An Evidence-Based Systematic Review of Saffron (Crocus sativus) by the Natural Standard Research Collaboration

Herbal Products as Complementary or Alternative Medicine for the Management of Hyperglycemia and Dyslipidemia in Patients with Type 2 Diabetes: Current Evidence Based on Findings of Interventional Studies

Type 2 diabetes (T2D) is known as a major public health problem with a noticeable adverse impact on quality of life and health expenditures worldwide. Despite using routine multiple pharmacological and nonpharmacological interventions, including diet therapy and increasing physical activity, controlling this chronic disease remains a challenging issue, and therapeutic goals are often not achieved. Therefore, recently, other therapeutic procedures, such as using herbal products and functional foods as complementary or alternative medicine (CAM), have received great attention as a new approach to managing T2D complications, according to the literature. We reviewed the existing evidence that supports using various fundamental medicinal herbs, including cinnamon, saffron, ginger, jujube, turmeric, and barberry, as CAM adjunctive therapeutic strategies for T2D patients. The current review addressed different aspects of the potential impact of the abovementioned herbal products in improving glycemic indices and lipid profiles, including the effect size reported in the studies, their effective dose, possible side effects, herbs-drug interactions, and their potential action mechanisms.

Current Knowledge of the Antidepressant Activity of Chemical Compounds from Crocus sativus L

Psychotropic effect of Crocus sativus L. (family Iridaceae) biologically active chemical compounds are quite well documented and they can therefore be used in addition to the conventional pharmacological treatment of depression. This systematic review on antidepressant compounds in saffron crocus and their mechanisms of action and side effects is based on publications released between 1995−2022 and data indexed in 15 databases under the following search terms: antidepressant effect, central nervous system, Crocus sativus, cognitive impairement, crocin, crocetin, depression, dopamine, dopaminergic and serotonergic systems, picrocrocin, phytotherapy, neurotransmitters, safranal, saffron, serotonin, and biologically active compounds. The comparative analysis of the publications was based on 414 original research papers. The investigated literature indicates the effectiveness and safety of aqueous and alcoholic extracts and biologically active chemical compounds (alkaloids, anthocyanins, carotenoids, flavonoid, phenolic, saponins, and terpenoids) isolated from various organs (corms, leaves, flower petal, and stigmas) in adjuvant treatment of depression and anxiety. Monoamine reuptake inhibition, N-methyl-d-aspartate (NMDA) receptor antagonism, and gamma-aminobutyric acid (GABA)-α agonism are the main proposed mechanism of the antidepressant action. The antidepressant and neuroprotective effect of extract components is associated with their anti-inflammatory and antioxidant activity. The mechanism of their action, interactions with conventional drugs and other herbal preparations and the safety of use are not fully understood; therefore, further detailed research in this field is necessary. The presented results regarding the application of C. sativus in phytotherapy are promising in terms of the use of herbal preparations to support the treatment of depression. This is particularly important given the steady increase in the incidence of this disease worldwide and social effects.

Medicinal Plants in the Treatment of Depression. II: Evidence from Clinical Trials

Depression is a syndrome characterized by deep sadness and the inhibition of psychic functions, sometimes accompanied by neurovegetative disorders, with symptoms of anxiety almost always present. The disease produces alterations in a variety of neural networks and neurotransmission systems, along with a dysfunction of the hypothalamic-pituitary-adrenal axis, which leads to concomitant alterations in the immunological response. Generally, there is a parallel increase in proinflammatory mediators as well as oxidative and nitrosative damage caused by a reduction of antioxidant defenses. In a previous review, we compiled and examined studies of medicinal plants that had been evaluated in preclinical assays, including existing data on 155 species studied and reported as antidepressants or as sources of active principles for treating this condition. This review will thus limit its focus to the 95 clinical trials found in PubMed among the 670 articles on antidepressant-like medicinal plants. To this end, we have reviewed the publications cited in the Cochrane Database of Systematic Reviews, PubMed, and the Science Citation Index from 2000 to 2020. Our review emphasizes those species that have demonstrated the greatest pharmacological potential when studied for their antidepressant properties in humans through clinical trials. Saffron, turmeric, St. John's wort, ginkgo, kava, and golden root are the most relevant plants that have provided important evidence for the treatment of depression in clinical trials.

Crocins for Ischemic Stroke: A Review of Current Evidence

Crocins (CRs) and the related active constituents derived from Crocus sativus L. (Saffron) have demonstrated protective effects against cerebral ischemia and ischemic stroke, with various bioactivities including neuroprotection, anti-neuroinflammation, antioxidant, and cardiovascular protection. Among CRs, crocin (CR) has been shown to act on multiple mechanisms and signaling pathways involved in ischemic stroke, including mitochondrial apoptosis, nuclear factor kappa light chain enhancer of B cells pathway, S100 calcium-binding protein B, interleukin-6 and vascular endothelial growth factor-A. CR is generally safe and well-tolerated. Pharmacokinetic studies indicate that CR has poor bioavailability and needs to convert to crocetin (CC) in order to cross the blood-brain barrier. Clinical studies have shown the efficacy of saffron and CR in treating various conditions, including metabolic syndrome, depression, Alzheimer’s disease, and coronary artery disease. There is evidence supporting CR as a treatment for ischemic stroke, although further studies are needed to confirm their efficacy and safety in clinical settings.

