Crocetin: A Systematic Review

Enhancement of dissolution and oral bioavailability by adjusting microenvironment pH in crocetin ternary solid dispersions: Optimization, characterization, in vitro evaluation, and pharmacokinetics

The most promising active ingredient of Crocus sativus L., crocetin (CCT), has been demonstrated to possess many biological activities. However, only a few studies have been conducted on CCT formulation, especially in oral formulation, mainly due to its insolubility in water, which limits its application for oral administration. This article reports an equilibrium saturation solubility and single-pass intestinal perfusion studies conducted to classify the biopharmaceutics classification system (BCS) of CCT. To enhance in vitro dissolution and in vivo oral bioavailability, ternary solid dispersions of CCT (CCT-SDs) with soluplus (SOL) as hydrophilic carrier and meglumine (MEG) as alkalizer were optimized using response surface methodology (RSM) with central composite design (CCD) experiments. Four different preparation methods were evaluated using the optimal formulation, including solvent evaporation, ball milling, spray drying, and freeze-drying. Prepared formulations were characterized by TG-DSC, FTIR, X-RPD, and SEM; the pharmacokinetic studies were performed in rats after oral administration. The cumulative dissolution rate of CCT-SDs containing SOL and MEG prepared by the ball milling method was 97.1% at 15 min and remained at 95.6% at 480 min, which was significantly higher than that of untreated CCT. The lower crystallinity, smaller particle size, and higher microenvironment pH (pHM) were observed in CCT-SDs prepared by the ball milling method. In vivo absorption of CCT-SDs (Cmax = 52.789 ± 12.441 μg/mL and AUC0-12 = 191.748 ± 35.043 μg/mL·h) was greater than untreated CCT (Cmax = 5.918 ± 1.388 μg/mL and AUC0-12 = 44.309 ± 7.264 μg/mL·h). In conclusion, the current study provides ternary solid dispersion formulation of CCT to increase the in vitro dissolution and in vivo bioavailability, which will benefit the commercial production and future clinical applications of CCT.

Crocetin protects mouse brain from apoptosis in traumatic brain injury model through activation of autophagy

BACKGROUND

Autophagy is recognized as a promising therapeutic target for traumatic brain injury (TBI). Crocetin is an aglycone of crocin naturally occurring in saffron and has been found to alleviate brain injury diseases. However, whether crocetin affects autophagy after TBI remains unknown. Therefore, we explore crocetin roles in autophagy after TBI.

METHODS

We used a weight-dropped model to induce TBI in C57BL/6J mice. Neurological severity scoring (NSS) and grip tests were used to evaluate the neurological level of injury. Brain edema, neuronal apoptosis, neuroinflammation and autophagy were detected by measurements of brain water content, TUNEL staining, ELISA kits and western blotting.

RESULTS

Crocetin ameliorated neurological dysfunctions and brain edema after TBI. Crocetin reduced neuronal apoptosis and neuroinflammation and enhanced autophagy after TBI.

CONCLUSION

Crocetin alleviates TBI by inhibiting neuronal apoptosis and neuroinflammation and activating autophagy.

Acute lung injury: a view from the perspective of necroptosis

BACKGROUND

ALI/ARDS is a syndrome of acute onset characterized by progressive hypoxemia and noncardiogenic pulmonary edema as the primary clinical manifestations. Necroptosis is a form of programmed cell necrosis that is precisely regulated by molecular signals. This process is characterized by organelle swelling and membrane rupture, is highly immunogenic, involves extensive crosstalk with various cellular stress mechanisms, and is significantly implicated in the onset and progression of ALI/ARDS.

METHODS

The current body of literature on necroptosis and ALI/ARDS was thoroughly reviewed. Initially, an overview of the molecular mechanism of necroptosis was provided, followed by an examination of its interactions with apoptosis, pyroptosis, autophagy, ferroptosis, PANOptosis, and NETosis. Subsequently, the involvement of necroptosis in various stages of ALI/ARDS progression was delineated. Lastly, drugs targeting necroptosis, biomarkers, and current obstacles were presented.

CONCLUSION

Necroptosis plays an important role in the progression of ALI/ARDS. However, since ALI/ARDS is a clinical syndrome caused by a variety of mechanisms, we emphasize that while focusing on necroptosis, it may be more beneficial to treat ALI/ARDS by collaborating with other mechanisms.

