Hinokiflavone resists HFD-induced obesity by promoting apoptosis in an IGF2BP2-mediated Bim m6A modification dependent manner.

Obesity has emerged as a major health risk on a global scale. Hinokiflavone (HF), a natural small molecule, extracted from plants like cypress, exhibits diverse chemical structures and low synthesis costs. Using high-fat diet-induced obese mice models, we found that HF suppresses obesity by inducing apoptosis in adipose tissue. Adipocyte apoptosis helps maintain tissue health by removing aging, damaged, or excess cells in adipose tissue, which is crucial in preventing obesity and metabolic diseases. We found that HF can specifically bind to insulin-like growth factor 2 mRNA binding protein 2 to promote the stability of N6-methyladenosine-modified Bim, inducing mitochondrial outer membrane permeabilization. Mitochondrial outer membrane permeabilization leads to Caspase9/3-mediated adipocyte mitochondrial apoptosis, alleviating obesity induced by a high-fat diet. The proapoptotic effect of HF offers a controlled means for weight loss. This study reveals the potential of small molecule HF in developing new therapeutic approaches in drug development and biomedical research.

Hinokiflavone Attenuates the Virulence of Methicillin-Resistant Staphylococcus aureus by Targeting Caseinolytic Protease P.

Drug-resistant bacteria was the third leading cause of death worldwide in 2019, which sounds like a cautionary note for global public health. Therefore, developing novel strategies to combat Methicillin-resistant Staphylococcus aureus (MRSA) infections is the need of the hour. Caseinolytic protease P (ClpP) represents pivotal microbial degradation machinery in MRSA involved in bacterial homeostasis and pathogenicity, considered an ideal target for combating S. aureus infections. Herein, we identified a natural compound, hinokiflavone, that inhibited the activity of ClpP of MRSA strain USA300 with an IC50 of 34.36 µg/mL. Further assays showed that hinokiflavone reduced the virulence of S. aureus by inhibiting multiple virulence factors expression. Results obtained from cellular thermal transfer assay (CETSA), thermal shift assay (TSA), local surface plasmon resonance (LSPR) and molecular docking (MD) assay enunciated that hinokiflavone directly bonded to ClpP with confirmed docking sites, including SER-22, LYS-26 and ARG-28. In vivo, the evaluation of anti-infective activity showed that hinokiflavone in combination with vancomycin effectively protected mice from MRSA-induced fatal pneumonia, which was more potent than vancomycin alone. As mentioned above, hinokiflavone, as an inhibitor of ClpP, could be further developed into a promising adjuvant against S. aureus infections.

Hinokiflavone, as a MDM2 inhibitor, activates p53 signaling pathway to induce apoptosis in human colon cancer HCT116 cells.

Hinokiflavone (HF), a natural biflavonoid that possesses various biological activities, has reported that HF could be a pre-mRNA splicing modulator, whereas its underlying mechanisms remain elusive. In the present study, we identified HF as a potential MDM2 inhibitor. What's more, we found that HF suppressed mdm2 mRNA synthesis at the transcriptional level. Then, this MDM2 inhibition led in turn to increase p53 protein expression and activate p53 pathway, which could decrease the survival of HCT116 colon cells by G2/M phase arrest and apoptosis induction. Then, bioinformatics suggested that ESR1 was a predicted and potential target of HF. Finally, we used molecular docking and molecular dynamics simulation to demonstrate the binding patterns of HF and ESR1. To sum up, our study unearthed that HF was a feasible agent for MDM2 inhibitor through down-regulating mdm2 RNA level and activating p53 signaling pathway.

Bioactivity of natural biflavonoids in metabolism-related disease and cancer therapies.