Isolation of high-quality RNA for high throughput applications from secondary metabolite-rich Crocus sativus L

Objective

Isolating high-quality RNA is a basic requirement while performing high throughput sequencing, microarray, and various other molecular investigations. However, it has been quite challenging to isolate RNA with absolute purity from plants like Crocus sativus that are rich in secondary metabolites, polysaccharides, and other interfering compounds which often irreversibly co-precipitate with the RNA. While many methods have been proposed for RNA extraction including CTAB, TriZol, and SDS-based methods, which invariably yield less and poor quality RNA and hence it necessitated the isolation of high-quality RNA suitable for high throughput applications.

Results

In the present study we made certain adjustments to the available protocols including modifications in the extraction buffer itself and the procedure employed. Our method led to the isolation of clear and non-dispersive total RNA with an RNA Integrity Number (RIN) value greater than 7.5. The quality of the RNA was further assessed by qPCR-based amplification of mRNA and mature miRNAs such as Cs-MIR166c and Cs-MIR396a.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06095-z.

Engineering high levels of saffron apocarotenoids in tomato

Crocins and picrocrocin are high-value hydrophilic pigments produced in saffron and used commercially in the food and pharmaceutical industries. These apocarotenoids are derived from the oxidative cleavage of zeaxanthin by specific carotenoid cleavage dioxygenases. The pathway for crocins and picrocrocin biosynthesis was introduced into tomato using fruit specific and constitutive promoters and resulted in 14.48 mg/g of crocins and 2.92 mg/g of picrocrocin in the tomato DW, without compromising plant growth. The strategy involved expression of CsCCD2L to produce crocetin dialdehyde and 2,6,6-trimethyl-4-hydroxy-1-carboxaldehyde-1-cyclohexene, and of glycosyltransferases UGT709G1 and CsUGT2 for picrocrocin and crocins production, respectively. Metabolic analyses of the engineered fruits revealed picrocrocin and crocetin-(β-D-gentiobiosyl)-(β-D-glucosyl)-ester, as the predominant crocin molecule, as well as safranal, at the expense of the usual tomato carotenoids. The results showed the highest crocins content ever obtained by metabolic engineering in heterologous systems. In addition, the engineered tomatoes showed higher antioxidant capacity and were able to protect against neurological disorders in a Caenorhabditis elegans model of Alzheimer's disease. Therefore, these new developed tomatoes could be exploited as a new platform to produce economically competitive saffron apocarotenoids with health-promoting properties.

Adjuvant effect of two polysaccharides from the petals of Crocus sativus and its mechanisms

Two polysaccharides from Crocus sativus petals (PCSPs), PCSPA and PCSPB, presented immunopotentiatory activity through activating macrophages via MAPK and NF-κB pathway. In this study, two PCSPs were investigated for the adjuvant effects and underlying mechanisms using ovalbumin (OVA) in mice. PCSPA and PCSPB remarkably not only boosted the OVA-specific IgG antibody and its isotype titers, but strengthened splenocyte proliferation and natural killer cell activities in immunized mice. Both PCSPs also dramatically triggered the production of Th1- and Th2-cytokines and facilitated the gene expression of Th1- and Th2-cytokines and transcription factors in OVA-stimulated splenocytes. In mechanisms, two PCSPs rapidly elicited the gene and protein expression of cytokines and chemokines, promoted the recruitment and antigen uptake of immune cells in the injected-muscles, and augmented the migration and antigen transport of immune cells to the draining lymph nodes. These findings demonstrated that PCSPs enhanced and improved immune responses and simultaneously elicited Th1- and Th2-immune responses to OVA through activating innate immune microenvironment, and that they could act as promising vaccine adjuvant candidates.

Antibiotic-resistance in medically important bacteria isolated from commercial herbal medicines in Africa from 2000 to 2021: a systematic review and meta-analysis

Background

Antimicrobial resistance is swiftly increasing all over the world. In Africa, it manifests more in pathogenic bacteria in form of antibiotic resistance (ABR). On this continent, bacterial contamination of commonly used herbal medicine (HM) is on the increase, but information about antimicrobial resistance in these contaminants is limited due to fragmented studies. Here, we analyzed research that characterized ABR in pathogenic bacteria isolated from HM in Africa since 2000; to generate a comprehensive understanding of the drug-resistant bacterial contamination burden in this region.

Methods

The study was conducted according to standards of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We searched for articles from 12 databases. These were: PubMed, Science Direct, Scifinder scholar, Google scholar, HerbMed, Medline, EMBASE, Cochrane Library, International Pharmaceutical Abstracts, Commonwealth Agricultural Bureau Abstracts, African Journal Online, and Biological Abstracts. Prevalence and ABR traits of bacterial isolates, Cochran’s Q test, and the I² statistic for heterogeneity were evaluated using MedCalcs software. A random-effects model was used to determine the pooled prevalence of ABR traits. The potential sources of heterogeneity were examined through sensitivity analysis, subgroup analysis, and meta-regression at a 95% level of significance.

Findings

Eighteen studies met our inclusion criteria. The pooled prevalence of bacterial resistance to at least one conventional drug was 86.51% (95% CI = 61.247–99.357%). The studies were highly heterogeneous (I² = 99.17%; p < 0.0001), with no evidence of publication bias. The most prevalent multidrug-resistant species was Escherichia coli (24.0%). The most highly resisted drug was Ceftazidime with a pooled prevalence of 95.10% (95% CI = 78.51–99.87%), while the drug-class was 3^rd generation cephalosporins; 91.64% (95% CI = 78.64–96.73%). None of the eligible studies tested isolates for Carbapenem resistance. Extended Spectrum β-lactamase genes were detected in 89 (37.2%) isolates, mostly Salmonella spp., Proteus vulgaris, and K. pneumonia. Resistance plasmids were found in 6 (5.8%) isolates; the heaviest plasmid weighed 23,130 Kilobases, and Proteus vulgaris harbored the majority (n = 5; 83.3%).

