Sensitive analysis and simultaneous assessment of pharmacokinetic properties of crocin and crocetin after oral administration in rats

Selective transformation of crocin-1 to crocetin-glucosyl esters by β-glucosidase (Lf18920) from Leifsonia sp. ZF2019: Insights from molecular docking and point mutations

Crocetin di/mono-glucosyl esters (crocin-4 and crocin-5) are rarely distributed in nature, limiting their potential applications in the food and pharmaceutical industries. In the present study, a novel GH3 family β-glucosidase Lf18920 was identified from Leifsonia sp. ZF2019, which selectively hydrolyzed crocin-1 (crocetin di-gentiobiosyl ester) to crocin-5 and crocin-4, but not to its aglycone, crocetin. Under the optimal condition of 40 °C and pH 6.0 for 120 min, Lf18920 almost completely hydrolyzed crocin-1, yielding 73.50±5.66 % crocin-4 and 16.19±1.38 % crocin-5. Molecular docking and point mutation studies revealed that Lf18920 formed a narrow binding channel that facilitated crocin-1 binding. Five single amino acid variants (D50A, D53A, W274A, G420A, and Q421A) were constructed, all of which showed reduced hydrolytic activity. Mutations at D50 and D53, located distal to the active site, increased binding energy and decreased hydrolytic activity, while mutations at W274, G420, and Q421, proximal to the active site, disrupted hydrolytic function. These findings suggest that the narrow binding channel and specific enzyme-substrate interactions are crucial for Lf18920's selective hydrolytic activity. Overall, this study is the first to report a β-glucosidase capable of selectively transforming crocin-1 to crocetin di/mono-glucosyl esters, offering potential for synthesizing crocin-4 and crocin-5.

Oral administration of crocin-loaded solid lipid nanoparticles inhibits neuroinflammation in a rat model of epileptic seizures by activating SIRT1 expression

Background and purpose

Epilepsy is a group of chronic neurological diseases caused by a complex set of neuronal hyper electrical activities and oxidative stress of neurons. Crocin is a natural bioactive agent of saffron with different pharmacological properties and low bioavailability. This study aimed to evaluate crocin-loaded solid lipid nanoparticles (SLNC) for neuroprotection activity and efficacy against pentylenetetrazol (PTZ)- induced epilepsy.

Experimental approach

The rats were pretreated with SLNC and pure-crocin (PC; 25 and 50 mg/kg/day; P.O.) for 28 days before PTZ induction. Behavioral functions were evaluated by passive avoidance learning (PAL) tasks. Then, total antioxidant capacity (TAC), malondialdehyde (MDA), and pro-inflammatory factors were measured in the brain tissue using ELISA kits. Gene expression levels were analyzed with real-time polymerase chain reaction and immunohistochemical assay was used to assess the protein expression of sirtuin1 SIRT 1).

Findings/Results

SLNC was prepared with an average particle size of 98.25 nm and 98.33% encapsulation efficiency. Memory deficit improved in rats treated with SLNC. Administering SLNC at 25 and 50 mg/kg significantly reduced MDA and proinflammatory cytokines while increasing TAC. Additionally, administering SLNC before treatment increased the levels of SIRT1, peroxisome proliferator-activated receptor coactivator 1α, cAMP-regulated enhancer binding protein, and brain-derived neurotrophic factor. Furthermore, SLNC administration resulted in the downregulation of caspase-3 and inflammation factor expression.

Conclusion and implications

Overall, the obtained results showed that SLNC has better protective effects on oxidative stress in neurons, neurocognitive function, and anti-apoptotic and neuromodulatory activity than PC, suggesting that it is a promising therapeutic strategy for inhibiting seizures.

ADME/PK Insights of Crocetin: A Molecule Having an Unusual Chemical Structure with Druglike Features

Crocetin is a promising phyto-based molecule to treat Alzheimer's disease (AD). The chemical structure of crocetin is incongruent with various standard structural features of CNS drugs. As poor pharmacokinetic behavior is the major hurdle for any candidate to become a drug, we elucidated its druggable characteristics by implementing in silico, in vitro, and in vivo approaches, as limited ADME/PK information is available. Results demonstrate several attributes of crocetin based on rules of drug-likeness, lipophilicity, pKa, P-gp inhibitory activity, plasma stability, RBC partitioning, metabolic stability, CYP inhibitory action, blood-brain barrier (BBB) permeability, oral bioavailability, and pharmacokinetic interaction with marketed anti-Alzheimer's drugs (memantine, donepezil, galantamine, and rivastigmine). However, aqueous solubility, chemical stability, plasma protein binding, and P-gp induction are some concerns associated with this molecule that should be taken into consideration during its further development. Overall results indicate favorable ADME/PK behavior and potential druggable candidature of crocetin.

Antibiofilm activity of carotenoid crocetin against Staphylococcal strains

Staphylococcus aureus and Staphylococcus epidermidis stand as notorious threats to human beings owing to the myriad of infections they cause. The bacteria readily form biofilms that help in withstanding the effects of antibiotics and the immune system. Intending to combat the biofilm formation and reduce the virulence of the pathogens, we investigated the effects of carotenoids, crocetin, and crocin, on four Staphylococcal strains. Crocetin was found to be the most effective as it diminished the biofilm formation of S. aureus ATCC 6538 significantly at 50 µg/mL without exhibiting bactericidal effect (MIC >800 µg/mL) and also inhibited the formation of biofilm by MSSA 25923 and S. epidermidis at a concentration as low as 2 µg/mL, and that by methicillin-resistant S. aureus MW2 at 100 µg/mL. It displayed minimal to no antibiofilm efficacy on the Gram-negative strains Escherichia coli O157:H7 and Pseudomonas aeruginosa as well as a fungal strain of Candida albicans. It could also curb the formation of fibrils, which partly contributes to the biofilm formation in S. epidermidis. Additionally, the ADME analysis of crocetin proclaims how relatively non-toxic the chemical is. Also, crocetin displayed synergistic antibiofilm characteristics in combination with tobramycin. The presence of a polyene chain with carboxylic acid groups at its ends is hypothesized to contribute to the strong antibiofilm characteristics of crocetin. These findings suggest that using apocarotenoids, particularly crocetin might help curb the biofilm formation by S. aureus and S. epidermidis.