Natural biflavonoids, such as amentoflavone, bilobetin, ginkgetin, isoginkgetin, taiwaniaflavone, morelloflavone, delicaflavone, hinokiflavone, and other derivatives (~ 40 biflavonoids), are isolated from Selaginella sp., Ginkgo biloba, Garcinia sp., and several other species of plants. They are able to exert therapeutic benefits by regulating several proteins/enzymes (PPAR-γ, CCAAT/enhancer-binding protein α [C/EBPα], STAT5, pancreatic lipase, PTP1B, fatty acid synthase, α-glucosidase [AG]) and insulin signaling pathways (via PI3K-AKT), which are linked to metabolism, cell growth, and cell survival mechanisms. Deregulated insulin signaling can cause complications of obesity and diabetes, which can lead to cognitive disorders such as Alzheimer's, Parkinson's, and dementia; therefore, the therapeutic benefits of these biflavones in these areas are highlighted. Since biflavonoids have shown potential to regulate metabolism, growth- and survival-related protein/enzymes, their relation to tumor growth and metastasis of cancer associated with angiogenesis are highlighted. The translational role of biflavones in cancer with respect to the inhibition of metabolism-related processes/pathways, enzymes, or proteins, such as STAT3/SHP-1/PTEN, kinesins, tissue kallikreins, aromatase, estrogen, protein modifiers, antioxidant, autophagy, and apoptosis induction mechanisms, are discussed. Finally, considering their observed bioactivity potential, oral bioavailability studies of biflavones and related clinical trials are outlined.

Hinokiflavone induces apoptosis via activating mitochondrial ROS/JNK/caspase pathway and inhibiting NF-κB activity in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the sixth most common malignancy with limited treatment options. Hinokiflavone (HF), a natural biflavonoid, has shown to inhibit the proliferation of melanoma, whereas its antitumour effect against HCC and the underlying mechanisms remain elusive. Here, we aimed at evaluating its antitumour effect against HCC in both in vitro and in vivo. Cell counting kit 8, colony formation assay, PI/RNase staining and Western blotting revealed that HF inhibited the proliferation of HCC cells via G0/G1 cell cycle arrest with p21/p53 up-regulation. DAPI staining, Annexin V-FITC/PI staining and Western blotting confirmed that HF triggered caspase-dependent apoptosis. Moreover, HF increased the levels of mitochondrial reactive oxygen species (mtROS) and activated c-Jun N-terminal kinase (JNK) pathway, as measured by MitoSOX Red staining and Western blotting. After respectively inhibiting mtROS (Mito-TEMPO) and JNK (SP600125), HF-induced apoptosis was reversed. Additionally, Western blotting documented that HF suppressed nuclear factor kappa B (NF-κB) activity and the anti-apoptotic genes downstream, contributing to cell apoptosis. Finally, in vivo studies demonstrated that HF significantly impaired tumour growth in HCC xenograft. Collectively, these findings suggested that HF induced apoptosis through activating mtROS/JNK/caspase pathway and inhibiting NF-κB signalling, which may represent a novel therapeutic agent for treating HCC.

Hinokiflavone induces apoptosis and inhibits migration of breast cancer cells via EMT signalling pathway.

Hinokiflavone is a natural product, isolated from Selaginella P. Beauv, Juniperus phoenicea and Rhus succedanea. Even though hinokiflavone was reported to possess cytotoxicity to many cancer cells, and has potential in cancer treatment, the anti-proliferation and anti-metastasis efficacy of hinokiflavone on human breast cancer cells has not a further research. In this study, we investigated the anti-cancer activity of hinokiflavone in human breast cancer cells in vitro and in vivo. Hinokiflavone exhibited a time- and dose-dependent manner apoptosis induction by upregulating expression of Bax and downregulating Bcl-2 in breast cancer cells. Furthermore, hinokiflavone significantly inhibited the migration and invasion of breast cancer cells by impairing the process of epithelial-to-mesenchymal transition. In addition, the tumour growth was distinctly inhibited by treatment of hinokiflavone in a xenograft tumour mouse model of MDA-MB-231 cells. Immunohistochemical analysis of tumour sections showed that MMP-2+ cells and Ki-67+ cells were remarkably decreased in tumour tissues of mice after treatment of hinokiflavone, indicating that hinokiflavone inhibits not only proliferation but also metastasis of breast cancer cells. Our study suggested that hinokiflavone can be a potential drug to breast cancer. SIGNIFICANCE OF THE STUDY: Hinokiflavone significantly inhibited proliferation and induced apoptosis in breast cancer cells. In addition, hinokiflavone remarkably inhibited migration and invasion of breast cancer cells via EMT signalling pathway. It is worth noting that hinokiflavone possesses anti-tumour effect in tumour mouse xenograft model of breast cancer. Overall, our results indicated that hinokiflavone may be a potential anticancer drug for breast cancer treatment.