Therapeutic Effects of Anti-Inflammatory and Anti-Oxidant Nutritional Supplementation in Retinal Ischemic Diseases

Appropriate nutrients are essential for cellular function. Dietary components can alter the risk of systemic metabolic diseases, including cardiovascular diseases, cancer, diabetes, and obesity, and can also affect retinal diseases, including age-related macular degeneration, diabetic retinopathy, and glaucoma. Dietary nutrients have been assessed for the prevention or treatment of retinal ischemic diseases and the diseases of aging. In this article, we review clinical and experimental evidence concerning the potential of some nutritional supplements to prevent or treat retinal ischemic diseases and provide further insights into the therapeutic effects of nutritional supplementation on retinopathies. We will review the roles of nutrients in preventing or protecting against retinal ischemic diseases.

Potential therapeutic effects of crocin

Crocin, a natural bioactive compound derived from saffron (Crocus sativus) and other Crocus genera, has gained significant attention recently due to its potential therapeutic properties. The multifaceted nature of crocin's biological effects has piqued the interest of researchers and health enthusiasts, prompting further investigations into its mechanisms of action and therapeutic applications. This review article comprehensively explores the emerging evidence supporting crocin's role as a promising ally in protecting against metabolic disorders. The review covers the molecular mechanisms underlying crocin's beneficial effects and highlights its potential applications in preventing and treating diverse pathological conditions. Understanding the mechanisms through which crocin exerts its protective effects could advance scientific knowledge and offer potential avenues for developing novel therapeutic interventions. As we uncover the potential of crocin as a valuable ally in the fight against disorders, it becomes evident that nature's palette holds remarkable solutions for enhancing our health.

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.

Optic Nerve Neuroprotection in Glaucoma: A Narrative Review

In recent years, researchers have been interested in neuroprotective therapies as a cutting-edge therapeutic strategy to treat neurodegenerative disorders by shielding the brain system from harmful events. Millions of individuals worldwide suffer from glaucoma, an ocular neurodegenerative disease characterized by gradual excavation of the optic nerve head, retinal axonal damage, and consequent visual loss. The pathology's molecular cause is still mostly unknown, and the current treatments are not able to alter the disease's natural progression. Thus, the modern approach to treating glaucoma consists of prescribing medications with neuroprotective properties, in line with the treatment strategy suggested for other neurodegenerative diseases. For this reason, several naturally derived compounds, including nicotinamide and citicoline, have been studied throughout time to try to improve glaucoma management by exploiting their neuroprotective properties. The purpose of this review is to examine the naturally derived compounds that are currently utilized in clinical practice for neuroprotection in glaucomatous patients based on scientific data, emphasizing these compounds' pivotal mechanism of action as well as their proven therapeutic and neuroprotective benefits.

Iodine-induced synthetic method and pharmacokinetic study of cis- and trans-crocetin

Objective

This experiment aimed to obtain the relatively rare cis-crocetin isomer from natural plants, which predominantly exist in the more stable all-trans configuration. This was achieved through iodine-induced isomerization, followed by purification and structural identification. The study also aimed to compare the pharmacokinetic differences between cis- and trans-crocetin in vivo.

Methods

Trans-crocetin of high purity was extracted by hydrolysis from gardenia yellow pigment. Cis-crocetin was then synthesized through an optimized electrophilic addition reaction induced by elemental iodine, and subsequently separated and purified via silica gel column chromatography. Structural identification of cis-crocetin was determined using IR, UV, and NMR techniques. In vivo pharmacokinetic studies were conducted for both cis- and trans-crocetin. In addition to this, we have conducted a comparative study on the in vivo anti-hypoxic activity of trans- and cis-crocetin.

Results

Under the selected reaction conditions using DMF as the solvent, with a concentration of 2.5 mg/mL for both trans-crocetin and the iodine solution, and adjusting the illumination time according to the amount of trans-crocetin, the rate of iodine-induced isomerization was the fastest. Cis-crocetin was successfully obtained and, after purification, its structure was identified and found to be consistent with reported data. Cis-crocetin exhibited a faster absorption rate and higher bioavailability, and despite its shorter half-life, it could partially convert to trans-crocetin in the body, thereby extending the duration of the drug's action within the body to some extent.