Exploring the therapeutic efficacy of crocetin in oncology: an evidence-based review

With cancer being a leading cause of death globally, there is an urgent need to improve therapeutic strategies and identify effective chemotherapeutics. This study aims to highlight the potential of crocetin, a natural product derived from certain plants, as an anticancer agent. It was  conducted an extensive review of the existing literature to gather and analyze the most recent data on the chemical properties of crocetin and its observed effects in various in vitro and in vivo studies. The study  particularly focused on studies that examined crocetin's impact on cell cycle dynamics, apoptosis, caspases and antioxidant enzyme levels, tumor angiogenesis, inflammation, and overall tumor growth. Crocetin exhibited diverse anti-tumorigenic activities including inhibition of tumor cell proliferation, apoptosis induction, angiogenesis suppression, and potentiation of chemotherapy. Multiple cellular and molecular pathways such as the PI3K/Akt, MAPK and NF-κB were modulated by it. Crocetin demonstrates promising anti-cancer properties and offers potential as an adjunctive or alternative therapy in oncology. More large-scale, rigorously designed clinical trials are needed to establish therapeutic protocols and ascertain the comprehensive benefits and safety profile of crocetin in diverse cancer types.

Antidiabetic and antioxidant potential of Crocin in high-fat diet plus streptozotocin-induced type-2 diabetic rats

OBJECTIVES

Crocin, the principal water-soluble active constituent of saffron, possesses numerous pharmacological activities. The present investigation examined the potential antidiabetic and antioxidant characteristics of Crocin in rats with type-2 diabetes by administering it orally and intraperitoneally (i.p.).

METHODS

After 2 weeks of a high-fat diet, streptozotocin (STZ) (i.p., 40 mg/kg) was administered to male adult rats to induce type-2 diabetes mellitus. Body weight and fasting blood glucose (FBG) were measured on days zero, weeks 1, and 2. At the end of 2 weeks of drug administration in their respective groups, fasting insulin and glucose levels were estimated, and insulin resistance (HOMA-IR) was determined. Intraperitoneal glucose (IPGTT) and insulin tolerance tests (ITT) were carried out. Histopathological investigation and biochemical parameters were estimated in pancreatic tissues.

RESULTS

The Crocin (100 mg/kg) treatment has significantly improved body weight, abatement of FBG, fasting insulin, and HOMA-IR. Likewise, Crocin treatment significantly improved the glucose and insulin challenges. We observed a significantly marked elevation in endogenous antioxidant enzymes in Crocin-treated groups. Similarly, Crocin treatment reversed the histopathological changes and restored the normal integrity and function of the pancreas.

CONCLUSION

The overall finding indicates that intraperitoneal administration of Crocin demonstrated better control of glycemic level and body weight. Further, it has improved insulin levels in the serum and potentiated antioxidant properties.

Crocin-Phospholipid Complex: Molecular Docking, Molecular Dynamics Simulation, Preparation, Characterization, and Antioxidant Activity

Background

Crocin is a water-soluble carotenoid compound present in saffron (Crocus sativus L.), known for its wide range of pharmacological activities, including cardioprotective, hepatoprotective, anti-tumorigenic, anti-atherosclerosis, and anti-inflammatory effects.

Objectives

The instability of crocin, its low miscibility with oils, and poor bioavailability pose challenges for its pharmaceutical applications. This study aimed to design and prepare a crocin-phospholipid complex (CPC) and assess its physicochemical properties.

Methods

The study investigated the formation of the complex and its binding affinity through molecular docking. Molecular dynamics (MD) simulations were conducted to find the optimal molar ratio of crocin to phospholipid for the complex's preparation. The CPC was produced using the solvent evaporation method. Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), nuclear magnetic resonance (NMR), and solubility studies were utilized to characterize and confirm the formation of CPC. Additionally, the in vitro antioxidant activity of crocin and CPC was evaluated.

Results

Molecular dynamic simulations explored molar ratios of 1: 1, 1: 1.5, and 1: 2 for crocin to phospholipid. The ratio of 1: 2 was found to be the most stable, exhibiting the highest probability of hydrogen bond formation. Molecular docking, FTIR, and NMR studies indicated hydrogen bond interactions between crocin and phospholipid, confirming CPC's formation. XRD and FE-SEM analyses showed a decrease in crocin's crystallinity within the phospholipid complex. Furthermore, the solubility of crocin in n-octanol was enhanced post-complexation, indicating an increase in crocin's lipophilic nature.

Conclusions

Phospholipid complexation emerges as a promising technique for enhancing the physicochemical characteristics of crocin.

