Cynaropicrin: A Comprehensive Research Review and Therapeutic Potential As an Anti-Hepatitis C Virus Agent

Antiproliferative Activities of Cynaropicrin and Related Compounds against Cancer Stem Cells

Glioblastoma (GBM) has a high mortality rate despite the availability of various cancer treatment options. Although cancer stem cells (CSCs) have been associated with poor prognosis and metastasis, and play an important role in the resistance to existing anticancer drugs and radiation; no CSC-targeting drugs are currently approved in clinical practice. Therefore, the development of antiproliferative agents against CSCs is urgently required. In this study, we evaluated the antiproliferative activities of 21 sesquiterpenoids against human GBM U-251 MG CSCs and U-251 MG non-CSCs. Particularly, the guaianolide sesquiterpene lactone cynaropicrin (1) showed strong antiproliferative activity against U-251 MG CSCs (IC50 = 20.4 µM) and U-251 MG non-CSCs (IC50 = 10.9 µM). Accordingly, we synthesized six derivatives of 1 and investigated their structure-activity relationships. Most of the guaianolide sesquiterpene lactones with the α-methylene-γ-butyrolactone moiety showed antiproliferative activities against U-251 MG cells. We conclude that the 5,7,5-ring and the α-methylene-γ-butyrolactone moiety are both important for antiproliferative activities against U-251 MG cells. The results of this study suggest that the α,β-unsaturated carbonyl moiety, which has recently become a research hotspot in drug discovery, is the active center of 1. Therefore, we consider 1 as a potential lead for developing novel drugs targeting CSCs.

Cynaropicrin disrupts tubulin and c-Myc-related signaling and induces parthanatos-type cell death in multiple myeloma

The majority of blood malignancies is incurable and has unforeseeable remitting-relapsing paths in response to different treatments. Cynaropicrin, a natural sesquiterpene lactone from the edible parts of the artichoke plant, has gained increased attention as a chemotherapeutic agent. In this study, we investigated the effects of cynaropicrin against multiple myeloma (MM) cells in vitro and assessed its in vivo effectiveness in a xenograft tumor zebrafish model. We showed that cynaropicrin exerted potent cytotoxicity against a panel of nine MM cell lines and two leukemia cell lines with AMO1 being the most sensitive cell line (IC50 = 1.8 ± 0.3 µM). Cynaropicrin (0.8, 1.9, 3.6 µM) dose-dependently reduced c-Myc expression and transcriptional activity in AMO1 cells that was associated with significant downregulation of STAT3, AKT, and ERK1/2. Cell cycle analysis showed that cynaropicrin treatment arrested AMO1 cells in the G2M phase along with an increase in the sub-G0G1 phase after 24 h. With prolonged treatment times, cells accumulated more in the sub-G0G1 phase, implying cell death. Using confocal microscopy, we revealed that cynaropicrin disrupted the microtubule network in U2OS cells stably expressing α-tubulin-GFP. Furthermore, we revealed that cynaropicrin promoted DNA damage in AMO1 cells leading to PAR polymer production by PARP1 hyperactivation, resulting in AIF translocation from the mitochondria to the nucleus and subsequently to a novel form of cell death, parthanatos. Finally, we demonstrated that cynaropicrin (5, 10 µM) significantly reduced tumor growth in a T-cell acute lymphoblastic leukemia (T-ALL) xenograft zebrafish model. Taken together, these results demonstrate that cynaropicrin causes potent inhibition of hematopoietic tumor cells in vitro and in vivo.

Cynaropicrin Averts the Oxidative Stress and Neuroinflammation in Ischemic/Reperfusion Injury Through the Modulation of NF-kB

Cerebral ischemia and successive reperfusion are the prevailing cause of cerebral stroke. Currently cerebral stroke is considered to be one of the prior causes for high mortality, disability, and morbidity. Cynaropicrin, a sesquiterpene lactone, exhibits various pharmacologic properties and also has an anti-inflammatory property associated with the suppression of the key pro-inflammatory NF-κB pathway. The protective effect of cynaropicrin against oxidative stress and neuroinflammation during CIR injury through the modulation of NF-κB pathway was studied in the current investigation. The experimental rats split into 5 groups as sham-operated control group (group 1), middle cerebral artery occlusion (MCAO)-induced rats (group 2), MCAO rats treated with cynaropicrin (diluted in saline) immediately 2 h after MCAO with 5, 10, and 25 mg/kg administration orally were designated as groups 3, 4, and 5, respectively. In MCAO-induced animals, the severity of ischemic was evident by the elevated level nitrate, MDA, MMPs, inflammatory mediators, Bax, caspase-3, and NF-κB. The level of Nrf-2, antioxidant enzymes, Bcl-2, and IL-10 was reduced in the MCAO-induced animals. Treatment with cynaropicrin in dosage-based manner increased the level of antioxidant enzymes, IL-10, Nrf-2, and Bcl-2 in the animals which indicates the antioxidative effect of cynaropicrin. The level of nitrate, MDA, MMPs, proinflammatory cytokines, inflammatory mediators, Bax, caspase-3, and NF-κB was reduced in the rats treated with cynaropicrin in a dosage-based manner. Experimental animals treated with cynaropicrin in a dosage-dependent way showed a defensive mechanism against oxidative stress and neuroinflammation by inhibiting the NF-κB pathway.

Bioactive Compounds from Artichoke and Application Potential

Cynara cardunculus L. var. scolymus, known as the artichoke, originated in the Mediterranean region and is now cultivated in several countries. The artichoke has leaves, a stem, and a head, also called a floral capitulum, covered with green and pointed bracts. It is rich in polyphenols, flavonoids, anthocyanins, phenolic compounds, inulin, coumarins, terpenes, dietary fibre, enzymes, polysaccharides, minerals and vitamins, and therefore has a wide range of uses, including in the food industry, medicine and biofuels. Several studies have shown that artichokes have properties such as antioxidant, anti-inflammatory, antimicrobial, anticancer, hypocholesterolaemic, anti-HIV, cardioprotective, hepatoprotective and lipid-lowering effects. The aim of this study is to provide a literature review on the phytochemical composition, bioactivity and applications, focusing on the methods of extraction, purification and concentration of enzymes present in artichoke.

