- Hibiscus (Hibiscus sabdariffa)
- uric Acid Excretion
- Renal Stone Formation
Re: Effect of Hibiscus on Uric Acid Excretion and Renal Stone Formation
Prasongwatana V, Woottisin S, Sriboonlue P, Kukongviriyapan V. Uricosuric effect of roselle (Hibiscus sabdariffa) in normal and renal-stone former subjects. J Ethophamarmacol. 2008;117(3): 491-495.
(roselle; Hibiscus sabdariffa) has been reported to act as a diuretic
and a uricosuric substance (one that increases the amount of uric acid in the
urine) in patients with urologic disorders. According to Thai traditional
medicine, it is used for the treatment and prevention of urinary stones.
However, no scientific study has ever reported any anti-lithiasic (stone)
and/or uricosuric effects, particularly in subjects with renal stones.
This study was
designed to evaluate the effects of hibiscus tea consumption on urinary
excretions of uric acid and other compounds related to stone formation in subjects
with normal urinary function and those with renal stones. It consisted of 3 periods: baseline (control), tea
drinking, and washout. During the tea-drinking period, the subjects were
assigned to take a cup of tea twice daily for 15 consecutive days. The tea was
prepared from a 1.5-gram tea bag of dried hibiscus calyx (Lampang Medicinal
Plant Conservation Assembly, Lampang province, Thailand), steeped in
approximately 150 ml of hot water for about 10 minutes. During the washout
period, the subjects were without tea for another 15 days. Analysis of the herbal
tea infusion for chemical content showed that it contained much less of 4
minerals and 4 organic compounds related to stone formation than found in
subjects from rural communities in Thailand were divided into 2 groups
of 9 subjects each: 1 group of healthy males (non-renal stone, NS) and 1 group
with a history of renal stones (RS). There were no significant differences in
any of the serum parameters between the 2 groups of subjects or between the
baseline and the tea-drinking periods. Most of the urinary baseline parameters
were also similar between the 2 groups.
There was no
significant difference in serum sodium and urinary volume between the baseline
and the tea-drinking periods, thus suggesting that the diuretic effect of this
herbal tea was not observed at the dose of 3 g/day.
After the intake
of tea, the trend was a non-significant increase in urinary oxalate and citrate
in both groups. Furthermore, mean levels of uric acid clearance (P<0.01) and
uric acid excretion (P<0.05) were increased significantly in the RS group.
The mean fractional excretion of uric acid was increased significantly in the
NS group (P<0.01) and the RS group (P<0.05). The levels decreased to
baseline level at the end of the washout period.
Increased urinary excretion of uric acid is known to be a
cause of calcium oxalate stone formation, and this study did not find
evidence of any anti-lithiasic effect of hibiscus tea at the dose used such as
increases in urinary citrate or magnesium. Therefore,
the authors suggest that the intake of hibiscus
tea could be a risk leading to urinary stone formation. Yet, they also
suggest that the uricosuric effects may be useful as a treatment for
hyperuricemia in gout disease, though no lowering of serum uric acid was
demonstrated at this dose. This potential
stone-inducing effect must be weighed against the positive uricosuric effect
that may offer a benefit for subjects with gout.
The intake of
hibiscus tea in this study did not cause any toxicity to hepatic and renal
tissues. However, because this is a relatively new venue in Western medicine,
further studies are warranted to discern potential efficacy and to identify any
-Jennifer Menigh, PhD