Stimulatory effect of Crocus sativus (saffron) on beta2-adrenoceptors of guinea pig tracheal chains

Medicinal Plants for the Treatment of Neuropathic Pain: A Review of Randomized Controlled Trials

Neuropathic pain is a disabling condition caused by various diseases and can profoundly impact the quality of life. Unfortunately, current treatments often do not produce complete amelioration and can be associated with potential side effects. Recently, herbal drugs have garnered more attention as an alternative or a complementary treatment. In this article, we summarized the results of randomized clinical trials to evaluate the effects of various phytomedicines on neuropathic pain. In addition, we discussed their main bioactive components and potential mechanisms of action to provide a better view of the application of herbal drugs for treating neuropathic pain.

Effect and mechanism of safranal on ISO-induced myocardial injury based on network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Sympathetic hyperactivation is a significant risk factor in the development of cardiovascular disease. Safranal has shown good myocardial protection in recent studies, but the mechanism of its role in myocardial injury caused by sympathetic hyperactivation remains unclear.

AIM OF THE STUDY

The purpose of this study was to investigate whether safranal can effectively reduce isoproterenol (ISO)-induced myocardial injury in rats and H9c2 cells and to reveal its pharmacological action and target in inhibiting myocardial injury caused by sympathetic hyperactivation.

MATERIALS AND METHODS

This study was carried out using network pharmacology, molecular docking, and in vitro and in vivo experiments. An in vivo model of myocardial injury was established by subcutaneous injection of ISO, and an in vitro model of H9c2 cell injury was induced by ISO.

RESULTS

Safranal ameliorated myocardial injury caused by sympathetic hyperactivation by reducing the level of myocardial apoptosis. According to the results of network pharmacological analysis and molecular docking, the mechanism by which safranal alleviates myocardial injury may be closely related to the TNF signaling pathway, and safranal plays a role by regulating the core targets of the TNF signaling pathway. Safranal significantly inhibited the protein expression of TNF, PTGS2, MMP9 and pRELA.

CONCLUSION

Safranal plays a protective role in myocardial injury induced by sympathetic hyperactivation by downregulating the TNF signaling pathway.

In Vitro Assessment of Myorelaxant and Antispasmodic Effects of Stigmas, Tepals, and Leaves Hydroethanolic Extracts of Crocus sativus

The valorization of Crocus sativus focuses mainly on the plant’s stigma because it is one of the most expensive and valuable spices in the world and has great value in the food, cosmetics, and pharmacological industries. Due to this high stigma value, the other parts of the plant are considered as by-products; our study aimed to evaluate the myorelaxant and antispasmodic activities of the byproducts (tepals and leaves) to compare them with the stigma of the plant. To investigate the myorelaxant and antispasmodic activities of the Crocus sativus on isolated rabbit and rat jejunum, we used an in vitro technic with an organ bath and an isotonic transducer. Our results showed that the STG (hydroethanolic extract of stigmas) and LV (hydroethanolic extract of leaves) had a moderate myorelaxant effect with IC50 = 6.61 ± 1.5 and 5.08 ± 0.45 mg/ml, respectively. TPL (hydroethanolic extract of tepals) had a significant ( $p˂0.001$ ) inhibitory effect on the amplitude of the rabbit jejunum basic contractions with an IC50 = 1.36 ± 0.15 mg/ml. TPL also caused a significant ( $p˂0.001$ ) antispasmodic activity depending on the dose of the contraction induced by CCh (10−6 M) and KCl (25 mM). The antispasmodic effect of the TPL is slightly altered in the presence of nifedipine by a percentage of 26.8%. This difference is statistically significant ( $p˂0.01$ ). Therefore, the extract could induce the inhibitory effect on L-type voltage-dependent Ca2+ channels, but not on the guanylate cyclase and nitric oxide pathways. That confirmed that the TPL has a comparable effect to the verapamil. The HPLC-DAD analysis of various parts of C. sativus shows that the three extracts contain the kaempferol flavanol compound, the STG also was revealed to be rich in carotenoids crocin, and these isomers are trans and cis-crocin, safranal, and picrocrocin. In contrast, the TPL revealed the presence of isorhamnetin and quercetin, but the LV was rich in hesperidin and mangiferin. In conclusion, this study supports the traditional use of this plant to treat digestive problems and will allow us to explore future possibilities for treating bowel spasms using natural molecules derived from saffron.