The wide spectrum of industrial applications for cultivated cardoon (Cynara cardunculus L. var. Altilis DC.): A review

Cynara cardunculus L. var. altilis DC. belongs to the Asteraceae family and is widely used. This species is integrated into the Mediterranean diet and has broad applicability due to its rich chemical composition. Its flowers, used as a vegetable coagulant for gourmet cheese production, are rich in aspartic proteases. Leaves are rich in sesquiterpene lactones, the most abundant being cynaropicrin, while stems present a higher abundance of hydroxycinnamic acids. Both classes of compounds exhibit a wide range of bioactive properties. Its chemical composition makes it applicable in other industrial sectors, such as energy (e.g., manufacturing of biodiesel and biofuel) or paper pulp production, among other biotechnological applications. In the last decade, cardoon has been identified as a competitive energy crop, constituting an opportunity for the economic recovery and development of the rural areas of the Mediterranean basin. This article reviews the chemical composition, bioactive properties, and multifaceted industrial applications of cardoon.

Byproducts of Globe Artichoke and Cauliflower Production as a New Source of Bioactive Compounds in the Green Economy Perspective: An NMR Study

The recovery of bioactive compounds from crop byproducts leads to a new perspective way of waste reutilization as a part of the circular economy. The present study aimed at an exhaustive metabolite profile characterization of globe artichoke and cauliflower byproducts (leaves, stalks, and florets for cauliflower only) as a prerequisite for their valorization and future implementations. The metabolite profile of aqueous and organic extracts of byproducts was analyzed using the NMR-based metabolomics approach. Free amino acids, organic acids, sugars, polyols, polyphenols, amines, glucosinolates, fatty acids, phospho- and galactolipids, sterols, and sesquiterpene lactones were identified and quantified. In particular, globe artichoke byproducts are a source of health-beneficial compounds including chiro-inositol (up to 10.1 mg/g), scyllo-inositol (up to 1.8 mg/g), sesquiterpene lactones (cynaropicrin, grosheimin, dehydrocynaropicrin, up to 45.5 mg/g in total), inulins, and chlorogenic acid (up to 7.5 mg/g), whereas cauliflower byproducts enclose bioactive sulfur-containing compounds S-methyl-L-cysteine S-oxide (methiin, up to 20.7 mg/g) and glucosinolates. A variable content of all metabolites was observed depending on the crop type (globe artichoke vs. cauliflower) and the plant part (leaves vs. stalks). The results here reported can be potentially used in different ways, including the formulation of new plant biostimulants and food supplements.

Blood pH and COVID-19

The coronavirus disease 2019 (COVID-19) pandemic is a worldwide war. Raising the blood pH might be a crucial strategy to chase COVID-19. The human blood is slightly alkaline, which is essential for cell metabolism, normal physiology, and balanced immunity since all of these biological processes are pH-dependent. Varieties of physiologic derangements occur when the blood pH is disrupted. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) proliferates in acidic blood that magnifies the severity of COVID-19. On the other side, blood acidemia is linked to increased morbidity and mortality because of its complications on immunity, especially in the elderly and in critical diseases such as cancer, musculoskeletal degradation, renal, cardiac, and pulmonary disorders, which result in many pathological disorders such as osteomalacia, and disturbing the hematopoiesis. Additionally, acidemia of the blood facilitates viral infection and progression. Thus, correcting the acid-base balance might be a crucial strategy for the treatment of COVID-19, which might be attributed to the distraction of the viral spike protein to its cognate receptor angiotensin-converting enzyme 2 and supporting the over-taxed immunity.

X-ray crystalographic data, absolute configuration, and anticholinesterase effect of dihydromyricitrin 3-O-rhamnoside

Based on our continuous effort to investigate chemistry and biology of the plant secondary metabolites, we were able to isolate a glycosidal flavonoid 1 from the Wild Egyptian Artichoke. The activity of dihydromyricetin 3-O-rhamnoside (sin. dihydromyricitrin, ampelopsin 3-O-rhamnoside) (1) against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE); its absolute configuration using X-ray crystallography were determined for the first time. Inhibitory activity of 1 against AChE and BChE enzymes were determined using a slightly modified version of Ellman's method. Compound 1 was revealed to have a potent inhibition against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC₅₀ values of 0.070 ± 0.008 and 0.071 ± 0.004 mM, respectively, where IC₅₀ values of the reference drug (galanthamine) were 0.023 ± 0.15 and 0.047 ± 0.91 mM. Compound 1 could be a promising molecule against Alzheimer's disease.

Potential of natural products in the treatment of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a kind of functional bowel disease that is characterized by bellyache, abdominal distension, and diarrhea. Although not life-threatening, IBS has a long course and recurrent attacks and seriously affects the life quality of patients. Current drugs for treating IBS possess remarkable limitations, such as limited efficacy and severe adverse reactions. Therefore, developing novel medications to treat IBS is quite essential, and natural products may be a substantial source.

PURPOSE

This is the first systematic review elaborating the recent advancement of natural products as potential drugs for the therapy of IBS.

METHODS

A comprehensive retrieval of studies was carried out in scientific databases including PubMed, Web of Science, Elsevier, and CNKI. By using ("irritable bowel syndrome" OR "IBS") AND ("natural product" OR "natural compound" OR "phytochemical") as keywords, the eligible studies were screened, and the relevant information about therapeutic action and mechanism of natural products treating IBS was extracted.

RESULTS

Natural products against IBS consisted of four categories, namely, terpenoids, flavonoids, alkaloids, and phenols. Furthermore, the underlying mechanisms for natural products treating IBS were tightly associated with increased TJs and mucus protein expression, regulation of the brain-gut axis and gut microbiota structure, and inhibition of inflammatory response and intestinal mucosal damage.