Conclusions

Herbal medicines in Africa harbor bacterial contaminants which are highly resistant to conventional medicines. This points to a potential treatment failure when these contaminants are involved in diseases causation. More research on this subject is recommended, to fill the evidence gaps and support the formation of collaborative quality control mechanisms for the herbal medicine industry in Africa.

Saffron for "toning down" COVID-19-related cytokine storm: Hype or hope? A mini-review of current evidence

AIM

To assess the potential role of saffron in downregulating inflammation and cytokine storm during COVID-19.

MAIN FINDINGS

Three main compounds of saffron, i.e., crocetin esters, picrocrocin, and safranal, present strong antioxidant and anti-inflammatory action for several disease states (e.g., Alzheimer's, cancer, and depression) but have also been studied in COVID-19. In particular, based on our comprehensive review of both in vitro and in silico studies, saffron's essential oils and other constituents appear to have both immunomodulatory and anti-asthmatic actions; these actions can be particularly helpful to treat patients with respiratory symptoms due to COVID-19. Moreover, crocin appears to reduce the COVID-19-related cytokine cascade and downregulate angiotensin-converting enzyme 2 (ACE2) gene expression. Last, in silico studies suggest that saffron's astragalin and crocin could have inhibitory actions on SARS-CoV-2 protease and spike protein, respectively.

CONCLUSION

Saffron represents a promising substance for toning down cytokine storm during COVID-19, as well as a potential preventive treatment for COVID-19. However, appropriate randomized clinical trials, especially those using biomarkers as surrogates to assess inflammatory status, should be designed in order to assess the clinical efficacy of saffron and allow its use as an adjunct treatment modality, particularly in resource-poor settings where access to drugs may be limited.

Bioactive Substances in Safflower Flowers and Their Applicability in Medicine and Health-Promoting Foods

Safflower flowers (Carthamus tinctorius) contain many natural substances with a wide range of economic uses. The most famous dye isolated from flower petals is hydroxysafflor A (HSYA), which has antibacterial, anti-inflammatory, and antioxidant properties. This review is aimed at updating the state of knowledge about their applicability in oncology, pulmonology, cardiology, gynecology, dermatology, gastrology, immunology, and suitability in the treatment of obesity and diabetes and its consequences with information published mainly in 2018-2020. They were also effective in treating obesity and diabetes and its consequences. The issues related to the possibilities of using HSYA in the production of health-promoting food were also analyzed.

Structural characteristics and immunopotentiation activity of two polysaccharides from the petal of Crocus sativus

The current experiments were designed to explore the structural features and immunopotentiation activity of two homogeneous polysaccharides PCSPA and PCSPB prepared from Crocus sativus petals using DEAE-Sephadex A-50 and Sephadex G200 column chromatography. The structures of PCSPA and PCSPB were systematically characterized using extensive chemical and spectroscopic methods including colorimetry, HPGPC-RID, GC-MS, Smith degradations, methylation, solvolytic desulfation, UV, FT-IR, NMR, SEM, and AFM. The average molecular weights of PCSPA and PCSPB were 1.98 × 10⁶ and 2.53 × 10⁶ Da, respectively. PCSPA consisted of Gal, Rha, Ara, and Xyl in the molar ratio of 16:5:7:3, while PCSPB were composed of Gal, Glc, Man, Rha, Ara, and Xyl with molar ratio of 16:2:7:19:15:16. Both polysaccharides contained sulfonic and acetyl groups. PCSPA and PCSPB significantly activated RAW264.7 cells by enhancing the phagocytic activity, up-regulating the expression of surface molecules, promoting the production and mRNA expression of cytokines and chemokines via MAPK and NF-κB pathway.

Prevalence and dynamics of clinically significant bacterial contaminants in herbal medicines sold in East Africa from 2000 to 2020: a systematic review and meta-analysis

BACKGROUND

Infectious diseases remain a leading cause of mortality and morbidity around the world, and those caused by bacteria are common in the East African region. In this region, trade and consumption of herbal medicine has been expanding in the recent decades. Herbal medicines may be contaminated with pathogenic bacteria; however, there is limited information due to fragmented studies in East Africa. In this meta-analysis, we critically analyzed original research related to the incidence of pathogenic bacterial contaminants of HM in the East African region since 2000. The aim was to create a comprehensive understanding of the extent and dynamics of bacterial contamination in HM, to guide future research and concerted public health protection in the region.

METHODOLOGY

The study was conducted according to the standards of the Preferred Reporting Items for Systematic Reviews and Meta-analyses. We searched and evaluated published articles from eleven electronic databases (Google Scholar, PubMed, HerbMed, MEDLINE, Science Direct, Scifinder Scholar, Cochrane Library, International Pharmaceutical Abstracts, EMBASE, Biological Abstracts and Commonwealth Agricultural Bureau Abstracts). Prevalences of different bacterial species, Cochran's Q test, and the I2 statistic for heterogeneity were evaluated using a software called MedCalcs. Random and fixed effects models were used to determine the pooled prevalence of clinically significant bacteria from studies which were included in this meta-analysis. The potential sources of heterogeneity were examined through sensitivity analysis, sub-group analysis, and meta-regression at 95% level of significance.