Crocus Sativus for Insomnia: A Systematic Review and Meta-Analysis

Insomnia is a common complaint affecting human performance in daily life activities. This study aimed to analyze the effects of Crocus sativus on insomnia. Methods: PRISMA guidelines were used according to the PICOS model. A systematic search of PubMed/Medline and the Cochrane Library was undertaken for literature until December 2021. A random effects model was used with I² statistic to assess heterogeneity and a GRADE assessment was used to assess the quality of the outcomes. Eight articles were included, involving 431 participants. Crocus sativus reduced insomnia severity (SMD: 0.53; 95%CI: -0.05 to 1.11; I² statistic = 59%; p = 0.08) and increased sleep quality (SMD 0.89, 95% CI 0.10 to 1.68; I² statistic = 90%; p = 0.03; 6 studies, 308 participants, very low-quality evidence) and duration (SMD: 0.57; 95%CI: 0.21 to 0.93; I² statistic = 40%; p = 0.002; 5 studies; 220 participants, moderate-quality evidence) compared with the placebos. Although there is limited evidence of a very low- to moderate-quality, Crocus sativus may benefit people with insomnia. This non-pharmacological intervention may reduce the chance of adults with insomnia taking sedative-hypnotic medication, thus reducing dependency and withdrawal symptoms.

The effects of Crocus sativus L. (Saffron) and its ingredients on dietary intakes in cardiovascular disease in Iranian population: A systematic review and meta-analysis

Cardiovascular disease (CVD) is one of the most common causes of mortality around the world. The aim of this study is to summarize and conclude the clinical evidence regarding the use of Crocus sativus (C. sativus) and its ingredients on cardiovascular risk factors. A systematic search was conducted with PubMed, Web of Science (ISI), and Scopus in the English language from 2015 until September 2021. A fixed-effect or random-effects model were applied to pool standard mean difference (SMD) and its 95 % confidence intervals (CI). Randomized controlled studies that assessed the clinical effects of C. sativus and its ingredients on dietary intake (Energy, Carbohydrate, Protein, and total Fat) in human subjects were included. Seven studies comprising 421 participants were included in the meta-analysis. Pooling of results showed significant effect of saffron on total fat (−0.14; 95% CI: −0.49 to 0.20; I² = 57.3%) and significant effect of crocin on Energy (0.94; 95% CI: −0.77 to 2.65; I² = 95.9%), Carbohydrate (0.44; 95% CI: −0.74 to 1.62; I² = 92.6%), and Protein (−0.04; 95% CI: −0.26 to 0.34; I² = 0.0%). Present meta-analysis suggests that treatment with crocins is more effective than saffron in energy, carbohydrate, and protein, while saffron is more effective than crocins in fat. However, further studies are needed to confirm these findings.

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.

Possible therapeutic effects of Crocus sativus stigma and its petal flavonoid, kaempferol, on respiratory disorders

CONTEXT

Crocus sativus L. (Iridaceae), or saffron, has been used as food additives and spices. In the traditional medicine of Iran, C. sativus has been used for the treatment of liver disorders, coughs, and as an anti-inflammatory agent for eyes.

OBJECTIVE

The current study reviewed the possible therapeutic effects of C. sativus stigma and its petal flavonoid (kaempferol) on respiratory disorders with several mechanisms such as anti-inflammatory, and smooth muscle relaxant effects.

MATERIALS AND METHODS

This review article searched databases including PubMed, Google Scholar, and ScienceDirect, up to November 2019. The keywords including; 'Crocus sativus', 'saffron', 'kaempferol', 'airway inflammation', and 'smooth muscle relaxant' were searched.

RESULTS

C. sativus reduced nitric oxide (NO), inducible nitric oxide synthase (iNOS) levels and inflammatory cytokines in the lung tissue. Saffron and kaempferol reduced white blood cells (WBCs) and the percentage of neutrophils and eosinophils in bronchoalveolar lavage fluid. Moreover, saffron reduced tracheal responsiveness to methacholine and ovalbumin on tracheal smooth muscles. In addition, kaempferol reduced the total leukocyte and eosinophil counts similar to the effect of dexamethasone and also showed relaxant effects on smooth muscle.

DISCUSSION AND CONCLUSION

Crocus sativus and its petal flavonoid, kaempferol, showed relatively potent therapeutic effects on respiratory disorders by relaxation of tracheal smooth muscles via stimulatory or blocking effects on β-adrenoceptor and muscarinic receptors, respectively. Saffron and kaempferol also decreased production of NO, inflammatory cytokines and chemokines in respiratory systems.