CONCLUSION

Natural products could be extremely prospective candidate drugs used to treat IBS, and further preclinical and clinical researches are needed to guarantee their efficacy and safety.

Sesquiterpenoid lactones as potential anti-cancer agents: an update on molecular mechanisms and recent studies

Plants-based natural compounds are well-identified and recognized chemoprotective agents that can be used for primary and secondary cancer prevention, as they have proven efficacy and fewer side effects. In today's scenario, when cancer cases rapidly increase in developed and developing countries, the anti-cancerous plant-based compounds become highly imperative. Among others, the Asteraceae (Compositae) family's plants are rich in sesquiterpenoid lactones, a subclass of terpenoids with wide structural diversity, and offer unique anti-cancerous effects. These plants are utilized in folk medicine against numerous diseases worldwide. However, these plants are now a part of the modern medical system, with their sesquiterpenoid lactones researched extensively to find more effective and efficient cancer drug regimens. Given the evolving importance of sesquiterpenoid lactones for cancer research, this review comprehensively covers different domains in a spectrum of sesquiterpenoid lactones viz (i) Guaianolides (ii) Pseudoguaianolide (iii) Eudesmanolide (iv) Melampodinin A and (v) Germacrene, from important plants such as Cynara scolymus (globe artichoke), Arnica montana (wolf weeds), Spilanthes acmella, Taraxacum officinale, Melampodium, Solidago spp. The review, therefore, envisages being a helpful resource for the growth of plant-based anti-cancerous drug development.

Suppression of endoplasmic reticulum stress-dependent autophagy enhances cynaropicrin-induced apoptosis via attenuation of the P62/Keap1/Nrf2 pathways in neuroblastoma

Autophagy has dual roles in cancer, resulting in cellular adaptation to promote either cell survival or cell death. Modulating autophagy can enhance the cytotoxicity of many chemotherapeutic and targeted drugs and is increasingly considered to be a promising cancer treatment approach. Cynaropicrin (CYN) is a natural compound that was isolated from an edible plant (artichoke). Previous studies have shown that CYN exhibits antitumor effects in several cancer cell lines. However, it anticancer effects against neuroblastoma (NB) and the underlying mechanisms have not yet been investigated. More specifically, the regulation of autophagy in NB cells by CYN has never been reported before. In this study, we demonstrated that CYN induced apoptosis and protective autophagy. Further mechanistic studies suggested that ER stress-induced autophagy inhibited apoptosis by activating the p62/Keap1/Nrf2 pathways. Finally, in vivo data showed that CYN inhibited tumour growth in xenografted nude mice. Overall, our findings suggested that CYN may be a promising candidate for the treatment of NB, and the combination of pharmacological inhibitors of autophagy may hold novel therapeutic potential for the treatment of NB. Our paper will contribute to the rational utility and pharmacological studies of CYN in future anticancer research.

Advances in UDP-N-Acetylglucosamine Enolpyruvyl Transferase (MurA) Covalent Inhibition

Peptidoglycan is a cross-linked polymer responsible for maintaining the bacterial cell wall integrity and morphology in Gram-negative and Gram-positive bacteria. The peptidoglycan pathway consists of the enzymatic reactions held in three steps: cytoplasmic, membrane-associated, and periplasmic. The Mur enzymes (MurA-MurF) are involved in a cytoplasmic stage. The UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) enzyme is responsible for transferring the enolpyruvate group from phosphoenolpyruvate (PEP) to UDP-N-acetylglucosamine (UNAG) to form UDP-N-acetylglucosamine enolpyruvate (EP-UNAG). Fosfomycin is a natural product analogous to PEP that acts on the MurA target enzyme via binding covalently to the key cysteine residue in the active site. Similar to fosfomycin, other MurA covalent inhibitors have been described with a warhead in their structure that forms a covalent bond with the molecular target. In MurA, the nucleophilic thiolate of Cys115 is pointed as the main group involved in the warhead binding. Thus, in this minireview, we briefly describe the main recent advances in the design of MurA covalent inhibitors.

Therapeutic Potential of Artichoke in the Treatment of Fatty Liver: A Systematic Review and Meta-Analysis

Nonalcoholic fatty liver disease (NAFLD) is a major chronic liver disease that can lead to liver cirrhosis, liver cancer, and death. Artichoke leaf extract (ALE) is well known in folk medicine for its hepatoprotective effect. Till recent times, no sufficient data from randomized clinical trials (RCTs) exist to support such use. This meta-analysis summarizes evidence from recent RCTs that evaluated ALE in NAFLD patients. Electronic databases were searched for RCTs that used ALE in NAFLD patients. The random-effects model was used to pool effect sizes (standardized change score). Data synthesis from five RCTs (333 patients) showed that ALE resulted in a significant reduction in alanine aminotransferase (standardized mean difference [SMD]: 1.1; 95% confidence interval [CI], 0.79-1.73; P < .001) and aspartate aminotransferase levels (SMD: 1.01; 95% CI, 0.52-1.51; P < .001) compared with the control group. ALE also resulted in a significant reduction in total cholesterol (SMD: 0.98; 95% CI, 0.53-1.43; P = .004), low-density lipoprotein (SMD: 0.96; 95% CI, 0.3-1.62; P < .001) and triglycerides (SMD: 0.95; 95% CI, 0.58-1.32; P < .001). The current review provides evidence from RCTs to support the use of ALE as a hepatoprotective agent in NAFLD patients. The study was registered on the PROSPERO database with the Registration No. CRD42020182502 (https://www.crd.york.ac.uk/prospero).