Conclusion

This study accomplished the successful preparation and structural identification of cis-crocetin. Additionally, through pharmacokinetic studies, it uncovered notable variations in bioavailability between cis- and trans-crocetin. These findings serve as a solid scientific foundation for future functional research and practical applications in this field.

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.

Gardenia yellow pigment: Extraction methods, biological activities, current trends, and future prospects

Food coloring plays a vital role in influencing consumers' food choices, imparting vibrant and appealing colors to various food and beverage products. Synthetic food colorants have been the most commonly used coloring agents in the food industry. However, concerns about potential health issues related to synthetic colorants, coupled with increasing consumer demands for food safety and health, have led food manufacturers to explore natural alternatives. Natural pigments not only offer a wide range of colors to food products but also exhibit beneficial bioactive properties. Gardenia yellow pigment is a water-soluble natural pigment with various biological activities, widely present in gardenia fruits. Therefore, this paper aims to delve into Gardenia Yellow Pigment, highlighting its significance as a food colorant. Firstly, a thorough understanding and exploration of various methods for obtaining gardenia yellow pigment. Subsequently, the potential functionality of gardenia yellow pigment was elaborated, especially its excellent antioxidant and neuroprotective properties. Finally, the widespread application trend of gardenia yellow pigment in the food industry was explored, as well as the challenges faced by the future development of gardenia yellow pigment in the field of food and health. Some feasible solutions were proposed, providing valuable references and insights for researchers, food industry professionals, and policy makers.

Discovery of the toxicity-related quality markers and mechanisms of Zhi-Zi-Hou-Po decoction based on Chinmedomics combined with differentially absorbed components and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-Zi-Hou-Po decoction (ZZHPD), as a representative traditional Chinese medicine (TCM) formula for the treatment of depression, has frequently triggered hepatorenal toxicity in recent years. However, its toxic effect, material basis, and underlying mechanisms have not been fully elucidated.

AIM OF THE STUDY

To explore the hepatorenal toxicity-material basis-quality markers (Q-markers) and multiple mechanisms of ZZHPD.

MATERIALS AND METHODS

ZZHPD-induced rat model of toxicity was evaluated by behavioral indicators, biochemical parameters, and histopathological sections. Then, UHPLC-Q-Exactive Orbitrap-MS combined with multivariate data analysis was utilized to identify the endogenous differential metabolites and the prototype components of ZZHPD in the plasma. A comprehensive strategy integrating in-house library, diagnostic ions, Compound Discover software, and network databases was constructed to identify the chemical constituents of ZZHPD. Additionally, the differentially absorbed components of ZZHPD were screened out based on the spectrum-effect relationship (toxic state and normal state), feature extraction of exogenous components, and variable influence on projection (VIP). Further, Chinmedomics and network pharmacology oriented by differentially absorbed components were performed to predict toxicity-related Q-markers and core targets, as well as relevant pathways. Finally, the binding ability between components and targets was predicted using molecular docking, and the mRNA expression of core target genes was determined by real-time qPCR experiment.

RESULTS

ZZHPD exerted significant hepatotoxicity and nephrotoxicity in rats accompanied by body weight loss, abnormal biochemical indicators, and pathologic characteristics with mild inflammation and cell damage. The results of plasma metabolomics indicated that 22 differential metabolites interfered by ZZHPD mainly involved in primary bile acid biosynthesis, arginine and proline metabolism, phenylalanine metabolism and biosynthesis, sphingolipid metabolism, pyrimidine and purine metabolism. Firstly, 106 chemical substances of ZZHPD were identified, 44 of them were absorbed into the blood, mainly including 7 iridoid glycosides, 15 flavonoids, 5 lignans, and others. Then, the correlation analysis results suggested that 12 of 19 differentially absorbed constituents were highly correlated with 22 differential metabolites and recognized as potential Q-markers. Finally, 9 toxicity-related Q-markers were predicted and confirmed with better binding ability to 5 core targets (PTGS2, CASP3, TNF, PPARG, HMOX1), including 3 flavonoids (naringin, hesperidin, and neohesperidin), 2 iridoid glycosides (geniposide and genipin-1-β-D-gentiobioside), 2 lignans (honokiol and magnolol), organic acid (chlorogenic acid), and crocin (crocetin). The real-time qPCR results showed that the mRNA levels of CASP3, TNF-α, and PPARG significantly increased in the damaged liver. Combining metabolomics and network pharmacology results, the multiple mechanisms of toxicity might involve in oxidative damage, inflammation, and apoptosis pathways.

