The Pharmacological Activities of Crocus sativus L.: A Review Based on the Mechanisms and Therapeutic Opportunities of its Phytoconstituents

Crocus species are mainly distributed in North Africa, Southern and Central Europe, and Western Asia, used in gardens and parks as ornamental plants, while Crocus sativus L. (saffron) is the only species that is cultivated for edible purpose. The use of saffron is very ancient; besides the use as a spice, saffron has long been known also for its medical and coloring qualities. Due to its distinctive flavor and color, it is used as a spice, which imparts food preservative activity owing to its antimicrobial and antioxidant activity. This updated review discusses the biological properties of Crocus sativus L. and its phytoconstituents, their pharmacological activities, signaling pathways, and molecular targets, therefore highlighting it as a potential herbal medicine. Clinical studies regarding its pharmacologic potential in clinical therapeutics and toxicity studies were also reviewed. For this updated review, a search was performed in the PubMed, Science, and Google Scholar databases using keywords related to Crocus sativus L. and the biological properties of its phytoconstituents. From this search, only the relevant works were selected. The phytochemistry of the most important bioactive compounds in Crocus sativus L. such as crocin, crocetin, picrocrocin, and safranal and also dozens of other compounds was studied and identified by various physicochemical methods. Isolated compounds and various extracts have proven their pharmacological efficacy at the molecular level and signaling pathways both in vitro and in vivo. In addition, toxicity studies and clinical trials were analyzed. The research results highlighted the various pharmacological potentials such as antimicrobial, antioxidant, cytotoxic, cardioprotective, neuroprotective, antidepressant, hypolipidemic, and antihyperglycemic properties and protector of retinal lesions. Due to its antioxidant and antimicrobial properties, saffron has proven effective as a natural food preservative. Starting from the traditional uses for the treatment of several diseases, the bioactive compounds of Crocus sativus L. have proven their effectiveness in modern pharmacological research. However, pharmacological studies are needed in the future to identify new mechanisms of action, pharmacokinetic studies, new pharmaceutical formulations for target transport, and possible interaction with allopathic drugs.

The therapeutic potential of Crocus sativus Linn.: A comprehensive narrative review of clinical trials

Crocus sativus Linn. (Saffron) is valued worldwide for its potential use in the management of various degenerative disorders, including cardiovascular diseases (CVDs), diabetes, cancer, metabolic syndrome (MetS), neurodegenerative diseases, immune disorders, and sexual dysfunction. Previous reports, based on clinical trials, suggest that crocetin, crocin, picrocrocin, and safranal are the main bioactive components of saffron with antioxidant, anti-inflammatory, and anti-apoptotic effects. In this comprehensive narrative review, we studied the recent clinical trials, investigating the medicinal applications of saffron and/or its components. The present results can provide important insights into the potential of saffron in preventing and treating different disorders, with a special focus on the underlying cellular and molecular mechanisms. However, further high-quality studies are needed to firmly establish the clinical efficacy of saffron in treating some degenerative diseases.

Effects of crocin and saffron aqueous extract on gene expression of SIRT1, AMPK, LOX1, NF-κB, and MCP-1 in patients with coronary artery disease: A randomized placebo-controlled clinical trial

This trial evaluated the potential impacts of saffron aqueous extract (SAE) and its main carotenoid on some of the atherosclerosis-related gene expression and serum levels of oxidized low-density cholesterol (ox-LDL) and Monocyte chemoattractant protein 1 (MCP-1) in patients with coronary artery disease (CAD). Participants of this randomized controlled trial included 84 CAD patients who categorized into three groups: Group 1 received crocin (30 mg/day), Group 2 SAE (30 mg/day), and Group 3 placebo for 8 weeks. Gene expression of Sirtuin 1 (SIRT1), 5'-adenosine monophosphate-activated protein kinase (AMPK), Lectin-like oxidized LDL receptor 1 (LOX1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and MCP-1 in peripheral blood mononuclear cells assessed by real-time PCR. Furthermore, serum ox-LDL and MCP-1 levels measured at the beginning and end of the intervention. Compared with the placebo group, gene expression of SIRT1 and AMPK increased significantly in the crocin group (p = .001), and the expression of LOX1 and NF-κB decreased significantly (p = .016 and .004, respectively). Serum ox-LDL levels decreased significantly in the crocin group after the intervention (p = .002) while MCP-1 levels decreased both in crocin and SAE groups (p = .001). Crocin may have beneficial effects on CAD patients by increasing the gene expression of SIRT1 and AMPK and decreasing the expression of LOX1 and NF-κB.