The Employment of Genera Vaccinium, Citrus, Olea, and Cynara Polyphenols for the Reduction of Selected Anti-Cancer Drug Side Effects

Cancer is one of the most widespread diseases globally and one of the leading causes of death. Known cancer treatments are chemotherapy, surgery, radiation therapy, targeted hormonal therapy, or a combination of these methods. Antitumor drugs, with different mechanisms, interfere with cancer growth by destroying cancer cells. However, anticancer drugs are dangerous, as they significantly affect both cancer cells and healthy cells. In addition, there may be the onset of systemic side effects perceived and mutagenicity, teratogenicity, and further carcinogenicity. Many polyphenolic extracts, taken on top of common anti-tumor drugs, can participate in the anti-proliferative effect of drugs and significantly reduce the side effects developed. This review aims to discuss the current scientific knowledge of the protective effects of polyphenols of the genera Vaccinium, Citrus, Olea, and Cynara on the side effects induced by four known chemotherapy, Cisplatin, Doxorubicin, Tamoxifen, and Paclitaxel. In particular, the summarized data will help to understand whether polyphenols can be used as adjuvants in cancer therapy, although further clinical trials will provide crucial information.

Perspectives on nano-nutraceuticals to manage pre and post COVID-19 infections

Optimized therapeutic bio-compounds supported by bio-acceptable nanosystems (i.e., precise nanomedicine) have ability to promote health via maintaining body structure, organ function, and controlling chronic and acute effects. Therefore, nano-nutraceuticals (designed to neutralize virus, inhibit virus bindings with receptors, and support immunity) utilization can manage COVID-19 pre/post-infection effects. To explore these approaches well, our mini-review explores optimized bio-active compounds, their ability to influence SARS-CoV-2 infection, improvement in performance supported by precise nanomedicine approach, and challenges along with prospects. Such optimized pharmacologically relevant therapeutic cargo not only affect SARS-CoV-2 but will support other organs which show functional alternation due to SARS-CoV-2 for example, neurological functions. Hence, coupling the nutraceuticals with the nano-pharmacology perspective of higher efficacy via targeted delivery action can pave a novel way for health experts to plan future research needed to manage post COVID-19 infection effect where a longer efficacy with no side-effects is a key requirement.

Bioactive Compounds from Cardoon as Health Promoters in Metabolic Disorders

Cardoon (Cynara cardunculus L.) is a Mediterranean plant and member of the Asteraceae family that includes three botanical taxa, the wild perennial cardoon (C. cardunculus L. var. sylvestris (Lamk) Fiori), globe artichoke (C. cardunculus L. var. scolymus L. Fiori), and domesticated cardoon (C. cardunculus L. var. altilis DC.). Cardoon has been widely used in the Mediterranean diet and folk medicine since ancient times. Today, cardoon is recognized as a plant with great industrial potential and is considered as a functional food, with important nutritional value, being an interesting source of bioactive compounds, such as phenolics, minerals, inulin, fiber, and sesquiterpene lactones. These bioactive compounds have been vastly described in the literature, exhibiting a wide range of beneficial effects, such as antimicrobial, anti-inflammatory, anticancer, antioxidant, lipid-lowering, cytotoxic, antidiabetic, antihemorrhoidal, cardiotonic, and choleretic activity. In this review, an overview of the cardoon nutritional and phytochemical composition, as well as its biological potential, is provided, highlighting the main therapeutic effects of the different parts of the cardoon plant on metabolic disorders, specifically associated with hepatoprotective, hypolipidemic, and antidiabetic activity.

Valuable Hepatoprotective Plants - How Can We Optimize Waste Free Uses of Such Highly Versatile Resources?

Humans used plants for thousand of years as food, drugs, or fuel to keep homes warm. People commonly used fruits and roots, and other parts of the plant were often wasted. This review aims to discuss the potential of rational stem-to-stern use of three highly versatile and valuable plants with hepatoprotective properties. Milk thistle (Silybum marianum L. Gaertn.), artichoke (Cynara cardunculus), and chicory (Cichorium intybus L.) have well-characterized hepatoprotective properties. These plants have been chosen since liver diseases are significant diseases of concern worldwide, and all parts of plants can be potentially utilized. Artichoke and chicory are commonly used as food or dietary supplements and less often as phytodrugs. Various dietary supplements and phytodrugs prepared from milk thistle (MT) fruits/seeds are well-known to consumers as remedies supporting liver functions. However, using these plants as functional food, farm animal feed, is not well-described in the literature. We also discuss bioactive constituents present in various parts of these plants, their pharmacological properties. Distinct parts of MT, artichoke, and chicory can be used to prepare remedies and food for humans and animals. Unused plant parts are potentially wasted. To achieve waste-free use of these and many other plants, the scientific community needs to analyze the complex use of plants and propose strategies for waste-free technologies. The government must stimulate companies to utilize by-products. Another problem associated with plant use as a food or source of phytodrug is the overharvesting of wild plants. Consequently, there is a need to use more active cultivation techniques for plants.

Cynaropicrin Induces Cell Cycle Arrest and Apoptosis by Inhibiting PKM2 to Cause DNA Damage and Mitochondrial Fission in A549 Cells

Metabolic reprogramming is critical for tumorigenesis. Pyruvate kinase M2 (PKM2) is overexpressed in lung carcinoma cells and plays a critical role in the Warburg effect, making the enzyme a research hotspot for anticancer drug development. Cynaropicrin (CYN), a natural sesquiterpene lactone compound from artichoke, has received increasing consideration due to its consumable esteem and pharmacological properties. Our data reveal that CYN not only inhibited the purified PKM2 activity but also decreased the cellular PKM2 expression in A549 cells. The inhibition of PKM2 leads to the upregulation of p53 and the downregulation of the DNA repair enzyme poly (ADP-ribose) polymerase (PARP), and subsequently causes the cell cycle arrest. Additionally, CYN inhibits the interaction of PKM2 and Nrf2, resulting in the impairment of cellular antioxidant capacity, induction of oxidative stress, and mitochondrial damages. Overexpression of PKM2 attenuates the CYN-induced DNA damage, mitochondrial fission, and cell viability. Thus, targeting PKM2 provides an original mechanism for understanding the pharmacological impact of CYN and assists in the further development of CYN as an anticancer agent.

