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- Saffron (Crocus sativus, Iridaceae)
- Efficacy and Safety
- Oxidative Stress
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Date:
02-15-2016 | HC# 091565-538
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Re: Saffron of Potential Benefit in Certain Cognitive, Mood, Vision, and Menstrual Conditions and Apparently Safe in Therapeutic Doses
Broadhead GK, Chang A, Grigg J, McCluskey P. Efficacy and safety of saffron supplementation: current
clinical findings. Crit Rev Food Sci Nutr. April 15, 2015; [epub ahead of
print]. doi: 10.1080/10408398.2013.879467.
Saffron (stigmas of Crocus sativus, Iridaceae) is used widely as a traditional medicine
and spice. Several compounds in saffron have been shown to be bioactive;
specifically, crocetin, crocin, and safranal have demonstrated antioxidant activity.
Also, crocin is considered to be the compound providing saffron's color, and
safranal is likely the compound contributing to the herb's aroma. This review
covers the efficacy and safety of saffron for the potential treatment of
several health conditions associated with chronic oxidative stress, as assessed
in human clinical studies and supported by preclinical research.
Alzheimer's disease progresses, in part, due
to nervous system damage from oxidative stress. In an in vitro study, crocin prevented
both amyloid plaque formation and neurofibrillary tangles, markers of Alzheimer's
disease pathology. Memory improvements in normal rats, rats with induced memory
problems, and rat models of both diabetic cerebral disease and Alzheimer's
disease, were seen with saffron consumption. Mechanistic studies suggest that
both safranal and crocetin share a similar anticholinesterase mechanism of
action as standard Alzheimer's disease pharmaceuticals. In a small clinical
trial with Alzheimer's disease patients, 30 mg of saffron daily for 16 weeks
resulted in better cognition; another study using the same dosage suggested
that saffron was comparable in efficacy to donepezil, a standard pharmaceutical
for this condition.
With in vivo studies addressing mood,
crocetin has been shown to interact with central nervous system receptors,
suggesting molecular modulation. Significant alleviation of depression was
observed in those suffering from mild to moderate depression (30 mg/day of
saffron for six weeks) in two small clinical studies. Another study found that
30 mg/day of saffron for nine weeks was comparable in efficacy to the
pharmaceutical imipramine in those with mild to moderate depression.
During in vivo studies investigating vision, topical
saffron showed positive impacts on retinal blood flow in rabbits, and cataracts
were prevented in a rat model via increased endogenous antioxidant defense. Another
in vivo study with a rat model showed potential benefits of saffron
supplementation in retinitis pigmentosa, perhaps due to antioxidant
bioactivity. In a small clinical study, saffron consumption positively impacted
aspects of age-related macular degeneration, including visual acuity.
Saffron has also been studied for possible
effects in reproductive issues. A clinical study in women reported that 30
mg/day of saffron during two menstrual cycles significantly improved
premenstrual syndrome (PMS) symptoms as compared with placebo (P<0.001). In
women exposed to saffron aroma, levels of 17-beta-estradiol were increased and
the stress hormone cortisol was reduced. Two small clinical trials with men and
women showed that saffron supplementation reduced fluoxetine-induced sexual
dysfunction.
In animal models of cardiovascular disease,
saffron was found to modulate cellular markers of myocardial infarction and attenuate
nuclear factor-kappa B (NF-κB) signaling involved with inflammation and
apoptosis. In addition, other in vivo studies in diabetic and hyperlipidemic
models have shown saffron and crocin decrease cholesterol and triglyceride
concentrations. In both healthy subjects and patients with coronary artery
disease consuming 50 mg of saffron daily for six weeks, a significant decrease
in lipoprotein oxidation susceptibility was observed (P<0.001), though not with
control subjects.
In toxicity investigations, no adverse side
effects were observed at a crocin dosage of 20 mg/day for one month in healthy
subjects; it is mentioned that certain blood parameters including prothrombin
time were lowered in this study. Another study using 400 mg/day of saffron for one
week reported no impacts on multiple blood coagulation parameters. Elevations
of immunoglobulins G and M (markers of the immune system) were observed in
healthy male subjects taking 100 mg of saffron daily for three weeks; these
markers were at normal concentrations following another three weeks of
supplementation. There has been one case of anaphylaxis associated with saffron,
but overall its allergic potential is considered low.
In conclusion, it is stated
that saffron and its bioactive components are effective in alleviating cellular
oxidative stress damage. Both in vivo and clinical trials (limited by small
size and short follow-up) suggest the use of saffron in multiple health
conditions and chronic diseases where excessive reactive oxygen species are a
factor. Further clinical investigations of saffron that are underway will
hopefully substantiate its therapeutic benefits and ideally identify mechanisms
of action in disease states, verifying its use for a variety of conditions.
—Amy C. Keller, PhD
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