Bakuchiol Is a Phenolic Isoprenoid with Novel Enantiomer-selective Anti-influenza A Virus Activity Involving Nrf2 Activation

Effect of glabridin combined with bakuchiol on UVB-induced skin damage and its underlying mechanism: An experimental study

BACKGROUND

Research has demonstrated the anti-photoaging properties of glabridin and bakuchiol.

METHODS

The impact of glabridin, glabridin + bakuchiol, and bakuchiol on the levels of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) in mice skin fibroblasts was observed. Furthermore, we investigated the potential roles of fibronectin (FN), interferon-γ (IFN-γ), interleukin-22 (IL-22), and transforming growth factor-β (TGF-β) in the tissues, and evaluated their impact on the enzymatic levels in the skin. In conjunction with transcriptomic analysis, metabolomic profiling, and network pharmacology, all samples underwent comprehensive metabolomic and principal component analysis. The Venny2.1 method was utilized to identify variances in shared metabolites between the treatment group and the UVB group, as well as between the UVB group and the control group. Subsequently, a cluster heat map was generated to forecast and analyze metabolic pathways and targets.

RESULTS

The outcomes from the hematoxylin and eosin and toluidine blue staining revealed that glabridin and bakuchiol markedly decreased dermal thickness and suppressed mast cell infiltration in photoaged mice. Immunohistochemistry and Elisa analysis revealed that glabridin and bakuchiol effectively attenuated the levels of pro-inflammatory factors, including IL-1β, tumor necrosis factor-α, IL-22, and IFN-γ. Furthermore, an increase in the levels of anti-inflammatory factors such as FN and TGF-β was also observed. The determination of the contents of superoxide dismutase, hydroxypropyltransferase and malondialdehyde in mice dorsal skin revealed that glabridin and bakuchiol not only elevated the levels of superoxide dismutase and hydroxyproline, but also reduced malondialdehyde content. Due to the limited number of shared differential metabolites exclusively within Kyoto Encyclopedia of Genes and Genomes, comprehensive pathway enrichment analysis was not feasible.

CONCLUSION

This study demonstrates that glabridin and bakuchiol effectively impede photoaging and alleviate skin inflammation in mice.

In Vitro Anti-Rotaviral Activity of Bavachin Isolated from Psoralea corylifolia L. (Fabaceae)

Rotavirus is the main causative agent of viral gastroenteritis among young animals worldwide. Currently, no clinically approved or effective antiviral drugs are available to combat rotavirus infections. Herein, we evaluated the anti-rotaviral activities of extracts and bavachin isolated from Psoralea corylifolia L. (Fabaceae) (P. corylifolia) against the bovine rotavirus G8P[7] and porcine rotavirus G5P[7] in vitro. Two assay strategies were performed: (1) a virucidal assay to reduce viral infectivity by virus neutralization and (2) a post-treatment assay to assess viral replication suppression. The results from the virucidal assay showed that the extracts and bavachin did not exert anti-rotaviral activities. In the follow-up analysis after treatment, bavachin exhibited robust antiviral efficacy, with 50% effective concentration (EC50) values of 10.6 μM (selectivity index [SI] = 2.38) against bovine rotavirus G8P[7] and 13.0 μM (SI = 1.94) against porcine rotavirus G5P[7]. Bavachin strongly suppressed viral RNA synthesis in the early (6 h) and late stages (18 h) after rotaviral infection. These findings strongly suggest that bavachin may have hindered the virions by effectively inhibiting the early stages of the virus replication cycle after rotaviral infection. Furthermore, confocal imaging showed that bavachin suppressed viral protein synthesis, notably that of the rotaviral protein (VP6). These results suggest that bavachin has strong antiviral activity against rotaviruses, inhibits viral replication, and is a candidate natural therapeutic drug targeting rotaviral infection. The utilization of bavachin isolated from P. corylifolia may contribute to decreased mortality rates, lower medication expenses, and enhanced economic viability in domestic farms.

Bakuchiol targets mitochondrial proteins, prohibitins and voltage-dependent anion channels: New insights into developing antiviral agents

We previously reported that bakuchiol, a phenolic isoprenoid anticancer compound, and its analogs exert anti-influenza activity. However, the proteins targeted by bakuchiol remain unclear. Here, we investigated the chemical structures responsible for the anti-influenza activity of bakuchiol and found that all functional groups and C6 chirality of bakuchiol were required for its anti-influenza activity. Based on these results, we synthesized a molecular probe containing a biotin tag bound to the C1 position of bakuchiol. With this probe, we performed a pulldown assay for Madin-Darby canine kidney cell lysates and purified the specific bakuchiol-binding proteins with SDS-PAGE. Using nanoLC-MS/MS analysis, we identified prohibitin (PHB) 2, voltage-dependent anion channel (VDAC) 1, and VDAC2 as binding proteins of bakuchiol. We confirmed the binding of bakuchiol to PHB1, PHB2, and VDAC2 in vitro using Western blot analysis. Immunofluorescence analysis showed that bakuchiol was bound to PHBs and VDAC2 in cells and colocalized in the mitochondria. The knockdown of PHBs or VDAC2 by transfection with specific siRNAs, along with bakuchiol cotreatment, led to significantly reduced influenza nucleoprotein expression levels and viral titers in the conditioned medium of virus-infected Madin-Darby canine kidney cells, compared to the levels observed with transfection or treatment alone. These findings indicate that reducing PHBs or VDAC2 protein, combined with bakuchiol treatment, additively suppressed the growth of influenza virus. Our findings indicate that bakuchiol exerts anti-influenza activity via a novel mechanism involving these mitochondrial proteins, providing new insight for developing anti-influenza agents.