Antitumor activity in colorectal cancer induced by hinokiflavone.

BACKGROUND AND AIM: Colorectal cancer is one of the most common malignant disease worldwide with highly metastatic potential. Identification of effective therapeutic treatment overcoming such disease is an urgent need. Our study focuses on hinokiflavone as an antitumor agent against colorectal cancer. METHODS: MTT assay, cell colony formation assay, Hoechst staining, flow cytometry, Western blot analysis, real-time polymerase chain reaction, and migration and invasion assay were performed to identify the effects of hinokiflavone on cell proliferation, apoptosis, and metastasis. CT26 tumor-bearing mice model was conducted to explore the antitumor activity of hinokiflavone in vivo. Immunohistochemistry staining was used to detect the protein expression of Ki-67, cleaved caspase-3, and MMP9 in treated tumors. Acute toxicity was evaluated by serological and hematological analyses, and drug side effect on organs was evaluated by hematoxylin and eosin staining. RESULTS: Hinokiflavone reduced the proliferation, migration, and invasion and promoted the apoptosis in colorectal tumor cells in vitro. Treatment of hinokiflavone at a tolerable and safe dose (50 mg/kg) significantly suppressed tumor growth in mice bearing CT26 tumors by reducing tumor proliferation and metastasis and inducing apoptosis. Mechanically, treatment of hinokiflavone induced apoptosis by loss of mitochondrial transmembrane potential and increased reactive oxygen species generation. CONCLUSIONS: Hinokiflavone suppressed colorectal tumor cell proliferation, induced apoptosis via the reactive oxygen species-mitochondria-mediated apoptotic pathway, and inhibited tumor cell migration and invasion. Antitumor activity of hinokiflavone was also validated in mice model without observed toxicity. Our findings suggested that the plant-derived hinokiflavone could be used as an antitumor agent against colorectal cancer.

Ionic Liquid-Microwave-Based Extraction of Biflavonoids from Selaginella sinensis.

Selaginella sinensis (Desv.) Spring has been used for many years as traditional Chinese medicine (TCM) for many years. Recently, ionic liquids (ILs) have attracted great attentions in extraction and separation technology of TCM as a new green solvent. In this paper, microwave assisted extraction-IL (MAE-IL) that extracted amentoflavone (AME) and hinokiflavone (HIN) from Selaginella sinensis was reported for the first time. The contents of two biflavonoids were simultaneously determined by a high performance liquid chromatography (HPLC) method. After different ionic liquids were compared, it was found [C6mim]BF4 had a high selectivity and efficiency. Moreover, the important extraction conditions, including solid-liquid ratio, IL concentration, extraction time, microwave power and radiation temperature, were also investigated and optimized by response surface methodology (RSM) using AME and HIN yields as index. The results showed that the extraction yields of AME and HIN from S. sinensis were 1.96 mg/g and 0.79 mg/g, respectively, under the optimal process parameters (0.55 mmol/L, 300 W, 40 min, 1:11 g/mL and 48 °C). Compared with the conventional extraction methods, MAE-IL could not only achieve higher yield in shorter time, but also could reduce the consumption of solvent. This effective, rapid and green MAE-IL method was suitable for the extraction of AME and HIN.

Biflavonoids Isolated from Selaginella tamariscina and Their Anti-Inflammatory Activities via ERK 1/2 Signaling.

Selaginella tamariscina (S. tamariscina) (Beauv.) Spring (Selaginellaceae) has been used in oriental medicine for the treatment of dysmenorrhea, chronic hepatitis, hyperglycemia, amenorrhea, hematuria, prolapse of the anus and metrorrhagia. In the present study, we isolated two strong anti-inflammatory compounds, the biflavonoids hinokiflavone (H) and 7'-O-methyl hinokiflavone (mH), from S. tamariscina and examined their anti-inflammatory activities in lipopolysaccharide (LPS)-mediated murine macrophages (RAW 264.7) and colon epithelial cells (HT-29). H and mH suppressed the production of the inflammatory mediators nitric oxide (NO), interleukin (IL)-6, IL-8, and tumor-necrosis factor (TNF)-α, which are most highly activated in inflammatory bowel disease (IBD). In addition, Western blot analysis revealed that H and mH suppressed the LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, and the activation of nuclear factor-κB (NF-κB) and extracellular regulated kinases (ERK) 1/2. These results suggest that H and mH are compounds having potent anti-inflammatory effects that could be used to treat such diseases as IBD.

