Licochalcone A, a licorice flavonoid: antioxidant, cytotoxic, genotoxic, and chemopreventive potential

Exploration of formation and in vitro release mechanism of supramolecular self-assembled Licochalcone A eutectogel for food application

Licochalcone A (LCA) is extracted from licorice plants and used as a food additive. Citric acid (CA) and alanine (Ala) are food additives with good regulatory functions. This study aims to investigate the formation and in vitro release mechanism of the LCA eutectogel using supramolecular self-assembly technology. The mechanism of self-assembly indicates that the resulting eutectogel has strong intermolecular interactions. The formation mechanism of LCA eutectogel suggests that LCA is dispersed in nano form in the DES solution before self-assembly and dispersed in molecular form in the eutectogel after self-assembly. Mesoscopic MD simulation studies indicate that the interaction energy between LCA Ala-CA(5:5) eutectogel and the solvent interface is relatively low, suggesting it may have a better drug release rate, consistent with the in vitro release results. In conclusion, the study successfully prepares LCA eutectogel and provides theoretical guidance for the development and application of novel eutectogel for food application.

Network pharmacology and experimental verification of the mechanism of licochalcone A against Staphylococcus aureus pneumonia

Staphylococcus aureus strains cause the majority of pneumonia cases and are resistant to various antibiotics. Given this background, it is very important to discover novel host-targeted therapies. Licochalcone A (LAA), a natural plant product, has various biological activities, but its primary targets in S. aureus pneumonia remain unclear. Therefore, the purpose of this study was to identify its molecular target against S. aureus pneumonia. Network pharmacology analysis, histological assessment, enzyme-linked immunosorbent assays, and Western blotting were used to confirm the pharmacological effects. Network pharmacology revealed 33 potential targets of LAA and S. aureus pneumonia. Enrichment analysis revealed that these potential genes were enriched in the Toll-like receptor and NOD-like receptor signaling pathways. The results were further verified by experiments in which LAA alleviated histopathological changes, inflammatory infiltrating cells and inflammatory cytokines (TNF, IL-6, and IL-1β) in the serum and bronchoalveolar lavage fluid in vivo. Moreover, LAA treatment effectively reduced the expression levels of NF-κB, p-JNK, p-p38, NLRP3, ASC, caspase 1, IL-1β, and IL-18 in lung tissue. The in vitro experimental results were consistent with the in vivo results. Thus, our findings demonstrated that LAA exerts anti-infective effects on S. aureus-induced lung injury via suppression of the Toll-like receptor and NOD-like receptor signaling pathways, which provides a theoretical basis for understanding the function of LAA against S. aureus pneumonia and implies its potential clinical application.

Investigation of the combined cytotoxicity induced by sodium butyrate and a flavonoid quercetin treatment on MCF-7 breast cancer cells

Quercetin (QUE) belonging to the flavonoid class is a common phytochemical present in the daily diet of some individuals. Quercetin is an important source of free radical scavengers. This property makes this flavonoid a reliable antioxidant with the following properties: anti-inflammatory, anti-diabetic, antimicrobial and anti-carcinogenic. Sodium butyrate (NaBu) acts as a histone deacetylase inhibitor (HDACi) and is known to regulate apoptosis in cancer cells. Combining natural flavonoids such as QUE with different substances may synergistically enhance their anti-carcinogenic capacity. Thus, the aim of this study was to examine the combined treatment effects of QUE and NaBu in hormone-sensitive breast cancer cells in vitro. MCF-7 breast cancer cells were treated with QUE alone, NaBu alone, as well as QUE and NaBu combined to determine the following: cell proliferation, levels of protein annexin A5 (ANXA5) and reactive oxygen species (ROS), mRNA protein expression, as well as cell and nuclear morphology. Data demonstrated that either QUE or NaBu alone inhibited cell proliferation, and reduced levels protein ANXA5, ROS and mRNA protein expression, The combination of QUE and NaBu produced a significant synergistic inhibitory effect compared to treatment groups of QUE or NaBu alone. In conclusion, our findings showed that the combination treatment of QUE and NaBu may constitute a promising therapeutic approach to breast cancer treatment but this needs further molecular and in vivo investigations.

Toxicological and chemoprevention studies of Brazilian brown propolis from Araucaria sp

Brazilian brown propolis (BBP) is a natural product derived predominantly from the south region of Brazil, where Araucaria forests are dominant. Despite its potential as a source of bioactive compounds with leishmanicidal, anti-inflammatory, nociceptive, and antimicrobial properties, BBP has not been comprehensively studied compared to green propolis. Therefore, this study aimed to determine the safety and chemopreventive potential of BBP. The cytotoxicity attributed to BBP was assessed using two different assays, while the Salmonella/microsome assay was employed to evaluate mutagenicity. The acute toxicity attributed to BBP was determined using a zebrafish model, while the chemopreventive potential was investigated utilizing Chinese hamster lung (V79) cell lines. Data demonstrated that BBP exerted cytotoxic effects at concentrations greater than or equal to 10 µg/ml and did not exhibit mutagenicity in Salmonella typhimurium strains TA98 and TA100. However, at the highest concentration tested (4000 µg/plate), BBP induced a significant increase in revertant colonies in S. typhimurium TA102 strain. The LC50 equivalent to 8.83 mg/L was obtained in the acute toxicity evaluation in zebrafish. BBP also showed antigenotoxic effect by significantly reducing chromosomal damage induced by the mutagen doxorubicin in V79 cell cultures at a concentration of 2.5 μg/ml. Compared to Brazilian green and red propolis, BBP exhibited greater toxicity. On the other hand, at lower concentrations, BBP displayed chemopreventive potential, which may be associated with the antioxidant capacity of the extract. These findings contribute to a better understanding of the biological properties and potential applications of BBP in treating various diseases.