The effects of crocin on psychological parameters in patients under methadone maintenance treatment: a randomized clinical trial

Background

Methadone maintenance treatment (MMT) might be associated with the symptoms of depression and anxiety, sleep disturbances and sexual dysfunctions. This study was designed to determine the effects of crocin on psychological parameters in patients under MMT.

Methods

Patients under MMT were randomly allocated into two groups to receive either 30 mg/day crocin (2 plus crocin tablet, 15 mg BID) (n = 25) or placebo (2 tablets per day, 15 mg BID) (n = 25), one hour after taking food, for 8 weeks. Psychological parameters were evaluated at baseline and end of the trial to determine related associations between crocin and patients’ mental health status.

Results

After 8-week intervention, crocin significantly decreased Beck Depression Inventory (b − 6.66; 95% CI, − 9.88, − 3.45; P < 0.0001), Beck Anxiety Inventory (b − 4.35; 95% CI, − 5.94, − 2.75; P < 0.0001), general health questionnaire (b − 4.45; 95% CI, − 7.68, − 1.22; P = 0.008) and Pittsburgh Sleep Quality Index (b − 2.73; 95% CI, − 3.74, − 1.73; P < 0.0001) in patients under MMT, compared with the placebo. Crocin also significantly improved International Index of Erectile Functions (b 4.98; 95% CI, 2.08, 7.88; P = 0.001) rather than placebo.

Conclusion

Our findings indicated that taking crocin for 8 weeks by patients under MMT had beneficial effects on their mental health status. Crocin can be recommended as an adjunct to methadone in opioid withdrawal protocols because of the ability to improve the quality of life and decrease opioids side effects in these patients.

This trial was registered in the Iranian website for clinical trials registry as http://www.irct.ir: IRCT2017110537243N1.

Clinical trial registration number

www.irct.ir: http://www.irct.ir: IRCT2017110537243N1.

The SAFE pathway is involved in the postconditioning mechanism of oxytocin in isolated rat heart

Oxytocin (OT) has a postconditioning effect against the ischemia-reperfusion (I/R) injury. However, its precise cardioprotection mechanism at the early reperfusion phase remains under debate. Our previous study revealed that OT postconditioning (OTpost) is cardioprotective by activating the Reperfusion Injury Salvage Kinase (RISK) pathway. Therefore, the present study is aimed to determine the biological effects of OTpost via the OT receptor and the activation of the JAK/STAT3 signaling pathway, mitochondrial adenosine triphosphate-dependent potassium channel (mitoKATP), nitric oxide (NO) release, and its anti-apoptotic effects against I/R injury in an isolated rat heart model. Sixty-three rats were randomly allocated to one of nine groups. OT was perfused 40 min prior to the regional ischemia or 15 min at the early reperfusion phase. AG490 (a JAK/STAT3 inhibitor), 5HD (a mitoKATP blocker), atosiban (an OT receptor antagonist), L-NAME (a nonspecific nitric oxide synthase inhibitor) were applied either alone or in combination with OT during the pre-ischemia phase and/or in the early reperfusion phase. Myocardial infarct size, hemodynamic factor, ventricular arrhythmia, coronary flow, cardiac biochemical marker, and the apoptosis index were determined at the end of reperfusion. Oxytocin postconditioning reduced infarct size, lactate dehydrogenase activity, arrhythmia score, ventricular fibrillation, and apoptosis. Moreover, AG490, 5HD, atosiban, and L-NAME abrogated the cardioprotective effects of OT. Our results demonstrated that the cardioprotective effects of OT are mediated by NO release, and the activation of mitoKATP and the SAFE pathway through the JAK/STAT3 signaling cascade that finally lead to decrease in the apoptosis index during the early reperfusion phase.

