With the increasing incidence of adrenal fatigue in the general population, we felt it was timely to take a look at an adrenal-sparing herb. In this month's issue, we investigate the diverse effects of liquorice on adrenal hormones.
Liquorice has been acknowledged for its ability to raise cortisol and researchers at the Queen's Medical Research Institute in Edinburgh sought to examine the broader range of its effects on adrenal hormones.
In a pilot crossover study examining liquorice's effect on adrenal steroidogenic hormones, 20 healthy volunteers (10 F/10 M, average age 23), were given 100g of 3% liquorice confectionery for a week, a 3-day washout period, then a week on a daily 100g carbohydrate and sugar-matched placebo confectionery. Salivary hormone levels were tested at baseline at three-time points during the day (waking, mid-morning and evening).
The results showed short-term liquorice consumption at 3g per day, induced significant increases in free cortisol P < 0.01, but also in other adrenal hormones including: free DHEA P <0.001, free testosterone P < 0.05 and free deoxycorticosterone P < 0.02, whilst significantly lowering free cortisone P < 0.01 and free aldosterone P < 0.02. Liquorice also significantly increased conjugated DHEA at P < 0.03 and conjugated deoxycorticosterone P < 0.01. They also noted it did not raise blood pressure at this dose in this normotensive cohort, confirming other studies.(2)The mechanism(s) by which liquorice affects these changes is unclear but liquorice appears to act directly to inhibit the activity of the enzyme SULT2A1.
The researchers concurrently studied in vitro human adrenal cell lines to assess whether glycyrrhetinic acid (an active component of liquorice) affects steroidogenesis via changes to the expression of the enzyme SUKLT2A which sulphonates three adrenal hormones ( pregnenolone, DHEA, 17 Hydroxypregnenolone and deoxycorticosterone), They used adrenocortical H295 cells and the results confirmed that glycyrrhetinic acid did affect the inhibition of cortisol to cortisone via the inhibition of the enzyme (11B-hydroxysteroid dehydrogenase Type II) production but hormonal changes were not associated with changes in SUKLT2A1 mRNA expression suggesting that liquorice active components may act directly on the enzymes themselves.
Summary: Taken as a whole, this preliminary research suggests that liquorice acts to improve adrenal function by prolonging cortisol levels through enzyme inhibition, but the in vitro research points to a role in improving several other important adrenal hormones.
Al-Dujaili EA, Kenyon CJ, Nicol MR, Mason JI. Liquorice and glycyrrhetinic acid increase DHEA and deoxycorticosterone levels in vivo and in vitro by inhibiting adrenal SULT2A1 activity. Molecular and cellular endocrinology. 2011 Apr 10;336(1-2):102-9.
Sigurjonsdottir HA, Manhem K, Axelson M, Wallerstedt S. Subjects with essential hypertension are more sensitive to the inhibition of 11 β-HSD by liquorice. Journal of human hypertension. 2003 Feb;17(2):125.