Effects of saffron ( Crocus sativus L.) supplementation on inflammatory biomarkers: A systematic review and meta‐analysis

Oral supplementation with crocin (a constituent of saffron) in subjects with cigarette smoking: a clinical trial

Smoking is one of the main causes of death in the world. Cigarette use is related with various components of metabolic syndrome (e.g., insulin resistance, raised blood pressure, dyslipidemia, oxidative stress, inflammation state) and psychiatric disorders. This study was conducted to determine the effect of crocin (Cro) supplementation on nicotine dependence, anxiety, depression, and metabolic indices in smokers. A total of 50 smokers were selected and randomly categorized into two groups (crocin and placebo). The intervention group received crocin (30 mg per day; n = 25) and placebo (containing Avicel; n = 25) once a day. The primary (nicotine dependence, depression, and anxiety inventory) and secondary (metabolic indices) outcomes were assessed at the start of the intervention and after the 3 months. Multiple linear regression models were used to assess the treatment effects on the outcomes adjusting for confounding variables. The primary outcome results such as nicotine dependence, depression, and anxiety inventory did not have a significant difference among the intervention groups (P > 0.05). Also in the secondary outcomes, fasting plasma glucose (FPG), insulin, and homeostasis model of assessment-insulin resistance (HOMA-IR) levels did indicate a significant difference by Cro intervention (β - 3.27 mg/dL; 95% CI, - 5.23, - 1.31; P = 0.002; β - 0.76 μIU/mL; 95% CI, - 1.38, - 0.15; P = 0.01; β - 0.18; 95% CI, - 0.29, - 0.07; P = 0.002), respectively. There were also significant reductions in serum levels of high-sensitivity C-reactive protein (hs-CRP) (β - 0.72 mg/L; 95% CI, - 1.37, - 0.07; P = 0.03), compared with the placebo. Cro intake may have favorable effects on the level of FPG, insulin, HOMA-IR, and hs-CRP in smokers. However, due to the small sample size and limited scientific reports on smokers, further studies are necessary. ClinicalTrial.gov Identifier: IRCT20170420033551N11.

Saffron as a Promising Therapy for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory illness of the gastrointestinal tract (GI), characterized by recurrent episodes of inflammation and tissue destruction. It affects an increasing number of individuals worldwide who suffer from Crohn's disease (CD) or ulcerative colitis (UC). Despite substantial advances in understanding the underlying causes of IBD, the available treatments remain restricted and are sometimes accompanied by severe consequences. Consequently, there is an urgent need to study alternate therapeutic options. This review assesses the present drugs, identifies their limitations, and proposes the use of saffron, a natural plant with great therapeutic potential based on preclinical and clinical investigations. Saffron has gained attention for its potential therapeutic benefits in treating various ailments due to its established bioactive compounds possessing antioxidant and anti-inflammatory properties. This review covers how saffron impacts the levels of calprotectin, an inflammatory marker, for various inflammatory responses in multiple diseases including IBD. Data from clinical trials were assessed to determine the efficacy and safety of using saffron to counter inflammation in multiple diseases. Studies have shown that saffron may protect against inflammatory bowel disease (IBD) through several mechanisms by inhibiting pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), reducing oxidative stress through antioxidant effects, enhancing mucosal barrier function by upregulating tight junction proteins, and modulating the gut microbiota composition to promote beneficial bacteria while suppressing pathogenic ones; these combined actions contribute to its therapeutic potential in managing and alleviating the symptoms of IBD. This will enable future research endeavors and expedite the translation of saffron-based interventions into clinical practice as a valuable adjunctive therapy or a potential alternative to conventional treatments, thereby enhancing the quality of life for individuals suffering from inflammatory diseases including IBD.

Saffron (Crocus sativus L.) and Its By-Products: Healthy Effects in Internal Medicine

Crocus sativus L., commonly known as saffron, is a precious spice coming from Asia, in particular from Iran, the country leader in its production. The spice is derived exclusively from dried stigmas and it is the most expensive one in the world. The areas of application of saffron are multiple, in fact ranging across the food, drinks, pharmaceuticals and cosmetics sectors. As is the case with other phytochemicals, not only the final product but also saffron by-products are considered a valuable source of bioactive natural compounds. In fact, its healthy effects, especially as antioxidants and anti-inflammatories (via reducing pro-inflammatory cytokines), are well-recognized in internal medicine. In particular, its healthy effects are related to counteracting degenerative maculopathy, depression and anxiety, neurodegenerative diseases, metabolic syndrome, cancer and chronic kidney disease, by promoting glucose metabolism. In this review, we summarize the most important papers in which saffron has turned out to be a valuable ally in the prevention and treatment of these pathologies. Moreover, we would like to promote the use of saffron by-products as part of a bio-circular economy system, aimed at reducing wastes, at maximizing the use of resources and at promoting environmental and economic sustainability.