Licochalcone a improves cardiac functions after ischemia-reperfusion via reduction of ferroptosis in rats

Myocardial ischemia-reperfusion (I/R) injury triggers several cell death types, including apoptosis, autophagy, and ferroptosis. Licochalcone A (LCA), a natural flavonoid compound isolated from the root of Glycyrrhiza glabra, has been demonstrated to exert potential pharmacological benefits, such as antioxidant, antitumor, and anti-inflammatory activities. The present study aimed to investigate the involvement of ferroptosis in the pathogenesis of I/R and determine whether LCA can inhibit ferroptosis to prevent the myocardial I/R injury in rats. The effects of LCA on myocardial I/R injury were detected by examining the left ventricular-developed pressure and triphenyltetrazolium chloride staining. We conducted Western blotting analyses, ELISA assay, and quantitative real-time PCR to determine the levels of ferroptosis-related molecules. To demonstrate the cardioprotective effect of LCA in vitro, H9c2 and primary neonatal rat cardiomyocytes were co-treated with ferroptosis inducers (erastin, RSL3, or Fe-SP) and LCA for 16 and 24 h. Our ex vivo study showed that LCA increased the cardiac contractility, and reduced the infarct volume and ferroptosis-related biomarkers in rat hearts after I/R. Moreover, LCA reduced the levels of ferroptosis inducers-induced reactive oxygen species generation, lipid peroxidation, and ferroptosis-related biomarkers in cultured H9c2 cells and cardiomyocytes. LCA also reduced the Fe-SP-increased nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 protein levels in cultured cardiomyocytes. In the present study, we showed that the LCA-induced cardioprotective effects in attenuating the myocardial I/R injury were correlated with ferroptosis regulation, and provided a possible new therapeutic strategy for prevention or therapy of the myocardial I/R injury.

Luteolin photo-protects zebrafish from environmental stressor ultraviolet radiation (UVB)

Ultraviolet B wavelength ray radiation (UVB) is an environmental stressor with detrimental effects to the aquatic and human systems but also enhances adverse effects when combined with several other environmental factors such as temperature and pollution. UV rays induce cellular oxidative damage and impair motility. This study aimed to examine the photo-protective activity of flavonoid luteolin against UV-B irradiation-induced oxidative stress and cellular damage using zebrafish. An in-vivo photoaging model was established using UV-B irradiation in zebrafish larvae exposed to 100 mJ/cm2. Data demonstrated that UV-B irradiation of swimming water enhanced production of ROS and superoxide anions as well as depleted total glutathione levels in zebrafish larvae. UV-B irradiation also triggered cellular damage and membrane rupture in zebra fish. Further, 100 mJ/cm2 of UV-B radiation exposure to adult-wild type zebrafish co-exposed with intraperitoneally (ip) injected luteolin upregulated the local neuroendocrine axes by activating vascular endothelial growth factor (VEGF) and elevating levels of pro-inflammatory cytokines IL-1β and TNF-α. Histologically, UV-B irradiation induced skin lesions and locomotory defects with clumping and degeneration of brain glial cells. However, luteolin effectively inhibited the excess production of reactive oxygen species (ROS) and decreased superoxide anion levels induced by UV-B irradiation. Luteolin restored the depleted glutathione levels. In addition, luteolin blocked apoptosis and lipidperoxidation. Luteolin protected adult zebrafish by downregulating the pro-inflammatory cytokine protein expression levels and diminishing VEGF activation. Luteolin also alleviated locomotory defects by inhibiting activation of microglia and inflammatory responses by preventing accumulation of glial cells and vacuolation. Data demonstrate that luteolin may protect zebrafish from UV-B-induced photodamage through DNA-protective, antioxidant and anti-inflammatory responses.

Licochalcone A Induces Ferroptosis in Hepatocellular Carcinoma via Reactive Oxygen Species Activated by the SLC7A11/GPX4 Pathway

Liver cancer is a common malignant tumor, and its incidence is increasing yearly. Millions of people suffer from liver cancer annually, which has a serious impact on global public health security. Licochalcone A (Lico A), an important component of the traditional Chinese herb licorice, is a natural small molecule drug with multiple pharmacological activities. In this study, we evaluated the inhibitory effects of Lico A on hepatocellular carcinoma cell lines (HepG2 and Huh-7), and explored the inhibitory mechanism of Lico A on hepatocellular carcinoma. First, we evaluated the inhibitory effects of Lico A on hepatocellular carcinoma, and showed that Lico A significantly inhibited and killed HepG2 and Huh-7 cells in vivo and in vitro. Transcriptomic analysis showed that Lico A inhibited the expression of solute carrier family 7 member 11 (SLC7A11), which induced ferroptosis. We confirmed through in vivo and in vitro experiments that Lico A promoted ferroptosis in hepatocellular carcinoma cells by downregulating SLC7A11 expression, thereby inhibiting the glutathione (GSH)-glutathione peroxidase 4 (GPX4) pathway and inducing activation of reactive oxygen species (ROS). In this study, we suggest that Lico A is a potential SLC7A11 inhibitor that induces ferroptotic death in hepatocellular carcinoma cells, thereby providing a theoretical basis for the development of natural small molecule drugs against hepatocellular carcinoma.

