocytic leukemia. Baicalin from an extract of Scutellaria baicalensis was noted to increase killing of cancer cells (apoptosis) and increase the overall immune function of T-cells derived from these children (1).

The second study was a phase one pre-clinical study done on breast cancer cells where skullcap was found to induce cell death in the breast cancer cells (2).

This encouraging preclinical data was followed by a study in Hollywood, which looked at 2700 women with confirmed metastatic breast cancer who were heavily pretreated with chemotherapy (3). These women were treated with four different doses of Scutellaria barbata. It was found that the Scutellaria was safe, well-tolerated and showed some promising clinical anti-cancer activity.

Bottom line: It is too early to say if skullcap has significant anti-cancer activity at this time.

Does It Calm Anxiety?

There are two clinical trial looking at the effect of Scutellaria on anxiety and mood.

This first was a placebo-controlled, double-blind, crossover study in 43 healthy volunteers in the UK (4). The study participants were randomized to Scutellaria lateriflora 350 milligrams or placebo daily for two weeks. The study found a statistically significant decrease in anxiety in volunteers treated with skullcap, but not in the placebo group.

Additionally Scutellaria lateriflora enhanced global mood, but without a reduction in energy or cognition. The researchers concluded that Scutellaria may have a valuable role to play in subjects with anxiety.

The second study reports positive benefits of skullcap on mood in healthy volunteers (5). There is only an abstract available for this study and as such it is not possible to asses the quality of the data in this study.

Bottom line: There is a single study suggesting that skullcap can play a role in calming anxiety.

Does It Reduce Inflammation?

There is one clinical trial looking at the anti-inflammatory effects of skullcap. The study was done in 79 men and women in Florida who had a diagnosis of mild to moderate osteoarthritis (6). Study subjects received either naproxen as pain relief, or a combination of Scutellaria baicalensis and Acacia catechu (UP446) daily for a week.

The study found that both the naproxen and UP446 group experienced reduced pain, but only the UP446 group reported enhanced ability to endure more rigorous activities. The authors of the study observed that they could not offer an explanation for this observation, and considered it counter-intuitive

Considering the fact that both agents reduced pain, they expected that both groups should have enhanced exercise tolerance, but this was not the case. The authors of the study recommend that further studies are done to specifically look at the effects of UP446 on mobility.

The study found no change in the levels of pro-inflammatory markers such as CRP, IL-6, and IL-1b in either treatment group.

Bottom line: Skullcap has a long history of use as an anti-inflammatory. The single clinical study looking at skullcap as an anti-inflammatory is inconclusive and the topic needs further work.

Does It Help Insomnia?

There are no specific clinical trials evaluating the effect of skullcap on sleep and insomnia (7). There is one study from China which comments on the fact that Scutellaria radix root drug extract was noted to contain melatonin. Therefore, it is biologically plausible that Scutellaria could have a role in sleep.

Bottom line: There is no clinical data to support the role of skullcap in sleep at present.

Does It Reduce Risk of Heart Disease?

There are no clinical trials evaluating the effect of skullcap on heart disease. Studies in rats show that Scutellaria improves vascular elasticity and stimulates catalase activity and thereby exerted a cardio-protective effect (8). It also improves myocardial contractility in rats with lipopolysaccharide-induced sepsis (9).

Bottom Line: There is currently no clinical evidence to support a role for Scutellaria in reducing the risk of heart disease.

Does It Lower Fevers Resulting From The Flu?

There are no human clinical trials looking at the effect of skullcap in influenza.

Studies of Huang Qin derived from the roots of Scutellaria baicalensis Georgi was shown to be more potent than the flu drug Tamiflu against laboratory strains of the H1N1 virus (10).

A second study identified that Scutellaria baicalensis Georgi exhibits anti-influenza A activity via induction of interferon-gamma (11).

The anti-influenza activity of skullcap was also confirmed in a more recent study using a new anti-neuraminidase assay in 2016 (12).

Bottom Line: There is preclinical but no clinical data to support the role of skullcap as an anti-influenza agent.

Does It Treat Epilepsy?

There are no human clinical trials looking at the effect of skullcap on epilepsy.  A study showed that male rats with artificially-induced epilepsy who were given a combination of three herbal fluid extracts (Scutellaria lateriflora, Gelsemium and Jimson Weed ) remained seizure-free as compared to rats who just received tap water  (13).

Further support for the role of skullcap in epilepsy comes from a laboratory based study in Korea which suggests that the anti-convulsant activity of skullcap is mediated via the benzodiazepine binding site of GABA receptors and relates to a dihydroxy group present on the flavonoids of Scutellaria (14).

Bottom line: There are no clinical studies to support the role of skullcap in epilepsy.

Is Skullcap Safe?

Single oral doses of 100-2800 mg of baicalein extracted from skullcap have been shown to be safe and well tolerated by healthy subjects (15).

However there are reports of adulteration of skullcap with Teucrium species which is known to be hepatotoxic (16).  It is therefore advisable to buy skullcap from a reputable company.

Skullcap is an inhibitor of the cytochrome P450 drug metabolising system and can cause toxicity if co-administered with other drugs metabolised by this pathway e.g. some drugs used in HIV disease.

Like many other herbal medicines, skullcap can increase the risk of bleeding in people taking blood thinning or anticoagulant therapies.

Skullcap can also decrease the effectiveness of lipid lowering statin drugs.

Conclusion

The lack of quality research on skullcap makes it very difficult to take an informed stand on this herbal remedy for any indication.