Variation in Headspace Volatiles of Saffron Determined by GC×GC-ToF-MS

Saffron, obtained from the stigmas of Crocus sativus L (Iridaceae), is the most expensive spice traded worldwide. In addition to its culinary uses, various medicinal properties have been confirmed for saffron, which has recently captured the interest of the phytotherapy industry. The quality of saffron is determined by the presence of 3 compounds, namely, crocin, picrocrocin, and safranal, with the latter being responsible for the distinct aroma characteristic of saffron. To determine the volatiles and assess possible geographical variation, headspace analysis using 1-dimensional and 2-dimensional gas chromatography (GC) on 26 samples collected from 9 countries was undertaken. The major constituents identified include safranal, 4-ketoisophorone, acetic acid, 2(5H)-furanone, and 1,4-cyclohexanedione-2,2,6-trimethyl. Quantitative rather than a qualitative variation was noted in the samples from different origins. The levels of safranal ranged from 22.1% to 62.4%. This study represents the first report on the headspace volatiles of saffron using GC×GC-time-of-flight-mass spectrometry and clearly demonstrates the superior chromatographic potential of 2-dimensional GC compared with conventional 1-dimensional GC.

The Relaxant Effect of Crocin on Rat Tracheal Smooth Muscle and Its Possible Mechanisms

Crocin, a component of saffron, showed hypotensive activity which is perhaps due to vascular smooth muscle relaxant effect. The relaxant effects of saffron on tracheal smooth muscle also could be due to its constituent, crocin. In the present study, the relaxant effects of crocin and its possible mechanisms on rat tracheal smooth muscle were investigated. The relaxant effects of three cumulative concentrations of crocin (30, 60, and 120 μM) or theophylline (0.2, 0.4, 0.6 mM) as positive control were examined on pre-contracted tracheal smooth muscle by methacholine or KCl in non-incubated or incubated conditions with different agents including atropine, chlorpheniramine, indomethacin, diltiazem, glibenclamide, and propranolol. In non-incubated tracheal smooth muscle, crocin showed significant relaxant effects on KCl induced muscle contraction (p < 0.001 for two higher concentrations). However, crocin did not show relaxant effect on methacholine induced tissue contraction. In incubated tissues with chlorpheniramine, indomethacin, diltiazem and propranolol, there were no significant differences in the relaxant effects of crocin between non-incubated and incubated tissues. However, the relaxant effects of crocin obtained in incubated tissues with atropine and glibenclamide were significant lower than non-incubated tracheal smooth muscle (p < 0.05 to p < 0.001). The EC₅₀ value obtained in incubated tissue with propranolol was significantly increased. Theophylline showed significant relaxant effect on both KCl and methacholine induced tissue contraction (p < 0.01 to p < 0.001). A relatively potent relaxant effect of crocin on tracheal smooth muscle, lower than that of theophylline was shown. Muscarinic receptor blocking, potassium channels opening and ß₂-adrenoreceptors stimulation were also suggested as possible mechanisms of this effect.

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.

Pharmacokinetic Properties of Saffron and its Active Components

Saffron as a medicinal plant has many therapeutic effects. Phytochemical studies have reported that saffron is composed of at least four active ingredients which include crocin, crocetin, picrocrocin and safranal. The carotenoids of saffron are sensitive to oxygen, light, heat and enzymatic oxidization. However, regulation of these factors is required for saffron quality. Some pharmacologic effects of saffron and its active compounds include cardioprotective, neuroprotective, memory enhancer, antidepressant and anxiolytic. Among more than 150 chemicals of saffron, the most biologically active components are two carotenoids including crocin and crocetin. Most of the pharmacokinetic studies are related to these compounds. The pharmacokinetic studies have shown that crocin is not available after oral administration in blood circulation. Crocin is converted to crocetin in intestine but after intravenous injection, the level of crocetin in plasma is low. Crocetin can distribute in different tissues because of weak interaction between crocetin and albumin. Also it can penetrate blood-brain barrier and reach CNS by passive transcellular diffusion; thus it can be effective in neurodegenerative disorders. The large portion of crocin is eliminated via feces.

Corilagin Attenuates the Parkinsonismin Japanese Encephalitis Virus Induced Parkinsonism

This study evaluates the protective effect of corilagin against Parkinsonismin Japanese encephalitis virus (JEV) induced Parkinson’s disease. The JaGAr-01 strain of virus was used to induce JE. The virus was injected into the rats (13 days age) at the midpoint between the two ears. Adult rats, 12 week after the inoculation of virus, were used for the further study. Corilagin (20 mg/kg) and levodopa with dopa decarboxylase inhibitor (LEV, 10 mg/kg) were administered intraperitoneally for the duration of one week. Bradykinesia and the levels of dopamine in the brain were estimated at the end of protocol. There was a significant decrease inthe motor function in the corilagin, LEV and LEV + corilagin treated groupscompared to the negative control group. However treatment with corilagin, LEV and LEV + corilagin significantly increases the level of dopamine in the brain compared to the negative control group. This study concludes that corilagin ameliorates the Parkinsonismin JEV induced Parkinsonism. Moreover it shows a synergistic effect when treated with LEV. Data presented in the investigation supports that corilagin can be used clinically.