The Role of the NRF2 Pathway in the Pathogenesis of Viral Respiratory Infections

In humans, acute and chronic respiratory infections caused by viruses are associated with considerable morbidity and mortality. Respiratory viruses infect airway epithelial cells and induce oxidative stress, yet the exact pathogenesis remains unclear. Oxidative stress activates the transcription factor NRF2, which plays a key role in alleviating redox-induced cellular injury. The transcriptional activation of NRF2 has been reported to affect both viral replication and associated inflammation pathways. There is complex bidirectional crosstalk between virus replication and the NRF2 pathway because virus replication directly or indirectly regulates NRF2 expression, and NRF2 activation can reversely hamper viral replication and viral spread across cells and tissues. In this review, we discuss the complex role of the NRF2 pathway in the regulation of the pathogenesis of the main respiratory viruses, including coronaviruses, influenza viruses, respiratory syncytial virus (RSV), and rhinoviruses. We also summarize the scientific evidence regarding the effects of the known NRF2 agonists that can be utilized to alter the NRF2 pathway.

Bakuchiol, a natural constituent and its pharmacological benefits

Background and aims

Natural compounds extracted from medicinal plants have recently gained attention in therapeutics as they are considered to have lower Toxicity and higher tolerability relative to chemically synthesized compounds. Bakuchiol from Psoralea corylifolia L. is one such compound; it is a type of meroterpene derived from the leaves and seeds of Psoralea corylifolia plants. Natural sources of bakuchiol have been used in traditional Chinese and Indian medicine for centuries due to its preventive benefits against tumors and inflammation. It plays a strong potential role as an antioxidant with impressive abilities to remove Reactive Oxygen Species (ROS). This review has focused on bakuchiol's extraction, therapeutic applications, and pharmacological benefits.

Methods

A search strategy has been followed to retrieve the relevant newly published literature on the pharmacological benefits of bakuchiol. After an extensive study of the retrieved articles and maintaining the inclusion and exclusion criteria, 110 articles were finally selected for this review.

Results

Strong support of primary research on the protective effects via antitumorigenic, anti-inflammatory, antioxidative, antimicrobial, and antiviral activities are delineated.

Conclusions

From ancient to modern life, medicinal plants have always been drawing the attention of human beings to alleviate ailments for a healthy and balanced lifestyle. This review is a comprehensive approach to highlighting bona fide essential pharmacological benefits and mechanisms underlying their therapeutic applications.

Non-Steroidal Estrogens Inhibit Influenza Virus by Interacting with Hemagglutinin and Preventing Viral Fusion

Influenza virus is one of the main causes of respiratory infections worldwide. Despite the availability of seasonal vaccines and antivirals, influenza virus infections cause an important health and economic burden. Therefore, the need to identify alternative antiviral strategies persists. In this study, we identified non-steroidal estrogens as potent inhibitors of influenza virus due to their interaction with the hemagglutinin protein, preventing viral entry. This activity is maintained in vitro, ex vivo, and in vivo. Therefore, we found a new domain to target on the hemagglutinin and a class of compounds that could be further optimized for influenza treatment.

Anti-influenza Activity of Povidone-Iodine-Integrated Materials

Personal protective equipment (PPE), including medical masks, should be worn for preventing the transmission of respiratory pathogens via infective droplets and aerosols. In medical masks, the key layer is the filter layer, and the melt-blown nonwoven fabric (NWF) is the most used fabric. However, the NWF filter layer cannot kill or inactivate the pathogens spread via droplets and aerosols. Povidone-iodine (PVP-I) has been used as an antiseptic solution given its potent broad-spectrum activity against pathogens. To develop PPE (e.g., medical masks) with anti-pathogenic activity, we integrated PVP-I into nylon-66 NWF. We then evaluated its antiviral activity against influenza A viruses by examining the viability of Madin-Darby canine kidney (MDCK) cells after inoculation with the virus strains exposed to the PVP-I-integrated nylon-66 NWF. The PVP-I nylon-66 NWF protected the MDCK cells from viral infection in a PVP-I concentration-dependent manner. Subsequently, we found to integrate PVP-I into nylon-66 and polyurethane materials among various materials. These PVP-I materials were also effective against influenza virus infection, and treatment with PVP-I nylon-66 NWF showed the highest cell survival among all the tested materials. PVP-I showed anti-influenza A virus activity when used in conjunction with PPE materials. Moreover, nylon-66 NWF integrated with PVP-I was found to be the best material to ensure anti-influenza activity. Therefore, PVP-I-integrated masks could have the potential to inhibit respiratory virus infection. Our results provide new information for developing multi-functional PPEs with anti-viral activity by integrating them with PVP-I to prevent the potential transmission of respiratory viruses.

Novel and Alternative Therapeutic Strategies for Controlling Avian Viral Infectious Diseases: Focus on Infectious Bronchitis and Avian Influenza

The growth of poultry farming has enabled higher spread of infectious diseases and their pathogens among different kinds of birds, such as avian infectious bronchitis virus (IBV) and avian influenza virus (AIV). IBV and AIV are a potential source of poultry mortality and economic losses. Furthermore, some pathogens have the ability to cause zoonotic diseases and impart human health problems. Antiviral treatments that are used often lead to virus resistance along with the problems of side effects, recurrence, and latency of viruses. Though target hosts are being vaccinated, the constant emergence and re-emergence of strains of these viruses cause disease outbreaks. The pharmaceutical industry is gradually focusing on plant extracts to develop novel herbal drugs to have proper antiviral capabilities. Natural therapeutic agents developed from herbs, essential oils (EO), and distillation processes deliver a rich source of amalgams to discover and produce new antiviral drugs. The mechanisms involved have elaborated how these natural therapeutics agents play a major role during virus entry and replication in the host and cause inhibition of viral pathogenesis. Nanotechnology is one of the advanced techniques that can be very useful in diagnosing and controlling infectious diseases in poultry. In general, this review covers the issue of the poultry industry situation, current infectious diseases, mainly IB and AI control measures and, in addition, the setup of novel therapeutics using plant extracts and the use of nanotechnology information that may help to control these diseases.