Protective effects and DNA repair induction of a coumarin-chalcone hybrid against genotoxicity induced by mutagens

Coumarins and chalcones are compounds widely found in plants or obtained by synthetic methods which possess several biological properties including antioxidant, anti-inflammatory, and antitumor effects. A series of coumarin-chalcone hybrids were synthesized to improve their biological actions and reduce potential adverse effects. Considering the applications of these molecules, a coumarin-chalcone hybrid [7-methoxy-3-(E)-3-(3,4,5-trimethoxyphenyl) acryloyl-2 H-chromen-2-one] (4-MET) was synthesized and the genotoxic, cytotoxic, and protective effects assessed against damage induced by different mutagens. First, in silico tools were used to predict biological activity of 4-MET which indicated a chemopreventive potential. Subsequently, the genotoxic/antigenotoxic activities of 4-MET were determined both in vitro (Ames test) and in vivo (micronucleus (MN) test and comet assay). In addition, molecular docking simulations were performed between 4-MET and glutathione reductase, an important cellular detoxifying enzyme. Our results indicated that 4-MET was not mutagenic in the Ames test; however, when co-treated with sodium azide or 4-nitroquinoline 1-oxide (4-NQO), 4-MET significantly reduced the harmful actions of these mutagens. Except for a cytotoxic effect after 120 hr treatment, 4-MET alone did not produce cytotoxicity or genotoxicity in the MN test and comet assay. Nonetheless, all treatments of 4-MET with cyclophosphamide (CPA) showed a chemoprotective effect against DNA damage induced by CPA. Further, molecular docking analysis indicated a strong interaction between 4-MET and the catalytic site of glutathione reductase. These effects may be related to (1) damage prevention, (2) interaction with detoxifying enzymes, and (3) DNA-repair induction. Therefore, data demonstrated that 4-MET presents a favorable profile to be used in chemopreventive therapies.

Natural compounds targeting glycolysis as promising therapeutics for gastric cancer: A review

Gastric cancer, a common malignant disease, seriously endangers human health and life. The high mortality rate due to gastric cancer can be attributed to a lack of effective therapeutic drugs. Cancer cells utilize the glycolytic pathway to produce energy even under aerobic conditions, commonly referred to as the Warburg effect, which is a characteristic of gastric cancer. The identification of new targets based on the glycolytic pathway for the treatment of gastric cancer is a viable option, and accumulating evidence has shown that phytochemicals have extensive anti-glycolytic properties. We reviewed the effects and mechanisms of action of phytochemicals on aerobic glycolysis in gastric cancer cells. Phytochemicals can effectively inhibit aerobic glycolysis in gastric cancer cells, suppress cell proliferation and migration, and promote apoptosis, via the PI3K/Akt, c-Myc, p53, and other signaling pathways. These pathways affect the expressions of HIF-1α, HK2, LDH, and other glycolysis-related proteins. This review further assesses the potential of using plant-derived compounds for the treatment of gastric cancer and sheds insight into the development of new drugs.

Red propolis exhibits chemopreventive effect associated with antiproliferative and anti-inflammatory activities

INTRODUCTION

Red propolis is synthetized from exudates of Dalbergia ecastophyllum (L) Taub. and Symphonia globulifera L.f., presents isoflavones, guttiferone E, xanthochymol, and oblongifolin B and has anti-inflammatory, antioxidant, and antiproliferative activities.

OBJECTIVES

This study aimed to evaluate the antigenotoxic and anticarcinogenic potential of red propolis hydroalcoholic extract (RPHE) in rodents.

METHODS

The influence of RPHE in doxorubicin (DXR)-induced genotoxicity was investigated through the micronucleus test in Swiss mice. Blood samples were also collected to investigate oxidative stress, hepatotoxicity, and nephrotoxicity. Was investigated the influence of RPHE in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci, as well as its influence in proliferating cell nuclear antigen (PCNA) and the cyclooxygenase-2 (COX-2) expression in colon of rats, by immunohistochemistry.

RESULTS

The results showed that RPHE (48 mg/kg) reduced DXR-induced genotoxicity. Animals treated with DXR showed significantly lower GSH serum levels in comparison to the negative control. RPHE treatments did not attenuated significantly the DXR-induced GSH depletion. No difference was observed in cytotoxicity parameters of mice hematopoietic tissues between the treatment groups, as well as the biochemical parameters of hepatotoxicity and nephrotoxicity. RPHE (12 mg/kg) reduced the DMH-induced carcinogenicity and toxicity, as well as DMH-induced PCNA and COX-2 expression in colon tissue.