Corilagin Attenuates Allergy and Anaphylactic Reaction by Inhibiting Degranulation of Mast Cells

Background

This study evaluated the anti-allergic activity of corilagin and also postulates the possible mechanism of its action.

Material/Methods

Corilagin was given orally at dose of 10, 20, and 40 mg/kg/day. All the animals (guinea pigs, rats, and mice) were sensitized for allergy such as eosinophilia and leukocytosis induced by milk; degranulation of mast cell by compound 48/80; and passive and active anaphylaxis. Moreover, the antagonistic effect was determined by estimating the effect of corilagin on contraction of guinea pig tracheal chain and ileum induced by Ach and histamine, respectively.

Result

There was a significant decrease in the leukocyte and eosinophil counts in the corilagin-treated group compared to the negative control group. Treatment with corilagin significantly protects the degranulation of mast cells, and it also has significant anti-muscarinic and antihistaminic activity by reducing the muscle contraction induced by Acetylcholine (Ach) and histamine in guinea pig tracheal chain and ileum.

Conclusions

Corilagin possess anti-anaphylactic and anti-allergic activity by inhibiting the release of mediators from mast cells and by decreasing the serum concentration of immunoglobulin E (IgE).

Corilagin protects the acute lung injury by ameliorating the apoptosis pathway

This study elucidates the protective effect of corilagin in acute lung injury rat model. Lung injury induced by ischemia/reperfusion (I/R) model was established by isolating the lungs from the rats. Ischemia was produced for the duration of 1h and thereafter reperfusion was done for 90min in isolated lung in presence and absence of corilagin (20 and 40mg/ml). Effect of corilagin was evaluated by estimating the pulmonary vein oxygen partial pressure (PaO2), airway compliance and tidal volume. Moreover the level of oxidative stress parameter, pro inflammatory parameters, phosphorylation of JNK and apoptosis rate was estimated in lung tissues. There was significant increase in the PaO2, airway compliance and tidal volume in corilagin treated group than I/R group. Treatment with corilagin significantly increases the activity of superoxide dismutase (SOD) and level of adenosine triphosphate (ATP) and decreases the level of MDA in the tissue homogenate of I/R induced lung injury model. Whereas expressions of proinflammatory gene such as tumor necrosis factor α, interlukin-6, IL-1β and cycloxygenase -2 (COX-2) was found to be reduced in corilagin treated group than I/R group. Posphorylation of JNK and apoptotic rate was also found to be decreased in corilagin treated group than I/R group. Present report concludes that treatment with corilagin attenuates the lung injury in ex vivo I/R induced lung injury rat model by decreasing oxidative stress, pro-inflammatory mediators and its anti apoptotic activity.

Cardiaprotective effect of crocetin by attenuating apoptosis in isoproterenol induced myocardial infarction rat model

Given study evaluates the cardioprotective effect of crocetin in myocardial infracted (MI) rats. MI was produced by administering isoproterenol (90mg/kg/day, i.p.) in rats for two consecutive days. all the animals were divided in to four groups such as control group receives only saline; MI group which receives only isoproterenol and crocetin treated group which receives crocetin (50, 100 and 200mg/kg/day, p.o.) for the duration of 15 days. At the end of dosing left ventricular functions was assessed to estimate its effect on cardiac functions. Catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), creatine kinase (CK-MB), lactate dehydrogenase (LDH) and inflammatory cytokines were determined in the cardiac tissue homogenate. Histopathology study was also carried out using hematoxylin and eosin staining. Immunohistochemistry was done for the estimation of Caspase-3, Bcl-2, Bax and Nrf-2 level in the myocardial tissues of MI rats. Result of the study suggested that GSH, CAT, CK-MB, and LDH were (p<0.01) increased in the tissue homogenate of crocetin treated group than MI group. However crocetin significantly (p<0.01) decreases the level of MDA and activity of SOD in the tissue homogenate than MI group. It was observed that treatment with crocetin attenuates the level of inflammatory cytokines in the myocardial tissues of MI rats. Moreover level of caspase-3, Bax and Nrf-2 significantly reduced and Bcl-2 enhanced in the myocardial tissues of MI rats than MI group. The altered cellular architecture of heart tissue sections in the myocardial infracted rats were reversed by administration of crocetin treatment. Taking all these data together, it may be suggested that the crocetin act as a possible protective agent in myocardial infarction by decreasing oxidative stress and inflammatory cytokines and thereby attenuates the apoptosis of myocardial cells.