CONCLUSION

Taken together, the toxicity-related Q-markers of ZZHPD screened for the first time in this work were reliable, and the holistic intervention for hepatorenal toxicity further revealed the multi-component, multi-target, and multi-pathway features in TCM. The integrated approach provides a novel perspective for the discovery of toxicity/efficacy-related substances and mechanistic studies in TCM.

Research Progress in Heterologous Crocin Production

Crocin is one of the most valuable components of the Chinese medicinal plant Crocus sativus and is widely used in the food, cosmetics, and pharmaceutical industries. Traditional planting of C. sativus is unable to fulfill the increasing demand for crocin in the global market, however, such that researchers have turned their attention to the heterologous production of crocin in a variety of hosts. At present, there are reports of successful heterologous production of crocin in Escherichia coli, Saccharomyces cerevisiae, microalgae, and plants that do not naturally produce crocin. Of these, the microalga Dunaliella salina, which produces high levels of β-carotene, the substrate for crocin biosynthesis, is worthy of attention. This article describes the biosynthesis of crocin, compares the features of each heterologous host, and clarifies the requirements for efficient production of crocin in microalgae.

Preparation of trans-Crocetin with High Solubility, Stability, and Oral Bioavailability by Incorporation into Three Types of Cyclodextrins

Crocetin (CRT), an active compound isolated from saffron, exhibits several pharmacological activities, including anti-tumor and immune-regulatory activities, and is effective against myocardial ischemia and coronary heart disease; however, its low stability and solubility limit its clinical application. Therefore, we investigated CRT inclusion complexes (ICs) with three cyclodextrins-α-CD, HP-β-CD, and γ-CD-suitable for oral administration prepared using an ultrasonic method. Fourier transform infrared spectroscopy and powder X-ray diffraction indicated that the crystalline state of CRT in ICs disappeared, and intermolecular interactions were observed between CRT and CDs. 1H nuclear magnetic resonance and phase solubility studies confirmed CRT encapsulation in the CD cavity and the formation of ICs. In addition, we observed the morphology of ICs using scanning electron microscopy. All ICs showed a high drug encapsulation efficiency (approximately 90%) with 6500-10,000 times better solubilities than those of the pure drug. CRT showed rapid dissolution, whereas pure CRT was water-insoluble. The formation of ICs significantly improved the storage stability of CRT under heat, light, and moisture conditions. Further, the peak time of CRT in rats significantly decreased, and the relative bioavailability increased by approximately 3-4 times. In addition, the oral bioavailability of CRT IC was evaluated. Notably, the absorption rate and degree of the drug in rats were improved. This study illustrated the potential applications of CRT/CD ICs in the food, healthcare, and pharmaceutical industries, owing to their favorable dissolution, solubility, stability, and oral bioavailability.

Identification of Crocetin as a Dual Agonist of GPR40 and GPR120 Responsible for the Antidiabetic Effect of Saffron

Crocin, a glycoside of crocetin, has been known as the principal component responsible for saffron's antidiabetic, anticancer, and anti-inflammatory effects. Crocetin, originating from the hydrolytic cleavage of crocin in biological systems, was subjected to ligand-based virtual screening in this investigation. Subsequent biochemical analysis unveiled crocetin, not crocin, as a novel dual GPR40 and GPR120 agonist, demonstrating a marked preference for GPR40 and GPR120 over peroxisome proliferator-activated receptors (PPAR)γ. This compound notably enhanced insulin and GLP-1 secretion from pancreatic β-cells and intestinal neuroendocrine cells, respectively, presenting a dual mechanism of action in glucose-lowering effects. Docking simulations showed that crocetin emulates the binding characteristics of natural ligands through hydrogen bonds and hydrophobic interactions, whereas crocin's hindered fit within the binding pocket is attributed to steric constraints. Collectively, for the first time, this study unveils crocetin as the true active component of saffron, functioning as a GPR40/120 agonist with potential implications in antidiabetic interventions.