Investigation of the effects of crocin on inflammation, oxidative stress, apoptosis, NF-κB, TLR-4 and Nrf-2/HO-1 pathways in gentamicin-induced nephrotoxicity in rats

The primary limitation of gentamicin (Gm) treatment is its potential to induce nephrotoxicity, which can restrict both its duration and efficacy. This study aims to investigate the protective effects of Crocin (Cr) against Gm-induced nephrotoxicity and its underlying mechanisms, including inflammation, apoptosis, TLR-4, Nrf-2/HO-1 pathways. 36 Sprague Dawley rats were divided into 6 groups for the study. Group I received only saline. Groups II and III were administered 25 and 50 mg/kg of crocin, respectively. Group IV was treated with 80 mg/kg of Gm. Groups V and VI received 25 and 50 mg/kg of crocin, respectively, in addition to Gm administration. Crocin demonstrated protective effects on kidney tissue. It down-regulated the genes NF-κB, COX-2, TLR-4, Bax, and Caspase-3, while up-regulating Bcl-2, Nrf-2, and HO-1. In conclusion, these findings hold promise for the prevention of Gm-induced nephrotoxicity through the modulation of the Nrf-2/HO-1 pathway.

Network Pharmacology Integrated Molecular Docking and Dynamics to Elucidate Saffron Compounds Targeting Human COX-2 Protein

Background and Objectives: Cyclooxygenase-2 (COX-2) is mostly linked to inflammation and has been validated as a molecular target for treating inflammatory diseases. The present study aimed to identify novel compounds that could inhibit COX-2, which is associated with various diseases including inflammation, and in such a scenario, plant-derived biomolecules have been considered as attractive candidates. Materials and Methods: In the present study, physiochemical properties and toxicity of natural compounds/drugs were determined by SWISSADME and ProTox-II. In the present study, the molecular docking binding features of saffron derivatives (crocetin, picrocrocin, quercetin, safranal, crocin, rutin, and dimethylcrocetin) against human COX-2 protein were assessed. Moreover, protein-protein interactions, topographic properties, gene enrichment analysis and molecular dynamics simulation were also determined. Results: The present study revealed that picrocrocin showed the highest binding affinity of -8.1 kcal/mol when docked against the COX-2 protein. PROCHECK analysis revealed that 90.3% of the protein residues were found in the most favored region. Compartmentalized Protein-Protein Interaction identified 90 interactions with an average interaction score of 0.62, and the highest localization score of 0.99 found in secretory pathways. The Computed Atlas of Surface Topography of Proteins was used to identify binding pockets and important residues that could serve as drug targets. Use of WEBnmα revealed protein dynamics by using normal mode analysis. Ligand and Receptor Dynamics used the Molecular Generalized Born Surface Area approach to determine the binding free energy of the protein. Gene enrichment analysis revealed that ovarian steroidogenesis, was the most significant enrichment pathway. Molecular dynamic simulations were executed for the best docked (COX-2-picrocrocin) complex, and the results displayed conformational alterations with more pronounced surface residue fluctuations in COX-2 with loss of the intra-protein hydrogen bonding network. The direct interaction of picrocrocin with various crucial amino-acid residues like GLN203, TYR385, HIS386 and 388, ASN382, and TRP387 causes modifications in these residues, which ultimately attenuates the activity of COX-2 protein. Conclusions: The present study revealed that picrocrocin was the most effective biomolecule and could be repurposed via computational approaches. However, various in vivo and in vitro observations are still needed.

Crocus sativus L. Extract (Saffron) Effectively Reduces Arthritic and Inflammatory Parameters in Monotherapy and in Combination with Methotrexate in Adjuvant Arthritis