Antidepressant Effect of Crocin in Mice with Chronic Mild Stress

This study aimed to investigate the antidepressant property of crocin (Crocetin digentiobiose ester) using a chronic mild stress (CMS)-induced depression model in experimental mice. The tail suspension test (TST) and the sucrose preference test were used to evaluate the antidepressant effect on albino mice of either sex after three weeks of CMS. The period of immobility in the TST and percentage preference for sucrose solution were recorded. By monitoring brain malondialdehyde (MDA) level, catalase (CAT) activity, and reduced glutathione (GSH) level, the antioxidant potential was assessed. Three dosages of crocin (4.84, 9.69, and 19.38 mg/kg) were evaluated. When compared to controls, animals that received crocin administration during three periods of CMS had considerably shorter immobility times during the TST. Crocin treatment also raised the percentage preference for sucrose solution in a dose-dependent manner, bringing it to parity with the conventional antidepressant, imipramine. Animals that received a high dose of crocin had a much greater spontaneous locomotor activity. Furthermore, a high dose of crocin remarkably lowered plasma corticosterone and nitrite levels brought on by CMS. Additionally, high doses of crocin given during CMS greatly enhanced reduced glutathione levels while considerably reducing the brain’s MDA and catalase activities. In conclusion, high doses of crocin may have an antidepressant effect in an animal model through several mechanisms. However, further studies should be carried out to explore the role of neurotransmitters for their antidepressant property.

The Effect of Triptolide Combined With Crocin on Arthritis in Mice: From Side Effect Attenuation to Therapy

Clinical use of triptolide (TP) is restricted due to severe toxicity. This study assessed the protective effect of crocin (CR) as a natural antioxidant against TP-induced toxicity in bovine collagen type II-induced arthritis (CIA) in mice. The mice in the CIA model group showed macroscopic signs of severe arthritis. The anti-arthritis effects in the control, TP + CR, and TP groups were evaluated through assessment of foot volume, arthritis score, and proinflammatory cytokines, and collagen antibody assay. Crocin reduced TP-induced toxicity, as evidenced by evaluation of survival rate, body weight, visceral index, hepatic and renal functions, histopathologic analyses, and antioxidant enzyme activities. Transcriptome sequencing resulted in identification of 76 differentially expressed genes (DEGs) associated with hepatotoxicity between the TP and TP + CR groups. Of these, Three DEGs (Cyp1a2,Gsta4, and Gstp1) were validated using quantitative real-time PCR analysis. In conclusion, CR protected CIA mice from TP-induced toxicity through modulation of the cytochrome P450 and glutathione metabolism pathways.

Comparative study of oral versus parenteral crocin in mitigating acrolein-induced lung injury in albino rats

Acrolein (Ac) is the second most commonly inhaled toxin, produced in smoke of fires, tobacco smoke, overheated oils, and fried foods; and usually associated with lung toxicity. Crocin (Cr) is a natural carotenoid with a direct antioxidant capacity. Yet, oral administration of crocin as a natural rout is doubtful, because of poor absorbability. Therefore, the current study aimed to compare the potential protective effect of oral versus intraperitoneal (ip) crocin in mitigating Ac-induced lung toxicity. 50 Adult rats were randomly divided into 5 equal groups; Control (oral-saline and ip-saline) group, Cr (oral-Cr and ip-Cr) group, Ac group, oral-Cr/Ac group, and ip-Cr/Ac group; for biochemical, histopathological, and immunohistochemical investigations. Results indicated increased oxidative stress and inflammatory biomarkers in lungs of Ac-treated group. Histopathological and immunohistochemical examinations revealed lung edema, infiltration, fibrosis, and altered expression of apoptotic and anti-apoptotic markers. Compared to oral-Cr/Ac group, the ip-Cr/Ac group demonstrated remarkable improvement in the oxidative, inflammatory, and apoptotic biomarkers, as well as the histopathological alterations. In conclusion, intraperitoneal crocin exerts a more protective effect on acrolein-induced lung toxicity than the orally administered crocin.

Circulating Human Serum Metabolites Derived from the Intake of a Saffron Extract (Safr'InsideTM) Protect Neurons from Oxidative Stress: Consideration for Depressive Disorders

Increases in oxidative stress have been reported to play a central role in the vulnerability to depression, and antidepressant drugs may reduce increased oxidative stress in patients. Among the plants exerting anti-inflammatory and anti-oxidant properties, saffron, a spice derived from the flower of Crocus sativus, is also known for its positive effects on depression, potentially through its SSRI-like properties. However, the molecular mechanisms underlying these effects and their health benefits for humans are currently unclear. Using an original ex vivo clinical approach, we demonstrated for the first time that the circulating human metabolites produced following saffron intake (Safr’Inside^TM) protect human neurons from oxidative-stress-induced neurotoxicity by preserving cell viability and increasing BNDF production. In particular, the metabolites significantly stimulated both dopamine and serotonin release. In addition, the saffron’s metabolites were also able to protect serotonergic tone by inhibiting the expression of the serotonin transporter SERT and down-regulating serotonin metabolism. Altogether, these data provide new biochemical insights into the mechanisms underlying the beneficial impact of saffron on neuronal viability and activity in humans, in the context of oxidative stress related to depression.

Crocetin: A Systematic Review

Crocetin is an aglycone of crocin naturally occurring in saffron and produced in biological systems by hydrolysis of crocin as a bioactive metabolite. It is known to exist in several medicinal plants, the desiccative ripe fruit of the cape jasmine belonging to the Rubiaceae family, and stigmas of the saffron plant of the Iridaceae family. According to modern pharmacological investigations, crocetin possesses cardioprotective, hepatoprotective, neuroprotective, antidepressant, antiviral, anticancer, atherosclerotic, antidiabetic, and memory-enhancing properties. Although poor bioavailability hinders therapeutic applications, derivatization and formulation preparation technologies have broadened the application prospects for crocetin. To promote the research and development of crocetin, we summarized the distribution, preparation and production, total synthesis and derivatization technology, pharmacological activity, pharmacokinetics, drug safety, drug formulations, and preparation of crocetin.

