Beneficial Effects of the Bioflavonoids Curcumin and
Quercetin on Early Function in Cadaveric Renal
Transplantation: A Randomized Placebo
Daniel Shoskes, Chantale Lapierre, Marcia Cruz-Corerra, Nicolas Muruve, Reinaldo Rosario,
Beth Fromkin, Mauro Braun, and John Copley
Background. The bioflavonoids quercetin and curcumin are renoprotective natural antioxidants. We wished to exam-
ine their effects on early graft function (EF).
Methods. Between September 2002 and August 2004, 43 dialysis dependent cadaveric kidney recipients were enrolled
into a study using Oxy-Q which contains 480 mg of curcumin and 20 mg of quercetin, started after surgery and taken
for 1 month. They were randomized into three groups: control (placebo), low dose (one capsule, one placebo) and high
dose (two capsules). Delayed graft function (DGF) was defined as first week dialysis need and slow function (SGF) as Cr
?2.5 mg/dl by day 10. Category variables were compared by chi squared and continuous variables by Kruskal-Wallis.
Results. There were four withdrawals: one by patient choice and three for urine leak. The control group had 2/14
patients with DGF vs. none in either treatment group. Incidence of EF was control 43%, low dose 71% and high dose
93% (P?0.013). Serum creatinine was significantly lower at 2 days (control 7.6?2.1, low 5.4?0.6, high 3.96?.35
P?0.0001) and 30 days (control 1.82?.16, low 1.65?.09, high 1.33 ?.1, P?0.03). Acute rejection incidence within 6
months was control 14.3%, low dose 14.3% and high dose 0%. Tremor was detected in 13% of high dose patients vs.
46% of others. Urinary HO-1 was higher in bioflavonoid groups.
Conclusion. Bioflavonoid therapy improved early graft function. Acute rejection and neurotoxicity were lowest in the high
dose group. These bioflavonoids improve early outcomes in cadaveric renal transplantation, possibly through HO-1 induc-
Keywords: Clinical transplantation, Immunosuppression, Kidney.
(Transplantation 2005;80: 1556–1559)
cadaveric renal transplantation that has been linked to
in the early posttransplant period in a randomized, placebo con-
increased rates of acute rejection and reduced graft survival
trolled study, in patients treated concomitantly with MMF.
(1). The primary mechanism is ischemia-reperfusion (IR) in-
jury; however, other factors such as alloimmunity and brain
death triggered tissue inflammation have also been impli-
MATERIALS AND METHODS
cated (2). Although there have been a succession of agents that
Between September 2002 and August 2004, 43 dialysis
can effectively ameliorate IR injury in rodent models, none has
dependent primary recipients of cadaveric kidneys were en-
yet proven effective in clinical transplantation.
rolled into this randomized placebo controlled study after
The bioflavonoids curcumin and quercetin are natu-
appropriate informed consent for this IRB approved proto-
rally occurring polyphenolic compounds with several docu-
col. During this period, 45 cadaveric transplants were per-
mented effects that might be beneficial in early posttransplant
formed. As in our open label study (5), we used the biofla-
injury. We have shown that quercetin and curcumin reduce
vonoid preparation Oxy-Q (Farr Labs, Santa Monica, CA)
IR injury in the rat (3) and reduce both IR injury and rejection
which contains 480 mg of curcumin and 20 mg of quercetin,
synergistically with mycophenolate mofetil (MMF) (4). Finally,
a ratio similar to what we found most beneficial in our rodent
in a phase I open label study, administration of curcumin and
experiments (3). Patients were randomized in a blinded fash-
quercetin to renal transplant recipients was associated with no
ion to receive either the Oxy-Q or placebo according to the
side effects, improvement in early renal function and a surpris-
following schedule: control: one placebo capsule twice a day;
ing decrease in drug induced tremor (5).
low dose: one Oxy-Q in the morning and one placebo in the
We therefore wished to study the effect of these biofla-
evening; high dose: one Oxy-Q capsule twice a day. Treat-
ment was started within 24 hr of surgery and continued for 1
Department of Kidney Transplantation, Cleveland Clinic Florida, Weston,
month. Immunosuppression included daclizumab (1 mg/kg
on day 0, 7, and every 2 weeks for five total doses), tacrolimus
Address correspondence to: Daniel Shoskes, M.D., Glickman Urologic Insti-
(adjusted to trough levels), mycophenolate mofetil (1 g twice
tute, Cleveland Clinic, Desk A100, 9500 Euclid Ave., Cleveland, OH
daily) and steroids on a tapering schedule. High immuno-
logic risk patients and those who developed DGF received
Received 11 January 2005. Revision requested 2 February 2005.
thymoglobulin (1–1.5 mg/k per day) instead of daclizumab.