Rheumatoid arthritis (RA), an autoimmune disease, is characterized by inflammation that affects not only the liver but also other organs and the musculoskeletal system. The standard therapy for RA is methotrexate (MTX), which has safety limitations. The extract from Crocus sativus L. (saffron-SF) is also known for its anti-inflammatory effects. Therefore, we decided to investigate the potential benefit of SF in monotherapy via two doses (SF1-25 mg/kg of b.w.; SF2-50 mg/kg of b.w.) and in combination with MTX (0.3 mg/kg of b.w., twice a week) using adjuvant arthritis in rats. To evaluate these therapeutic settings, we used biometric, immunological, and biochemical parameters, as well as the relative gene expression of the mRNA in the liver. Our results showed a statistically significant increase in the experimental animals' body weight and the arthritic score (AS) on day 14 for monotherapy with SF1 and SF2. The change of hind paw volume (CHPV) was significant only for SF2 monotherapy on the 14th day of the experiment. A combination of SF1 and SF2 with MTX significantly modulated all the biometric parameters during the experimental period. Additionally, AS and CHPV improved considerably compared to MTX monotherapy on day 21. Furthermore, all monotherapies and combination therapies were significant for the biochemical parameter γ-glutamyl transferase (GGT) in the joint. GGT activity in the spleen was less pronounced; only MTX in combination with SF1 significantly modified this parameter. The higher dose of SF monotherapy (SF2) was similarly significant with respect to immunological parameters, such as plasmatic IL-17A, IL-1β, and MMP-9 on day 21. The combination of both doses of SF with MTX significantly improved these immunological parameters, except for C-reactive protein (CRP), which was influenced only by the higher dose of SF2 in combination with MTX in plasma at the end of the experiment. A different effect was found for the relative expression of CD36 mRNA, where only SF1 significantly decreased gene expression in the liver. However, the relative gene mRNA expression of IL-1β in the liver was significantly reduced by the SF monotherapies and the combination of both SF doses with MTX. Our findings showed SF's partial antiarthritic and anti-inflammatory potential in monotherapy, but the effect was stronger in combination with MTX.

Effects of Supplementation with the Standardized Extract of Saffron (affron®) on the Kynurenine Pathway and Melatonin Synthesis in Rats

Melatonin is a hormone that regulates sleep-wake cycles and is mainly synthesized in the pineal gland from tryptophan after its conversion into serotonin. Under normal conditions, less than 5% of tryptophan is reserved for the synthesis of serotonin and melatonin. The remaining 95% is metabolized in the liver through the kynurenine pathway. Increased levels of proinflammatory cytokines and cortisol increase the metabolism of tryptophan through the kynurenine pathway and reduce its availability for the synthesis of melatonin and serotonin, which may cause alterations in mood and sleep. The standardized saffron extract (affron®) has shown beneficial effects on mood and sleep disorders in humans, but the underlying mechanisms are not well understood. Thus, the aim of this work was to study the effects of affron® supplementation on the kynurenine pathway and the synthesis of melatonin in rats. For this purpose, adult male Wistar rats were supplemented for 7 days with 150 mg/kg of affron® or vehicle (2 mL/kg water) administered by gavage one hour before sleep. Affron® supplementation reduced body weight gain and increased the circulating levels of melatonin, testosterone, and c-HDL. Moreover, animals supplemented with affron® showed decreased serum levels of kynurenine, ET-1, and c-LDL. In the pineal gland, affron® reduced Il-6 expression and increased the expression of Aanat, the key enzyme for melatonin synthesis. In the liver, affron® administration decreased the mRNA levels of the enzymes of the kynurenine pathway Ido-2, Tod-2, and Aadat, as well as the gene expression of Il-1β and Tnf-α. Finally, rats treated with affron® showed increased mRNA levels of the antioxidant enzymes Ho-1, Sod-1, Gsr, and Gpx-3, both in the liver and in the pineal gland. In conclusion, affron® supplementation reduces kynurenine levels and promotes melatonin synthesis in rats, possibly through its antioxidant and anti-inflammatory effects, making this extract a possible alternative for the treatment and/or prevention of mood and sleep disorders.

Microbiomic and Metabolomic Analyses Unveil the Protective Effect of Saffron in a Mouse Colitis Model

Despite the existence of effective drugs used to treat inflammatory bowel disease (IBD), many patients fail to respond or lose response over time. Further, many drugs can carry serious adverse effects, including increased risk of infections and malignancies. Saffron (Crocus sativus) has been reported to have anti-inflammatory properties. Its protective role in IBD and how the microbiome and metabolome play a role has not been explored extensively. We aimed to establish whether saffron treatment modulates the host microbiome and metabolic profile in experimental colitis. Colitis was induced in C57BL/6 mice with 3% DSS and treated with either saffron in a dose of 20 mg/kg body weight or vehicle through daily gavage. On day 10, stool pellets from mice were collected and analyzed to assess saffron's effect on fecal microbiota and metabolites through 16S rRNA sequencing and untargeted primary metabolite analysis. Saffron treatment maintained gut microbiota homeostasis by counter-selecting pro-inflammatory bacteria and maintained Firmicutes/Bacteroides ratio, which was otherwise disturbed by DSS treatment. Several metabolites (uric acid, cholesterol, 2 hydroxyglutaric acid, allantoic acid, 2 hydroxyhexanoic acid) were altered significantly with saffron treatment in DSS-treated mice, and this might play a role in mediating saffron's colitis-mitigating effects. These data demonstrate saffron's therapeutic potential, and its protective role is modulated by gut microbiota, potentially acting through changes in metabolites.