Crocetin Alleviates Ovariectomy-Induced Metabolic Dysfunction through Regulating Estrogen Receptor β

Metabolic dysfunction (MD) is a major health problem threatening the life quality of menopausal women. Saffron has been widely used in herb prescriptions for treating menopausal syndrome. However, the pharmacological effects and mechanisms of saffron are poorly understood. Here, we investigated the effect of crocin, the major ingredient of saffron and its active metabolite in blood, crocetin, on MD and lipid metabolism in ovariectomized (OVX) mice and 3T3-L1 adipocytes. The present study showed that intragastric treatment of crocin prevented weight gain, fat accumulation, and insulin resistance in OVX mice by increasing energy expenditure and fat oxidation. Mechanistically, crocin influenced adipose tissue homeostasis by regulating adipogenic and lipolytic factors, which was strongly associated with the restoration of the downregulated ERβ function in white adipose tissue (WAT). In vitro, crocetin facilitated lipid metabolism in an ERβ-dependent manner. Our results demonstrated the beneficial effects of crocetin/crocin-mediated intervention against metabolic dysfunction, revealing a prospective therapeutic application in menopausal women.

Preparation and Anti-Tobacco Mosaic Virus Activities of Crocetin Diesters

The development of antiviral agents with an original structure and noticeable effect is always in great need. Natural products are important lead compounds in the development of new pesticides. Crocin-1 and crocin-2 were effectively isolated from Gardeniae fructus and found to have higher anti-tobacco mosaic virus (TMV) activity levels than ribavirin. A series of the crocetin diester derivatives were synthesized with separated crocetin-1 as material and evaluated for their anti-TMV activities. They could be dissolved in common organic solvents as dichloromethane, ethyl acetate, tetrahydrofuran, and methanol. Compounds 5, 9, 13, 14, and 15 displayed higher activities in vivo than ribavirin. Compound 14 with significantly higher antiviral activities than lead compounds (crocin-1 and crocin-2) emerged as a new antiviral candidate.

Crocins: A comprehensive review of structural characteristics, pharmacokinetics and therapeutic effects

Crocins, as a kind of water-soluble carotenoid pigment, are a series of ester compounds formed from crocetin and gentibiose or glucose, and mainly distributed among Crocus sativus L. (CSL), Gardenia jasminoides Ellis. (GJE). Crocins exhibit a wide range of pharmacological effects on neurodegeneration, cardiovascular disease, cerebrovascular disease, depression, liver disease, arthritis, tumor, diabetes, etc. This review systematically discussed the pharmacologic study of crocins in the aspect of structural characteristic and pharmacokinetics, and summarized the mechanism of treating disease. It summarized the abundant research of crocins from 1984 to 2020 based on the above aspects, which provide a reference for the deeply development and application of crocins.

Crocetin and Its Glycoside Crocin, Two Bioactive Constituents From Crocus sativus L. (Saffron), Differentially Inhibit Angiogenesis by Inhibiting Endothelial Cytoskeleton Organization and Cell Migration Through VEGFR2/SRC/FAK and VEGFR2/MEK/ERK Signaling Pathways

Crocetin and crocin are two important carotenoids isolated from saffron (Crocus sativus L.), which have been used as natural biomedicines with beneficial effects for improving the suboptimal health status associated with abnormal angiogenesis. However, the anti-angiogenic effects and underlying mechanisms of the effects of crocetin and crocin have not been investigated and compared. The anti-angiogenic effects of crocetin and crocin were tested on human umbilical vein endothelial cells (HUVECs) in vitro, and in zebrafish in vivo. In vivo, crocetin (20 μM) and crocin (50 and 100 μM) significantly inhibited subintestinal vein vessels formation, and a conversion process between them existed in zebrafish, resulting in a difference in their effective concentrations. In the HUVEC model, crocetin (10, 20 and 40 μM) and crocin (100, 200 and 400 μM) inhibited cell migration and tube formation, and inhibited the phosphorylation of VEGFR2 and its downstream pathway molecules. In silico analysis further showed that crocetin had a higher ability to bind with VEGFR2 than crocin. These results suggested that crocetin was more effective than crocin in inhibiting angiogenesis through regulation of the VEGF/VEGFR2 signaling pathway. These compounds, especially crocetin, are potential candidate natural biomedicines for the management of diseases associated with abnormal blood vessel growth, such as age-related macular degeneration.

Crocetin and related oxygen diffusion-enhancing compounds: Review of chemical synthesis, pharmacology, clinical development, and novel therapeutic applications

The current pandemic forced us to introspect and revisit our armamentarium of medicinal agents which could be life‐saving in emergency situations. Oxygen diffusion‐enhancing compounds represent one such class of potential therapeutic agents, particularly in ischemic conditions. As rewarding as the name suggests, these agents, represented by the most advanced and first‐in‐class molecule, trans‐sodium crocetinate (TSC), are the subject of intense clinical investigation, including Phase 1b/2b clinical trials for COVID‐19. Being a successor of a natural product, crocetin, TSC is being investigated for various cancers as a radiosensitizer owing to its oxygen diffusion enhancement capability. The unique properties of TSC make it a promising therapeutic agent for various ailments such as hemorrhagic shock, stroke, heart attack, among others. The present review outlines various (bio)synthetic strategies, pharmacological aspects, clinical overview and potential therapeutic benefits of crocetin and related compounds including TSC. The recent literature focusing on the delivery aspects of these compounds is covered as well to paint the complete picture to the curious reader. Given the potential TSC holds as a first‐in‐class agent, small‐ and/or macromolecular therapeutics based on the core concept of improved oxygen diffusion from blood to the surrounding tissues where it is needed the most, will be developed in future and satisfy the unmet medical need for many diseases and disorders.

Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

Crocus sativus L. Extracts and Its Constituents Crocins and Safranal; Potential Candidates for Schizophrenia Treatment?

Schizophrenia is a chronic mental devastating disease. Current therapy suffers from various limitations including low efficacy and serious side effects. Thus, there is an urgent necessity to develop new antipsychotics with higher efficacy and safety. The dried stigma of the plant Crocus sativus L., (CS) commonly known as saffron, are used in traditional medicine for various purposes. It has been demonstrated that saffron and its bioactive components crocins and safranal exert a beneficial action in different pathologies of the central nervous system such as anxiety, depression, epilepsy and memory problems. Recently, their role as potential antipsychotic agents is under investigation. In the present review, I intended to critically assess advances in research of these molecules for the treatment of schizophrenia, comment on their advantages over currently used neuroleptics as well-remaining challenges. Up to our days, few preclinical studies have been conducted to this end. In spite of it, results are encouraging and strongly corroborate that additional research is mandatory aiming to definitively establish a role for saffron and its bioactive components for the treatment of schizophrenia.

Effects of Saffron Extract Supplementation on Mood, Well-Being, and Response to a Psychosocial Stressor in Healthy Adults: A Randomized, Double-Blind, Parallel Group, Clinical Trial

Anxiety, stress, and low mood are closely related and may contribute to depressive symptoms. Among non-pharmacological solutions to improve subclinical mood symptoms and resilience to stress, natural products such as saffron—identified as promising following preliminary beneficial effects in major depressive disorder—represent a relevant strategy. This study aimed to assess the efficacy of 8 weeks' supplementation with 30 mg standardized saffron extract on emotional well-being in healthy adults with subclinical feelings of low mood and anxiety and/or stress and evaluate the acute effect of saffron in response to a lab-based psychosocial stressor. The study adopted a double-blind, randomized, parallel groups design in which 56 healthy male and female individuals (18–54 years) received either a saffron extract or a placebo for 8 weeks. Chronic effects of saffron on subjective anxiety, stress, and depressive feelings were assessed using a questionnaire battery [including Profile of Mood State-2, (POMS)] and acute effects in response to a lab-based psychosocial stressor were measured through psychological and physiological parameters. Urinary crocetin levels were quantified. Participants who received the saffron extract reported reduced depression scores and improved social relationships at the end of the study. Urinary crocetin levels increased significantly with saffron supplementation and were correlated with change in depression scores. The typical stress-induced decrease in heart rate variability (HRV) during exposure to the stressor was attenuated following acute saffron intake. Saffron extract appears to improve subclinical depressive symptoms in healthy individuals and may contribute to increased resilience against the development of stress-related psychiatric disorders.

Clinical trials number: NCT03639831.

Nutritional and health beneficial properties of saffron (Crocus sativus L): a comprehensive review

Saffron (Crocus sativus L., family Iridaceae) is used traditionally for medicinal purpose in Chinese, Ayurvedic, Persian and Unani medicines. The bioactive constituents such as apocarotenoids, monoterpenoids, flavonoids, phenolic acids and phytosterols are widely investigated in experimental and clinical studies for a wide range of therapeutic effects, especially on the nervous system. Some of the active constituents of saffron have high bioavailability and bioaccessibility and ability to pass the blood-brain barrier. Multiple preclinical and clinical studies have supported neuroprotective, anxiolytic, antidepressant, learning and memory-enhancing effect of saffron and its bioactive constituents (safranal, crocin, and picrocrocin). Thus, this plant and its active compounds could be a beneficial medicinal food ingredient in the formation of drugs targeting nervous system disorders. This review focuses on phytochemistry, bioaccessibility, bioavailability, and bioactivity of phytochemicals in saffron. Furthermore, the therapeutic effect of saffron against different nervous system disorders has also been discussed in detail.

Effects of Intestinal Microbiota on Pharmacokinetics of Crocin and Crocetin in Male Sprague-Dawley Rats

In addition to the hepatic metabolism, the role of intestinal microbiota in drug metabolism has been considered important in the biotransformation of xenobiotics. Crocin and its aglycone, crocetin, isolated from many plants, including the dried stigma of Crocus sativus and the fruit of Gardenia jasminoides, have been used in treatment of inflammation, cancer, and metabolic disorders. In this study, the effect of intestinal microbiota on the pharmacokinetics of crocin was studied following single oral treatment with 600 mg/kg crocin to male rats pre-treated with a mixture of antibiotics, such as cefadroxil, oxytetracycline, and erythromycin, for three consecutive days. Following crocin treatment, blood, urine, and feces were collected at various time points for evaluating pharmacokinetic characteristics of crocin and crocetin by using LC-MS. Results showed that intestinal absorption of crocin was relatively marginal when compared with that of crocetin, and that crocin metabolism to crocetin by intestinal microbiota would be a critical step for absorption. The present results clearly suggested that the in vivo pharmacological effects of crocin might be considered as the effects by its aglycone, crocetin, mainly, and that the metabolism of glycosidic natural products by intestinal microbiota should be considered to understand their pharmacodynamic actions.