Total synthesis of cynaropicrin

Cynaropicrin is found in artichoke (Cynara scolymus) and is the source of its bitter taste and it is a sesquiterpene lactone with a 5-7-5 tricyclic skeleton, six chiral centers, and four exo-olefins. This natural product has numerous attractive biological activities including the inhibition of NF-κB activation, antihepatitis C activity, and antitrypanosomal activity. In this study, the first total synthesis of cynaropicrin was achieved starting from (S)-α-pinene. The synthesis involved a stereoselective Favorskii rearrangement and an indium-promoted diastereoselective Barbier reaction.

Synthesis and Molecular Docking of Some Grossgemin Amino Derivatives as Tubulin Inhibitors Targeting Colchicine Binding Site

Six amino derivatives of grossgemin (2–7) were synthesized according to the reported essential pharmacophoric features of colchicine binding site inhibitors (CBSIs). The derivatives 4–6 were obtained for the first time. The pharmacophoric features of 2–7 as CBSIs were studied to be almost identical. Furthermore, the 3D-flexible alignment of compound 5 as a representative example with colchicine showed a very good overlapping. In agreement, compounds 2–7 docked into CBS with binding modes very similar to that of colchicine and exhibited binding free energies of −24.57, −25.05, −32.16, −29.34, −26.38, and −26.86 (kcal/mol), respectively. The binding free energies of 4–7 were better than that of colchicine (−26.13 kcal/mol) with a noticeable superiority to compound 4.

Marine endophytic fungal metabolites: A whole new world of pharmaceutical therapy exploration

The growing threat arises due to diseases such as cancer and the infections around the world leading to a critical requirement for novel and constructive compounds with unique ways of action capable of combating these deadly diseases. At present, it is evident that endophytic fungi constitute an enormous as well as comparatively untapped source of great biodiversity that can be considered as a wellspring of effective novel natural products for medical, agricultural and industrial use. Marine endophytic fungi have been found in every marine plants (algae, seagrass, driftwood, mangrove plants), marine vertebrates (mainly, fish) or marine invertebrates (mainly, sponge and coral) inter- and intra-cellular without causing any palpable symptoms of illness. Since evolution of microbes and eukaryotes to a higher level, coevolution has resulted in specific interaction mechanisms. Endophytic fungi are known to influence the life cycle and are necessary for the homeostasis of their eukaryotic hosts and the chemical signals of their host have been shown to activate gene expression in endophytes to induce expression of endophytic secondary metabolites. Marine endophytic fungi are receiving increasing attention by chemists because of their varied and structurally unmatched compounds that have strong biological roles in life as lead pharmaceutical compounds, including anticancer, antiviral, insulin mimetic, antineurodegenerative, antimicrobial, antioxidant and immuno-suppressant compounds. Moreover, fungal endophytes proved to have different biological activities for exploitation in the environmental and agricultural sustainability.

Therapeutic opportunities of edible antiviral plants for COVID-19

The pandemic of Serious Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) that produces corona virus disease (COVID-19) has challenged the entire mankind by rapidly spreading globally in 210 countries affecting over 25 million people and about 1 million deaths worldwide. It continues to spread, afflicting the health system globally. So far there is no remedy for the ailment and the available antiviral regimens have been unsatisfactory for the clinical outcomes and the mode of treatment has been mainly supportive for the prevention of COVID-19-induced morbidity and mortality. From the time immortal the traditional plant-based ethno-medicines have provided the leads for the treatment of infectious diseases. Phytopharmaceuticals have provided potential and less toxic antiviral drugs as compared to conventional modern therapeutics which are associated with severe toxicities. The ethnopharmacological knowledge about plants has provided food supplements and nutraceuticals as a promise for prevention and treatment of the current pandemic. In this review article, we have attempted to comprehend the information about the edible medicinal plant materials with potential antiviral activity specifically against RNA virus which additionally possess property to improve immunity along with external and internal respiration and exhibit anti-inflammatory properties for the prevention and treatment of the disease. This will open an arena for the development of novel nutraceutical herbal formulations as an alternative therapy that can be used for the prevention and treatment of COVID-19.

COVID-19 Prophylaxis Efforts Based on Natural Antiviral Plant Extracts and Their Compounds

During the time of the novel coronavirus disease 2019 (COVID-19) pandemic, it has been crucial to search for novel antiviral drugs from plants and well as other natural sources as alternatives for prophylaxis. This work reviews the antiviral potential of plant extracts, and the results of previous research for the treatment and prophylaxis of coronavirus disease and previous kinds of representative coronaviruses group. Detailed descriptions of medicinal herbs and crops based on their origin native area, plant parts used, and their antiviral potentials have been conducted. The possible role of plant-derived natural antiviral compounds for the development of plant-based drugs against coronavirus has been described. To identify useful scientific trends, VOSviewer visualization of presented scientific data analysis was used.

Cynaropicrin Shows Antitumor Progression Potential in Colorectal Cancer Through Mediation of the LIFR/STATs Axis

BACKGROUND

Colorectal cancer (CRC) is the second deadliest malignant disease in the world and the leukemia inhibitory factor receptor/signal transducers and activators of transcriptions (LIFR/STATs) signaling axis plays an important role in the molecular biology of CRC.

METHODS

Cell function tests were performed to observe the inhibitory effect of cynaropicrin on human CRC cells (RKO, HCT116, and DLD-1). Expression levels of LIFR, P-STAT3, P-STAT4, and apoptotic proteins were detected by Western blotting. Immunoprecipitation confirmed the presence of LIFR/STAT3/STAT4 complex. Cell immunofluorescence assay was used to observe the subcellular localization of STAT3 and STAT4. In vivo efficacy of cynaropicrin was evaluated by a xenotransplantation model in nude mice.