Mechanistic Understanding of Lung Inflammation: Recent Advances and Emerging Techniques

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury characterized by an acute inflammatory response in the lung parenchyma. Hence, it is considered as the most appropriate clinical syndrome to study pathogenic mechanisms of lung inflammation. ARDS is associated with increased morbidity and mortality in the intensive care unit (ICU), while no effective pharmacological treatment exists. It is very important therefore to fully characterize the underlying pathobiology and the related mechanisms, in order to develop novel therapeutic approaches. In vivo and in vitro models are important pre-clinical tools in biological and medical research in the mechanistic and pathological understanding of the majority of diseases. In this review, we will present data from selected experimental models of lung injury/acute lung inflammation, which have been based on clinical disorders that can lead to the development of ARDS and related inflammatory lung processes in humans, including ventilation-induced lung injury (VILI), sepsis, ischemia/reperfusion, smoke, acid aspiration, radiation, transfusion-related acute lung injury (TRALI), influenza, Streptococcus (S.) pneumoniae and coronaviruses infection. Data from the corresponding clinical conditions will also be presented. The mechanisms related to lung inflammation that will be covered are oxidative stress, neutrophil extracellular traps, mitogen-activated protein kinase (MAPK) pathways, surfactant, and water and ion channels. Finally, we will present a brief overview of emerging techniques in the field of omics research that have been applied to ARDS research, encompassing genomics, transcriptomics, proteomics, and metabolomics, which may recognize factors to help stratify ICU patients at risk, predict their prognosis, and possibly, serve as more specific therapeutic targets.

Bakuchiol – a natural meroterpenoid: structure, isolation, synthesis and functionalization approaches

Bakuchiol is an emblematic meroterpene class of natural product extracted from Psoralea corylifolia. It has been reported to possess a broad range of biological and pharmacological properties and is considered as a leading biomolecule. It is highly desirable to devise an efficient approach to access bakuchiol and its chemical biology applications. In this review we provided structural features, isolation methods, various chemical routes and late-stage functionalization (LSF) approaches for bakuchiol and its derivatives. Moreover, this review encompasses the structure–activity relationships (SAR), value-added contributions and future perspectives of bakuchiol

The isolation methods, various chemical routes and late-stage functionalization approaches and structure–activity relationships of bakuchiol – a meroterpene class of natural product has been discussed in detail.

NRF2 in Viral Infection

The transcription factor NRF2 is central to redox homeostasis in animal cells and is a well-known driver of chemoresistance in many types of cancer. Recently, new roles have been ascribed to NRF2 which include regulation of antiviral interferon responses and inflammation. In addition, NRF2 is emerging as an important factor in antiviral immunity through interferon-independent mechanisms. In the review, we give an overview of the scientific progress on the involvement and importance of NRF2 in the context of viral infection.

Promising traditional Indian medicinal plants for the management of novel Coronavirus disease: A systematic review

Traditional Indian medical practices (Ayurveda, Siddha, Unani, and homeopathy) are a vast reservoir of knowledge about medicinal plants. The promising pharmacological properties of these plants have paved the way for developing therapy against novel Coronavirus (CoV) infection. The current review will summarize published works of literature on the effects of traditional Indian medicinal plants against acute respiratory infection (COVID‐19, SARS, Influenza, and Respiratory syncytial virus infection) and registered clinical trials of traditional Indian herbal medicines in COVID‐19. The current study aims to comprehensively evaluate the data of traditional Indian medicinal plants to warrant their use in COVID‐19 management. PubMed, Embase, and Cochrane databases were searched along with different clinical trial databases. A total of 22 relevant traditional Indian medicinal plants (35 relevant studies) were included in the current study having potential antiviral properties against virus‐induced respiratory illness along with promising immunomodulatory and thrombolytic properties. Further, 36 randomized and nonrandomized registered clinical trials were also included that were aimed at evaluating the efficacy of herbal plants or their formulations in COVID‐19 management. The antiviral, immunomodulatory, and thrombolytic activities of the traditional Indian medicinal plants laid down a strong rationale for their use in developing therapies against SARS‐CoV‐2 infection. The study identified some important potential traditional Indian medicinal herbs such as Ocimum tenuiflorum, Tinospora cordifolia, Achyranthes bidentata, Cinnamomum cassia, Cydonia oblonga, Embelin ribes, Justicia adhatoda, Momordica charantia, Withania somnifera, Zingiber officinale, Camphor, and Kabusura kudineer, which could be used in therapeutic strategies against SARS‐CoV‐2 infection.

Substantial effect of phytochemical constituents against the pandemic disease influenza-a review

Background

Influenza is an acute respiratory tract infection caused by the influenza virus. Vaccination and antiviral drugs are the two methods opted to control the disease. Besides their efficiency, they also cause adverse side effects. Hence, scientists turned their attention to powerful herbal medicines. This review put focus on various proven, scientifically validated anti-influenza compounds produced by the plants suggested for the production of newer drugs for the better treatment of influenza and its related antiviral diseases too.

Main body

In this review, fifty medicinal herb phytochemical constituents and their anti-influenza activities have been documented. Specifically, this review brings out the accurate and substantiates mechanisms of action of these constituents. This study categorizes the phytochemical constituents into primary and secondary metabolites which provide a source for synthesizing and developing new drugs.

Conclusion

This article provides a summary of the actions of the herbal constituents. Since the mechanisms of action of the components are elucidated, the pandemic situation arising due to influenza and similar antiviral diseases can be handled promisingly with greater efficiency. However, clinical trials are in great demand. The formulation of usage may be a single drug compound or multi-herbal combination. These, in turn, open up a new arena for the pharmaceutical industries to develop innovative drugs.