RESULTS

Fourteen studies met our inclusion criteria. Overall, the studies were highly heterogeneous (I2 = 98.48%) and there was no evidence of publication bias. Escherichia coli was the most prevalent contaminant. Salmonella spp. and Shigella spp. were the most frequently reported primary pathogens with pooled prevalence of 10.4% and 6.3%, respectively. Our findings are in tandem with recent systematic reviews conducted in Europe and Asia, but are in discrepancy with the reviews recently conducted in southern Africa.

CONCLUSION AND RECOMMENDATIONS

The East African herbal medicine industry poses considerable health risks to communities through dissemination of clinically significant bacteria. Presence of enteric bacterial contaminants indicates possible fecal pollution of herbal medicine region-wide. Adequate research pertaining to microbial safety of herbal medicine in the East African countries remains highly desired. The latter will enable establishment of strong, region-wide herbal safety mechanisms in order to support comprehensive public health protection in East Africa.

Crocetin Isolated from the Natural Food Colorant Saffron Reduces Intracellular Fat in 3T3-L1 Adipocytes

Saffron, as a food colorant, has been displaced by low-cost synthetic dyes. These have unhealthy properties; thus, their replacement with natural food colorants is an emerging trend. Obesity is a worldwide health problem due to its associated comorbidities. Crocetin esters (crocins) are responsible for the red saffron color. Crocetin (CCT) exhibits healthful properties. We aimed to broaden the existing knowledge on the health properties of CCT isolated from saffron, to facilitate its consideration as a healthy natural food colorant in the future. We evaluated the ability of CCT (1 and 5 μM) to reduce lipid accumulation during the differentiation of 3T3-L1 preadipocytes. Intracellular fat was quantified by Oil Red O staining. CTT cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The number and size of lipid droplets were analyzed using WimLipid software. The expression of adipogenic genes (CCAAT/enhancer-binding protein (C/EBPβ, C/EBPδ, C/EBPα), and peroxisome proliferator-activated receptor γ (PPARγ)) was analyzed using quantitative real-time PCR (qRT-PCR). CCT 5 μM decreased intracellular fat by 22.6%, without affecting viability or lipid droplet generation, via a decrease in C/EBPα expression, implicated in lipid accumulation. Thus, CCT is a potential candidate to be included in dietary therapies aimed at reversing adipose tissue accumulation in obesity.

Bioactivity and Bioavailability of the Major Metabolites of Crocus sativus L. Flower

Crocus sativus L. has been cultivated throughout history to obtain its flowers, whose dried stigmas give rise to the spice known as saffron. Crocetin esters, picrocrocin, and safranal are the main metabolites of this spice, which possess a great bioactivity, although the mechanisms of action and its bioavailability are still to be solved. The rest of the flower is composed by style, tepals, and stamens that have other compounds, such as kaempferol and delphinidin, which have an important antioxidant capacity, and these can be applied in foods, phytopharmaceuticals, and cosmetics. The aim of this work was to provide an updated and critical review of the research on the main compounds of Crocus sativus L. flower, including the adequate analytical methods for their identification and quantification, with a focus on their bioactivity and bioavailability.

Characterization of Crocetin-Monoglucuronide as a Neuron-Protective Metabolite of Crocin-1

SCOPE

Crocins are important apocarotenoids in the extract of saffron (Crocus sativus L.) and fruits of gardenia (Gardenia jasminoides E.). Crocins have shown versatile biological activities and thus they have been considered to be promising therapeutics for neurodegenerative and heart diseases. Metabolism studies report that crocetin-monoglucuronide (CM) is produced and detected in rat blood plasma after oral administration of crocins. However, due to the lack of standard compound of CM, its unambiguous identification, quantification, and bioactivity studies have been hindered.

METHODS AND RESULTS

CM is synthetized and its existence in blood plasma in Sprague-Dawley (SD) rats is quantified. The pharmacokinetic studies show that CM is produced in blood and brain after oral administration of crocin-1. It is then discovered that CM possesses neuroprotective activity against beta-amyloid (Aβ) toxicity in PC-12 cells and drosophila models. The enzymatic assay shows that CM can effectively inhibit AChE and docking studies indicate that CM may bind in the gorge channel of AChE.

CONCLUSION

The work discovered that CM is a neuron-protective metabolite of the orally administrated crocin-1. It is demonstrated that AChE can be one of the targets of CM in its neuron-protective activity.

Saffron; An updated review on biological properties with special focus on cardiovascular effects

OBJECTIVE

Saffron as a natural product has long been used to impede and treat different disorders including cardiovascular disease (CVDs). Stigma is the most principal part of saffron. Various compounds such as carotenoids and flavonoids are the essential components of saffron stigma. The health benefits of saffron have been shown in previous studies; however, there is a lack of comprehensive data on the mechanistic aspects of its cardiovascular-health properties. This current comprehensive review focuses on the medicinal applications of saffron, and then the new findings regarding its cardiovascular-health effects and various cellular and molecular mechanisms of action will be debated.

METHODS

The literature search of MEDLINE, Embase, PubMed, Google Scholar and Cochrane Library was performed for all comparative studies since 2000-2018 with the limitations of the English language.