RESULTS

Cynaropicrin significantly reduced the survival ability of human CRC cells and promoted apoptosis in a dose-dependent manner. Western blotting results suggested that the antitumor effects of cynaropicrin might be mediated by inhibition of the LIFR/STATs axis. Cynaropicrin reduced the formation of STAT3/STAT4 heterodimers and blocked their entry into the nucleus. Cynaropicrin also suppressed tumor growth in the xenograft model.

CONCLUSION

The results showed that cynaropicrin exerted a strong inhibitory effect on CRC in vitro and in vivo. Our study concluded that cynaropicrin has potential application prospects in the field of anti-CRC therapy.

Pharmacological Activities of Psoralidin: A Comprehensive Review of the Molecular Mechanisms of Action

Analysis of the most relevant studies on the pharmacological properties and molecular mechanisms of psoralidin, a bioactive compound from the seeds of Cullen corylifolium (L.) Medik. confirmed its complex therapeutic potential. In the last years, the interest of the scientific community regarding psoralidin increased, especially after the discovery of its benefits in estrogen-related diseases and as a chemopreventive agent. Growing preclinical pieces of evidence indicate that psoralidin has anticancer, antiosteoporotic, anti-inflammatory, anti-vitiligo, antibacterial, antiviral, and antidepressant-like effects. Here, we provide a comprehensive and critical review of psoralidin on its bioavailability, pharmacological activities with focus on molecular mechanisms and cell signaling pathways. In this review, we conducted literature research on the PubMed database using the following keywords: “Psoralidin” or “therapeutic effects” or “biological activity” or “Cullen corylifolium” in order to identify relevant studies regarding PSO bioavailability and mechanisms of therapeutic effects in different diseases based on preclinical, experimental studies. In the light of psoralidin beneficial actions for human health, this paper gathers complete information on its pharmacotherapeutic effects and opens new natural therapeutic perspectives in chronic diseases.

Inhibitory effects of cynaropicrin on human melanoma progression by targeting MAPK, NF-κB, and Nrf-2 signaling pathways in vitro

Malignant melanoma is the deadliest skin cancer, due to its propensity to metastasize. MAPKs and NF-κB pathways are constitutively activated in melanoma and promote cell proliferation, cell invasion, metastasis formation, and resistance to therapeutic regimens. Thus, they represent potential targets for melanoma prevention and treatment. Phytochemicals are gaining considerable attention for the management of melanoma because of their several cellular and molecular targets. A screening of a small library of sesquiterpenes lactones selected cynaropicrin, isolated from the aerial parts of Centaurea drabifolia subsp. detonsa, for its potential anticancer effect against melanoma cells. Treatment of human melanoma cells A375 with cynaropicrin resulted in inhibition of cell proliferation and induction of caspase-3-dependent apoptosis. Furthermore, cynaropicrin reduced several cellular malignant features such migration, invasion, and colonies formation through the inhibition of ERK1/2 and NF-κB activity. Cynaropicrin was able to reduce intracellular reactive oxygen species generation, which are involved in all the stages of carcinogenesis. Indeed, cynaropicrin increased the expression of several antioxidant genes, such as glutamate-cysteine ligase and heme oxygenase-1, by promoting the activation of the transcription factor Nrf-2. In conclusion, our results individuate cynaropicrin as a potential adjuvant chemotherapeutic agent for melanoma by targeting several protumorigenic signaling pathways.

Applications of Sesquiterpene Lactones: A Review of Some Potential Success Cases

Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors’ opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.

Polyphenols and Sesquiterpene Lactones from Artichoke Heads: Modulation of Starch Digestion, Gut Bioaccessibility, and Bioavailability following In Vitro Digestion and Large Intestine Fermentation

Artichoke is a relevant source of health-promoting compounds such as polyphenols and sesquiterpene lactones. In this study, the bioaccessibility and gut bioavailability of artichoke constituents were evaluated by combining in vitro digestion and large intestine fermentation, metabolomics, and Caco-2 human intestinal cells model. Moreover, the ability of artichoke polyphenols to modulate the in vitro starch digestibility was also explored. An untargeted metabolomic approach based on liquid chromatography quadrupole-time-of-flight (UHPLC/QTOF) mass spectrometry coupled with multivariate statistics was used to comprehensively screen the phytochemical composition of raw, digested, and fermented artichoke. Overall, a large abundance of phenolic acids and sesquiterpene lactones was detected, being 13.77 and 11.99 mg·g-1, respectively. After 20 h of in vitro large intestine fermentation, a decrease in polyphenols and sesquiterpene lactones content was observed. The most abundant compounds characterizing the raw material (i.e., chlorogenic acid and cynaropicrin equivalents) showed an average % bioaccessibility of 1.6%. The highest % bioaccessibility values were recorded for flavonoids such as anthocyanin and flavone equivalents (on average, 13.6%). However, the relatively high bioavailability values recorded for flavonols, phenolic acids, and sesquiterpene lactones (from 71.6% up to 82.4%) demonstrated that these compounds are able to be transported through the Caco-2 monolayer. The phenolic compounds having the highest permeation rates through the Caco-2 model included low molecular weight phenolics such as tyrosol and 4-ethylcatechol; the isoflavonoids 3'-O-methylviolanone, equol 4'-O-glucuronide, and hydroxyisoflavone; together with the methyl and acetyl derivatives of glycosylated anthocyanins. Therefore, although human in vivo confirmatory trials are deemed possible, current findings provide insights into the mechanistic effects underlying artichoke polyphenols and sesquiterpenoids bioavailability following gastrointestinal and large intestine processes.