Beyond Seasoning-The Role of Herbs and Spices in Rheumatic Diseases

Although we have witnessed remarkable progress in understanding the biological mechanisms that lead to the development of rheumatic diseases (RDs), remission is still not achieved in a substantial proportion of patients with the available pharmacological treatment. As a consequence, patients are increasingly looking for complementary adjuvant therapies, including dietary interventions. Herbs and spices have a long historical use, across various cultures worldwide, for both culinary and medicinal purposes. The interest in herbs and spices, beyond their seasoning properties, has dramatically grown in many immune-mediated diseases, including in RDs. Increasing evidence highlights their richness in bioactive molecules, such as sulfur-containing compounds, tannins, alkaloids, phenolic diterpenes, and vitamins, as well as their antioxidant, anti-inflammatory, antitumorigenic, and anticarcinogenic properties. Cinnamon, garlic, ginger, turmeric, and saffron are the most popular spices used in RDs and will be explored throughout this manuscript. With this paper, we intend to provide an updated review of the mechanisms whereby herbs and spices may be of interest in RDs, including through gut microbiota modulation, as well as summarize human studies investigating their effects in Rheumatoid Arthritis, Osteoarthritis, and Fibromyalgia.

Crocus sativus Extract as a Biological Agent for Disease-Modifying Therapy of Collagenase-Induced Mouse Model of Osteoarthritis

Objectives: Osteoarthritis (OA) is an age-related joint disease that involves the degeneration of cartilage and is the most prevalent form of arthritis, affecting a large part of the population. OA is a multifactorial disorder, and no single etiological mechanism has been found to be common to all forms of the disease. Currently used therapies for control of the disease are mainly nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroid medications. The aim of this study was to investigate the extract from Crocus sativus as a biological disease-suppressing therapy agent. Methods: Balb/c mice were injected intra-articularly with Clostridium histolyticum type IA for induction of osteoarthritis. The mice were randomized to five groups: control group, I group (CIOA untreated), II group (CIOA + 100 mg/kg/daily saffron), III group (CIOA + 50 mg/kg/daily saffron), IV group (CIOA + 25 mg/kg/daily saffron). Flow-cytometry analysis was used to study the splenocytes’ phenotype isolated from the treated animals. The serum levels of inflammatory and anti-inflammatory cytokines were analyzed with ELISA. The histological assessment was used to analyze the saffron extract effect on histopathological alterations. Results: Saffron treatment significantly decreased osteoarthritis-associated joint histological manifestations and decreased serum TNFα levels. The flow-cytometry analysis showed a decrease in pro-inflammatory immune cell subtypes in the spleen. Conclusions: The results obtained suggest that saffron affected the disease progression and could be a potential therapeutic approach in osteoarthritic patients’ therapy.

A Picrocrocin-Enriched Fraction from a Saffron Extract Affects Lipid Homeostasis in HepG2 Cells through a Non-Statin-like Mode

Dyslipidemia is a lipid metabolism disorder associated with the loss of the physiological homeostasis that ensures safe levels of lipids in the organism. This metabolic disorder can trigger pathological conditions such as atherosclerosis and cardiovascular diseases. In this regard, statins currently represent the main pharmacological therapy, but their contraindications and side effects limit their use. This is stimulating the search for new therapeutic strategies. In this work, we investigated in HepG2 cells the hypolipidemic potential of a picrocrocin-enriched fraction, analyzed by high-resolution 1H NMR and obtained from a saffron extract, the stigmas of Crocus sativus L., a precious spice that has already displayed interesting biological properties. Spectrophotometric assays, as well as expression level of the main enzymes involved in lipid metabolism, have highlighted the interesting hypolipidemic effects of this natural compound; they seem to be exerted through a non-statin-like mechanism. Overall, this work provides new insights into the metabolic effects of picrocrocin, thus confirming the biological potential of saffron and paving the way for in vivo studies that could validate this spice or its phytocomplexes as useful adjuvants in balancing blood lipid homeostasis.

Effect of saffron supplementation on oxidative stress markers (MDA, TAC, TOS, GPx, SOD, and pro-oxidant/antioxidant balance): An updated systematic review and meta-analysis of randomized placebo-controlled trials

Introduction

This study aimed to perform an updated systematic review and meta-analysis to evaluate the effectiveness of saffron supplementation on oxidative stress markers [malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS), glutathione peroxidase (GPx), superoxide dismutase (SOD), and prooxidant/antioxidant balance (PAB)] in randomized controlled trials (RCTs).