CONCLUSION

Therefore, was observed that the RPHE has chemopreventive effect, associated to antiproliferative and anti-inflammatory activities.

Therapeutic effects of shaogan fuzi decoction in rheumatoid arthritis: Network pharmacology and experimental validation

Shaogan Fuzi Decoction (SGFD), one of the classical prescriptions of Chinese Medicine, has a long history in the treatment of rheumatoid arthritis (RA), but definitive studies on its efficacy and mechanism of action are lacking. This study aims to elucidate the pharmacodynamic role of SGFD against RA and the potential mechanisms based on a combination of network pharmacology and experimental verification. The RA model in rats was induced by intradermal injection of bovine type Ⅱ collagen and incomplete Freund’s adjuvant at the tail root. SGFD was administered once a day by oral gavage for 4 weeks. After SGFD administration, rat’s arthritis index (AI) score and paw swelling decreased to some extent, and synovial inflammation, vascular hyperplasia, and cartilage destruction of the ankle joint were improved. Simultaneously, thymus and spleen index and serum levels of C-reactive protein (CRP) were lowered. Network pharmacology revealed that quercetin, kaempferol, naringenin, formononetin isorhamnetin and licochalcone A were the potentialiy active components, and IL6, TP53, TNF, PTGS2, MAPK3 and IL-1β were potential key targets for SGFD in the treatment of RA. Ingredients-targets molecular docking showed that the components had the high binding activity to these target proteins. The mechanism of SGFD for RA involves various biological functions and is closely correlated with TNF signaling pathway, Osteoclast differentiation, T cell receptor signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, NF-κB signaling pathway, toll-like receptor signaling pathway, and so on. Western blot and ELISA showed that the expression of toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB) p65, phosphorylated c-Jun N-terminal kinase (p-JNK), p-p38, phosphorylated extracellular regulated kinase (p-ERK) and TNF-α was significantly upregulated in the synovium of RA rats, and the levels of serum inflammatory factors were significantly increased. SGFD inhibits the activation of the TLR4/NF-κB/MAPK pathway and the expression/production of pro-inflammatory cytokines. In summary, SGFD could improve the symptoms and inflammatory response in collagen-induced arthritis (CIA) rat model. The mechanism might be related to the regulation of TLR4/MAPKs/NF-κB signaling pathway and the reduction of inflammatory factor release, which partially confirms the results predicted by network pharmacology.

Protective Effect of Resveratrol against Hexavalent Chromium-Induced Genotoxic Damage in Hsd:ICR Male Mice

The aim of this study is to examine the ability of resveratrol to counteract hexavalent chromium [Cr(VI)]-induced genetic damage, as well as the possible pathways associated with this protection. Hsd:ICR male mice are divided into groups of the following five individuals each: (a) control 1, distilled water; (b) control 2, ethanol 30%; (c) resveratrol, 50 mg/kg by gavage; (d) CrO₃, 20 mg/kg intraperitoneally; (e) resveratrol + CrO₃, resveratrol administered 4 h prior to CrO₃. The assessment is performed on peripheral blood. Micronuclei (MN) kinetics are measured from 0 to 72 h, while 8-hydroxydeoxyguanosine (8-OHdG) adduct repair levels, endogenous antioxidant system biomarkers, and apoptosis frequency were quantified after 48 h. Resveratrol reduces the frequency of Cr(VI)-induced MN and shows significant effects on the 8-OHdG adduct levels, suggesting that cell repair could be enhanced by this polyphenol. Concomitant administration of resveratrol and Cr(VI) results in a return of the activities of glutathione peroxidase and catalase to control levels, accompanied by modifications of superoxide dismutase activity and glutathione levels. Thus, antioxidant properties might play an important role in resveratrol-mediated inhibition of Cr(VI)-induced oxidant genotoxicity. The increase in apoptotic cells and the decrease in necrosis further confirmed that resveratrol effectively blocks the actions of Cr(VI).

Four new cycloartane-type triterpenoids from the leaves of Combretum mellifluum Eichler: assessment of their antioxidant and antileishmanial activities

The beneficial pharmacological actions including antioxidant effects as an antileishmanial, antibacterial, antifungal, antidiabetic, anti-inflammatory, antitumor, antiviral, and analgesic of compounds isolated from Combretum mellifluum Eichler (Combretaceae) are well established. The aim of the present study was to determine the phytochemistry as well as assess the antioxidant and antileishmanial activities of the leaves from Combretum mellifluum Eichler (Combretaceae). Analysis of ethanolic extract resulted in isolation and identification of two epimeric mixtures of four previously unknown cycloartane-type triterpenoids, methyl quadrangularate M and methyl 24-epiquadrangularate M, and 2α,3β,24β-trihydroxy-cycloart-25-ene and 2α, 3β, 24α-trihydroxy-cycloart-25-ene, and eight known compounds. Their structures were using one-dimensional nuclear magnetic resonance (1D NMR), 2D NMR and high-resolution electrospray ionization mass spectroscopy (HRESIMS) analysis. Further, the extract and fractions were tested for antioxidant potential. The ethyl acetate and aqueous fractions demonstrated the highest antioxidant activity against 2,2-dipheny-1-picrylhydrazl (DPPH) free radicals, which correlated directly with total flavonoid content. All extracts and fractions from C. mellifluum Eichler were assessed for antileishmanial activity. The supernatant fraction exhibited highest potential, inhibiting the growth of Leishmania amazonensis with IC₅₀ value 31.29 μg/ml. Our findings provide information on the chemical composition of C. mellifluum and the potential beneficial therapeutic usefulness as an antioxidant agent in various diseases.