A Perspective on Crocus sativus L. (Saffron) Constituent Crocin: A Potent Water-Soluble Antioxidant and Potential Therapy for Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia, in which the death of brain cells causes memory loss and cognitive decline. Several factors are thought to play roles in the development and course of AD. Existing medical therapies only modestly alleviate and delay cognitive symptoms. Current research has been focused on developing antibodies to remove the aggregates of amyloid-β (Aβ) and tau protein. This approach has achieved removal of Aβ; however, no cognitive improvement in AD patients has been reported. The biological properties of saffron, the dry stigma of the plant Crocus sativus L., and particularly its main constituent crocin, have been studied extensively for many conditions including dementia and traumatic brain injury. Crocin is a unique antioxidant because it is a water-soluble carotenoid. Crocin has shown potential to improve learning and memory as well as protect brain cells. A search of the studies on saffron and crocin that have been published in recent years for their impact on AD as well as crocin's effects on Aβ and tau protein has been conducted. This review demonstrates that crocin exhibits multifunctional protective activities in the brain and could be a promising agent applied as a supplement or drug for prevention or treatment of AD.

The Relaxant Activity of Safranal in Isolated Rat Aortas is Mediated Predominantly via an Endothelium-Independent Mechanism: -Vasodilatory mechanism of safranal

OBJECTIVES

Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas.

METHODS

To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using 10^-6-M phenylephrine (PE) or 80-mM KCl. Dimethyl sulfoxide (DMSO) was used as a control. The vasodilatory effect of safranal was also evaluated both on intact and denuded endothelium aortic rings. Furthermore, to study the role of nitric oxide and prostacyclin in the relaxation induced by safranal, we incubated the aortic rings by using L-NAME (10^-6 M) or indomethacin (10^-5 M), each for 20 minutes.

RESULTS

Safranal induced relaxation in endothelium-intact aortic rings precontracted by using PE or KCl in a concentration-dependent manner, with a maximum relaxation of more than 100%. The relaxant activity of safranal was not eliminated by incubating the aortic rings with L-NAME (EC₅₀ = 0.29 vs. EC₅₀ = 0.43) or with indomethacin (EC₅₀ = 0.29 vs. EC₅₀ = 0.35), where EC₅₀ is the half maximal effective concentration. Also, the vasodilatory activity of safranal was not modified by endothelial removal.

CONCLUSION

This study indicated that relaxant activity of safranal is mediated predominantly through an endothelium- independent mechanism.

Antiinflammatory, Antioxidant, and Immunomodulatory Effects of Crocus sativus L. and its Main Constituents

Crocus sativus L. (C. sativus), commonly known as saffron, is used as a food additive, preservative, and medicinal herb. Traditionally, it has been used as an alternative treatment for different diseases. C. sativus' medicinal effects are related to its major constituents like crocins, crocetin, and safranal. According to the literature, C. sativus and its constituents could be considered as an effective treatment for neurodegenerative disorders, coronary artery diseases, asthma, bronchitis, colds, fever, diabetes, and so on. Recently, numerous studies have reported such medicinal properties and found that the underlying mechanisms of action may be mediated by antioxidant, inflammatory, and immunomodulatory effects. C. sativus enhances the antioxidant capacity and acts as a free radical scavenger. As an antiinflammatory and immunomodulatory agent, it modulates inflammatory mediators, humoral immunity, and cell-mediated immunity responses. This review highlights in vitro and animal findings regarding antiinflammatory, antioxidant, and immunomodulatory effects of C. sativus and its constituents. Present review found that the C. sativus and its main constituents such as safranal, crocins, and crocetin could be effective against various diseases because of their antioxidant, anti-inflammation, and immunomodulatory effects. Copyright © 2016 John Wiley & Sons, Ltd.

A review of the relaxant effect of various medicinal plants on tracheal smooth muscle, their possible mechanism(s) and potency

ETHNOPHARMACOLOGICAL RELEVANCE

The therapeutic effects of the medicinal plants described in the current review on obstructive pulmonary diseases have found mention in ancient Iranian medical texts and in traditional folk medicine. These effects are attributed to their bronchodilatory activity, which relaxes the smooth muscles of the airway. Therefore, in the present review, the relaxant effects of various extracts, fractions and constituents of medicinal plants on tracheal smooth muscle are reviewed in light of their therapeutic effects on obstructive pulmonary diseases.