Evaluation of the hepatoprotective effect of combination between hinokiflavone and Glycyrrhizin against CCl4 induced toxicity in rats.

Liver diseases are one of the fatal syndromes due to the vital role of the liver. Most of the effective treatment of liver conditions are of natural origin. Silymarin (SI) is the standard drug used for treatment of impaired liver functions. Two natural compounds possessing promising liver protection and with different chemical structures namely; the bioflavonoid hinokiflavone (HF) isolated from Junipers phoenicea family Cupressaceae and the sweet saponin Glycyrrhizin (GL) present in Glycyrrhiza glabra (liquorice) were selected for the current study. Since the two compounds are of different nature, they may act by different mechanisms and express synergistic effect. Combination of the two compounds using to dose levels were challenged with single doses of HF, GL and SI as well. The comparison was monitored via measuring serum biochemical parameters including, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltranspeptidase (GGT), alkaline phosphatase (ALP) and total bilirubin, tissue parameters such as MDA, NP-SH and TP, histopathological study using light and electron microscope. Protective effect on kidney was also monitored histopathologically and biochemically through observing the levels of LDH, creatinine, creatinine-kinase, urea and uric acid. The combinations of HF and GL showed protective effect more than the used single doses of HF and GL alone. However, SI was superior to the used combination in the two used doses in all the measured parameters. The liver and kidney cells appearance under normal and electron microscope showed that SI treated groups showed almost normal cells with slight toxic signs. Cells from group treated with the higher doses of the combination of HF and GL showed slight signs of intoxication under light and electron microscope indicating good level of protection. Although the combination of HF and GL expressed good protection in the higher dose, however, the combination did not exceed the protective effect of SI.

Development and validation of an LC-MS/MS method for the determination of hinokiflavone in rat plasma and its application to a pharmacokinetic study.

Hinokiflavone has drawn a lot of attention for its multiple biological activities. In this study, a sensitive and selective method for determination of hinokiflavone in rat plasma was developed for the first time, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Amentoflavone was used as an internal standard. Separation was achieved on a Hypersil Gold C18 column with isocratic elution using methanol-water (65:35, v/v) as mobile phase at a flow rate of 0.3 mL/min. A triple quadrupole mass spectrometer operating in the negative electrospray mode with selected reaction monitoring was used to detect the transitions of m/z 537 → 284 for hinokiflavone and m/z 537 → 375 for IS. The LOQ was 0.9 ng/mL with a linear range of 0.9-1000 ng/mL. The intra- and inter-day accuracy (RE%) ranged from -3.75 to 6.91% and from -9.20 to 2.51% and the intra- and inter-day precision (RSD) was between 0.32-14.11 and 2.85-10.04%. The validated assay was successfully applied to a pharmacokinetic study of hinokiflavone in rats. The half-life of drug elimination at the terminal phase was 6.10 ± 1.86 h, and the area under the plasma concentration-time curve from time zero to the time of last measurable concentration and to infinity values obtained were 2394.42 ± 466.86 and 2541.93 ± 529.85 h ng/mL, respectively.

Hinokiflavone exerts dual regulation on apoptosis and pyroptosis via the SIX4/Stat3/Akt pathway to alleviate APAP-induced liver injury.