Mechanisms of Penetration Enhancement and Transport Utilizing Skin Keratine Liposomes for the Topical Delivery of Licochalcone A

Keratin liposomes have emerged as a useful topical drug delivery system given theirenhanced ability to penetrate the skin, making them ideal as topical drug vehicles. However, the mechanisms of the drug penetration enhancement of keratin liposomes have not been clearly elucidated. Therefore, licochalcone A(LA)-loaded skin keratin liposomes (LALs) were prepared to investigate their mechanisms of penetration enhancement on the skin and inB16F10 cells. Skin deposition studies, differential scanning calorimetry (DSC), attenuated total reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and skin distribution and intracellular distribution studies were carried out to demonstrate the drug enhancement mechanisms of LALs. We found that the optimal application of LALs enhanced drug permeation via alterations in the components, structure, and thermodynamic properties of the stratum corneum (SC), that is, by enhancing the lipid fluidization, altering the skin keratin, and changing the thermodynamic properties of the SC. Moreover, hair follicles were the main penetration pathways for the LA delivery, which occurred in a time-dependent manner. In the B16F10 cells, the skin keratin liposomes effectively delivered LA into the cytoplasm without cytotoxicity. Thus, LAL nanoparticles are promising topical drug delivery systems for pharmaceutical and cosmetic applications.

Licochalcone A Promotes the Ubiquitination of c-Met to Abrogate Gefitinib Resistance

Met proto-oncogene (MET) amplification and tyrosine-protein kinase Met (c-Met) overexpression confer gefitinib resistance in non-small cell lung cancer (NSCLC). The natural product Licochalcone A (Lico A) exhibits a broad range of inhibitory effects against various tumors. However, the effects of Lico A on c-Met signaling and gefitinib resistance in NSCLC remain unclear. In the present study, Lico A efficiently overcame gefitinib-acquired resistance in NSCLC cells by suppressing c-Met signaling. Lico A decreased cell viability and colony formation dose-dependently and impaired in vivo tumorigenesis of gefitinib-resistant HCC827 and PC-9 cells. Furthermore, Lico A induced intrinsic apoptosis and upregulated the protein expression levels of cleaved poly (ADP-ribose) polymerase and cleaved caspase 3. Lico A promoted the interaction between c-Met and E3 ligase c-Casitas B-lineage lymphoma (Cbl), which enhanced c-Cbl-mediated c-Met ubiquitination and degradation. Depletion of c-Cbl compromised Lico A-induced c-Met ubiquitination and its inhibitory efficacy in gefitinib-resistant NSCLC cells. Taken together, the results suggest that Lico A is a promising antitumor agent that might be used to overcome c-Met overexpression-mediated gefitinib resistance in NSCLC cells.

Development of Peptide Targeted PLGA-PEGylated Nanoparticles Loading Licochalcone-A for Ocular Inflammation

Licochalcone-A is a natural compound with anti-inflammatory properties. However, it possesses low water solubility, making its application for the treatment of ocular inflammation difficult. To overcome this drawback, biodegradable nanoparticles incorporating Licochalcone-A have been developed. Additionally, to avoid fast clearance and increase cellular internalization into the ocular tissues, PLGA nanoparticles have been functionalized using PEG and cell penetrating peptides (Tet-1 and B6). To optimize the formulations, a factorial design was carried out and short-term stability of the nanoparticles was studied. Moreover, morphology was also observed by transmission electron microcopy and in vitro drug release was carried out. Ocular tolerance of the formulations was ensured in vitro and in vivo and anti-inflammatory therapeutic efficacy was also assessed. Surface functionalized nanoparticles loading Licochalcone-A were developed with an average size below 200 nm, a positive surface charge, and a monodisperse population. The formulations were non-irritant and showed a prolonged Licochalcone-A release. Despite the fact that both Licochalcone-A Tet-1 and B6 functionalized nanoparticles demonstrated to be suitable for the treatment of ocular inflammation, B6 targeted nanoparticles provided greater therapeutic efficacy in in vivo assays.

Modulating effect of DL-kavain on the mutagenicity and carcinogenicity induced by doxorubicin in Drosophila melanogaster

Kavain, kavalactone, present in Piper methysticum exhibits anticonvulsive, analgesic, anxiolytic, antiepileptic, antithrombotic, anti-inflammatory and antioxidant properties. Given its importance, the aim of the present study was to assess (1) the mutagenic and carcinogenicity of kavain administered alone and (2) the antimutagenic and anticarcinogenic potential when administered simultaneously with the chemotherapeutic drug doxorubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) and Epithelial Tumor Test (ETT) using Drosophila melanogaster as a model system. Third-stage larvae from a standard (ST) and high metabolic bioactivation (HB) crosses were treated with different kavain concentrations (32, 64 or 128 μg/ml), alone or in conjunction with DXR (0.125 mg/ml). In ST descendants, kavain produced no significant mutagenic or recombinogenic effects. In the HB cross, mutagenic activity was observed at kavain concentrations of 64 and 128 μg/ml. In the DXR and kavain co-treatment, a modulating effect of the DXR-mediated mutagenic response dependent upon the concentration was detected in both crosses. In ETT, no marked carcinogenic or anticarcinogenic activity was noted for kavain. However, when kavain was combined with DXR synergistic induction of tumors by the chemotherapeutic drug occurred indicating that kavain enhanced the carcinogenic action of DXR.