Bakuchiol ameliorates cerebral ischemia-reperfusion injury by modulating NLRP3 inflammasome and Nrf2 signaling

Cerebral ischemia/reperfusion (I/R) injury is a common cerebrovascular disease with high mortality. Bakuchiol (BAK), extracted from the seeds of psoralea corylifolia, exhibits anti-inflammatory effects on lung, kidney and heart injuries. However, the effect of BAK on brain I/R injury remains elusive. In our study, a cerebral I/R model in mice was established by 1-h middle cerebral artery occlusion and 24-h reperfusion (1-h MCAO/24-h R). Prior to it, mice were gavaged with BAK (2.5 or 5 mg/kg) per day for 5 days. BAK pre-treatment improved neurological deficit, and reduced infarct volume, cerebral edema and neuronal injury in MCAO/R-injured mice. BAK decreased the number of Iba1-immunoreactive cells in the brain, indicating a reduction of microglial activation. BAK also reduced the expressions of NLRP3, ASC, cleaved-caspase-1, IL-1β and IL-18. BAK triggered Nrf2 nuclear accumulation and elevated HO-1 level. Further, the role of BAK was explored in BV-2 microglia with 3-h oxygen-glucose deprivation/24-h reperfusion (3-h OGD/24-h R). It was found that the functions of BAK in vitro were consistent with those in vivo, as manifested by reduced NLRP3 inflammasome and activated Nrf2 signaling. In addition, BV-2 cells were treated with Brusatol, an Nrf2 inhibitor. Results showed that Brusatol partially reversed the protective effect of BAK on OGD/R-injured BV-2 cells, further confirming that BAK might exhibit its anti-inflammatory property via activating Nrf2 signaling. In short, BAK is more meaningful in improving cerebral ischemic injury through suppressing NLRP3-mediated inflammatory response and activating the Nrf2 signaling pathway.

Organic synthesis and anti-influenza A virus activity of cyclobakuchiols A, B, C, and D

Novel antiviral agents for influenza, which poses a substantial threat to humans, are required. Cyclobakuchiols A and B have been isolated from Psoralea glandulosa, and cyclobakuchiol C has been isolated from P. corylifolia. The structural differences between cyclobakuchiol A and C arise due to the oxidation state of isopropyl group, and these compounds can be derived from (+)-(S)-bakuchiol, a phenolic isoprenoid compound present in P. corylifolia seeds. We previously reported that bakuchiol induces enantiospecific anti-influenza A virus activity involving nuclear factor erythroid 2-related factor 2 (Nrf2) activation. However, it remains unclear whether cyclobakuchiols A–C induce anti-influenza A virus activity. In this study, cyclobakuchiols A, B, and C along with cyclobakuchiol D, a new artificial compound derived from cyclobakuchiol B, were synthesized and examined for their anti-influenza A virus activities using Madin-Darby canine kidney cells. As a result, cyclobakuchiols A–D were found to inhibit influenza A viral infection, growth, and the reduction of expression of viral mRNAs and proteins in influenza A virus-infected cells. Additionally, these compounds markedly reduced the mRNA expression of the host cell influenza A virus-induced immune response genes, interferon-β and myxovirus-resistant protein 1. In addition, cyclobakuchiols A–D upregulated the mRNA levels of NAD(P)H quinone oxidoreductase 1, an Nrf2-induced gene, in influenza A virus-infected cells. Notably, cyclobakuchiols A, B, and C, but not D, induced the Nrf2 activation pathway. These findings demonstrate that cyclobakuchiols have anti-influenza viral activity involving host cell oxidative stress response. In addition, our results suggest that the suitably spatial configuration between oxidized isopropyl group and phenol moiety in the structure of cyclobakuchiols is required for their effect.

A novel aqueous extract from rice fermented with Aspergillus oryzae and Saccharomyces cerevisiae possesses an anti-influenza A virus activity

Human influenza virus infections occur annually worldwide and are associated with high morbidity and mortality. Hence, development of novel anti-influenza drugs is urgently required. Rice Power^® extract developed by the Yushin Brewer Co. Ltd. is a novel aqueous extract of rice obtained via saccharization and fermentation with various microorganisms, such as Aspergillus oryzae, yeast [such as Saccharomyces cerevisiae], and lactic acid bacteria, possessing various biological and pharmacological properties. In our previous experimental screening with thirty types of Rice Power^® extracts, we observed that the 30^th Rice Power^® (Y30) extract promoted the survival of influenza A virus-infected Madin-Darby canine kidney (MDCK) cells. Therefore, to identify compounds for the development of novel anti-influenza drugs, we aimed to investigate whether the Y30 extract exhibits anti-influenza A virus activity. In the present study, we demonstrated that the Y30 extract strongly promoted the survival of influenza A H1N1 Puerto Rico 8/34 (A/PR/8/34), California 7/09, or H3N2 Aichi 2/68 (A/Aichi/2/68) viruses-infected MDCK cells and inhibited A/PR/8/34 or A/Aichi/2/68 viruses infection and growth in the co-treatment and pre-infection experiments. The pre-treatment of Y30 extract on MDCK cells did not induce anti-influenza activity in the cell. The Y30 extract did not significantly affect influenza A virus hemagglutination, and neuraminidase and RNA-dependent RNA polymerase activities. Interestingly, the electron microscopy experiment revealed that the Y30 extract disrupts the integrity of influenza A virus particles by permeabilizing the viral membrane envelope, suggesting that Y30 extract has a direct virucidal effect against influenza A virus. Furthermore, we observed that compared to the ethyl acetate (EtOAc) extract, the water extract of Y30 extract considerably promoted the survival of cells infected with A/PR/8/34 virus. These results indicated that more anti-influenza components were present in the water extract of Y30 extract than in the EtOAc extract. Our results highlight the potential of a rice extract fermented with A. oryzae and S. cerevisiae as an anti-influenza medicine and a drug source for the development of anti-influenza compounds.