Methods

We searched PubMed/Medline, Web of Science, Scopus, Cochrane CENTRAL, and Google Scholar until December 2022. Trial studies investigating the effects of oral saffron supplements on MDA, TAC, TOS, GPx, SOD, and PAB concentrations were included in the study. To analyze the results, mean differences (SMD) and 95% confidence intervals (CI) were pooled using a random effects model. Heterogeneity was assessed using the Cochrane Q and I ² values. Sixteen cases were included in the meta-analysis (468 and 466 subjects in the saffron and control groups, respectively).

Results

It was found that saffron consumption caused a significant decrease in MDA (SMD: -0.322; 95% CI: -0.53, -0.16; I ² = 32.58%) and TOS (SMD: -0.654; 95% CI: -1.08, -0.23; I ² = 68%) levels as well as a significant increase in TAC (SMD: 0.302; 95% CI: 0.13, 0.47; I ² = 10.12%) and GPx (SMD: 0.447; 95% CI: 0.10, 0.80; I ² = 35%). Subgroup analysis demonstrated a significant reduction in MDA levels in studies with a saffron dosage of >30 mg/day, age of <50 years, and study duration of <12 weeks. Among the limitations of the study, we can point out that the studies were from Iran, the different nature of the diseases included, and were not considered of some potential confounders such as smoking, physical activity, and diet in the studies.

Discussion

In summary, the results showed that saffron has beneficial effects on oxidative stress markers.

The effects of saffron supplementation on cardiovascular risk factors in adults: A systematic review and dose-response meta-analysis

Introduction

Cardiovascular disease (CVD) is one of the leading causes of death and disability in the world and is estimated to involve more people in the next years. It is said that alternative remedies such as herbs can be used to manage the complications of this disease. For this reason, we aimed to conduct this meta-analysis to systematically assess and summarize the effects of saffron supplementation as an important herb on cardiovascular risk factors in adults.

Methods

A systematic search was done in PubMed, Scopus, and Web of Science to find eligible articles up to September 2022. Randomized controlled trials (RCTs) that evaluated the effects of saffron on lipid profiles, glycemic control, blood pressure, anthropometric measures, and inflammatory markers were included. In the meta-analysis, 32 studies were taken into account (n = 1674).

Results

Consumption of saffron significantly decreased triglyceride (TG) (WMD = -8.81 mg/dl, 95%CI: -14.33, -3.28; P = 0.002), total cholesterol (TC) (WMD = -6.87 mg/dl, 95%CI: -11.19, -2.56; P = 0.002), low density lipoprotein (LDL) (WMD = -6.71 mg/dl, 95%CI: -10.51, -2.91; P = 0.001), (P = 0.660), fasting blood glucose (FBG) level (WMD = -7.59 mg/dl, 95%CI: -11.88, -3.30; P = 0.001), HbA1c (WMD = -0.18%, 95%CI: -0.21, -0.07; P < 0.001), homeostasis model assessment-insulin resistance (HOMA-IR) (WMD = -0.49, 95%CI: -0.89, -0.09; P = 0.016), systolic blood pressure (SBP) (WMD = -3.42 mmHg, 95%CI: -5.80, -1.04; P = 0.005), tumor necrosis factor α (TNF-α) (WMD = -2.54 pg/ml, 95%CI: -4.43, -0.65; P = 0.008), waist circumference (WC) (WMD = -1.50 cm; 95%CI: -2.83, -0.18; P = 0.026), malondialdehyde (MDA) (WMD = -1.50 uM/L, 95%CI: -2.42, -0.57; P = 0.001), and alanine transferase (ALT) (WMD = -2.16 U/L, 95%CI: -4.10, -0.23; P = 0.028). Also, we observed that saffron had an increasing effect on total antioxidant capacity (TAC) (WMD = 0.07 mM/L, 95%CI: 0.01, 0.13; P = 0.032). There was linear regression between FBG and the duration of saffron intake. Additionally, the non-linear dose-response analysis has shown a significant association of saffron intervention with HDL (P = 0.049), HOMA-IR (P = 0.002), weight (P = 0.036), ALP (P = 0.016), FBG (P = 0.011), HbA1c (P = 0.002), and TNF-α (P = 0.042). A non-linear association between the length of the intervention and the level of HDL and DBP was also found.

Discussion

That seems saffron could effectively improve TG, TC, LDL, FBG, HbA1c, HOMA-IR, SBP, CRP, TNF-α, WC, MDA, TAC, and ALT.