Ameliorative effects and mechanism of crocetin in arsenic trioxide‑induced cardiotoxicity in rats

Arsenic trioxide (ATO) is commonly used to treat patients with acute promyelocytic leukemia since it was authorized by the U.S. Food and Drug Administration in the 1970s, but its applicability has been limited by its cardiotoxic effects. Therefore, the aim of the present study was to investigate the cardioprotective effects and underlying mechanism of crocetin (CRT), the critical ingredient of saffron. Sprague-Dawley rats were then randomly divided into four groups (n=10/group): i) Control group; ii) ATO group, iii) CRT-low (20 mg/kg) group; and iv) CRT-high (40 mg/kg) group. Rats in the Control and ATO groups were intraperitoneally injected with equal volumes of 0.9% sodium chloride solution, and CRT groups were administered with either 20 and 40 mg/kg CRT. Following 6 h, all groups except the Control group were intraperitoneally injected with 5 mg/kg ATO over 10 days. Cardiotoxicity was indicated by changes in electrocardiographic (ECG) patterns, morphology and marker enzymes. Histomorphological changes in the heart tissue were observed by pathological staining. The levels of superoxide dismutase, glutathione peroxidase, malondialdehyde and catalase in the serum were analyzed using colometric commercial assay kits, and the levels of reactive oxygen species in the heart tissue were detected using the fluorescent probe dihydroethidium. The expression levels of inflammatory factors and activities of apoptosis-related proteins were analyzed using immunohistochemistry. The protein expression levels of silent information regulator of transcription 1 were measured using western blotting. Cardiotoxicity was induced in male Sprague-Dawley rats with ATO (5 mg/kg). CRT (20 and 40 mg/kg) and ATO were co-administered to evaluate possible cardioprotective effects. CRT significantly reduced the heart rate and J-point elevation induced by ATO in rats. Histological changes were evaluated via hematoxylin and eosin staining. CRT decreased the levels of creatine kinase and lactate dehydrogenase, increased the activities of superoxide dismutase, glutathione-peroxidase and catalase, and decreased the levels of malondialdehyde and reactive oxygen species. Moreover, CRT downregulated the expression levels of the pro-inflammatory factors IL-1, TNF-α, IL-6, Bax and p65, as well as increased the expression of Bcl-2. It was also identified that CRT enhanced silent information regulator of transcription 1 protein expression. Thus, the present study demonstrated that CRT treatment effectively ameliorated ATO-induced cardiotoxicity. The protective effects of CRT can be attributed to the inhibition of oxidative stress, inflammation and apoptosis. Therefore, CRT represents a promising therapeutic method for improving the cardiotoxic side effects caused by ATO treatment, and additional clinical applications are possible, but warrant further investigation.

Neuroprotective Potency of Saffron Against Neuropsychiatric Diseases, Neurodegenerative Diseases, and Other Brain Disorders: From Bench to Bedside

The increasing morbidity rates of brain disorders and conditions such as anxiety, depression, Alzheimer’s disease, and Parkinson’s disease have become a severe problem in recent years. Although researchers have spent considerable time studying these diseases and reported many positive outcomes, there still are limited drugs available for their treatment. As a common traditional Chinese medicine (TCM), saffron was employed to treat depression and some other inflammatory diseases in ancient China due to its antioxidant, anti-inflammatory, and antidepressant properties. In modern times, saffron and its constituents have been utilized, alone and in TCM formulas, to treat neuropsychiatric and neurodegenerative diseases. In this review, we mainly focus on recent clinical and preclinical trials of brain disorders in which saffron was applied, and summarize the neuroprotective properties of saffron and its constituents from chemical, pharmacokinetic, and pharmacological perspectives. We discuss the properties of saffron and its constituents, as well as their applications for treating brain disorders; we hope that this review will serve as a comprehensive reference for studies aimed at developing therapeutic drugs based on saffron.

Intra-cerebroventricular Administration of Crocin Attenuates Sleep Deprivation-induced Hyperalgesia in Rats

Introduction

Sleep deprivation can cause hyperalgesia and interfere with analgesic treatments. The aim of the present study was to establish an obligatory sleep-abstinence model and also evaluate the effects of Intracerebroventricular (ICV) injection of crocin on pain perception in Wistar rats.

Methods

In this experimental study, 35 adult male Wistar rats were randomly divided into 5 groups (n=7). The intra-ventricular cannulation was done for all rats before sleep deprivation. Sleep deprivation was performed by placing animals on a chamber equipped with an automatic animated conveyor (5 s with an interval of 3 min) for 72 h. Subsequently, the sleep-deprived animals received ICV injection of saline (MOD), Morphine 10 μg (MOR), Crocin 10 ug (Cr10), and Crocin40 μg (Cr40) using a microsyringe. Besides, a non-sleep-deprived group was allocated as a Control Group (NC) and only received an ICV injection of saline. Fifteen minutes after the ICV injections, pain perception was evaluated by the hot plate test (54±0.4°C).

Results

Compared with the NC group, latency significantly decreased in the MOD group (6.28±0.48 vs. 4.28± 0.48, P<0.0001). In comparison with the MOD group, both morphine (8.42±1.53) and crocin (7.60±1.45 for Cr10 and 8.14±0.89 for Cr40) could significantly increase latency in the sleep-deprived animals (P<0.0001). There was no statistically significant difference between the Cr10 and Cr40 (P=0.42), Cr10, and MOR (P=0.059) and Cr40 with MOR (P=0.86) groups.

Conclusion

Our results indicated that crocin could attenuate hyperalgesia induced by sleep deprivation in rats.