Accepted 2 April 2005.
Cause of donor death was not recorded.
Copyright © 2005 by Lippincott Williams & Wilkins
DGF was defined as dialysis need in the first week, slow
function (SGF) as failure of creatinine (Cr) to drop within the
Transplantation • Volume 80, Number 11, December 15, 2005
© 2005 Lippincott Williams & Wilkins
Shoske et al.
first 48 hr and/or Cr?2.5 mg/dl by day 10 and early function
surgical repair. All withdrawals were between postoperative
(EF) as the rest. Standard laboratory work was collected on all
day 2 and 10, therefore data on early function was on an
patients including serum creatinine and tacrolimus trough
intent-to-treat basis and later mean creatinine values were per
levels. Urine was collected from the Foley bag or as a mid-
stream urine on days 2, 14 and 30. Patients had a protocol
In terms of early functioning of the grafts, the control
biopsy at 1 month and all presumed acute rejection episodes
group had 2/15 patients with DGF compared with none in
in the first 6 months were biopsy proven. Patients were asked
either treatment group. We then compared EF kidneys
specifically about noticeable tremor and also examined for
against those with DGF or SGF, since SGF has been shown to
tremor in the clinic on days 14 and 30.
have a deleterious impact on graft survival and increased risk
HO-1 was measured using the Stress XPress Human
of acute rejection similar to that seen with DGF (6). EF was
HO-1 ELISA kit from Stressgen (Vancouver, Canada). The
seen in 6 of 14 (43%) of controls, 10 of 14 (71%) of low dose
HO-1 was extracted from the pellet obtained after the centrif-
and 13 of 14 (93%) of the high dose group (P?0.013). As seen
ugation of 3 ml of urine. The extraction and immunoassay
in Figure 1, serum creatinine was lower at every time point in
were performed following the manufacturer’s instructions.
patients treated with the bioflavonoids. Median serum Cr was
Lipoxin A4 and 15-epi-lipoxin A4 was also measured by
significantly lower at 2 days (control 7.65 mg/dl, range 4.7–
ELISA. Prior to performing the immunoassay, 5 ml of centri-
11.4, low dose 5.85, 1.4 –9.3, high dose 4.15, 1.6 –5.7;
fuged recipient urine was acidified with 1N HCl and applied
P?0.0002) and 30 days (control 1.6 mg/dl, 1.2–3.0, low dose
to a preconditioned C18 column (JTBaker, Phillipsburg, NJ).
1.65, 1.0 –2.3, high dose 1.2, 0.9 –2.2; P?0.026). Incidence of
The column was then washed with water and petroleum
acute rejection within 6 months (including protocol biopsy)
ether. The Lipoxin A4 and 15-epi-lipoxin A4 were eluted with
was 2 of 14 control (14.3%), 2 of 14 low dose 14.3% and 0 high
methyl formate. After evaporation of the methyl formate the
dose. Both rejections in the control group were Banff IIb,
samples were resuspended in 250 ?l of Extraction Buffer
while the two rejections in the low dose group were Ia (as well
(supplied with the kit). To measure the concentrations of
as being subclinical) and Ib. Tacrolimus associated tremor
lipoxin A4 and 15-epi-lipoxin A4 we used enzyme immuno-
was detected on physical examination on day 30 in 2 high
assay kits from Neogen Corporation (Lexington, KY), 50 ?l
dose patients (13%) vs. 18 of 40 (45%) of the rest. It was
of extracted samples was assayed in duplicate according to the
mentioned as a problem by patients in 7% of the high dose
group (1 patient) vs. 10.3% of the rest.
Category variables were compared by chi squared and
Because there were more men in the control group, we
continuous variables by the Kruskal-Wallis test. Other possi-
performed a variance weighted least square regression to in-
ble covariates for confounders were sought using the vari-
sure that the lower creatinines in the bioflavonoid groups was
ance-weighted least square regression model. Level of signif-
not due to having lower creatinine in females. For baseline
icance was taken at P?0.05. Sample size calculation was based
characteristics, sex was not a cofounder between the groups
upon primary endpoints of early function and day 30 creati-
(P?0.642). For serum creatinine, use of Oxy-Q was signifi-
nine with an estimated power of 80% to detect a 20% differ-
cantly associated with decrease serum creatinine at 2 days
ence, with a target of 40 patients, given the standard devia-
(both high and low dose vs. placebo, P?0.0001) and at 30
tions calculated in our open label study.