Hinokiflavone (HF), classified as a flavonoid, is a main bioactive compound in Platycladus orientalis and Selaginella. HF exhibits activities including anti-HIV, anti-inflammatory, antiviral, antioxidant and anti-tumor effects. The study aimed to explore the function and the mechanisms of HF on acetaminophen (APAP)-induced acute liver injury. Results indicated that HF treatment mitigated the impact of APAP on viability and restored levels of MDA, GSH and SOD on HepG2 cells. The accumulation of reactive oxygen species (ROS) mitochondrial membrane potential (MMP) in HepG2 cells stimulated by APAP were also blocked by HF. HF reduced the levels of pro-apoptotic and pro-pyroptotic proteins. Flow cytometry analysis and fluorescence staining results were consistent with western blot analysis. Following HF treatment in the APAP-induced cell model, there was observed an augmentation in the phosphorylation of Stat3 and an increase in the expression of SIX4. However, not only silenced the SIX4 protein in HepG2 cells by siRNA, but also adding the Stat3 inhibitor (Stattic), attenuated the anti-apoptotic and anti-pyroptotic effects of HF significantly. Furthermore, HF alleviated liver damage in C57BL/6 mice model. Overall, our study demonstrated that HF mitigates apoptosis and pyroptosis induced by APAP in drug-induced liver injury (DILI) through the SIX4/Akt/Stat3 pathway in vivo and in vitro. HF may have promising potential for for the treatment of DILI.

Hinokiflavone from Platycladi cacumen as a potent broad-spectrum inhibitor of gut microbial Loop-1 ß-glucuronidases: Inhibition kinetics and molecular simulation.

Gut microbial Loop-1 ß-glucuronidases (gmGUS) played an important role in irinotecan-induced gastrointestinal toxicity by regulating the level of its active metabolite SN38 through enterohepatic recirculation. gmGUS inhibition has emerged as a promising approach to relieve its dose-limiting intestinal toxicity and improve its medication efficacy. This study aims to investigate the inhibitory effects and mechanisms of Platycladi cacumen and its main constituent hinokiflavone against four different types of Loop-1 gmGUS (EeGUS, SaGUS, CpGUS and EcGUS). Our results showed that the ethanol extract of Platycladi cacumen displayed strong broad-spectrum inhibition against four gmGUS, and hinokiflavone could potently inhibit EeGUS, SaGUS, CpGUS and EcGUS with IC50 values of 0.09 ± 0.01 µM, 0.44 ± 0.01 µM, 0.20 ± 0.01 µM and 0.69 ± 0.10 µM, respectively. Inhibition kinetic analyses demonstrated that hinokiflavone acted as a strong competitive inhibitor of EeGUS with Ki value of 0.13 µM, while it displayed non-competitive inhibition against SaGUS, CpGUS and EcGUS, with the Ki values of 0.43 µM, 0.33 µM and 0.76 µM, respectively. Docking simulations revealed that hinokiflavone could tightly bind with Tyr-485 and Glu-516 in catalytic sites of EeGUS, as well it created strong interactions with amino acids in loop structures of SaGUS (Asn-362), CpGUS (Phe-363, Met-364, Ala-365 and Arg-375) and EcGUS (Leu-361) to interfere the substrate entry into the catalytic pocket. Collectively, these results confirmed that hinokiflavone from Platycladi cacumen is a potent naturally occurring inhibitor of gmGUS with broad efficiency, suggesting hinokiflavone will be helpful for alleviating intestinal toxicity in irinotecan therapy.

Preparation of PEG/ZIF-8@HF drug delivery system for melanoma treatment via oral administration.

Melanoma is one of the highly malignant tumors whose incidence and fatality rates have been increased year by year. However, in addition to early surgical resection, there still lacks specific targeted drugs and treatment strategies. In this study, it was discovered that hinokiflavone (HF) encapsulated in zeolitic imidazolate framework-8 (ZIF-8) exhibited a superior anti-melanoma effect in vitro and in vivo. HF was encapsulated in ZIF-8 through a one-step synthesis method, and polyethylene glycol (PEG-2000) was used to optimize the size and dispersion of the drug-loaded complex (PEG/ZIF-8@HF). The results show that the prepared PEG/ZIF-8@HF has a high encapsulation efficiency (92.12%) and can achieve selective drug release in an acidic microenvironment. The results of in vitro anti-melanoma experiments indicate that PEG/ZIF-8@HF shows up-regulation of reactive oxygen species (ROS) levels and can restrain the migration and invasion of B16F10 cells. Moreover, in vivo animal experiments further confirm that PEG/ZIF-8@HF shows anti-tumor effect by up-regulating the pro-apoptotic proteins caspase-3 and caspase-8, and down-regulating the migration-promoting invasion protein MMP-9. This study developed a safe and effective oral administration of HF based on the high-efficiency delivery ZIF-8 system, which provides an effective treatment strategy for melanoma.