Comparative Pharmacokinetics of Geniposidic Acid, Genipin-1-β-Gentiobioside, Geniposide, Genipin, and Crocetin in Rats after Oral Administration of Crude Gardeniae Fructus and Its Three Processed Products Using LC-MS/MS

The extract of Gardeniae Fructus (GF) with different processing methods processed the different medicinal properties and efficacy. Crude GF (CGF) could be processed into stir-frying GF (SGF), gancao mix-frying GF (GCGF), and ginger mix-frying GF (GIGF) in practice. An LC-MS/MS method was established for simultaneous quantification of geniposidic acid, geniposide, genipin-1-β-gentiobioside, genipin, and crocetin in the rat plasma. The LLOQs for determination of all five components were 10 ng/mL. The accuracies of intraday and interday were in the range of 91%-105%. The recoveries of 5 analytes ranged from 81.0% to 114% with RSD less than 14%. The results showed that the AUCs (area under the plasma concentration-time curve) and C _max (maximum plasma concentration) of geniposidic acid, genipin-1-β-gentiobioside, and geniposide after oral administration of the CGF extract were apparently higher than those after oral administration of other processed extracts. C _max of geniposide in plasma after administration of GIGF significantly decreased (p < 0.01). Genipin was not detected in rat plasma after administration of the GIGF extract, but it can be detected in plasma after administration of CGF, SGF, and GCGF extract. Furthermore, crocin I and crocin II were not detected in plasma samples. Crocetin had higher concentration in rat plasma versus lower contents in extract. It was demonstrated that the different processing methods might influence the pharmacokinetics of geniposidic acid, genipin-1-β-gentiobioside, geniposide, genipin, and crocetin.

Plant-Based Antidiabetic Nanoformulations: The Emerging Paradigm for Effective Therapy

Diabetes mellitus is a life-threatening metabolic syndrome. Over the past few decades, the incidence of diabetes has climbed exponentially. Several therapeutic approaches have been undertaken, but the occurrence and risk still remain unabated. Several plant-derived small molecules have been proposed to be effective against diabetes and associated vascular complications via acting on several therapeutic targets. In addition, the biocompatibility of these phytochemicals increasingly enhances the interest of exploiting them as therapeutic negotiators. However, poor pharmacokinetic and biopharmaceutical attributes of these phytochemicals largely restrict their clinical usefulness as therapeutic agents. Several pharmaceutical attempts have been undertaken to enhance their compliance and therapeutic efficacy. In this regard, the application of nanotechnology has been proven to be the best approach to improve the compliance and clinical efficacy by overturning the pharmacokinetic and biopharmaceutical obstacles associated with the plant-derived antidiabetic agents. This review gives a comprehensive and up-to-date overview of the nanoformulations of phytochemicals in the management of diabetes and associated complications. The effects of nanosizing on pharmacokinetic, biopharmaceutical and therapeutic profiles of plant-derived small molecules, such as curcumin, resveratrol, naringenin, quercetin, apigenin, baicalin, luteolin, rosmarinic acid, berberine, gymnemic acid, emodin, scutellarin, catechins, thymoquinone, ferulic acid, stevioside, and others have been discussed comprehensively in this review.

Beneficial effects of saffron (Crocus sativus L.) in ocular pathologies, particularly neurodegenerative retinal diseases

Saffron (Crocus sativus L.) has been traditionally used in food preparation and as a medicinal plant. It currently has numerous therapeutic properties attributed to it, such as protection against ischemia, as well as anticonvulsant, antidepressant, anxiolytic, hypolipidemic, anti-atherogenic, anti-hypertensive, antidiabetic, and anti-cancer properties. In addition, saffron has remarkable beneficial properties, such as anti-apoptotic, anti-inflammatory and antioxidant activities, due to its main metabolites, among which crocin and crocetin stand out. Furthermore, increasing evidence underwrites the possible neuroprotective role of the main bioactive saffron constituents in neurodegenerative diseases, such as Parkinson’s and Alzheimer’s diseases, both in experimental models and in clinical studies in patients. Currently, saffron supplementation is being tested for ocular neurodegenerative pathologies, such as diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration and glaucoma, among others, and shows beneficial effects. The present article provides a comprehensive and up to date report of the investigations on the beneficial effects of saffron extracts on the main neurodegenerative ocular pathologies and other ocular diseases. This review showed that saffron extracts could be considered promising therapeutic agents to help in the treatment of ocular neurodegenerative diseases.

Regulated preparation of Crocin-1 or Crocin-2' Triggered by the Cosolvent DMSO Using Bs-GT/At-SuSy One-Pot Reaction

Crocins are the primary coloring ingredients of saffron. The low-glycosylated members of this compound family, such as crocin-1 (crocetin mono-glucosyl ester) and crocin-2' (crocetin di-glucosyl ester), are rarely distributed in nature and attracting interest for their therapeutic uses. In the present study, a one-pot reaction system was used for efficient preparation of crocin-1 and crocin-2' with in situ regeneration of UDP-Glc by coupling Bs-GT with At-SuSy, a sucrose synthase from Arabidopsis thaliana. Noticeably, DMSO was used as a cosolvent and resulted in improvement of the solubility of the substrate crocetin and regulation of the selectivity of glycosylation. With periodic addition of crocetin, the biosynthesis of crocin-2' was performed with a high yield of 3.25 g/L in 2% DMSO aqueous solution, whereas crocin-1 (2.12 g/L) was selectively obtained in a 10% DMSO aqueous solution. The present study provided a simple approach for the biosynthesis of crocin-1 and crocin-2'.