References

  1. Orzechowska B, Chaber R, Wiśniewska A, Pajtasz-Piasecka E, Jatczak B, Siemieniec I, Gulanowski B, Chybicka A, Błach-Olszewska Z. Baicalin from the extract of Scutellaria baicalensis affects the innate immunity and apoptosis in leukocytes of children with acute lymphocytic leukemia. Int Immunopharmacol. 2014 Dec;23(2):558-67. doi: 10.1016/j.intimp.2014.10.005. Epub 2014 Oct 22.
  2. Rugo H, Shtivelman E, Perez A, Vogel C, Franco S, Tan Chiu E, Melisko M, Tagliaferri M, Cohen I, Shoemaker M, Tran Z, Tripathy D. Phase I trial and antitumor effects of BZL101 for patients with advanced breast cancer. Breast Cancer Res Treat. 2007 Sep;105(1):17-28. Epub 2006 Nov 17
  3. Perez AT, Arun B, Tripathy D, Tagliaferri MA, Shaw HS, Kimmick GG, Cohen I, Shtivelman E, Caygill KA, Grady D, Schactman M, Shapiro CL. A phase 1B dose escalation trial of Scutellaria barbata (BZL101) for patients with metastatic breast cancer. Breast Cancer Res Treat. 2010 Feb;120(1):111-8. doi: 10.1007/s10549-009-0678-5.
  4. Brock C, Whitehouse J, Tewfik I, Towell T. American Skullcap (Scutellaria lateriflora): a randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers. Phytother Res. 2014 May;28(5):692-8. doi: 10.1002/ptr.5044. Epub 2013 Jul 22.
  5. Wolfson P, Hoffmann DL. An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers. Altern Ther Health Med. 2003 Mar-Apr;9(2):74-8.
  6. Arjmandi BH, Ormsbee LT, Elam ML, Campbell SC, Rahnama N, Payton ME, Brummel-Smith K, Daggy BP. A combination of Scutellaria baicalensis and Acacia catechu extracts for short-term symptomatic relief of joint discomfort associated with osteoarthritis of the knee. J Med Food. 2014 Jun;17(6):707-13. doi: 10.1089/jmf.2013.0010. Epub 2014 Mar 10
  7. Watanabe H, Kobayashi T, Tomii M, Sekiguchi Y, Uchida K, Aoki T, Cyong JC. Effects of Kampo herbal medicine on plasma melatonin concentration in patients. Am J Chin Med. 2002;30(1):65-71
  8. Chan E, Liu XX, Guo DJ, Kwan YW, Leung GP, Lee SM, Chan SW. Extract of Scutellaria baicalensis Georgi root exerts protection against myocardial ischemia-reperfusion injury in rats. Am J Chin Med. 2011;39(4):693-704.
  9. Lee YM, Cheng PY, Chim LS, Kung CW, Ka SM, Chung MT, Sheu JR. Baicalein, an active component of Scutellaria baicalensis Georgi, improves cardiac contractile function in endotoxaemic rats via induction of heme oxygenase-1 and suppression of inflammatory responses. J Ethnopharmacol. 2011 Apr 26;135(1):179-85. doi: 10.1016/j.jep.2011.03.009. Epub 2011 Mar 17.
  10. Zhu HY, Han L, Shi XL, Wang BL, Huang H, Wang X, Chen DF, Ju DW, Feng MQ. Baicalin inhibits autophagy induced by influenza A virus H3N2. Antiviral Res. 2015 Jan;113:62-70. doi: 10.1016/j.antiviral.2014.11.003. Epub 2014 Nov 10.
  11. Zhu HY, Han L, Shi XL, Wang BL, Huang H, Wang X, Chen DF, Ju DW, Feng MQ. Baicalin inhibits autophagy induced by influenza A virus H3N2. Antiviral Res. 2015 Jan;113:62-70. doi: 10.1016/j.antiviral.2014.11.003. Epub 2014 Nov 10.
  12. Han X, Zhang DK, Guo YM, Feng WW, Dong Q, Zhang CE, Zhou YF, Liu Y, Wang JB, Zhao YL, Xiao XH, Yang M. Screening and evaluation of commonly-used anti-influenza Chinese herbal medicines based on anti-neuraminidase activity. Chin J Nat Med. 2016 Oct;14(10):794-800. doi: 10.1016/S1875-5364(16)30095-4. Epub 2016 Oct 31.
  13. Peredery O, Persinger MA.Herbal treatment following post-seizure induction in rat by lithium pilocarpine: Scutellaria lateriflora (Skullcap), Gelsemium sempervirens (Gelsemium) and Datura stramonium (Jimson Weed) may prevent development of spontaneous seizures. Phytother Res. 2004 Sep;18(9):700-5.
  14. Yoon SY, dela Peña IC, Shin CY, Son KH, Lee YS, Ryu JH, Cheong JH, Ko KH. Convulsion-related activities of Scutellaria flavones are related to the 5,7-dihydroxyl structures. Eur J Pharmacol. 2011 Jun 1;659(2-3):155-60. doi: 10.1016/j.ejphar.2011.03.012. Epub 2011 Mar 31.
  15. Li M, Shi A, Pang H, Xue W, Li Y, Cao G, Yan B, Dong F, Li K, Xiao W, He G, Du G, Hu X Safety, tolerability, and pharmacokinetics of a single ascending dose of baicalein chewable tablets in healthy subjects. J Ethnopharmacol. 2014 Oct 28;156:210-5. doi: 10.1016/j.jep.2014.08.031. Epub 2014 Sep 8.
  16. Sandasi M, Vermaak I, Chen W, Viljoen AM. Skullcap and germander: preventing potential toxicity through the application of hyperspectral imaging and multivariate image analysis as a novel quality control method. Planta Med. 2014 Oct;80(15):1329-39. doi: 10.1055/s-0034-1383037. Epub 2014 Sep 3.
Summary
Does Skullcap Have Health Benefits? A Scientist Explains
Article Name
Does Skullcap Have Health Benefits? A Scientist Explains
Author
Healthy But Smart

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