Hinokiflavone induces apoptosis, cell cycle arrest and autophagy in chronic myeloid leukemia cells through MAPK/NF-κB signaling pathway.

BACKGROUND: Chronic myeloid leukemia (CML) is a myeloproliferative tumor originating from hematopoietic stem cells, and resistance to tyrosine kinase inhibitors (TKI) has become a major cause of treatment failure. Alternative drug therapy is one of the important ways to overcome TKI resistance. Hinokiflavone (HF) is a C-O-C type biflavonoid with low toxicity and antitumor activity. This study investigated the antitumor effect and possible mechanisms of HF in CML cells. METHODS: Cell viability was measured by CCK-8 assay. Cell apoptosis and cell cycle distribution were analyzed by flow cytometry. Western blotting was used to assess protein expression levels. RESULTS: Our results showed that HF significantly inhibited the viability of K562 cells in a concentration- and time-dependent manner and induced G2/M phase arrest by up-regulating p21 and down-regulating Cdc2 protein. Furthermore, HF induced caspase-dependent apoptosis by activating JNK/p38 MAPK signaling pathway and inhibiting NF-κB activity. In addition, HF induced autophagy by increasing LC3-II expression and p62 degradation. Pretreatment with CQ, a late autophagy inhibitor, significantly increased the levels of LC3-II and p62 proteins and promoted cell survival. CONCLUSION: HF shows a good anti-leukemia effect and is expected to become a potential therapeutic drug for CML.

Corrigendum: Hinokiflavone Inhibits Growth of Esophageal Squamous Cancer By Inducing Apoptosis via Regulation of the PI3K/AKT/mTOR Signaling Pathway.

[This corrects the article DOI: 10.3389/fonc.2022.833719.].

Hinokiflavone Inhibits Growth of Esophageal Squamous Cancer By Inducing Apoptosis via Regulation of the PI3K/AKT/mTOR Signaling Pathway.

BACKGROUND: Globally, esophageal cancer ranks as the seventh most common cancer. Esophageal squamous cell carcinoma (ESCC) is one of its major histological types. ESCC accounts for the vast majority of cases in China, and the mortality rate is high. Cisplatin, the standard adjuvant chemotherapy drug for ESCC, has a modest response rate due to the development of drug resistance. Hinokiflavone (HF) is a natural biflavonoid compound with anti-melanoma activity. However, its anti-tumor effect on ESCC and the underlying mechanisms remain largely unknown. METHODS: The ESCC cell lines KYSE150 and TE14 were used. The cell counting kit-8 assay and flow cytometry analysis, along with colony formation, EdU, wound healing, and Transwell migration assays, were performed to assess cell characteristics (viability, migration, invasion, and apoptosis) following treatment with HF. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), western blotting, and molecular docking were used to investigate the pathways potentially modulated by HF. In vivo anti-tumor effects of HF were also investigated using a mouse xenograft model. RESULTS: Our findings revealed that HF inhibited ESCC cell proliferation. Hoechst 33342 staining, annexin V-FITC/PI staining, and western blotting confirmed that HF causes caspase-dependent apoptosis. KEGG pathway enrichment analysis and western blotting indicated that the PI3K/AKT/mTOR pathway played an important role in the process of HF-induced apoptosis. Furthermore, HF effectively impaired the migration and invasion abilities of KYSE150 cells and downregulated the expression of the matrix metalloproteinases (MMP) MMP2 and MMP9. HF inhibited tumor growth and exhibited minimal toxicity in the organs of the KYSE150 xenograft model. CONCLUSION: This is the first study to demonstrate the inhibition of ESCC growth and progression by HF. The underlying mechanism is through blocking the PI3K/AKT/mTOR signaling pathway, thereby inhibiting cell proliferation and inducing apoptosis. HF can be used as a complementary/alternative agent for ESCC therapy.

Camphor, Artemisinin and Sumac Phytochemicals as inhibitors against COVID-19: Computational approach.