Interaction of saffron carotenoids with catalase: in vitro, in vivo and molecular docking studies

The effects of saffron carotenoids, crocetin (Crt) and crocin (Cro) on the structure, function and kinetics of catalase (CAT) were investigated. Both Crt and Cro quenched the fluorescence emission of CAT through the dynamic mechanism, but Crt (Ksv= 8.1 × 10⁴ mol^-1) was more effective than Cro (Ksv= 0.6 × 10⁴ mol^-1) at 300 °K. The UV-vis and circular dichroism spectra showed conformational changes of CAT in the presence of both carotenoids, but with different degrees. Kinetic studies showed strong inhibition of CAT by Crt, while, different concentrations of Cro showed different effects. Our in vitro data showed that Crt treatment significantly (p = 0.002) reduced the CAT activity in MCF-7, up to 24 h. The in vivo results showed that both Crt and Cro significantly increased the CAT activity in the tumor (p = 0.000 for both), and liver (p = 0.000 and p = 0.026 for Crt and Cro, respectively) tissues of 4T1-induced breast cancer in BALB/c mice, after 4 weeks of treatment. These findings are consistent with the binding, thermodynamic and molecular docking data. In conclusion, Crt and Cro with some differences in the structure affect CAT structure, function and activity, but in a slightly different manner.Communicated by Ramaswamy H. Sarma.

Orally Administered Crocin Protects Against Cerebral Ischemia/Reperfusion Injury Through the Metabolic Transformation of Crocetin by Gut Microbiota

Our pilot study suggested that orally administered crocin was hardly absorbed into circulatory system, but it was effective against cerebral ischemic/reperfusion (I/R) injury. The pharmacologically active component and targeting site of crocin remain elusive. In this study, the cerebral-protective effect of crocin was evaluated on a rat transient middle cerebral artery occlusion (MCAO) model. Our data showed that oral administration of crocin had better effectiveness in cerebral protection than an intravenous injection. Neither crocin nor its metabolite crocetin were determined in the brain of cerebral I/R rats, indicating a target site of periphery. Abundant crocetin was detected in plasma after oral administration instead of intravenous injection of crocin. Meanwhile, orally administered crocetin showed similar cerebral protection to that of crocin, but this exciting effect was not clearly observed by intravenous administration of crocetin, indicating the importance of crocetin in gut. Moreover, orally administered crocin showed less cerebral-protective effect in pseudo germ-free (pGF) MCAO rats. In vitro and in vivo experiments confirmed that crocin could be deglycosylated to crocetin in gut content of normal rats, rather than that of pGF rats, indicating that gut microbiota facilitated the transformation of crocin into crocetin, which played a key role in the activation of the pharmacological effect. Metabolomic study revealed that microbial-host co-metabolic molecules were significantly perturbed after oral administration of crocin, indicating a regulation on intestinal ecosystem. It was further suggested that gut microbiota may be the potential target of the cerebral-protective effect of crocin.

Saffron: The Golden Spice with Therapeutic Properties on Digestive Diseases

Saffron is a natural compound that has been used for centuries in many parts of the world as a food colorant and additive. It was shown to have the ability to mitigate various disorders through its known anti-inflammatory and anti-oxidant properties. Several studies have shown the effectiveness of saffron in the treatment of various chronic diseases like inflammatory bowel diseases, Alzheimer's, rheumatoid arthritis as well as common malignancies of the colon, stomach, lung, breast, and skin. Modern day drugs generally have unwanted side effects, which led to the current trend to use naturally occurring products with therapeutic properties. In the present review, the objective is to systematically analyze the wealth of information regarding the potential mechanisms of action and the medical use of saffron, the "golden spice", especially in digestive diseases. We summarized saffron influence on microbiome, molecular pathways, and inflammation in gastric, colon, liver cancers, and associated inflammations.

Efficient Synthesis of Crocins from Crocetin by a Microbial Glycosyltransferase from Bacillus subtilis 168

Crocins are the most important active ingredient found in Crocus sativus, a well-known "plant gold". The glycosyltransferase-catalyzed glycosylation of crocetin is the last step of biosynthesizing crocins and contributes to their structural diversity. Crocin biosynthesis is now hampered by the lack of efficient glycosyltransferases with activity toward crocetin. In this study, two microbial glycosyltransferases (Bs-GT and Bc-GTA) were successfully mined based on the comprehensive analysis of the PSPG motif and the N-terminal motif of the target plant-derived UGT75L6 and Cs-GT2. Bs-GT from Bacillus subtilis 168, an enzyme with a higher activity of glycosylation toward crocetin than that of Bc-GTA, was characterized. The efficient synthesis of crocins from crocetin catalyzed by microbial GT (Bs-GT) was first reported with a high molecular conversion rate of 81.9%, resulting in the production of 476.8 mg/L of crocins. The glycosylation of crocetin on its carboxyl groups by Bs-GT specifically produced crocin-5 and crocin-3, the important rare crocins.

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.

Saffron (Crocus sativus L.): As an Antidepressant

Saffron, Crocus sativus (Iridaceae), is a perennial herb, which earned its popularity as both medicine and spice. It is an inhabitant of different mountainous regions of Asia Minor to Greece, Western Asia, Egypt, and India. The benefits of saffron as an antidepressant are well-documented. Almost 150 volatile and nonvolatile compounds are obtained from the chemical analysis of this plant. Fewer than 50 constituents elucidated and identified so far showed phytochemical characteristics. The major bioactive compounds identified are safranal, crocin, and picrocrocin, which are responsible for its aroma as well as its bitter taste. This review is an attempt to encompass the methods of analysis and pharmacodynamic and pharmacokinetic properties of saffron followed by its efficacious and safe potential.

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.