Crocin molecular signaling pathways at a glance: A comprehensive review

Crocin is a hydrophilic carotenoid that is synthesized in the flowers of the Crocus genus. Numerous in vitro and in vivo research projects have been published about the biological and pharmacological properties and toxicity of crocin. Crocin acts as a memory enhancer, anxiolytic, aphrodisiac, antidepressant, neuroprotective, and so on. Here, we introduce an updated and comprehensive review of crocin molecular mechanisms based on previously examined and mentioned in the literature. Different studies confirmed the significant effect of crocin to control pathological conditions, including oxidative stress, inflammation, metabolic disorders, neurodegenerative disorders, and cancer. The neuroprotective effect of crocin could be related to the activation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT)/mammalian target of rapamycin (mTOR), Notch, and cyclic-AMP response element-binding protein signaling pathways. The crocin also protects the cardiovascular system through the inhibitory effect on toll-like receptors. The regulatory effect of crocin on PI3K/AKT/mTOR, AMP-activated protein kinase, mitogen-activated protein kinases (MAPK), and peroxisome proliferator-activated receptor pathways can play an effective role in the treatment of metabolic disorders. The crocin has anticancer activity through the PI3K/AKT/mTOR, MAPK, vascular endothelial growth factor, Wnt/β-catenin, and Janus kinases-signal transducer and activator of transcription suppression. Also, the nuclear factor-erythroid factor 2-related factor 2 and p53 signaling pathway activation may be effective in the anticancer effect of crocin. Finally, among signaling pathways regulated by crocin, the most important ones seem to be those related to the regulatory effect on the PI3K/AKT/mTOR pathway.

The effect of saffron supplementation on glycemic parameters: An overview of systematic reviews

Due to the widespread use of herbal medicine and evidence pointing to the health benefits of saffron supplementation, this review was performed to evaluate the effects of saffron supplementation on glycemic parameters and lipid profiles based on previous reviews. Relevant articles were retrieved from various databases, which included PubMed, Scopus, ProQuest, Web of Science, Embase, and Cochrane until 2020, with no date restrictions. The quality of the included reviews was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) checklist. Finally, of 877 obtained articles, eight reviews meeting the inclusion criteria were included for analysis. Among the eight included reviews, seven articles were meta-analyses. In addition, one review had an average quality while seven had a good quality. A narrative description of the included reviews was performed, while a network meta-analysis was not conducted. A brief review of the results was reported according to the weighted mean difference and mean difference. Seven included reviews assessed the effects of saffron or crocin supplementation on glycemic parameters, and six examined these effects on lipid profile parameters. Almost half of the articles reported significant effects of these supplements on glycemic parameters and lipid profiles. Taken together, results suggest that saffron supplementation may improve glycemic and lipid profile parameters; however, further high-quality studies are needed to confirm the clinical efficacy of saffron on glycemic parameters and lipid profiles.

The Effect of Saffron (Crocus sativus L.) Supplementation on Renal Function: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials

BACKGROUND

The present systematic review and meta-analysis of randomized controlled trials (RCTs) aimed at determining the effect of saffron supplementation on renal function.

METHODS

Electronic databases were searched up to February 2021. The risk of bias in individual studies was assessed using the Cochrane Collaboration tool. The overall weighted mean difference (WMD) and their 95% confidence intervals (CIs) were calculated using random-effect models. P < 0.05 was considered statistically significant.

RESULTS

A total of 11 trials were included in this study. Saffron had beneficial effect on BUN (WMD = -0.69 mg/dl; 95% CI, -1.36 to -0.01; P=0.046) compared to placebo, with significant heterogeneity (I ² = 49.6%, P=0.037). However, it had no significant effect on serum Cr (WMD = 0.04 mg/dl; 95% CI: -0.01 to 0.09; P=0.127).

CONCLUSION

It seems that saffron supplementation had no significant effect on Cr as a renal function factor. However, BUN reduction was significant in the saffron group compared to placebo.

Effect of Crocus sativus (Saffron) Intake on Top of Standard Treatment, on Disease Outcomes and Comorbidities in Patients with Rheumatic Diseases: Synthesis without Meta-Analysis (SWiM) and Level of Adherence to the CONSORT Statement for Randomized Controlled Trials Delivering Herbal Medicine Interventions