days (high dose vs. placebo, P?0.022) and this effect was
independent of sex, although women were also indepen-
dently associated with lower creatinine levels on 30-days as
As seen in Table 1, the three treatment groups were well
compared to men.
matched by age, cold ischemia time, timing of pulsatile per-
Activity of HO-1 in the urine was measured in the early
fusion, HLA mismatches and proportion of highly sensitized
postoperative period. As seen in Figure 2, there was a stepwise
(PRA?80%) patients. The only difference was the control
dose response progression of increasing HO-1 activity from
group having a higher proportion of men (71%). There were
control to low dose to high dose groups at all days measured
four withdrawals: one by patient choice and three for urine
(P?0.046), with pairwise significance in the control vs. high
leak (data prior to withdrawal was included). One urine leak
dose comparison (P?0.04). Similarly, as seen in Figure 3,
was in the low-dose group and two were in the high-dose
there was lowest HO-1 activity in the 2 patients with DGF,
group, although one of these was due to a technical stent
intermediate activity in the patients with SGF and highest
problem and no ureteral ischemia was seen at the time of
activity in the EF group (P?0.006), with pairwise significance
Demographic and Transplant Variables by Treatment Groups
Age, median (range)
?12 hours before pulsatile perfusion (%)
Cold ischemia time, median hours (range)
Thymoglobulin induction (%)
Transplantation • Volume 80, Number 11, December 15, 2005
Renal function following renal transplant by
Hemoxygenase 1 levels in urine of renal trans-
treatment group. *P?0.05; **P?0.001.
plant recipients by early function. HO-1, hemoxygenase 1.
unexplained elevation of liver function tests. In the control
group, one patient had a new onset of a seizure disorder and
another patient had a prolonged ileus.
The deleterious effects of DGF (7) and SGF (6) on short
and long term graft function, especially when associated with
acute rejection, are well described. Multiple therapeutic inter-
ventions are successful in reversing acute ischemic injury in
rodent models but that success has not yet translated into
clinically effective therapies (8, 9). The failure of therapies
targeted to a specific pathway in the IR cascade likely stems
from the multifactorial nature of DGF including both anti-
gen-dependent and -independent mechanisms as well as the
fact that much of the injury leading to DGF may begin at the
onset of brain death prior to organ procurement (10).
The bioflavonoids quercetin and curcumin have mul-
tiple effects that should theoretically be of benefit in IR and
immune mediated injury. They are antioxidants that inhibit
xanthine oxide (11) and scavenge free radicals (12). They re-
duce pro-inflammatory cytokines through blockade of
NF-kB (13) and induction of the hemoxygenase-1 (HO-1)
enzyme (14). They are renoprotective in several models of
rodent ischemic and toxic injury (15). We have shown that
quercetin and curcumin prevent renal injury in rodent mod-
Hemoxygenase 1 levels in urine of renal trans-
els of IR (3) and ureteral obstruction (16). Furthermore, these
plant recipients by treatment group. HO-1, hemoxygenase 1.
bioflavonoids were synergistic with MMF in reducing isch-
emic injury as well as acute rejection (17). Alloimmune re-
for EF vs. SGF (P?0.05) and EF vs. DGF (P?0.02). Total anti-
sponses may be inhibited by bioflavonoids through blockade
oxidant capacity, lipoxin A4 and 15-epi lipoxin A4 were also
of cell mediated cytotoxicity (14) and T cell activation (13).
measured, however results were statistically and clinically equiv-
These findings led to an open label phase I study of quercetin
alent in all treatment and outcome groups (data not shown).
and curcumin in renal transplant recipients (5). We found
The medication was well tolerated with minimal side
that it was well tolerated, did not effect cyclosporine or ta-
effects. One patient in the high dose group had a transient
crolimus levels, had no deleterious effects in patients with
© 2005 Lippincott Williams & Wilkins
Shoske et al.
good graft function and showed improvement in graft func-
tion in those with DGF or chronic allograft nephropathy.
1. Shoskes DA, Shahed AR, Kim S. Delayed graft function. Influence on
Surprisingly, we also saw that patients with drug induced
outcome and strategies for prevention. Urol Clin North Am 2001; 28:
tremor reported a reduction or cessation when they were tak-
2. Pratschke J, Wilhelm MJ, Kusaka M, et al. Brain death and its influence
ing the bioflavonoids.