Bakuchiol Alleviates Hyperglycemia-Induced Diabetic Cardiomyopathy by Reducing Myocardial Oxidative Stress via Activating the SIRT1/Nrf2 Signaling Pathway

Bakuchiol (BAK), a monoterpene phenol reported to have exerted a variety of pharmacological effects, has been related to multiple diseases, including myocardial ischemia reperfusion injury, pressure overload-induced cardiac hypertrophy, diabetes, liver fibrosis, and cancer. However, the effects of BAK on hyperglycemia-caused diabetic cardiomyopathy and its underlying mechanisms remain unclear. In this study, streptozotocin-induced mouse model and high-glucose-treated cell model were conducted to investigate the protective roles of BAK on diabetic cardiomyopathy, in either the presence or absence of SIRT1-specific inhibitor EX527, SIRT1 siRNA, or Nrf2 siRNA. Our data demonstrated for the first time that BAK could significantly abate diabetic cardiomyopathy by alleviating the cardiac dysfunction, ameliorating the myocardial fibrosis, mitigating the cardiac hypertrophy, and reducing the cardiomyocyte apoptosis. Furthermore, BAK achieved its antifibrotic and antihypertrophic actions by inhibiting the TGF-β1/Smad3 pathway, as well as decreasing the expressions of fibrosis- and hypertrophy-related markers. Intriguingly, these above effects of BAK were largely attributed to the remarkable activation of SIRT1/Nrf2 signaling, which eventually strengthened cardiac antioxidative capacity by elevating the antioxidant production and reducing the reactive oxygen species generation. However, all the beneficial results were markedly abolished with the administration of EX527, SIRT1 siRNA, or Nrf2 siRNA. In summary, these novel findings indicate that BAK exhibits its therapeutic properties against hyperglycemia-caused diabetic cardiomyopathy by attenuating myocardial oxidative damage via activating the SIRT1/Nrf2 signaling.

Strategies for Targeting SARS CoV-2: Small Molecule Inhibitors-The Current Status

Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2) induced Coronavirus Disease - 19 (COVID-19) cases have been increasing at an alarming rate (7.4 million positive cases as on June 11 2020), causing high mortality (4,17,956 deaths as on June 11 2020) and economic loss (a 3.2% shrink in global economy in 2020) across 212 countries globally. The clinical manifestations of this disease are pneumonia, lung injury, inflammation, and severe acute respiratory syndrome (SARS). Currently, there is no vaccine or effective pharmacological agents available for the prevention/treatment of SARS-CoV2 infections. Moreover, development of a suitable vaccine is a challenging task due to antibody-dependent enhancement (ADE) and Th-2 immunopathology, which aggravates infection with SARS-CoV-2. Furthermore, the emerging SARS-CoV-2 strain exhibits several distinct genomic and structural patterns compared to other coronavirus strains, making the development of a suitable vaccine even more difficult. Therefore, the identification of novel small molecule inhibitors (NSMIs) that can interfere with viral entry or viral propagation is of special interest and is vital in managing already infected cases. SARS-CoV-2 infection is mediated by the binding of viral Spike proteins (S-protein) to human cells through a 2-step process, which involves Angiotensin Converting Enzyme-2 (ACE2) and Transmembrane Serine Protease (TMPRSS)-2. Therefore, the development of novel inhibitors of ACE2/TMPRSS2 is likely to be beneficial in combating SARS-CoV-2 infections. However, the usage of ACE-2 inhibitors to block the SARS-CoV-2 viral entry requires additional studies as there are conflicting findings and severe health complications reported for these inhibitors in patients. Hence, the current interest is shifted toward the development of NSMIs, which includes natural antiviral phytochemicals and Nrf-2 activators to manage a SARS-CoV-2 infection. It is imperative to investigate the efficacy of existing antiviral phytochemicals and Nrf-2 activators to mitigate the SARS-CoV-2-mediated oxidative stress. Therefore, in this review, we have reviewed structural features of SARS-CoV-2 with special emphasis on key molecular targets and their known modulators that can be considered for the development of NSMIs.

UP256 Inhibits Hyperpigmentation by Tyrosinase Expression/Dendrite Formation via Rho-Dependent Signaling and by Primary Cilium Formation in Melanocytes

Skin hyperpigmentation is generally characterized by increased synthesis and deposition of melanin in the skin. UP256, containing bakuchiol, is a well-known medication for acne vulgaris. Acne sometimes leaves dark spots on the skin, and we hypothesized that UP256 may be effective against hyperpigmentation-associated diseases. UP256 was treated for anti-melanogenesis and melanocyte dendrite formation in cultured normal human epidermal melanocytes as well as in the reconstituted skin and zebrafish models. Western blot analysis and glutathione S-transferase (GST)-pull down assays were used to evaluate the expression and interaction of enzymes related in melanin synthesis and transportation. The cellular tyrosinase activity and melanin content assay revealed that UP256 decreased melanin synthesis by regulating the expression of proteins related on melanogenesis including tyrosinase, TRP-1 and -2, and SOX9. UP256 also decreased dendrite formation in melanocytes via regulating the Rac/Cdc42/α-PAK signaling proteins, without cytotoxic effects. UP256 also inhibited ciliogenesis-dependent melanogenesis in normal human epidermal melanocytes. Furthermore, UP256 suppressed melanin contents in the zebrafish and the 3D human skin tissue model. All things taken together, UP256 inhibits melanin synthesis, dendrite formation, and primary cilium formation leading to the inhibition of melanogenesis.

Redox control in the pathophysiology of influenza virus infection

Triggered in response to external and internal ligands in cells and animals, redox homeostasis is transmitted via signal molecules involved in defense redox mechanisms through networks of cell proliferation, differentiation, intracellular detoxification, bacterial infection, and immune reactions. Cellular oxidation is not necessarily harmful per se, but its effects depend on the balance between the peroxidation and antioxidation cascades, which can vary according to the stimulus and serve to maintain oxygen homeostasis. The reactive oxygen species (ROS) that are generated during influenza virus (IV) infection have critical effects on both the virus and host cells. In this review, we outline the link between viral infection and redox control using IV infection as an example. We discuss the current state of knowledge on the molecular relationship between cellular oxidation mediated by ROS accumulation and the diversity of IV infection. We also summarize the potential anti-IV agents available currently that act by targeting redox biology/pathophysiology.