Randomized Clinical Trial: Bergamot Citrus and Wild Cardoon Reduce Liver Steatosis and Body Weight in Non-diabetic Individuals Aged Over 50 Years

Background: Non-alcoholic fatty liver disease is the most common cause of liver-related morbidity and mortality in the world. However, no effective pharmacological treatment for this condition has been found. Purpose: This study evaluated the effect of a nutraceutical containing bioactive components from Bergamot citrus and wild cardoon as a treatment for individuals with fatty liver disease. The primary outcome measure was the change in liver fat content. Methods: A total of 102 patients with liver steatosis were enrolled in a double-blind placebo controlled clinical trial. The intervention group received a nutraceutical containing a Bergamot polyphenol fraction and Cynara Cardunculus extract, 300 mg/day for 12 weeks. The control group received a placebo daily. Liver fat content, by transient elastography, serum transaminases, lipids and glucose were measured at the baseline and the end of the study. Results: We found a greater liver fat content reduction in the participants taking the nutraceutical rather than placebo (-48.2 ± 39 vs. -26.9 ± 43 dB/m, p = 0.02); The percentage CAP score reduction was statistically significant in those with android obesity, overweight/obesity as well as in women. However, after adjustment for weight change, the percentage CAP score reduction was statistically significant only in those over 50 years (44 vs. 78% in placebo and nutraceutical, respectively, p = 0.007). Conclusions: This specific nutraceutical containing bioactive components from Bergamot and wild cardoon reduced the liver fat content during 12 weeks in individuals with liver steatosis over 50 years. If confirmed, this nutraceutical could become the cornerstone treatment of patients affected by liver steatosis. Clinical Trial Registration: www.isrctn.com, identifier ISRCTN12833814.

Cardoon as a Sustainable Crop for Biomass and Bioactive Compounds Production

Cardoon is a multi-purpose and versatile Mediterranean crop, adapted to climate change, with a wide spectrum of potential applications due its added value as a rich source of fibers, oils and bioactive compounds. The Cynara species are a component of the Mediterranean diet and have been used as food and medicine since ancient times. The important role of cardoon in human nutrition, as a functional food, is due to its high content of nutraceutical and bioactive compounds such as oligofructose inulin, caffeoylquinic acids, flavonoids, anthocyanins, sesquiterpenes lactones, triterpenes, fatty acids and aspartic proteases. The present review highlights the characteristics and functions of cardoon biomass which permits the development of innovative products in food and nutrition, pharmaceutics and cosmetics, plant protection and biocides, oils and energy, lignocellulose materials, and healthcare industries following the actual trends of a circular economy.

Antiproliferative Effects of Cynaropicrin on Anaplastic Thyroid Cancer Cells

BACKGROUND

The sesquiterpene lactone cynaropicrin, a major constituent of the artichoke leaves extracts, has shown several biologic activities in many preclinical experimental models, including anti-proliferative effects.

OBJECTIVE

Herein we evaluated the effects of cynaropicrin on the growth of three human anaplastic thyroid carcinoma cell lines, investigating the molecular mechanism underlying its action.

METHOD

MTT assay was used to evaluate the viability of CAL-62, 8505C and SW1736 cells, and flow cytometry to analyse cell cycle distribution. Western blot was performed to detect the levels of STAT3 phosphorylation and NFkB activation. Antioxidant effects were analyzed by measuring the reactive oxygen species and malonyldialdehyde dosage was used to check the presence of lipid peroxidation.

RESULTS

Viability of CAL-62, 8505C and SW1736 cells was significantly reduced by cynaropicrin in a dose- and time-dependent way, with an EC50 of about 5 µM observed after 48 h of treatment with the compound. Cellular growth inhibition was accompanied both by an arrest of the cell cycle, mainly in the G2/M phase, and the presence of a significant percentage of necrotic cells. After 48 h of treatment with 10 µM of cynaropicrin, a reduced nuclear expression of NFkB and STAT3 phosphorylation were also revealed. Moreover, we observed an increase in lipid peroxidation, without any significant effect on the reactive oxygen species production.

CONCLUSION

These results demonstrate that cynaropicrin reduces the viability and promotes cytotoxic effects in anaplastic thyroid cancer cells associated with reduced NFkB expression, STAT3 phosphorylation and increased lipid peroxidation. Further characterization of the properties of this natural compound may open the way for using cynaropicrin as an adjuvant in the treatment of thyroid cancer.

Promotion of HeLa cells apoptosis by cynaropicrin involving inhibition of thioredoxin reductase and induction of oxidative stress

Cancer is considered as one of the highly mortal diseases globally. This is largely due to the lack of efficacious medicines for tumors, and thus development of potent anticancer agents is urgently needed. The thioredoxin (Trx) system is crucial to the survival ability of cells and its expression is up-regulated in many human tumors. Recently, increasing evidence has been established that mammalian thioredoxin reductase (TrxR), a selenocysteine-containing protein and the core component of the thioredoxin system, is a promising therapeutic target. The sesquiterpene lactone compound cynaropicrin (CYN), a major component of Cynara scolymus L., has shown multiple pharmacological functions, especially the anticancer effect, in many experimental models. Most of these functions are concomitant with the production of reactive oxygen species (ROS). Nevertheless, the target of this promising natural anticancer product in redox control has rarely been explored. In this study, we showed that CYN induces apoptosis of Hela cells. Mechanistic studies demonstrated that CYN impinges on the thioredoxin system via inhibition of TrxR, which leads to Trx oxidation and ROS accumulation in HeLa cells. Particularly, the cytotoxicity of CYN is enhanced through the genetic knockdown of TrxR, supporting the pharmacological effect of CYN is relevant to its inhibition of TrxR. Together, our studies reveal an unprecedented mechanism accounting for the anticancer effect of CYN and identify a promising therapeutic agent worthy of further development for cancer therapy.