MATERIALS AND METHODS

The online literature was searched using Medline, PubMed, ScienceDirect, Scopus, Google Scholar, Web of Science and SID (for articles written in Persian). Moreover, local books on ethnopharmacology from 1918 to 2014 were searched with keywords such as tracheal smooth muscle, airway smooth muscle, relaxant effect, bronchodilatory effect and related mechanisms to identify studies on the relaxant effects of medicinal plants on tracheal smooth muscle and the possible mechanism(s) of these effects.

RESULTS

All studied plants showed significant relaxant effects on tracheal smooth muscle, which were similar or superior to the effect of theophylline at the used concentrations. According to the results, most of these plants also showed an inhibitory effect on muscarinic and histamine (H1) receptors, whereas some plants showed more pronounced stimulatory effects on the beta-adrenergic receptor. Some of the studied plants also showed inhibitory effects on calcium and potassium channels.

CONCLUSION

The present article reviewed the relaxant effects of several medicinal plants on tracheal smooth muscle, which were comparable or superior to the effect of theophylline at the studied concentration. The possible mechanisms of the relaxant effects of the studied medicinal plants and a comparison of these effects were also reviewed. This review presents the fractions and constituents of plants with potent relaxant effects on tracheal smooth muscle, which can be used to treat obstructive pulmonary disease.

Laūq

Laūq is a pharmaceutical dosage form that had been mainly used for the treatment of various respiratory disorders in traditional Persian medicine. It is important from 2 aspects: a dosage form with efficient and optimum delivery of drugs to the respiratory tract and biological effects of its ingredients. Natural medicine in laūq has been demonstrated to act in respiratory disorders by their antitussive, antiallergic, anti-inflammatory, antioxidant, spasmolytic, and antibacterial activities. Some of these natural remedies act by most of the mentioned mechanisms such as Cydonia oblonga, Glycyrrhiza glabra, Crocus sativus, Hyssopus officinalis, Foeniculum vulgare, and honey. However, the evidence is limited including Cassia fistula, Papaver somniferum, and Drimia maritima. According to positive pharmacokinetic and pharmacodynamic aspects of laūqs, they may be considered as efficient dosage forms for delivery of drugs to the respiratory tract. For better compatibility of patients, it could be substituted laūqs with newer drug delivery systems like lozenges.

The Effect of Hydroethanol Extract of Achillea Millefolium on β-adrenoceptors of Guinea Pig Tracheal Smooth Muscle

Different pharmacological effects of Achillea millefolium including its relaxant effect on smooth muscle have been shown previously. In the present study the stimulatory effect of the plant extract on β-adrenoceptor of tracheal muscle was examined in order to investigate one possible mechanism for its observed relaxant effect. Effect of three concentrations of hydroethanol extract, 10 nM propranolol, and saline on β-adrenoceptor was tested in two experimental groups including; nonincubated tracheal smooth muscles (group 1) and incubated tracheal smooth muscle with chlorpheniramine (group 2). Concentration response curves to isoprenaline were performed in precontracted tracheal smooth muscle in the presence of the extract, propranolol and saline. Values of EC₅₀ and CR-1 were measured. Leftward shifts in isoprenaline curves were observed in the presence of medium and high concentrations of the extract compared with saline in both groups. The values of EC₅₀ obtained in the presence of medium and high concentrations of the extract only in group 1 were nonsignificantly lower than that of saline. The values of CR-1 obtained in the presence of all concentrations of the extract in both groups were negative and significantly different with that of propranolol. The results indicated a small stimulatory effect of the extract on ß₂-adrenoceptors.

The effect of the extract of Crocus sativus on tracheal responsiveness and plasma levels of IL-4, IFN-γ, total NO and nitrite in ovalbumin sensitized guinea-pigs

ETHNOMEDICAL RELEVANCE: Anti-inflammatory, anti oxidant and effect of Crocus sativus (C. sativus) on Th1/Th2 balance were described previously.

AIM OF THE STUDY

The preventive effects of the extract of Crocus sativus on tracheal responsiveness and plasma levels of IL-4, IFN-γ, total NO and nitrite were examined on sensitized guinea pigs.

MATERIALS AND METHODS

Five groups of sensitized guinea pigs to ovalbumin (OVA), were given drinking water containing three concentrations of the extract of Crocus sativus, dexamethasone (S+D) or alone (group S). Tracheal responses (TR) of control animals (group C) and sensitized guinea pigs (n=6, for each group) to methacholine, OVA and the levels of IL-4, IFN-γ, total NO and nitrite in serum were examined.