Epidermal and Dermal Hallmarks of Photoaging are Prevented by Treatment with Night Serum Containing Melatonin, Bakuchiol, and Ascorbyl Tetraisopalmitate: In Vitro and Ex Vivo Studies

INTRODUCTION

Photoaging is a complex process that is chiefly the result of oxidative stress caused by ultraviolet (UV)-generated reactive oxygen species. To counter this process, we developed a 3-in-1 night facial serum (3-in-1 NFS) containing a combination of direct and indirect antioxidants and polyphenols that is designed to attenuate UV-generated free radicals and stimulate dermal protein synthesis. In clinical trials 3-in-1 NFS improved the appearance of photoaged skin. In this study we sought to identify some of the main histologic changes responsible for this.

METHODS

We performed an immunolabeling analysis of some of the salient epidermal and dermal proteins in 3-in-1 NFS-treated primary epidermal keratinocytes (HEKs) and dermal fibroblasts (HDFs) in vitro, and in UV-exposed skin explants ex vivo. Numbers of apoptotic sunburn cells following exposure of 3-in-1 NFS-treated skin explants to UV radiation were also determined.

RESULTS

We demonstrate that 3-in-1 NFS increases levels of filaggrin and aquaporin 3 in HEKs, and levels of collagen I and collagen III in HDFs in vitro. Levels of precursor procollagen type I and tropoelastin were increased in ex vivo skin explants. Numbers of apoptotic sunburn cells were significantly reduced in UV-exposed skin explants. These effects were only observed with the combination of ingredients in 3-in-1 NFS, suggesting that they have a synergistic effect on photoaged skin biology.

CONCLUSION

Our results show that some of the histological hallmarks of photoaging are improved with the use of 3-in-1 NFS.

Toosendanin From Melia Fructus Suppresses Influenza A Virus Infection by Altering Nuclear Localization of Viral Polymerase PA Protein

Toosendanin (TSN) is a major bioactive component of Melia Fructus (MF) with anti-inflammatory, anti-botulinum, anti-microbial, and analgesic efficacy. Our previous study demonstrated that MF has anti-influenza A virus activity; however, the contribution of TSN is still unclear. In this study, we found that TSN suppressed influenza A virus infection when administered before or concurrent with the virus, but not after infection. TSN pretreatment inhibited viral hemagglutinin (HA), nucleoprotein (NP), polymerase acidic (PA) protein, and matrix protein 2 (M2) mRNA synthesis as well as NP, PA, M2, and nonstructural protein 1 (NS1) expression but had no effect on HA or neuraminidase (NA) activity. In addition, TSN induced cytoplasmic location of PA protein disrupting nuclear translocation. Docking simulation suggested that the binding affinity of TSN to PA protein may be stronger than that of a known PA protein inhibitor. Pretreatment with TSN also suppressed the infection-induced phospho-AKT expression but not the host immune response. Oral pretreatment with TSN enhanced the survival of infected mice. These results suggest that TSN inhibits influenza A virus infection at an early stage by altering PA protein nuclear localization. Thus, TSN may be a promising candidate for anti-influenza agent targeting the PA protein of the influenza A virus RNA polymerase complex.

Development of a lipoplex-type mRNA carrier composed of an ionizable lipid with a vitamin E scaffold and the KALA peptide for use as an ex vivo dendritic cell-based cancer vaccine

A dendritic cells (DCs)-based vaccine (DC-vaccine) system is an attractive technology for eliciting antigen-specific immune responses that can protect subjects from infectious diseases and for curing various types of cancers. For the insertion of a foreign antigen to DCs, the transfection of an antigen-coding mRNA to the cells is a promising approach. In order to introduce an antigen, a carrier for mRNA transfection is required, since the mRNA molecule per se is unstable in serum-containing medium. We previously reported on an ionizable lipid-like material with vitamin E-scaffolds (ssPalmE) as a material for a lipid nanoparticle (LNP)-based carrier for nucleic acids. In the present study, we report on the development of a lipoplex-type mRNA carrier for use as a DC-vaccine by using a combination of an ssPalmE-LNP and an α-helical cationic peptide "KALA" (ssPalmE-KALA). The transfection of mRNAs complexed with the ssPalmE-KALA achieved a significantly higher protein expression and the production of proinflammatory cytokines from murine bone marrow derived DCs (BMDCs) in comparison with a lipoplex that was prepared with an ssPalm with fatty acid-scaffolds (myristic acid; ssPalmM-KALA). A cellular uptake process and a pH-responsive membrane-destabilization activity cannot explain the preferred protein expression and immune-stimulation caused by the ssPalmE-KALA. Proteomic analyses suggest that transfection with the ssPalmM-KALA stimulates a down-regulatory pathway of translation, while the transfection with the ssPalmE-KALA does not stimulate it. In the vaccination with the BMDCs that were preliminarily transfected with an ovalbumin (OVA)-encoding mRNA elicited the induction OVA specific cytotoxic T-lymphocyte activity in vivo. In parallel, the vaccination induced significant prophylactic anti-tumor effects against a model tumor that stably expressed the OVA protein. Based on the above findings, the ssPalmE-KALA appears to be a potent ex vivo DCs-based RNA vaccine platform.

Genus Psoralea: A review of the traditional and modern uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Psoralea (Fabaceae) harbours 105 accepted species that are extensively used by local peoples and medicinal practitioners of China, India, and other countries for treatment of tooth decay, psoriasis, leucoderma, leprosy, kidney problems, tuberculosis, indigestion, constipation and impotence. Presently, pharmacological research reports are available on only few species namely Bituminaria bituminosa (Syn: P. bituminosa), P. canescens, P. corylifolia, P. esculenta, P. plicata and P. glandulosa which are valued for their chemical constituents and traditional uses.