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In the present randomized placebo controlled study,
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3. Shoskes DA. Effect of bioflavonoids quercetin and curcumin on isch-
had beneficial effects in the early posttransplant period. Be-
emic renal injury: a new class of renoprotective agents. Transplantation
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4. Shoskes DA, Jones EA, Shahed A. Synergy of mycophenolate mofetil
fusion pump, our incidence of dialysis dependent DGF is low.
and bioflavonoids in prevention of immune and ischemic injury.
We do, however, have long cold ischemia times. Nevertheless,
Transplant Proc 2000; 32: 798.
the only 2 instances of DGF in our study were in the control
5. Shoskes DA, Thomas M, Pobgee R, et al. Phase I study of oral bioflavonoids
in cadaveric renal transplant recipients: effects on delayed graft function
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and calcineurin inhibitor toxicities. Transplant Proc 2003; 35: 841.
in patients who don’t require posttransplant dialysis, SGF has
6. Humar A, Johnson EM, Payne WD, et al. Effect of initial slow graft
been shown to be deleterious to outcomes (6). In this study,
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DGF and SGF were least likely in the high dose bioflavonoid
7. Shoskes DA, Cecka JM. Deleterious effects of delayed graft function in
group. In addition, the high dose bioflavonoid group had the
cadaveric renal transplant recipients independent of acute rejection.
lowest serum creatinine values, the least neurotoxicity and an
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8. Noel C, Hazzan M, Coppin MC, et al. A randomized controlled trial of
tion) of 0%. This beneficial effect may have come from any of
pentoxifylline for the prevention of delayed graft function in cadaveric
kidney graft. Clin Transplant 1997; 11: 169.
the previously mentioned known mechanisms of biofla-
9. Salmela K, Wramner L, Ekberg H, et al. A randomized multicenter trial
vonoids or from other undiscovered pathways.
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One plausible explanation for the beneficial effects of
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these bioflavonoids is the induction of HO-1, an inducible
renal transplantation: a report of the European Anti-ICAM-1 Renal
enzyme that produces carbon monoxide. There has been
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enges superoxide and increases nitric oxide concentration in ischaemia-
to increased HO-1 activity have lower serum creatinines at 1
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year (20). In our study there was a stepwise increase in urinary
Ranjan D, Chen C, Johnston TD, et al. Curcumin inhibits mitogen
HO-1 activity with increasing bioflavonoid dose. Quercetin
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signaling. J Surg Res 2004; 121: 171.
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muscle cells (21). Furthermore, curcumin induces HO-1
suppression of lymphocyte proliferation, development of cell-medi-
mRNA in human renal proximal tubule cells (22) and that
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this induction depends upon the Nrf2 transcription factor
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Singh D, Chander V, Chopra K. Quercetin, a bioflavonoid, attenuates
(23). These results are completely observational and it is pos-
ferric nitrilotriacetate-induced oxidative renal injury in rats. Drug
sible that the increased urinary HO-1 activity seen in this
Chem Toxicol 2004; 27: 145.
study did not reflect intra-renal changes and may have been
Jones EA, Shahed A, Shoskes DA. Modulation of apoptotic and inflam-
due to factors other than the ingested bioflavonoids. The
matory genes by bioflavonoids and angiotensin II inhibition in ureteral
obstruction. Urology 2000; 56: 346.
mechanism of this effect deserves further study.
Jones EA, Shoskes DA. The effect of mycophenolate mofetil and poly-
Neurotoxicity associated with calcineurin inhibitors is
phenolic bioflavonoids on renal ischemia reperfusion injury and re-
a common and often annoying problem for patients that does
pair. J Urol 2000; 163: 999.
not always resolve with dose reduction. We had previously
Bach FH. Heme oxygenase-1 as a protective gene. Wien Klin Wochen-
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Kapturczak MH, Wasserfall C, Brusko T, et al. Heme oxygenase-1
tremor had reduction or resolution while taking biofla-
modulates early inflammatory responses: evidence from the heme ox-
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study, observation of hand tremor was lowest in the high dose
Exner M, Bohmig GA, Schillinger M, et al. Donor heme oxygenase-1
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however in one animal model, administration of curcumin
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mediated by induction of HO-1 activity. Future studies
Balogun E, Hoque M, Gong P, et al. Curcumin activates the heme
should examine whether the benefits are also seen in cadav-
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element. Biochem J 2003; 371: 887.
Shukla PK, Khanna VK, Khan MY, Srimal RC. Protective effect of cur-
treatment of the donor and/or recipient would give equiva-
cumin against lead neurotoxicity in rat. Hum Exp Toxicol 2003; 22:
lent or superior results.