RESULTS

The results provided new evidence about antioxidant, anti-inflammatory, anti- atherogenic, anti- apoptotic, anti- hypertensive, and hypolipidemic effects of saffron. Pharmacological effects of saffron are due to a number of ingredients contained within this spice, including safranal, crocetin and crocins.

CONCLUSIONS

Our study concludes that saffron with wide range of usefulness in medicine may be the potent candidate in the process of new drug production for the treatment of CVDs.

Olive oil aromatization with saffron by liquid-liquid extraction

A new aromatization method for olive oils with saffron aqueous extracts rich in safranal has been developed using liquid-liquid extraction. Four flavoured olive oils were obtained (SO1-SO4). SO1 showed the highest safranal concentration (145.89 mg L^-1), followed by SO2 (79.33 mg L^-1), SO3 (0.30 mg L^-1) and SO4 (0.01 mg L^-1). Although flavouring originated a decrease in the quality parameters and the oxidative stability of the oils, even after 7 months of storage, at room and refrigeration temperatures, the oil parameters evaluated were still comparable to those of extra virgin olive oil. Flavored olive oils with less safranal (SO3, SO4) are preferred by consumers.

Saffron: An Old Medicinal Plant and a Potential Novel Functional Food

The spice saffron is made from the dried stigmas of the plant Crocus sativus L. The main use of saffron is in cooking, due to its ability to impart colour, flavour and aroma to foods and beverages. However, from time immemorial it has also been considered a medicinal plant because it possesses therapeutic properties, as illustrated in paintings found on the island of Santorini, dated 1627 BC. It is included in Catalogues of Medicinal Plants and in the European Pharmacopoeias, being part of a great number of compounded formulas from the 16th to the 20th centuries. The medicinal and pharmaceutical uses of this plant largely disappeared with the advent of synthetic chemistry-produced drugs. However, in recent years there has been growing interest in demonstrating saffron's already known bioactivity, which is attributed to the main components-crocetin and its glycosidic esters, called crocins, and safranal-and to the synergy between the compounds present in the spice. The objective of this work was to provide an updated and critical review of the research on the therapeutic properties of saffron, including activity on the nervous and cardiovascular systems, in the liver, its antidepressant, anxiolytic and antineoplastic properties, as well as its potential use as a functional food or nutraceutical.

Sensory Threshold Studies of Picrocrocin, the Major Bitter Compound of Saffron

This study is part of a wider project on the bitter taste of saffron and its preparations. A deeper knowledge on the taste perception of picrocrocin is necessary in order to develop products that satisfy consumer senses and provide them with adequate amounts of saffron major constituents, also appreciated for bioactivity. A systematic approach on the bitterness of picrocrocin, the major responsible compound, was conducted. A panel was trained specifically for the determination of taste detection and recognition thresholds of picrocrocin, which were found to be 5.34 and 7.26 mg/L, respectively, using the Ascending Forced Choice of Limits methodology. The threshold values were examined in water in absence and presence of other saffron constituents and ethanol and were found to decrease when served hot (61 ± 4 °C). Bitterness was enhanced in 40% (v/v) aqueous ethanol. In both aqueous and ethanol extracts, the presence of saffron volatiles improved bitterness perception. The usefulness of the study was tested in the case of commercial saffron based infusions.

A systematic review of randomized controlled trials examining the effectiveness of saffron (Crocus sativus L.) on psychological and behavioral outcomes

BACKGROUND

Throughout the past three decades, increased scientific attention has been given to examining saffron's (Crocus sativus L.) use as a potential therapeutic or preventive agent for a number of health conditions, including cancer, cardiovascular disease, and depression.

OBJECTIVE

The purpose of this systematic review is to examine and categorize the current state of scientific evidence from randomized controlled trials (RCTs) regarding the efficacy of saffron on psychological/behavioral outcomes.

SEARCH STRATEGY

Electronic and non-electronic systematic searches were conducted to identify all relevant human clinical research on saffron. The search strategy was extensive and was designed according to the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)." Reference lists of articles that met the inclusion criteria were searched. Only English language studies were reviewed.

INCLUSION CRITERIA

Saffron trials in combination with other substances and saffron safety studies were considered, in accordance with the PRISMA statement. Included studies must have a control group. Included studies must measure a physiological and/or a behavioral outcome.

DATA EXTRACTION AND ANALYSIS

The methodological quality of all included studies was independently evaluated by two reviewers using the Jadad score. Mean scores and P-values of measures were compared both inter- and intra-study for each parameter (i.e., depression).

RESULTS

Twelve studies met our inclusion criteria. These studies examined the effects of saffron on psychological/behavioral outcomes of: major depressive disorder (n=6), premenstrual syndrome (n = 1), sexual dysfunction and infertility (n=4), and weight loss/snacking behaviors (n=1). The data from these studies support the efficacy of saffron as compared to placebo in improving the following conditions: depressive symptoms (compared to anti-depressants and placebo), premenstrual symptoms, and sexual dysfunction. In addition, saffron use was also effective in reducing excessive snacking behavior.

CONCLUSION

Findings from initial clinical trials suggest that saffron may improve the symptoms and the effects of depression, premenstrual syndrome, sexual dysfunction and infertility, and excessive snacking behaviors. Larger multi-site clinical trials are needed to extend these preliminary findings.

Comparing the efficacy and safety of Crocus sativus L. with memantine in patients with moderate to severe Alzheimer's disease: a double-blind randomized clinical trial

OBJECTIVES

Limited pharmacological options are available for the management of Alzheimer's disease (AD) in severe stages. Cognitive-enhancing properties of saffron, the dried stigma of Crocus sativus L., have been evidenced in different studies. We aimed to compare the efficacy and safety of saffron extract versus memantine in reducing cognitive deterioration of patients with moderate to severe AD.