Licochalcone A inhibits MAS-related GPR family member X2-induced pseudo-allergic reaction by suppressing nuclear migration of nuclear factor-κB

Licochalcone A (Lico A) is a natural flavonoid belonging to the class of substituted chalcone that has various biological effects. Mast cells (MCs) are innate immune cells that mediate hypersensitivity and pseudo-allergic reactions. MAS-related GPR family member X2 (MRGPRX2) on MCs has been recognized as the main receptor for pseudo-allergic reactions. In this study, we investigated the anti-pseudo-allergy effect of Lico A and its underlying mechanism. Substance P (SP), as an MC activator, was used to establish an in vitro and in vivo model of pseudo-allergy. The in vivo effect of Lico A was investigated using passive cutaneous anaphylaxis (PCA) and active systemic allergy, along with degranulation, Ca²⁺ influx in vitro. SP-induced laboratory of allergic disease 2 (LAD2) cell mRNA expression was explored using RNA-seq, and Lico A inhibited LAD2 cell activation by reverse transcription polymerase chain reaction (RT-PCR), western blotting, and immunofluorescence staining. Lico A showed an inhibitory effect on SP-induced MC activation and pseudo-allergy both in vitro and in vivo. The nuclear factor (NF)-κB pathway is involved in MRGPRX2 induced MC activation, which is inhibited by Lico A. In conclusion, Lico A inhibited the pseudo-allergic reaction mediated by MRGPRX2 by blocking NF-κB nuclear migration.

Licochalcone B attenuates neuronal injury through anti-oxidant effect and enhancement of Nrf2 pathway in MCAO rat model of stroke

BACKGROUND

Investigating anti-oxidant therapies that lead to the diminution of oxidative injury is priority in clinical. We herein aimed to explore whether and how Licochalcone B (Lico B) act as an anti-oxidant in the stroke model.

METHODS

Middle cerebral artery occlusion (MCAO) was constructed as stroke model and exposed to various doses of Lico B. Behavioral tests and neurological behavior status were detected for neurological function examination. Histological staining was used for evaluating cerebral injury, and neuronal apoptosis or damage. Levels of oxidative stress and inflammation were also assessed by biochemical analysis and expression analysis. Nrf2 knockdown induced by lentiviral vector was used for the research on mechanism.

RESULTS

Lico B had improvement effects on cerebral infarction size, memory impairments, and neurological deficits after MCAO. Histological evaluation also revealed the amelioration of neuronal injury and apoptosis by Lico B, along with down-regulation of apoptosis-related proteins. Additionally, Lico B rescued the down-regulation of BDNF and NGF after MCAO. Moreover, Lico B suppressed the oxidative stress and inflammation, manifesting as the enhancement of SOD, GSH and IL-4, but the decline of MDA, iNOS, and TNF-α. Finally, Nrf2 knockdown reversed the Lico B-caused improvement in neuronal injury, apoptosis and oxidative stress levels.

CONCLUSIONS

The present study revealed the neuroprotective effects of Lico B in MCAO rats. Importantly, we proposed a potential mechanism that Lico B activated the Nrf2 pathway, thereby acting as anti-oxidant to attenuate neuronal injury and apoptosis after stroke. The proposed mechanism provided an encouraging possibility for anti-oxidant therapy of stroke.

Styrax camporum, a typical species of the Brazilian cerrado, attenuates DNA damage, preneoplastic lesions and oxidative stress in experimental rat colon carcinogenesis

Styrax camporum Pohl, a typical species from the Brazilian cerrado, commonly known as "benjoeiro", is used to treat gastroduodenal diseases. In previous studies carried out by our research group, hydroalcoholic extract of S. camporum stems (SCHE) exhibited antigenotoxic and antiproliferative effects. For a comparative analysis of the chemopreventive effect of SCHE, the aim of this study was to investigate the influence of SCHE against carcinogen 1,2-dimethylhydrazine (DMH)-induced DNA damage and pre-neoplastic lesions in Wistar rat colon. Animals were treated orally with SCHE at 250, 500 or 1000 mg/kg body weight in conjunction with a subcutaneous injection of DMH. DNA damage was assessed using the comet assay while tpre-neoplastic lesions by aberrant crypt foci (ACF) assay. The following hepatic oxidative stress markers were determined including activities of catalase (CAT) and glutathione S-transferase (GST) as well as levels of reduced glutathione (GSH) and malondialdehyde (MDA). Treatment with SCHE was not genotoxic or carcinogenic at the highest dose tested (1000 mg/kg b.w.). The extract effectively inhibited DNA damage and pre-neoplastic lesions induced by DMH administration at all concentrations tested. Measurement of CAT, and GST activities and levels of GSH showed that SCHE did not reduce oxidative processes. In contrast, treatment with SCHE (1000 mg/kg b.w.) decreased liver MDA levels. Taken together, these findings suggested the chemopreventive effect attributed to SCHE in colon carcinogenesis, may be related to its capacity to inhibit DNA damage as well as an antioxidant action associated with its chemical constituents egonol and homoegonol.