Covid-19 is an emerging infectious disease caused by coronavirus SARS-CoV-2. Due to the rapid rise in deaths resulted from this infection all around the world, the identification of drugs against this new coronavirus is an important requirement. Among the drugs that can fight this type of infection; natural products are substances that serve as sources of beneficial chemical molecules for the development of effective therapies. In this study, Camphor, Artemisinin and 14 Sumac phytochemicals were docked in the active site of SARS-CoV-2 main protease (PDB code: 6LU7). We have also performed molecular dynamic simulation at 100 ns with MM-GBSA/PBSA analysis for the structures with the best affinity in the binding site of the studied enzyme (Hinokiflavone and Myricetin) after docking calculations to consider parameters like RMSD, covariance, PCA, radius of gyration, potential energy, temperature and pressure. The result indicates that Hinokiflavone and Myricetin are the structures with best affinity and stability in the binding site of the studied enzyme and they respect the conditions mentioned in Lipinski's rule and have acceptable ADMET proprieties; so, these compounds have important pharmacokinetic properties and bioavailability, and they could have more potent antiviral treatment of COVID-19 than the other studied compounds.

Hinokiflavone and Related C-O-C-Type Biflavonoids as Anti-cancer Compounds: Properties and Mechanism of Action.

Biflavonoids are divided in two classes: C-C type compounds represented by the dimeric compound amentoflavone and C-O-C-type compounds typified by hinokiflavone (HNK) with an ether linkage between the two connected apigenin units. This later sub-group of bisflavonyl ethers includes HNK, ochnaflavone, delicaflavone and a few other dimeric compounds, found in a variety of plants, notably Selaginella species. A comprehensive review of the anticancer properties and mechanism of action of HNK is provided, to highlight the anti-proliferative and anti-metastatic activities of HNK and derivatives, and HNK-containing plant extracts. The anticancer effects rely on the capacity of HNK to interfere with the ERK1-2/p38/NFκB signaling pathway and the regulation of the expression of the matrix metalloproteinases MMP-2 and MMP-9 (with a potential direct binding to MMP-9). In addition, HNK was found to function as a potent modulator of pre-mRNA splicing, inhibiting the SUMO-specific protease SENP1. As such, HNK represents a rare SENP1 inhibitor of natural origin and a scaffold to design synthetic compounds. Oral formulations of HNK have been elaborated to enhance its solubility, to facilitate the compound delivery and to enhance its anticancer efficacy. The review shed light on the anticancer potential of C-O-C-type biflavonoids and specifically on the pharmacological profile of HNK. This compound deserves further attention as a regulator of pre-mRNA splicing, useful to treat cancers (in particular hepatocellular carcinoma) and other human pathologies.

Investigation of the Antibacterial Activity and Efflux Pump Inhibitory Effect of Cycas thouarsii R.Br. Extract against Klebsiella pneumoniae Clinical Isolates.

The vast spread of multidrug-resistant bacteria has encouraged researchers to explore new antimicrobial compounds. This study aimed to investigate the phytochemistry and antibacterial activity of Cycas thouarsii R.Br. leaves extract against Klebsiella pneumoniae clinical isolates. The minimum inhibitory concentration (MIC) values of C. thouarsii extract ranged from 4 to 32 µg/mL. The impact of the treatment of the isolates with sub-inhibitory concentrations of C. thouarsii extract was investigated on the bacterial growth, membrane integrity, inner and outer membrane permeability, membrane depolarization, and bacterial morphology using a scanning electron microscope (SEM) and on the efflux activity using qRT-PCR. Interestingly, most K. pneumoniae isolates treated with C. thouarsii extract showed growth inhibition-a decrease in membrane integrity. In addition, we observed various morphological changes, a significant increase in inner and outer membrane permeability, a non-significant change in membrane depolarization, and a decrease in efflux activity after treatment. The phytochemical investigation of C. thouarsii extract revealed the isolation of one new biflavonoid, 5,7,7″,4‴-tetra-O-methyl-hinokiflavone (3), and five known compounds, stigmasterol (1), naringenin (2), 2,3-dihydrobilobetin (4), 4',4‴-O-dimethyl amentoflavone (5), and hinokiflavone (6), for the first time. Moreover, the pure compounds' MICs' ranged from 0.25 to 2 µg/mL. Thus, C. thouarsii could be a potential source for new antimicrobials.