Salicin from Alangium chinense Ameliorates Rheumatoid Arthritis by Modulating the Nrf2-HO-1-ROS Pathways

Rheumatoid arthritis (RA) is a chronic inflammatory disorder linked to oxidative stress of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs). The effects and potential mechanism of salicin on inflammation and oxidative stress of RA-FLSs were examined by MTT, ELISA, and Western blot methods. Salicin significantly reduced cell viability (82.03 ± 7.06, P < 0.01), cytokines (47.70 ± 1.48 ng/L for TNF-α, 30.03 ± 3.49 ng/L for IL-6) ( P < 0.01), and matrix metalloproteinases-1/-3 expression ( P < 0.01) in IL-1β-induced RA-FLSs and inhibited ROS generation and p65 phosphorylation ( P < 0.01) as compared with IL-1β-induced treatment. Moreover, salicin promoted Nrf2 nuclear translocation (2.15 ± 0.21) and HO-1 expression (1.12 ± 0.05) and reduced ROS production in IL-1β-induced RA-FLSs ( P < 0.01). Salicin not only reduced the collagen-induced arthritis by reducing the clinical score ( P < 0.01), inflammatory infiltration, and synovial hyperplasia in vivo but also suppressed the oxidative damage indexes (SOD 155.40 ± 6.53 U/mg tissue, MDA 152.80 ± 5.89 nmol/g tissue, GSH 50.98 ± 3.45 nmol/g tissue, and CAT 0.92 ± 0.10 U/g protein) ( P < 0.01) of ankle joint cells. Conclusively, our findings indicate that salicin ameliorates rheumatoid arthritis, which may be associated with oxidative stress and Nrf2-HO-1-ROS pathways in RA-FLSs.

Deep Eutectic Solvents as Efficient Media for the Extraction and Recovery of Cynaropicrin from Cynara cardunculus L. Leaves

In recent years a high demand for natural ingredients with nutraceutical properties has been witnessed, for which the development of more environmentally-friendly and cost-efficient extraction solvents and methods play a primary role. In this perspective, in this work, the application of deep eutectic solvents (DES), composed of quaternary ammonium salts and organic acids, as alternative solvents for the extraction of cynaropicrin from Cynara cardunculus L. leaves was studied. After selecting the most promising DES, their aqueous solutions were investigated, allowing to obtain a maximum cynaropicrin extraction yield of 6.20 wt %, using 70 wt % of water. The sustainability of the extraction process was further optimized by carrying out several extraction cycles, reusing either the biomass or the aqueous solutions of DES. A maximum cynaropicrin extraction yield of 7.76 wt % by reusing the solvent, and of 8.96 wt % by reusing the biomass, have been obtained. Taking advantage of the cynaropicrin solubility limit in aqueous solutions, water was added as an anti-solvent, allowing to recover 73.6 wt % of the extracted cynaropicrin. This work demonstrates the potential of aqueous solutions of DES for the extraction of value-added compounds from biomass and the possible recovery of both the target compounds and solvents.

Analgesic activity of cynaropicrinon on post-inflammatory irritable bowel syndrome visceral hypersensitivity in a rat model

Visceral hypersensitivity is one of the most common symptoms in patients with post-inflammatory-irritable bowel syndrome (PI-IBS). Enterochromaffin (EC) cells and 5-hydroxytryptamine (5-HT) are important in the development of visceral hyperalgesia, and EC cells are influenced by helper T-cell subtype 1 or 2 cytokine predominant environments. In the present study, the analgesic effect of cynaropicrin and its underlying mechanism on the treatment of trinitrobenzene sulfonic (TNBS)-induced PI-IBS visceral hyperalgesia rats was investigated. The results from the abdominal withdrawal reflex tests and electromyography recordings indicated that treatment with cynaropicrin significantly and dose-dependently alleviated the visceral hyperalgesia of PI-IBS rats (P<0.05). In addition, the increased colonic 5-HT content, colonic tryptophan hydroxylase expression, EC cell number and the cytokine levels, including tumor necrosis factor-α and interleukin-6 in PI-IBS rats were significantly alleviated by cynaropicrin (P<0.05). These data demonstrate that the analgesic activity of cynaropicrin on TNBS-induced PI-IBS visceral hypersensitive rats was mediated via reduction of cytokines levels. Thus, cynaropicrin as a bioactive natural product may offer promising therapeutic avenues for visceral hypersensitivity in IBS.

Screening of several biological activities induced by different sesquiterpene lactones isolated from Centaurea behen L. and Rhaponticum repens (L.) Hidalgo

This study aims to evaluate the in vitro cytotoxic, in vitro and in ovo anti-angiogenic effects and antimicrobial activity of sesquiterpene lactones (SLs) from two plants Centaurea behen and Rhaponticum repens (L.). Five SLs, including cynaropicrin (1), 4β,15-dehydro-3-dehydrosolstitialin A (2), aguerin B (3), janerin (4), cebellin E (5), and a flavone hispidulin (6) were isolated from C. behen (compounds 1-3) and R. repens (compounds 4-6). Cynaropicrin (1) and aguerin B (3) were characterised by strong cytotoxic activities against A2780 cells with IC₅₀ values of 1.15 and 1.62 μg mL^-1, respectively, comparable to that of doxorubicin (IC₅₀ = 1.17 μg mL^-1). The anti-angiogenic study showed the remarkable inhibitory effect of cynaropicrin (1) and aguerin B (3) on the proliferation and migration of HUVECs. In addition, cynaropycrin and aguerin B exhibited significant angio-inhibitory effects in CAM assay. These findings may be useful for the development of novel chemotherapeutic agents for the treatment of cancer.

Research progress on the direct antiviral drugs for hepatitis C virus

Hepatitis C, caused by the hepatitis C virus (HCV) that attacks the liver and leads to inflammation, is a severe threat to human health. Pegylated interferon α (INF-α) and ribavirin based therapy was once the standard therapy for HCV infection. However, it is suboptimal in efficacy and poorly tolerated in some patients. In the last five years, four classes of direct antiviral drugs (NAAs) that target non-structural proteins (NS) of the virus including NS3/NS4A, NS5A, and NS5B have been developed and opened a new era in HCV treatment as they are more effective and tolerable than the INF-α and ribavirin combination regimen. Importantly, the newly introduced multiple NAAs combination therapy makes it possible to eradicate all genotypes of HCV. We review recent progress on the research and development of DAAs in the present article.