Saffron (Crocus sativus) and its constituents for pain management: A review of current evidence

Pain can become a chronic and deliberating experience with a significant burden. In preclinical and clinical studies, Saffron (Crocus sativus L.) has shown analgesic activities. Considering the unsatisfactory results of current therapeutic management for chronic pain conditions, we aimed to review saffron's analgesic activity and underlying mechanisms. Saffron showed antinociceptive activities in formalin-, carrageenan-, and capsaicin-induced experimental pain models. Saffron analgesic activities affected several targets, including ion channels of nociceptors; the adrenergic system and central histaminic system; inhibition of inflammatory pathways, apoptotic pathways, and oxidative stress; regulation of NO pathway, and the endocannabinoid system. Clinical studies showed analgesia of Saffron in rheumatoid arthritis, after-pain following childbirth, dysmenorrhea, and fibromyalgia. Our literature review showed that saffron can be beneficial as an adjunct therapy to commonly used analgesics in practice, particularly in chronic pain conditions.

Transcrocetin Meglumine Salt Inhibits Spinal Glial Cell-Mediated Proinflammatory Cytokines and Attenuates Complete Freund's Adjuvant-Induced Inflammatory Pain

INTRODUCTION

Inflammatory pain is a significant global clinical challenge that involves both unpleasant sensory and emotional experiences. The treatment of pain is imminent, and we are committed to seeking new analgesics for pain relief. Transcrocetin meglumine salt (TCMS), a saffron metabolite derived from the crocin apocarotenoids, has exhibited the ability to cross the blood-brain barrier and exert neuroprotective effects. In this study, we aimed to investigate whether TCMS could ameliorate complete Freund's adjuvant (CFA)-induced inflammatory pain in mice and elucidate its underlying mechanisms.

METHODS

Here, we established an inflammatory pain model in mice by injecting CFA into the left hind paw. Three days later, we administered intraperitoneal injections of TCMS (10 mg/kg) or saline to the animals. We examined mechanical allodynia, thermal hypersensitivity, and anxiety behavior. Furthermore, the activation of glial cells and proinflammatory cytokines in the spinal cord were detected.

RESULTS

Our results showed that TCMS significantly reversed the mechanical allodynia and thermal hypersensitivity in the CFA-injected mice. Furthermore, TCMS administration effectively inhibited the activation of microglia and astrocytes in the spinal cord induced by CFA. Additionally, TCMS suppressed the production and release of spinal proinflammatory cytokines, including TNF-α, IL-1β, and IL-6, in CFA-injected mice.

CONCLUSION

Taken together, our findings demonstrate that TCMS holds promise as an innovative analgesic due to its ability to ameliorate inflammatory reactions.

Crocetin Regulates Functions of Neural Stem Cells to Generate New Neurons for Cerebral Ischemia Recovery

Many neurons undergo apoptosis after ischemic stroke. In the brain, neurogenesis has the potential for neuronal replacement and can be activated by external conditions to repair the injury. Crocetin (CRO), naturally extracted from the plant saffron, acts as a neuroprotective agent for ischemic stroke. However, the underlying mechanism remains unknown. In this work, the effect of CRO on neural stem cell (NSC) behaviors and subventricular zone neurogenesis is investigated. Initially, NSCs are incubated with different concentrations of CRO to detect the cell proliferation and differentiation in vitro. Second, ischemic stroke induced rats are treated with CRO using nimodipine (NMDP) as a comparison. The behavioral functions, infarcted volume, and apoptotic Nissl bodies of rats are noticeably improved after CRO-treatment, comparable to those of NMDP. In addition, the increased regional cerebral blood flow and promoted neuronal differentiation are achieved by CRO-treatment. Brain tissue examination shows significantly increased neuronal regeneration in the focal ischemic injury area. Meanwhile, the length of neurites is prolonged, indicating that CRO could potentially promote neurite extension to enhance cell-cell communication. These findings demonstrate that CRO facilitated the neuronal differentiation of NSCs by activating subventricular zone neurogenesis in damaged cortex and striatum sites to repair ischemic stroke.