AIM OF THE REVIEW

This review article provides explicit information on traditional uses, phytochemistry, and pharmacological activities of selected Psoralea species. The possible trends and perspectives for future research on these plants are also discussed.

MATERIALS AND METHODS

An extensive and systematic review of the extant literature was carried out, and the data under various sections were identified using a computerized bibliographic search via the PubMed, Web of Science and Google Scholar, CAB Abstracts, MEDLINE, EMBASE, INMEDPLAN, NATTS as well as several websites.

KEY FINDINGS

A total of 291 bioactive compounds from 06 species of genus Psoralea have been isolated and characterized. However, P. bituminosa alone possess nearly 150 compounds. These bioactive compounds belong to different chemical classes, including flavonoids, coumarins, furanocoumarins, chalcones, quinines, terpenoids and some others due to which these species exhibit significant anti-oxidant, anti-bacterial, anti-fungal, anti-viral, anti-helmintic, anti-diabetic, diuretic, hepatoprotective, anti-cancer and anti-tumor activities. P. corylifolia L. (Babchi), a Chinese traditional medicinal plant has been used in traditional medicine for many decades for its healing properties against numerous skin diseases such as leprosy, psoriasis and leucoderma.

CONCLUSIONS

The in vitro studies and in vivo models have provided a simple bio-scientific justification for various ethnopharmacological uses of Psoralea species. From the toxicological perspective, the root, leaf, and seed extracts and their preparations have been proven to be safe when consumed in the recommended doses. But, meticulous studies on the pharmaceutical standardization, mode of action of the active constituents, and sustainable conservation of Psoralea species are needed, to meet the growing demands of the pharmaceutical industries, and to fully exploit their preventive and therapeutic potentials.

Anti-tumour activity of oncolytic reovirus against canine histiocytic sarcoma cells

Canine histiocytic sarcoma is an aggressive, fatal neoplastic disease with a poor prognosis. Lomustine is generally accepted as the first-line systemic therapy, although this compound does not provide complete regression. Therefore, research into a novel approach against canine histiocytic sarcoma is needed. However, anti-tumour effects of oncolytic therapy using reovirus against histiocytic sarcoma are unknown. Here, we showed that reovirus has oncolytic activity in canine histiocytic sarcoma cell lines in vitro and in vivo. We found that reovirus can replicate and induce caspase-dependent apoptosis in canine histiocytic sarcoma cell lines. A single intra-tumoural injection of reovirus completely suppressed the growth of subcutaneously grafted tumours in NOD/SCID mice. Additionally, we demonstrated that susceptibility to reovirus-induced cell death was attributable to the extent of expression of type I interferons induced by reovirus infection in vitro. In conclusion, oncolytic reovirus appears to be an effective treatment option for histiocytic sarcoma, and therefore warrants further investigation in early clinical trials.

Role of Nrf2 and Its Activators in Respiratory Diseases

Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a major regulator of antioxidant response element- (ARE-) driven cytoprotective protein expression. The activation of Nrf2 signaling plays an essential role in preventing cells and tissues from injury induced by oxidative stress. Under the unstressed conditions, natural inhibitor of Nrf2, Kelch-like ECH-associated protein 1 (Keap1), traps Nrf2 in the cytoplasm and promotes the degradation of Nrf2 by the 26S proteasome. Nevertheless, stresses including highly oxidative microenvironments, impair the ability of Keap1 to target Nrf2 for ubiquitination and degradation, and induce newly synthesized Nrf2 to translocate to the nucleus to bind with ARE. Due to constant exposure to external environments, including diverse pollutants and other oxidants, the redox balance maintained by Nrf2 is fairly important to the airways. To date, researchers have discovered that Nrf2 deletion results in high susceptibility and severity of insults in various models of respiratory diseases, including bronchopulmonary dysplasia (BPD), respiratory infections, acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), asthma, idiopathic pulmonary fibrosis (IPF), and lung cancer. Conversely, Nrf2 activation confers protective effects on these lung disorders. In the present review, we summarize Nrf2 involvement in the pathogenesis of the above respiratory diseases that have been identified by experimental models and human studies and describe the protective effects of Nrf2 inducers on these diseases.

Bakuchiol protects against pathological cardiac hypertrophy by blocking NF-κB signaling pathway

Bakuchiol (Bak), a monoterpene phenol isolated from the seeds of Psoralea corylifolia, has been widely used to treat a large variety of diseases in both Indian and Chinese folkloric medicine. However, the effects of Bak on cardiac hypertrophy remain unclear. Therefore, the present study was designed to determine whether Bak could alleviate cardiac hypertrophy. Mice were subjected to aortic banding (AB) to induce cardiac hypertrophy model. Bak of 1 ml/100 g body weight was given by oral gavage once a day from 1 to 8 weeks after surgery. Our data demonstrated for the first time that Bak could attenuate pressure overload-induced cardiac hypertrophy and could attenuate fibrosis and the inflammatory response induced by AB. The results further revealed that the effect of Bak on cardiac hypertrophy was mediated by blocking the activation of the NF-κB signaling pathway. In vitro studies performed in neonatal rat cardiomyocytes further proved that the protective effect of Bak on cardiac hypertrophy is largely dependent on the NF-κB pathway. Based on our results, Bak shows profound potential for its application in the treatment of pathological cardiac hypertrophy, and we believe that Bak may be a promising therapeutic candidate to treat cardiac hypertrophy and heart failure.