Rheumatic diseases (RDs) are often complicated by chronic symptoms and frequent side-effects associated with their treatment. Saffron, a spice derived from the Crocus sativus L. flower, is a popular complementary and alternative medicine among patients with RDs. The present systematic review aimed to summarize the available evidence regarding the efficacy of supplementation with saffron on disease outcomes and comorbidities in patients with RD diagnoses. PubMed, CENTRAL, clinicaltrials.gov and the grey literature were searched until October 2021, and relevant randomized controlled trials (RCTs) were screened for eligibility using Rayyan. Risk of bias was assessed using the Cochrane’s Risk of Bias-2.0 (RoB) tool. A synthesis without meta-analysis (SWiM) was performed by vote counting and an effect direction plot was created. Out of 125 reports, seven fulfilled the eligibility criteria belonging to five RCTs and were included in the SWiM. The RCTs involved patients with rheumatoid arthritis, osteoarthritis and fibromyalgia, and evaluated outcomes related to pain, disease activity, depression, immune response, inflammation, oxidative stress, health, fatigue and functional ability. The majority of trials demonstrated some concerns regarding overall bias. Moreover, the majority of trialists failed to adhere to the formula elaborations suggested by the CONSORT statement for RCTs incorporating herbal medicine interventions. Standardization of herbal medicine confirms its identity, purity and quality; however, the majority of trials failed to adhere to these guidelines. Due to the great heterogeneity and the lack of important information regarding the standardization and content of herbal interventions, it appears that the evidence is not enough to secure a direction of effect for any of the examined outcomes.

Saffron (Crocus sativus L.) and health outcomes: a meta-research review of meta-analyses and an evidence mapping study

BACKGROUND

Although a number of systematic reviews and meta-analyses of saffron (Crocus sativus L.) have been published, no study has comprehensively summarized the clinical evidence from meta-analyses, or assessed the reporting or methodological quality of these reviews.

PURPOSE

The present meta-research study was designed to fill the gaps in knowledge to inform future studies and allow enhanced clinical decision-making on saffron.

METHODS

The PubMed, Cochrane Library, Embase, and CNKI databases were systematically searched from inception to April 3 rd, 2021, for meta-analyses of clinical trials that assessed the efficacy and safety of saffron. PRISMA 2009 and AMSTAR-2 were employed to assess the reporting and methodological quality of meta-analyses identified in the search, respectively. The present study was registered on PROSPERO with registration number CRD42020220274.

RESULTS

Nineteen eligible systematic reviews with meta-analyses published in English were identified from 235 records. These meta-analyses were published in 12 peer-reviewed journals from 2013 to 2021. The heterogeneous results indicated that saffron significantly reduced fasting blood glucose, waist circumference, diastolic blood pressure, concentrations of total cholesterol and low-density lipoprotein cholesterol, and improved symptoms of depression, cognitive function and sexual dysfunction compared with controls (mainly placebos). Common side effects of saffron consumption included nausea, dry mouth, poor appetite, and headache, but no serious adverse reactions were reported. Primary analysis and sensitivity analysis confirmed that the reporting and methodological quality of reviews included in the study were highly correlated (p < 0.001). The quality of meta-analyses of saffron requires improvement by including a structured abstract, a prospective protocol and registration, explanation of the study designs within each study that is reviewed, the searches, risk of bias assessment, literature selection, and reporting of funding sources.

CONCLUSION

The available evidence indicates that saffron is a safe plant for administration as a medicine and can improve diverse clinical outcomes, but the scientific quality of the published systematic reviews needs to be improved. Moreover, the clinical effects of saffron need to be confirmed through high-quality randomized trials in multiple countries with large sample sizes.

The Effect of Saffron Supplementation on Blood Pressure in Adults: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Background: The favorable influences of saffron supplementation on metabolic diseases have previously been shown. We aimed to assess the effects of saffron supplementation on blood pressure in adults. Methods: A systematic search was performed in Scopus, Embase, and the Cochrane library databases to find randomized controlled trials (RCTs) related to the effect of saffron supplementation on blood pressure in adults up to March 2021. The primary search yielded 182 publications, of which eight RCTs were eligible. Results: Our results showed that saffron supplementation resulted in a significant decrease in systolic blood pressure (weighted mean difference (WMD): −0.65 mmHg; 95% CI: −1.12 to −0.18, p = 0.006) and diastolic blood pressure (DBP) (WMD: −1.23 mmHg; 95% CI: −1.64 to −0.81, p < 0.001). Moreover, saffron supplementation reduced DBP in a non-linear fashion, based on duration (r = −2.45, p-nonlinearity = 0.008). Conclusions: Saffron supplementation may significantly improve both systolic and diastolic blood pressure in adults. It should be noted that the hypotensive effects of saffron supplementation were small and may not reach clinical importance.