Genotoxicity induced by nerol, an essential oil present in citric plants using human peripheral blood mononuclear cells (PBMC) and HepG2/C3A cells as a model

Nerol (cis-3,7-dimethyl-2,6-octadien-1-ol) is a monoterpene widely used in cosmetic products, household detergents and cleaners, as well as a flavoring in several food products. Despite the high level of human exposure to nerol, an absence of studies regarding potential genetic toxicity in human cells exists. The aim of this investigation was to examine the cytotoxic and genotoxic potential of this monoterpene on human peripheral blood mononuclear cells as well as hepatic metabolizing HepG2/C3A human cell line. Cytotoxicity was assessed using trypan blue staining and MTT assay while genotoxicity was determined utilizing the comet and micronucleus test. Cytotoxicity tests showed cell viability greater than 70% for concentrations between 2.5 and 500 µg/ml. Both cell types exhibited significant DNA damage and chromosomal mutations after medium and high concentration incubation with nerol indicating that the safety of use of this monoterpene in various formulations to which humans are exposed needs to be monitored and requires more comprehensive investigations.

Anti-inflammatory mechanisms of fruits and by-products from Mauritia flexuosa, an exotic plant with functional benefits. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2021;84:441-457. [PMID: 33641623 DOI: 10.1080/15287394.2021.1881672]

Mauritia flexuosa L., traditionally known as "buriti", exhibits chemoprotective properties including antioxidant, antithrombotic, and nutritional actions. The aim of this study was to examine the oral anti-inflammatory activity of epicarp, mesocarp and endocarp obtained from M. flexuosa fruits using in vivo models to verify physiological benefits. The anti-edematogenic action was determined using phlogistic agents to induce paw edema and peritonitis. Pro-inflammatory cytokines, cell migration of peritoneal cells, histological changes, and abdominal swelling induced by acetic acid were also investigated. Carrageenan-induced edema was found to be decreased in mice pre-treated with epicarp by 50.8%, 53.7% and 39.2% and mesocarp by 41.8%, 65.3% and 71.9% after 2, 3, and 4 hr stimuli, respectively. Edema initiated by specific agents such as compound 48/80, histamine, serotonin, and prostaglandin E₂ were also reduced, and better outcomes were found against histamine-induced edema, as evidenced by the decline at all times analyzed (30-120 min) with both doses of water extract of mesocarp (500 or 1000 mg/kg). Mesocarp-pre-treatment reduced inflammatory tissue parameters such as number of peritoneal leukocytes and TNF-α levels, but only epicarp diminished abdominal pain. In summary, M. flexuosa fruits, especially mesocarp, exhibited oral physiological benefits and capacity to modify biochemical and cellular steps in the inflammatory cascade, indicating that dietary supplements containing these fruits may be combined with pharmacological tools to ameliorate or prevent diseases of inflammatory origin.

Phytochemical screening, phenolic and flavonoid contents, antioxidant and cytogenotoxicity activities of Combretum leprosum Mart. (Combretaceae)

Combretum leprosum Mart. (Combretaceae), a shrub popularly known as mofumbo, is used in folk medicine for treatment of uterine bleeding, pertussis, gastric pain, and as a sedative. The aim of this study was to (1) determine the phytochemical profile,(2) identify chemical constituents and (3) examine antioxidant and cytogenotoxic activity of ethanolic extracts and fractions of stem bark and leaves. The plant material (leaf and stem bark) was submitted to extraction with ethanol, followed by partition using hexane, chloroform, and ethyl acetate. It was possible to identify and quantify the epicatechin in the ethanolic stem bark extract (0.065 mg/g extract) and rutin in the leaf extract (3.33 mg/g extract). Based upon in vitro tests a significant relationship was noted between findings from antioxidant tests and levels of total phenolic and flavonoid. Comparing all samples (extracts and fractions), the ethyl acetate fractions of stem bark (411.40 ± 15.38 GAE/g) and leaves (225.49 ± 9.47 GAE/g) exhibited higher phenolic content, whereas hexanic fraction of stem bark (124.28 ± 56 mg/g sample) and ethyl acetate fraction of leaves (238.91 ± 1.73 mg/g sample) demonstrated a higher content of flavonoids. Among the antioxidant tests, the intermediate fraction of stem bark (28.5 ± 0.60 μg/ml) and ethyl acetate fraction of leaves (40 ± 0.56 μg/ml) displayed a higher % inhibition of free radical DPPH activity, whereas intermediate fraction of stem bark (27.5 ± 0.9 μg/ml) and hydromethanol fraction of leaves (81 ± 1.4 μg/ml) demonstrated inhibition of the free radical ABTS. In biological tests (Allium cepa and micronucleus in peripheral blood), data showed that none of the tested concentrations of ethanolic extracts of leaves and stem bark produced significant cytotoxicity, genotoxicity, and mutagenic activity.Abbreviations AA%: percentage of antioxidant activity; ABTS: 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid); CEUA: Ethics Committee in the Use of Animals; TLC: Thin Layer Chromatography; DNA: deoxyribonucleic acid; DPPH: 1,1-diphenyl-2-picrylhydrazyl; ROS: Reactive oxygen species; EEB: ethanol extract of the stem bark; HFB: Hexanic fraction of stem bark; IFB: Intermediate fraction of stem bark; CFB: Chloroform fraction of stem bark; EAFB: Ethyl acetate fraction of stem bark; HMFB: Hydromethanol fraction of the stem bark; EEL: Ethanol extract from leaves; HFL: Hexane fraction of leaves; CFL: Chloroform fraction of leaves; EAFL: Ethyl acetate fraction of leaves; HMFL: Hydromethanol fraction of leaves; GAE: Gallic Acid Equivalent; IC₅₀: 50% inhibition concentration; HCOOH: Formic acid; HCl: hydrochloric acid; HPLC: High-performance liquid chromatography; MN: micronucleus; WHO: World Health Organization; UFLC: Ultra-Fast Liquid Chromatography; UESPI: State University of Piauí.