METHODS

In this randomized double-blind parallel-group study, 68 patients with moderate to severe AD (Mini-Mental State Examination score of 8-14) received memantine (20 mg/day) or saffron extract (30 mg/day) capsules for 12 months. Participants were evaluated every month by Severe Cognitive Impairment Rating Scale (SCIRS) and Functional Assessment Staging (FAST) in addition to recording the probable adverse events.

RESULTS

Both treatment groups showed similar outcomes as demonstrated by insignificant effect for time × treatment interaction on SCIRS scores [F(2.95, 194.78) = 2.25, p = 0.08]. There was no significant difference between the two groups in the scores changes from baseline to the endpoint on SCIRS (p = 0.38) and FAST (p = 0.87). The frequency of adverse events was not significantly different between the two groups as well.

CONCLUSIONS

In addition to its favorable safety profile, 1-year administration of saffron extract capsules showed to be comparable with memantine in reducing cognitive decline in patients with moderate to severe AD. Confirmatory studies with larger sample sizes and longer follow-up periods are warranted.

Antitumor effects of saffron-derived carotenoids in prostate cancer cell models

Crocus sativus L. extracts (saffron) are rich in carotenoids. Preclinical studies have shown that dietary intake of carotenoids has antitumor effects suggesting their potential preventive and/or therapeutic roles. We have recently reported that saffron (SE) and crocin (CR) exhibit anticancer activity by promoting cell cycle arrest in prostate cancer (PCa) cells. It has also been demonstrated that crocetin esters are produced after SE gastrointestinal digestion by CR hydrolysis. The aim of the present report was to investigate if SE, crocetin (CCT), and CR affected in vivo tumor growth of two aggressive PCa cell lines (PC3 and 22rv1) which were xenografted in male nude mice treated by oral gavage with SE, CR, and CCT. We demonstrated that the antitumor effects of CCT were higher when compared to CR and SE and treatments reverted the epithelial-mesenchymal transdifferentiation (EMT) as attested by the significant reduction of N-cadherin and beta-catenin expression and the increased expression of E-cadherin. Additionally, SE, CR, and CCT inhibited PCa cell invasion and migration through the downmodulation of metalloproteinase and urokinase expression/activity suggesting that these agents may affect metastatic processes. Our findings suggest that CR and CCT may be dietary phytochemicals with potential antitumor effects in biologically aggressive PCa cells.

Flavonoid Determination in the Quality Control of Floral Bioresidues from Crocus sativus L

A high-performance liquid chromatography with photodiode array detection method (HPLC-DAD) was validated for the analysis of floral bioresidues obtained in saffron spice production by using three different solvent mixtures [water/hydrochloric acid (HCl) (100:1, v/v), water/acetonitrile/trifluoroacetic acid (47:50:3, v/v/v), and water/acetonitrile/HCl (50:50:1, v/v/v)]. Fifteen phenolic compounds were tentatively identified, kaempferol 3-O-sophoroside and delphinidin 3,5-di-O-glucoside being the main ones. The extracts showed very different phenolic profiles obtained by HPLC-DAD coupled with electrospray ionization mass spectrometry (ESI-MSⁿ), and several experiments were carried out to explain this. The use of acetonitrile as solvent causes the chromatographic splitting of the peak of the delphinidin 3,5-di-O-glucoside into two peaks. Results obtained in this paper show that the extract prepared with water/HCl (100:1, v/v) would be the best suited for determining phenolic compounds in the quality control of the floral bioresidues from Crocus sativus L.

Saffron (Crocus sativus L.) and major depressive disorder: a meta-analysis of randomized clinical trials

BACKGROUND

Due to safety concerns and side effects of many antidepressant medications, herbal psychopharmacology research has increased, and herbal remedies are becoming increasingly popular as alternatives to prescribed medications for the treatment of major depressive disorder (MDD). Of these, accumulating trials reveal positive effects of the spice saffron (Crocus sativus L.) for the treatment of depression. A comprehensive and statistical review of the clinical trials examining the effects of saffron for treatment of MDD is warranted.

OBJECTIVE

The purpose of this study was to conduct a meta-analysis of published randomized controlled trials examining the effects of saffron supplementation on symptoms of depression among participants with MDD.

SEARCH STRATEGY

We conducted electronic and non-electronic searches to identify all relevant randomized, double-blind controlled trials. Reference lists of all retrieved articles were searched for relevant studies.

INCLUSION CRITERIA

The criteria for study selection included the following: (1) adults (aged 18 and older) with symptoms of depression, (2) randomized controlled trial, (3) effects of saffron supplementation on depressive symptoms examined, and (4) study had either a placebo control or antidepressant comparison group.

DATA EXTRACTION AND ANALYSIS

Using random effects modeling procedures, we calculated weighted mean effect sizes separately for the saffron supplementation vs placebo control groups, and for the saffron supplementation vs antidepressant groups. The methodological quality of all studies was assessed using the Jadad score. The computer software Comprehensive Meta-analysis 2 was used to analyze the data.