RESULTS

The TR to both methacholine and OVA, the levels of serum IL-4, total NO and nitrite in S guinea pigs were significantly increased but that of IFN-γ and IFN-γ/IL-4 ratio (Th1/Th2 balance) were decreased compared to the controls (p<0.05 to p<0.001). In the treated animals with dexamethasone and all concentrations of the extract, TR to both methacholine and OVA, IL-4, total NO and nitrite were significantly decreased but IFN-γ and IFN-γ/IL-4 ratio increased compared to S group (p<0.05 to p<0.001). The effects of the highest concentration of the extract was greater than those of other concentrations and the effect of dexamethasone (p<0.05 to p<0.01).

CONCLUSIONS

These results not only showed a preventive effect of C. sativus extract on tracheal responses and serum levels of inflammatory mediators in sensitized guinea pigs but also showed increased Th1/Th2 balance.

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.

Avicenna's (Ibn Sina) the Canon of Medicine and saffron (Crocus sativus): a review

In this review, we introduce the traditional uses of saffron and its pharmacological activities as described by either Avicenna in Book II, Canon of Medicine (al-Qanun fi al-tib) or from recent scientific studies. Modern pharmacological findings on saffron are compared with those mentioned in Avicenna's monograph. A computerized search of published articles was performed using MEDLINE, Scopus and Web of Science databases as well as local references. The search terms used were saffron, Crocus sativus, crocin, crocetin, safranal, picrocrocin, Avicenna and 'Ibn Sina'. Avicenna described various uses of saffron, including its use as an antidepressant, hypnotic, anti-inflammatory, hepatoprotective, bronchodilatory, aphrodisiac, inducer of labour, emmenagogue and others. Most of these effects have been studied in modern pharmacology and are well documented. The pharmacological data on saffron and its constituents, including crocin, crocetin and safranal, are similar to those found in Avicenna's monograph. This review indicates that the evaluation of plants based on ethnobotanical information and ancient books may be a valuable approach to finding new biological activities and compounds.

The effect of the extract of Crocus sativus and its constituent safranal, on lung pathology and lung inflammation of ovalbumin sensitized guinea-pigs

Different pharmacological effects of Crocus sativus have been demonstrated on guinea pig tracheal chains in previous studies. In the present study, the prophylactic effect of the extract of C. sativus and its constituent, safranal on lung pathology and total and differential white blood cells (WBC) of sensitized guinea pigs was examined. Guinea pigs were sensitized with injection and inhalation of ovalbumin (OA). One group of sensitized guinea pigs were given drinking water alone (group S) and three groups were given drinking water containing three concentrations of safranal (S+SA1, S+SA2 and S+SA3 groups), three groups, drinking water containing three concentrations of extract (S+CS1, S+CS2 and S+CS3 groups) and one group drinking water containing one concentration of dexamethasone (S+D group) (n=6, for all groups). The lung pathology was evaluated in control, non treated and treated sensitized groups. Total and differential WBC counts of lung lavage were also examined. All pathological indices in group S showed significant increased compared to control group (p<0.05 for lung congestion and p<0.001 for other groups). Total WBC number (p<0.001), eosinophyl percentage (p<0.001) in lung lavage and serum histamine levels (p<0.01) were also increased in sensitized animals compared to those of controls. Treatment of S animals with dexamethasone, all concentrations of the extract and safranal significantly improved lung pathological changes, most types of WBC and serum histamine levels compared to group S (p<0.05-0.001). Treatment of S group with first concentration of safranal also decreased total WBC. Treatment with safranal was more effective in improvement of most pathological changes, total and differential WBC count as well as serum histamine level (p<0.05-0.001). These results showed a preventive effect of the extract of C. sativus and its constituent safranal on lung inflammation of sensitized guinea pigs. The results also showed that the effect of the plant is perhaps due to its constituent safranal.

The effect of Crocus sativus extract on human lymphocytes' cytokines and T helper 2/T helper 1 balance

The effects of macerated extracts of Crocus sativus (Family Iridaceae) (saffron) on cell viability and cytokine release of stimulated peripheral blood mononuclear cells by phytohemagglutinin (PHA) and nonstimulated cells were examined. The effects of three concentrations of macerated extract, dexamethasone, and saline on cell viability and production of cytokines, including interleukin (IL)-4, IL-10, and interferon-γ (IFN-γ) were evaluated. In cells stimulated with PHA, different concentrations of the extract significantly inhibited cell viability of lymphocytes (P<.001 for all concentrations). High concentrations of the extract (500 μg/mL) also inhibited secretion of IFN-γ in stimulated cells and IL-10 secretion in both stimulated and nonstimulated cells (P<.05 for all cases). The effects of high and low concentrations of the extract (500 and 50 μg/mL, respectively) on IL-4 secretion were lower than that of dexamethasone (P<.05 to P<.001). The extract showed a stimulatory effect on IFN-γ and IL-4 secretion in nonstimulated cells. The ratios of IFN-γ to IL-4 in the presence of all concentrations of saffron on stimulated cells were significantly higher than for the control group (P<.05 to P<.01). These results indicated that the extract of saffron leads to increased ratio of IFN-γ to IL-4.