Mechanism of Yiqi Huoxue Huatan recipe in the treatment of coronary atherosclerotic disease through network pharmacology and experiments

In recent years, with population aging and economic development, morbidity and mortality of atherosclerotic cardiovascular disease associated with atherosclerosis (AS) have gradually increased. In this study, a combination of network pharmacology and experimental verification was used to systematically explore the action mechanism of Yiqi Huoxue Huatan Recipe (YHHR) in the treatment of coronary atherosclerotic heart disease (CAD). We searched and screened the active ingredients of Coptis chinensis, Astragalus membranaceus, Salvia miltiorrhiza, and Hirudo. We also searched multiple databases for related target genes corresponding to the compounds and CAD. STRING was used to construct the protein-protein interaction (PPI) network of genes. Metascape was used to perform gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis for common targets to analyze the main pathways, and finally, the molecular docking and main possible pathways were verified by experimental studies. Firstly, a total of 1480 predicted target points were obtained through the Swiss Target Prediction database. After screening, merging, and deleting duplicate values, a total of 768 targets were obtained. Secondly, "Coronary atherosclerotic heart disease" was searched in databases such as the OMIM, GeneCards, and TTD. 1844 disease-related targets were obtained. Among PPI network diagram of YHHR-CAD, SRC had the highest degree value, followed by AKT1, TP53, hsp90aa1 and mapk3. The KEGG pathway bubble diagram was drawn using Chiplot, the Signal pathways such as NF kappa B signaling pathway, Lipid and AS, and Apelin signaling pathway are closely related to the occurrence of CAD. The PCR and Western blot methods were used to detect the expression of NF-κB p65. When compared with that in the model group, the expression of NF-κB p65mRNA decreased in the low-concentration YHHR group, with P < .05, while the expression of NF-κB p65mRNA decreased significantly in the high-concentration YHHR group, with P < .01. On the other hand, when compared with that in the model group, the expression of NF-κB p65 decreased in the low-concentration YHHR group, but was not statistically significant, while the expression of NF-κB p65 was significant in the high-concentration YHHR group, and has statistical significance with P < .05. YHHR has been shown to resist inflammation and AS through the SRC/NF-κB signaling pathway.

Advances on the anti-tumor mechanisms of the carotenoid Crocin

Saffron is located in the upper part of the crocus stigma of iridaceae, which has a long history of medicinal use. Crocin (molecular formula C44H64O24) is a natural floral glycoside ester compound extracted from saffron, which is a type carotenoid. Modern pharmacological studies have shown that crocin has multiple therapeutic effects including anti-inflammatory, anti-oxidant, anti-hyperlipidemic and anti-stone effects. In recent years, crocin has been widely noticed due to its considerable anti-tumor effects manifested by the induction of tumor cell apoptosis, inhibition of tumor cell proliferation, inhibition of tumor cell invasion and metastasis, enhancement of chemotherapy sensitivity and improvement of immune status. The anti-tumor effects have been shown in various malignant tumors such as gastric cancer, liver cancer, cervical cancer, breast cancer and colorectal cancer. In this review, we compiled recent studies on the anti-tumor effects of crocin and summarized its anti-tumor mechanism for developing ideas of treating malignancies and exploring anti-tumor drugs.

Clinically Translatable Transcrocetin Delivery Platform for Correction of Tumor Hypoxia and Enhancement of Radiation Therapy Effects

Improving the tumor reoxygenation to sensitize the tumor to radiation therapy is a cornerstone in radiation oncology. Here, the pre-clinical development of a clinically transferable liposomal formulation encapsulating trans sodium crocetinate (NP TSC) is reported to improve oxygen diffusion through the tumor environment. Early pharmacokinetic analysis of the clinical trial of this molecule performed on 37 patients orient to define the optimal fixed dosage to use in a triple-negative breast cancer model to validate the therapeutic combination of radiation therapy and NP TSC. Notably, it is reported that this formulation is non-toxic in both humans and mice at the defined fixed concentration, provides a normalization of the tumor vasculature within 72 h window after systemic injection, leads to a transient increase (50% improvement) in the tumor oxygenation, and significantly improves the efficacy of both mono-fractionated and fractionated radiation therapy treatment. Together, these findings support the introduction of a first-in-class therapeutic construct capable of tumor-specific reoxygenation without associated toxicities.