RESULTS

Based on our pre-specified criteria, five randomized controlled trials (n = 2 placebo controlled trials, n = 3 antidepressant controlled trials) were included in our review. A large effect size was found for saffron supplementation vs placebo control in treating depressive symptoms (M ES = 1.62, P < 0.001), revealing that saffron supplementation significantly reduced depression symptoms compared to the placebo control. A null effect size was evidenced between saffron supplementation and the antidepressant groups (M ES = -0.15) indicating that both treatments were similarly effective in reducing depression symptoms. The mean Jadad score was 5 indicating high quality of trials.

CONCLUSION

Findings from clinical trials conducted to date indicate that saffron supplementation can improve symptoms of depression in adults with MDD. Larger clinical trials, conducted by research teams outside of Iran, with long-term follow-ups are needed before firm conclusions can be made regarding saffron's efficacy and safety for treating depressive symptoms.

A randomized, double-blind, clinical trial comparing the efficacy and safety of Crocus sativus L. with fluoxetine for improving mild to moderate depression in post percutaneous coronary intervention patients

OBJECTIVE

A significant correlation exists between coronary artery diseases and depression. The aim of this trial was to compare the efficacy and safety of saffron versus fluoxetine in improving depressive symptoms of patients who were suffering from depression after performing percutaneous coronary intervention (PCI).

METHODS

In this randomized double-blind parallel-group study, 40 patients with a diagnosis of mild to moderate depression who had undergone PCI in the last six months were randomized to receive either fluoexetine (40mg/day) or saffron (30mg/day) capsule for six weeks. Participants were evaluated by Hamilton depression rating scale (HDRS) at weeks 3 and 6 and the adverse events were systemically recorded.

RESULTS

By the study endpoint, no significant difference was detected between two groups in reduction of HDRS scores (P=0.62). Remission and response rates were not significantly different as well (P=1.00 and P=0.67; respectively). There was no significant difference between two groups in the frequency of adverse events during this trial.

LIMITATIONS

Relatively small sample size and short observational period were the major limitations of this study.

CONCLUSION

Short-term therapy with saffron capsules showed the same antidepressant efficacy compared with fluoxetine in patients with a prior history of PCI who were suffering from depression.

Herb-drug interactions: an overview of systematic reviews

OBJECTIVES

The aim of this overview of systematic reviews (SRs) is to evaluate critically the evidence regarding interactions between herbal medicinal products (HMPs) and synthetic drugs.

METHODS

Four electronic databases were searched to identify relevant SRs.

RESULTS

Forty-six SRs of 46 different HMPs met our inclusion criteria. The vast majority of SRs were of poor methodological quality. The majority of these HMPs were not associated with severe herb-drug interactions. Serious herb-drug interactions were noted for Hypericum perforatum and Viscum album. The most severe interactions resulted in transplant rejection, delayed emergence from anaesthesia, cardiovascular collapse, renal and liver toxicity, cardiotoxicity, bradycardia, hypovolaemic shock, inflammatory reactions with organ fibrosis and death. Moderately severe interactions were noted for Ginkgo biloba, Panax ginseng, Piper methysticum, Serenoa repens and Camellia sinensis. The most commonly interacting drugs were antiplatelet agents and anticoagulants.

CONCLUSION

The majority of the HMPs evaluated in SRs were not associated with drug interactions with serious consequences. However, the poor quality and the scarcity of the primary data prevent firm conclusions.

Changes in total and individual crocetin esters upon in vitro gastrointestinal digestion of saffron aqueous extracts

Changes that may be expected in crocetin esters (crocins) upon digestion were examined in saffron aqueous extracts for the first time. Chemical characterization of total and individual crocins and other bioactive compounds was achieved by UV-vis spectrophotometry, RP-HPLC-DAD, and LC-ESI-MS. Antioxidant activity was evaluated using in vitro assays and the comet assay. The observed loss for both total and trans-crocins was higher in saffron (∼50%) than in gardenia extracts (∼30%), which were also examined for comparison. Loss was lower than that reported for hydrophobic carotenoids. cis-Isomers were less affected, leading to the hypothesis that trans/cis isomerization may occur in parallel to degradation reactions. Monitoring changes in the extracts at oral, gastric, or intestinal phases, separately, verified this view pointing out the critical effect of pH, temperature, and duration of process but not of digestive enzymes. No isomerization and less degradation (<20% loss) was evidenced when pure trans-crocetin (di-β-D-gentiobiosyl) ester was subjected to gastric or intestinal conditions.

Adverse effects of herbal medicines: an overview of systematic reviews

This overview of systematic reviews (SRs) aims to evaluate critically the evidence regarding the adverse effects of herbal medicines (HMs). Five electronic databases were searched to identify all relevant SRs, with 50 SRs of 50 different HMs meeting our inclusion criteria. Most had only minor weaknesses in methods. Serious adverse effects were noted only for four HMs: Herbae pulvis standardisatus, Larrea tridentate, Piper methysticum and Cassia senna. The most severe adverse effects were liver or kidney damage, colon perforation, carcinoma, coma and death. Moderately severe adverse effects were noted for 15 HMs: Pelargonium sidoides, Perna canaliculus, Aloe vera, Mentha piperita, Medicago sativa, Cimicifuga racemosa, Caulophyllum thalictroides, Serenoa repens, Taraxacum officinale, Camellia sinensis, Commifora mukul, Hoodia gordonii, Viscum album, Trifolium pratense and Stevia rebaudiana. Minor adverse effects were noted for 31 HMs: Thymus vulgaris, Lavandula angustifolia Miller, Boswellia serrata, Calendula officinalis, Harpagophytum procumbens, Panax ginseng, Vitex agnus-castus, Crataegus spp., Cinnamomum spp., Petasites hybridus, Agave americana, Hypericum perforatum, Echinacea spp., Silybum marianum, Capsicum spp., Genus phyllanthus, Ginkgo biloba, Valeriana officinalis, Hippocastanaceae, Melissa officinalis, Trigonella foenum-graecum, Lagerstroemia speciosa, Cnicus benedictus, Salvia hispanica, Vaccinium myrtillus, Mentha spicata, Rosmarinus officinalis, Crocus sativus, Gymnema sylvestre, Morinda citrifolia and Curcuma longa. Most of the HMs evaluated in SRs were associated with only moderately severe or minor adverse effects.