Carotenoids supplementation and inflammation: a systematic review and meta-analysis of randomized clinical trials

The aim of this study was to perform a systematic review and meta-analysis on randomized controlled trials investigating the effects of carotenoids on selected inflammatory parameters. PubMed, SCOPUS, and Web of science were searched from inception until April 2021. The random-effect model was used to analyze data and the overall effect size was computed as weighted mean difference (WMD) and corresponding 95% of confidence interval (CI). A total of 26 trials with 35 effect sizes were included in this meta-analysis. The results indicated significant effects of carotenoids on C-reactive protein (CRP) (WMD: ‒0.54 mg/L, 95% CI: ‒0.71, ‒0.37, P < 0.001), and interleukin-6 (IL-6) (WMD: ‒0.54 pg/mL, 95% CI: ‒1.01, ‒0.06, P = 0.025), however the effect on tumor necrosis factor-alpha (TNF-α) was not significant (WMD: ‒0.97 pg/ml, 95% CI: ‒1.98, 0.03, P = 0.0.059). For the individual carotenoids, astaxanthin, (WMD: ‒0.30 mg/L, 95% CI: ‒0.51, ‒0.09, P = 0.005), lutein/zeaxanthin (WMD: ‒0.30 mg/L, 95% CI: ‒0.45, ‒0.15, P < 0.001), and β-cryptoxanthin (WMD: ‒0.35 mg/L, 95% CI: ‒0.54, ‒0.15, P < 0.001) significantly decreased CRP level. Also, only lycopene (WMD: ‒1.08 pg/ml, 95%CI: ‒2.03, ‒0.12, P = 0.027) led to a significant decrease in IL-6. The overall results supported possible protective effects of carotenoids on inflammatory biomarkers.

Does saffron supplementation have favorable effects on liver function indicators? A systematic review and meta-analysis of randomized controlled trials

Several pharmaceutical and non-pharmaceutical approaches have been suggested to improve liver health. There is a large discrepancy in the effects of saffron supplementation on liver function in adults. To fill this knowledge gap, this systematic review and meta-analysis of randomized controlled trials (RCTs) assess the effects of saffron supplementation on liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). A systematic search current to August 2020 was performed in PubMed/Medline, Scopus, Web of Science, and Google Scholar using relevant keywords to detect eligible articles. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence (95% CI). Nine eligible trials were included in the final analysis. The pooled analysis revealed that serum ALT concentrations were significantly reduced using saffron compared to placebo (WMD: -2.39 U/L; 95% CI: -4.57 to -0.22; P = 0.03, I²= 87.9%, P < 0.001). However, saffron supplementation did not affect levels of serum AST (WMD: 1.12 U/L; 95% CI: -1.42 to 3.65; P = 0.39) or ALP (WMD: 4.32 U/L; 95% CI: -6.91 to 15.54; P = 0.78). In the dose-response analysis, we did not find a significant dose-response relationship between dosage and duration of saffron supplementation on serum levels of ALT, AST, and ALP. We found that saffron supplementation can reduce ALT serum concentrations without significant effects on other liver function indicators, including AST and ALP. Nevertheless, future large RCTs on diverse populations are needed to understand better the effects of saffron and its constituents on these enzymes.

The effects of Anethum graveolens (dill) supplementation on lipid profile and glycemic control: a systematic review and meta-analysis of randomized controlled trials

There is an increased interest in the potential health benefits of nutraceutical therapies, such as Anethum graveolens (dill). Therefore, this systematic review and meta-analysis aimed to evaluate the effects of Anethum graveolens supplementation on lipid profiles and glycemic indices in adults. A systematic search was performed for literature published through November 2020 via PubMed/Medline, Scopus, ISI Web of Science, and Embase to find randomized controlled trials (RCTs) evaluating the effects of oral supplementation with A. graveolens on lipid profile and measures of glycemic control in adults. The random-effects model was applied to establish the weighted mean difference (WMD) and associated 95% confidence intervals (CI). Seven RCTs with a total number of 330 subjects were included in the final analysis. Pooled results indicated that A. graveolens supplementation significantly decreased low-density lipoprotein cholesterol (LDL) concentration (WMD: -15.64 mg/dL; 95% CI: -24.55 to -6.73; P = 0.001), serum insulin (WMD: -2.28 μU/ml; 95% CI: -3.62 to -0.93; P = 0.001), and HOMA-IR (WMD: -1.06; 95% CI: -1.91 to -0.20; P = 0.01). However, there was no significant effect on serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL), and fasting blood glucose (FBS). Subgroup analysis suggested that using A. graveolens in higher doses and long-term duration had beneficial effects on lipid profiles. Dose-response analysis also showed a significant reduction in FBS at doses of 1500 mg/d. The present meta-analysis indicated that Anethum graveolens could exert favorable effects on insulin resistance and serum LDL. Further research is necessary to confirm our findings.