Natural Carotenoids as Neuroprotective Agents for Alzheimer's Disease: An Evidence-Based Comprehensive Review

Alzheimer's disease (AD) is a neurodegenerative disorder of an ever-increasing aging population with various pathological features such as β-amyloid (Aβ) aggregation, oxidative stress, an impaired cholinergic system, and neuroinflammation. Several therapeutic drugs have been introduced to slow the progression of AD by targeting the above-mentioned pathways. In addition, emerging evidence suggests that naturally occurring compounds have the potential to serve as adjuvant therapies to alleviate AD symptoms. Carotenoids, a group of natural pigments with antioxidative and anti-inflammatory properties, are proposed to be implicated in neuroprotection. To obtain a comprehensive picture of the effect of carotenoids on AD prevention and development, we critically reviewed and discussed recent evidence from in silico, in vitro, in vivo, and human studies in databases including PubMed, Web of Science, Google Scholar, and Cochrane (CENTRAL). After analyzing the existing evidence, we found that high-quality randomized controlled trials (RCTs) are lacking to explore the neuroprotective role of carotenoids in AD pathogenesis and symptoms, especially carotenoids with solid preclinical evidence such as astaxanthin, fucoxanthin, macular carotenoids, and crocin, in order to develop effective preventive dietary supplements for AD patients to ameliorate the symptoms. This review points out directions for future studies to advance the knowledge in this field.

Small molecules in the treatment of COVID-19

The outbreak of COVID-19 has become a global crisis, and brought severe disruptions to societies and economies. Until now, effective therapeutics against COVID-19 are in high demand. Along with our improved understanding of the structure, function, and pathogenic process of SARS-CoV-2, many small molecules with potential anti-COVID-19 effects have been developed. So far, several antiviral strategies were explored. Besides directly inhibition of viral proteins such as RdRp and M^pro, interference of host enzymes including ACE2 and proteases, and blocking relevant immunoregulatory pathways represented by JAK/STAT, BTK, NF-κB, and NLRP3 pathways, are regarded feasible in drug development. The development of small molecules to treat COVID-19 has been achieved by several strategies, including computer-aided lead compound design and screening, natural product discovery, drug repurposing, and combination therapy. Several small molecules representative by remdesivir and paxlovid have been proved or authorized emergency use in many countries. And many candidates have entered clinical-trial stage. Nevertheless, due to the epidemiological features and variability issues of SARS-CoV-2, it is necessary to continue exploring novel strategies against COVID-19. This review discusses the current findings in the development of small molecules for COVID-19 treatment. Moreover, their detailed mechanism of action, chemical structures, and preclinical and clinical efficacies are discussed.

An In Vitro Study of Saffron Carotenoids: The Effect of Crocin Extracts and Dimethylcrocetin on Cancer Cell Lines

Crocus sativus L. has various pharmacological properties, known for over 3600 years. These properties are attributed mainly to biologically active substances, which belong to the terpenoid group and include crocins, picrocrocin and safranal. The aim of the current work was to examine the effects of crocins (CRCs) and their methyl ester derivate dimethylcrocetin (DMCRT) on glioblastoma and rhabdomyosarcoma cell lines, in terms of cytotoxicity and gene expression, implicated in proapoptotic and cell survival pathways. Cell cytotoxicity was assessed with Alamar Blue fluorescence assay after treatment with saffron carotenoids for 24, 48 and 72 h and concentrations ranging from 22.85 to 0.18 mg/mL for CRCs and 11.43 to 0.09 mg/mL for DMCRT. In addition, BAX, BID, BCL2, MYCN, SOD1, and GSTM1 gene expression was studied by qRT-PCR analysis. Both compounds demonstrated cytotoxic effects against glioblastoma and rhabdomyosarcoma cell lines, in a dose- and time-dependent manner. They induced apoptosis, via BAX and BID upregulation, MYCN and BCL-2, SOD1, GSTM1 downregulation. The current research denotes the possible anticancer properties of saffron carotenoids, which are considered safe phytochemicals, already tested in clinical trials for their health promoting properties.