A comprehensive review of the pharmacological potential of Crocus sativus and its bioactive apocarotenoids

Crocus sativus is an herbaceous plant that belongs to family Iridaceae. It is commonly known as saffron and has been used for medicinal purposes since many centuries in India and other parts of the world. Saffron of commercial importance comprises of dried stigmas of the plant and is rich in flavonoids, vitamins, and carotenoids. Carotenoids represent the main components of saffron and their cleavage results in the formation of apocarotenoids such as crocin, picrocrocin, and safranal. Studies conducted during the past two decades have revealed the immense therapeutic potential of saffron. Most of the therapeutic properties are due to the presence of unique apocarotenoids having strong free radical scavenging activity. The mode of action of these apocarotenoids could be: modulatory effects on detoxifying enzymes involved in combating oxidative stress, decreasing telomerase activity, increased the proapoptotic effect, inhibition of DNA, RNA and protein synthesis, and by a strong binding capacity of crocetin with tRNA. The present review focuses on the therapeutic role of saffron and its bio oxidative cleavage products and also highlights the possible molecular mechanism of action. The findings reported in this review describes the wide range of applications of saffron and attributes its free radical scavenging nature the main property which makes this spice a potent chemotherapeutic agent for the treatment of various diseases.

Efficacy and Safety of Saffron Supplementation: Current Clinical Findings

Saffron (Crocus savitus) is a Middle-Eastern herb with strong antioxidant properties. Its major constituents, safranal, crocin, and crocetin, are also antioxidants and bear structural similarities to other well-known natural antixodant substances, such as zeaxanthin. Given the role of oxidative stress in many diseases, considerable interest has been shown into the potential role of saffron supplementation as a treatment for a range of diseases. In vitro and animal studies have provided evidence that saffron and its constituents may be potent therapies for a range of pathologies, including Alzheimer's disease, age-related macular degeneration (AMD) and cardiac ischemia. Whether these findings translate into clinical efficacy, however, has as of yet been incompletely assessed. This makes assessing the role of saffron supplementation in these diseases difficult. Here, we review the current human clinical evidence supporting saffron supplementation as a treatment for a range of pathologies and the underlying science supporting its use.

Saffron (Crocus sativus) pretreatment confers cardioprotection against ischemia-reperfusion injuries in isolated rabbit heart

Restoration of blood flow to the ischemic myocardium is imperative to avoid demise of cardiomyocytes, but is paradoxically associated with irreversible damage to cardiac tissues due to the excessive generation of reactive oxygen species (ROS). We have previously reported that saffron, a natural antioxidant, attenuated ischemia-reperfusion (IR) injuries in vitro; however, its role in a meaningful cardiac recovery remains unknown. Here, we show that saffron supplement (oral administration for 6 weeks) reduced myocardial damage and restored cardiac function in an IR model of rabbit hearts. This was evidenced by improved left ventricle pressure, heart rate and coronary flow, and left ventricle end diastolic pressure (LVEDP) in IR hearts (isolated from rabbits pre-exposed to saffron (S/IR)). Electrophysiological recordings revealed a significant decline in both premature ventricle contraction and ventricle tachycardia/fibrillation in S/IR compared to IR hearts. This was paralleled by increased expression of the contractile proteins α-actinin and Troponin C in the myocardium of S/IR hearts. Histological examination combined to biochemical analysis indicated that hearts pre-exposed to saffron exhibited reduced infarct size, lower lipid peroxidation, with increased glutathione peroxidase activity, and oxidation of nitro blue tetrazolium (by reactive oxygen species). Furthermore, in contrast with IR hearts, saffron pretreatment induced restoration of the phosphorylation level of the survival proteins Akt and 4EBP1 and reduced activity of p38. Collectively, our data demonstrate that the natural antioxidant saffron plays a pivotal role in halting IR-associated cardiac injuries and emerges as a novel preventive tool for ischemic heart disease.

Evaluation of Melissa officinalis (Lemon Balm) Effects on Heart Electrical System

Background:

Melissa officinalis, an herbal drug, is well known and frequently applied in traditional and modern medicine. Yet, there is inadequate information regarding its effects on electrical properties of the heart. The present study attempted to elucidate the effects of Melissa officinalis aqueous extract on electrocardiogram (ECG) in rat.

Objectives:

ECG is an easy, fast and valuable tool to evaluate the safety of used materials and drugs on heart electrical and conductivity properties. Many drugs with no cardiovascular indication or any overt cardiovascular effects of therapeutic dosing become cardiotoxic when overdosed (16). On the other hand, there are numerous substances and drugs that can cause ECG changes, even in patients without a history of cardiac disease. Therefore, this study was conducted to elucidate safety and outcome of one-week administration of M. officinalis aqueous extract on blood pressure and ECG parameters of rats.

Materials and Methods:

Four animal groups received tap water (control group), aqueous extracts of Melissa officinalis 50 (M50), 100 (M100) and 200 (M200) mg/kg/day, respectively and orally for a week. ECG and blood pressure were recorded on the eighth day of experiment.