Chemical constituents and bioactivities of the liposoluble fraction from different medicinal parts of Crocus sativus

CONTEXT

Crocus sativus Linn. (Iridaceae), commonly known as saffron, becomes more and more popular due to its versatile biological and medicinal properties. At present, studies mainly focus on the traditional medicinal part, the saffron stigma, with less attention to the other parts of saffron, such as the perianth, the stamen, and the corm, which are high yield compared to the stigma and also possess various pharmacological effects.

OBJECTIVE

To determine the chemical compositions, antifungal, cytotoxic, and antioxidant activities of the ether fractions from the stamen, perianth, and stigma of saffron.

MATERIALS AND METHODS

The chemical constituents of the ether fractions from different parts of saffron were investigated by gas chromatography/mass spectrometry. Several pathogenic fungi isolates and tumor cell lines were employed to evaluate the antifungal and cytotoxic activities of these three ether fractions. 1,1-Diphenyl-2-picrylhydrazyl assay was used to determine the free radical-scavenging activity.

RESULTS

The ether fractions composition of the three C. sativus parts are different from each other, but lauric acid, hexadecanoic acid, 4-hydroxydihydro-2(3H)-furanone, and stigmasterol were the common constituents shared by all the three fractions. The stamen ether fraction displayed the strongest antifungal and cytotoxic activities, whereas both of the saffron stamen and perianth ether fractions exhibited significant antioxidant activities.

DISCUSSION AND CONCLUSION

These findings demonstrate that the saffron stamen and perianth possess significant antifungal, cytotoxic, and antioxidant activities as well as the stigma, though not to the same extent, prompting us to expand the medicinal resource and make best use of this valuable plant.

Saffron extract and trans-crocetin inhibit glutamatergic synaptic transmission in rat cortical brain slices

Saffron, the dried stigmata of Crocus sativus L., is used in traditional medicine for a wide range of indications including cramps, asthma, and depression. To investigate the influence of hydro-ethanolic saffron extract (CSE) and trans-crocetin on synaptic transmission, postsynaptic potentials (PSPs) were elicited by focal electrical stimulation and recorded using intracellular placed microelectrodes in pyramidal cells from rat cingulate cortex. CSE (10-200 μg/ml) inhibited evoked PSPs as well as the isolated NMDA and non-NMDA component of PSPs. Glutamate (500 μM) added into the organ bath induced membrane depolarization. CSE decreased glutamate-induced membrane depolarization. Additionally, CSE at 100 μg/ml decreased NMDA (20 μM) and kainate (1 μM)-induced depolarization, whereas AMPA (1 μM)-induced depolarization was not affected. Trans-crocetin (1-50 μM) showed inhibition of evoked PSPs and glutamate-induced membrane depolarization comparable to CSE. Trans-crocetin at 10 μM decreased NMDA (20 μM)-induced membrane depolarization, but did not inhibit the isolated non-NMDA component of PSPs. We conclude that trans-crocetin is involved in the antagonistic effect of CSE on NMDA but not on kainate receptors.

Crocus sativus L.: A comprehensive review

Crocus sativus L. belonging to the family Iridaceae (syn - kesar) comprises the dried red stigma and is widely cultivated in Iran and other countries such as India and Greece. Saffron contains more than 150 volatile and aroma-yielding compounds mainly terpenes, terpene alcohol, and their esters. The bitter taste and an iodoform or hay-like fragrance are caused by chemicals picrocrocin and safranal. C. sativus possesses a number of medicinally important activities such as antihypertensive, anticonvulsant, antitussive, antigenototoxic and cytotoxic effects, anxiolytic aphrodisiac, antioxidant, antidepressant, antinociceptive , anti-inflammatory, and relaxant activity. It also improves memory and learning skills, and increases blood flow in retina and choroid. The present review explores the historical background, chemical constituents, pharmacological actions, uses, substitutes and adulterants, and toxicity. It also deals with its evaluation, formulations, and chemical tests in detail.