Recombinogenic, genotoxic, and cytotoxic effects of azathioprine using in vivo assays

Azathioprine (Aza) is a purine antimetabolite immunosuppressant that is widely employed for immunosuppressive therapy in post-transplant recipients or patients with autoimmune diseases. Chronic use of immunosuppressants might produce several side effects, including a high rate of neoplasms in these patients. Considering that genotoxic effects are associated with an increased risk of developing cancer, the aim of this study was to examine the recombinogenic, genotoxic, and cytotoxic effects of Aza using Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster, as well as comet and micronucleus assays in mouse bone marrow cells. Further, the adverse effects of Aza were determined in mouse hepatic and renal tissues using histopathological analysis. Data demonstrated that Aza induced significant increased genotoxicity in D. melanogaster and mouse bone marrow cells at all concentrations tested. Homologous recombination was the predominant genotoxic event noted for the first time to be initiated by Aza in SMART. In histopathological analysis, Aza did not show any marked toxic activity in mouse hepatic and renal tissues. Therefore, the high rate of neoplasms reported in patients with long-term use of Aza may be attributed, at least partially, to the genotoxic action of this drug.

Cellular and biochemical antileukemic mechanisms of the meroterpenoid Oncocalyxone A

Oncocalyxone A, a 1,4-benzoquinone derived from Cordia oncocalyx, exhibits anti-inflammatory, antimicrobial and antidiabetic properties. The aim of this study was to (1) examine the cytotoxic actions of oncocalyxone A on human normal and tumor cell lines and (2) determine mechanistic actions underlying effects upon leukemia cells using cellular and molecular techniques. Antiproliferative studies on cancer cell lines, peripheral blood mononuclear cells, and human erythrocytes were performed using colorimetric assays. To understand cytotoxicity, assessments were performed with HL-60 leukemia cells (8, 16.5, or 33 µM) after 24 hr incubation using light and fluorescence microscopy, trypan blue, flow cytometry, Comet assay, western blot of caspases and poly-ADP-ribose polymerase (PARP), and effects on topoisomerase I and II. Oncocalyxone A exhibited cytotoxic action upon HL-60 cells and dividing leukocytes, but minimal hemolytic action on erythrocytes. Mechanistic investigations demonstrated reduction of cell viability, loss of membrane integrity, cell shrinking, chromatin condensation, blebbings, externalization of phosphatidylserine, caspase activation, PARP cleavage, mitochondrial depolarization, and DNA damage. Pre-treatment with N-acetylcysteine 4 mM significantly reduced DNA damage and prevented membrane integrity loss. Oncocalyxone A displayed free radical dependent antileukemic activity via apoptotic pathways and induced DNA damage in HL-60 cells. Oncocalyxone A possesses structural chemical simplicity enabling it to be a cost-effective alternative. These properties justify further improvements to enhance activity and selectivity and the development of pharmaceutical formulations. Abbreviations Acridine orange, AO; ANOVA, analysis of variance; BSA, bovine serum albumin; DI, Damage Index; DMSO, dimethylsulfoxide; EC₅₀, effective concentration 50%; EDTA, ethylenediamine tetraacetic acid; EB, ethidium bromide; HCT-116, colon carcinoma line; HL-60, promyelocytic leukemia line; IC₅₀, inhibitory concentration 50%; MTT, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide; OVCAR-8, ovarian carcinoma line; NAC, N-acetylcysteine, PBMC, peripheral blood mononuclear cells; PBS, phosphate-buffered saline; PI, propidium iodide; PARP, poly-ADP-ribose polymerase; RPMI-1640, Roswell Park Memorial Institute medium; SF-295, glioblastoma line; ROS, reactive oxygen species; 7-AAD, 7-amino-actinomycin D; H₂-DCF-DA, 7'-dichlorodihydrofluorescein diacetate.