Increasing the applications of Crocus sativus flowers as natural antioxidants

Large amounts of floral bio-residues (92.6 g per 100 g of flowers) are generated and wasted in the production of saffron (Crocus sativus) spice. Progress in mechanization of saffron crop offer the opportunity to expand the uses of C. sativus flowers, beyond the spice (dried stigmas). The antioxidant potential of flowers of saffron, their separate parts (tepals, stamens, styles, and stigmas) and floral bio-residues were evaluated by 4 in vitro assays: lipid peroxidation, deoxyribose assay, Rancimat test, and Trolox equivalent antioxidant capacity. Phenolic content and crocetin ester composition were also determined. All the samples studied showed to be potential antioxidants. The highest phenolic, flavonoid, and anthocyanin contents were observed in tepals. Stamens showed lower phenolic, flavonoid, and anthocyanin contents than those of whole flowers, tepals, and floral bio-residues. Crocetin esters were not found in tepals or stamens. Stamens exhibited the most potent LOO(•) and OH(•) radicals scavenging activity, being higher than those of food antioxidant propyl gallate. Flowers of saffron, tepals, stamens, styles, and floral bio-residues showed LOO(•), OH(•), and ABTS(•-) radicals scavenging activity, while stigmas showed LOO(•) and ABTS(•-) radicals scavenging activity. All samples studied improved the oxidative stability of sunflower oil in Rancimat test. These antioxidant properties could suggest the application of this floral material as functional ingredients with the subsequent added value.

PRACTICAL APPLICATION

Saffron spice, the most valuable spice worldwide, is the dried stigma that only represents 7.4% of Crocus sativus flowers. Other parts of the flowers different to stigmas are discarded. Flower harvest and all the postharvest steps to produce saffron spice are performed manually. Mechanization of flower collection, stigma separation, and dehydration process is a revolution in saffron spice production, which increases the productive capacity making it possible to extend the uses of C. sativus flowers, beyond the production of saffron spice. Flowers possessed high-phenolic content and excellent antioxidant properties that could contribute to their application as functional ingredients.

Contamination and adulteration of herbal medicinal products (HMPs): an overview of systematic reviews

PURPOSE

The aim of this overview of systematic reviews is to summarise and critically evaluate the evidence from systematic reviews of the adulteration and contamination of herbal medicinal products (HMPs).

METHODS

Five electronic databases were searched to identify all relevant systematic reviews.

RESULTS

Twenty-six systematic reviews met our inclusion criteria. The most commonly HMPs were adulterated or contaminated with dust, pollens, insects, rodents, parasites, microbes, fungi, mould, toxins, pesticides, toxic heavy metals and/or prescription drugs. The most severe adverse effects caused by these adulterations were agranulocytosis, meningitis, multi-organ failure, perinatal stroke, arsenic, lead or mercury poisoning, malignancies or carcinomas, hepatic encephalopathy, hepatorenal syndrome, nephrotoxicity, rhabdomyolysis, metabolic acidosis, renal or liver failure, cerebral edema, coma, intracerebral haemorrhage, and death. Adulteration and contamination of HMPs were most commonly noted for traditional Indian and Chinese remedies, respectively.

CONCLUSIONS

Collectively these data suggest that there are reasons for concerns with regards to the quality of HMPs. Adulteration and contamination of HMPs can cause serious adverse effects. More stringent quality control and its enforcement seem to be necessary to avoid health risks.

Contamination and adulteration of herbal medicinal products (HMPs): an overview of systematic reviews

PURPOSE

The aim of this overview of systematic reviews is to summarise and critically evaluate the evidence from systematic reviews of the adulteration and contamination of herbal medicinal products (HMPs).

METHODS

Five electronic databases were searched to identify all relevant systematic reviews.

RESULTS

Twenty-six systematic reviews met our inclusion criteria. The most commonly HMPs were adulterated or contaminated with dust, pollens, insects, rodents, parasites, microbes, fungi, mould, toxins, pesticides, toxic heavy metals and/or prescription drugs. The most severe adverse effects caused by these adulterations were agranulocytosis, meningitis, multi-organ failure, perinatal stroke, arsenic, lead or mercury poisoning, malignancies or carcinomas, hepatic encephalopathy, hepatorenal syndrome, nephrotoxicity, rhabdomyolysis, metabolic acidosis, renal or liver failure, cerebral edema, coma, intracerebral haemorrhage, and death. Adulteration and contamination of HMPs were most commonly noted for traditional Indian and Chinese remedies, respectively.

CONCLUSIONS

Collectively these data suggest that there are reasons for concerns with regards to the quality of HMPs. Adulteration and contamination of HMPs can cause serious adverse effects. More stringent quality control and its enforcement seem to be necessary to avoid health risks.