Results:

Consumption of Melissa officinalis extract associated with prolonged QRS interval (P < 0.05 for M50 and M100 groups and P < 0.01 for M200 group versus the control group, respectively), prolonged QTc and JT intervals (P < 0.01 for different M groups versus the control group) and prolonged TpTe interval (P < 0.001 when M groups compared with the control group) of ECG. However, different doses of the extract had no significant effect on RR interval, PR interval, amplitudes of ECG waves, heart rate and blood pressure.

Conclusions:

For the first time, this study revealed that consumption of Melissa officinalis extract is associated with significant ECG alterations in rat. Future studies are necessary to determine potential clinical outcomes.

Protective effects of saffron (Crocus sativus) against lethal ventricular arrhythmias induced by heart reperfusion in rat: a potential anti-arrhythmic agent

CONTEXT

Saffron (Crocus sativus L.) has been used as a cuisine spice in eastern and western societies for thousands of years. In traditional medicine, saffron is recommended for the treatment of various kinds of disorders including heart palpitations.

OBJECTIVE

We investigated the hypothesis of the protective effect of saffron on lethal cardiac arrhythmias induced by heart ischemia-reperfusion in rat.

MATERIALS AND METHODS

Animals were divided into a control (CTL) group that received tap water, Saf50, Saf100 and Saf200 groups that were orally treated with aqueous extracts of saffron, at dosages of 50, 100 and 200 mg/kg/day, respectively, and amiodarone (Amio) group that orally received 30 mg/kg/day for seven days. On day 8, heart ischemia-reperfusion was induced by ligation and releasing of the left anterior descending coronary artery.

RESULTS

During reperfusion, the numbers and durations of ventricular fibrillation (VF) decreased in all groups compared to the CTL group (p < 0.05). Ventricular tachycardia (VT)/VF numbers (3.2 ± 1.2), durations (4.9 ± 2.6) and also arrhythmia severity (1.9 ± 0.35) were decreased significantly in the Saf100 group versus CTL group values (18.4 ± 11.6, 52 ± 31 and 3.3 ± 0.3, respectively). The PR and QTcn intervals of ECG were significantly longer in the Saf200 group (p < 0.001 versus CTL). The other doses of saffron only significantly prolonged the QTcn interval.

CONCLUSION

The results suggest that pretreatment with saffron, especially at the dosage of 100 mg/kg/day, attenuates the susceptibility and incidence of fatal ventricular arrhythmia during the reperfusion period in the rat. This protective effect is apparently mediated through reduction of electrical conductivity and prolonging the action potential duration.

Effect of saffron on fluoxetine-induced sexual impairment in men: randomized double-blind placebo-controlled trial

RATIONALE

Saffron (Crocus sativus L.) has shown aphrodisiac effects in some animal and human studies.

OBJECTIVES

To assess the efficacy and tolerability of saffron in fluoxetine-related sexual dysfunction.

METHODS

This was a 4-week randomized double-blind placebo-controlled study. Thirty-six married male patients with major depressive disorder whose depressive symptoms had been stabilized on fluoxetine and had subjective complaints of sexual impairment entered the study. The patients were randomly assigned to saffron (15 mg twice per day) or placebo for 4 weeks. International Index of Erectile Function scale was used to assess sexual function at baseline and weeks 2 and 4.

RESULTS

Thirty patients finished the study. Baseline characteristics as well as baseline and final depressive symptoms scores were similar between the two groups. Effect of time × treatment interaction on the total score was significant [Greenhouse-Geisser-corrected, F (1.444, 40.434) = 6.154, P = 0.009]. By week 4, saffron resulted in significantly greater improvement in erectile function (P < 0.001) and intercourse satisfaction domains (P = 0.001), and total scores (P < 0.001) than the placebo group. Effect of saffron did not differ significantly from that of placebo in orgasmic function (P = 0.095), overall satisfaction (P = 0.334), and sexual desire (P = 0.517) domains scores. Nine patients (60%) in the saffron group and one patient (7%) in the placebo group achieved normal erectile function (score > 25 on erectile function domain) at the end of the study (P value of Fisher's exact test = 0.005). Frequency of side effects were similar between the two groups.

CONCLUSIONS

Saffron is a tolerable and efficacious treatment for fluoxetine-related erectile dysfunction.