Therapeutic Modulation of Virus-Induced Oxidative Stress via the Nrf2-Dependent Antioxidative Pathway

Virus-induced oxidative stress plays a critical role in the viral life cycle as well as the pathogenesis of viral diseases. In response to reactive oxygen species (ROS) generation by a virus, a host cell activates an antioxidative defense system for its own protection. Particularly, a nuclear factor erythroid 2p45-related factor 2 (Nrf2) pathway works in a front-line for cytoprotection and detoxification. Recently, a series of studies suggested that a group of clinically relevant viruses have the capacity for positive and negative regulations of the Nrf2 pathway. This virus-induced modulation of the host antioxidative response turned out to be a crucial determinant for the progression of several viral diseases. In this review, virus-specific examples of positive and negative modulations of the Nrf2 pathway will be summarized first. Then a number of successful genetic and pharmacological manipulations of the Nrf2 pathway for suppression of the viral replication and the pathogenesis-associated oxidative damage will be discussed later. Understanding of the interplay between virus-induced oxidative stress and antioxidative host response will aid in the discovery of potential antiviral supplements for better management of viral diseases.

Fatty Acid Metabolism is Associated With Disease Severity After H7N9 Infection

BACKGROUND

Human infections with the H7N9 virus could lead to lung damage and even multiple organ failure, which is closely associated with a high mortality rate. However, the metabolic basis of such systemic alterations remains unknown.

METHODS

This study included hospitalized patients (n = 4) with laboratory-confirmed H7N9 infection, healthy controls (n = 9), and two disease control groups comprising patients with pneumonia (n = 9) and patients with pneumonia who received steroid treatment (n = 10). One H7N9-infected patient underwent lung biopsy for histopathological analysis and expression analysis of genes associated with lung homeostasis. H7N9-induced systemic alterations were investigated using metabolomic analysis of sera collected from the four patients by using ultra-performance liquid chromatography-mass spectrometry. Chest digital radiography and laboratory tests were also conducted.

FINDINGS

Two of the four patients did not survive the clinical treatments with antiviral medication, steroids, and oxygen therapy. Biopsy revealed disrupted expression of genes associated with lung epithelial integrity. Histopathological analysis demonstrated severe lung inflammation after H7N9 infection. Metabolomic analysis indicated that fatty acid metabolism may be inhibited during H7N9 infection. Serum levels of palmitic acid, erucic acid, and phytal may negatively correlate with the extent of lung inflammation after H7N9 infection. The changes in fatty acid levels may not be due to steroid treatment or pneumonia.

INTERPRETATION

Altered structural and secretory properties of the lung epithelium may be associated with the severity of H7N9-infection-induced lung disease. Moreover, fatty acid metabolism level may predict a fatal outcome after H7N9 virus infection.

Influenza A virus nucleoprotein is acetylated by histone acetyltransferases PCAF and GCN5

Histone acetylation plays crucial roles in transcriptional regulation and chromatin organization. Viral RNA of the influenza virus interacts with its nucleoprotein (NP), whose function corresponds to that of eukaryotic histones. NP regulates viral replication and has been shown to undergo acetylation by the cAMP-response element (CRE)–binding protein (CBP) from the host. However, whether NP is the target of other host acetyltransferases is unknown. Here, we show that influenza virus NP undergoes acetylation by the two host acetyltransferases GCN5 and P300/CBP-associated factor (PCAF) and that this modification affects viral polymerase activities. Western blot analysis with anti–acetyl-lysine antibody on cultured A549 human lung adenocarcinoma epithelial cells infected with different influenza virus strains indicated acetylation of the viral NP. A series of biochemical analyses disclosed that the host lysine acetyltransferases GCN5 and PCAF acetylate NP in vitro. MS experiments identified three lysine residues as acetylation targets in the host cells and suggested that Lys-31 and Lys-90 are acetylated by PCAF and GCN5, respectively. RNAi-mediated silencing of GCN5 and PCAF did not change acetylation levels of NP. However, interestingly, viral polymerase activities were increased by the PCAF silencing and were decreased by the GCN5 silencing, suggesting that acetylation of the Lys-31 and Lys-90 residues has opposing effects on viral replication. Our findings suggest that epigenetic control of NP via acetylation by host acetyltransferases contributes to regulation of polymerase activity in the influenza A virus.

The role of oxidative stress in influenza virus infection

Virus-induced oxidative stress plays an important role in the regulation of the host immune system. In this review, we provide backgrounds of the pathogenic mechanism of oxidative stress induced by influenza virus and the specific oxidant-sensitive pathways, and highlight that antioxidant is one of the effective strategies against influenza virus infection.

Are Dopamine Oxidation Metabolites Involved in the Loss of Dopaminergic Neurons in the Nigrostriatal System in Parkinson's Disease?

In 1967, L-dopa was introduced as part of the pharmacological therapy of Parkinson's disease (PD) and, in spite of extensive research, no additional effective drugs have been discovered to treat PD. This brings forward the question: why have no new drugs been developed? We consider that one of the problems preventing the discovery of new drugs is that we still have no information on the pathophysiology of the neurodegeneration of the neuromelanin-containing nigrostriatal dopaminergic neurons. Currently, it is widely accepted that the degeneration of dopaminergic neurons, i.e., in the substantia nigra pars compacta, involves mitochondrial dysfunction, the formation of neurotoxic oligomers of alpha-synuclein, the dysfunction of protein degradation systems, neuroinflammation, and oxidative and endoplasmic reticulum stress. However, the initial trigger of these mechanisms in the nigrostriatal system is still unknown. It has been reported that aminochrome induces the majority of these mechanisms involved in the neurodegeneration process. Aminochrome is formed within the cytoplasm of neuromelanin-containing dopaminergic neurons during the oxidation of dopamine to neuromelanin. The oxidation of dopamine to neuromelanin is a normal and harmless process, because healthy individuals have intact neuromelanin-containing dopaminergic neurons. Interestingly, aminochrome-induced neurotoxicity is prevented by two enzymes: DT-diaphorase and glutathione transferase M2-2, which explains why melanin-containing dopaminergic neurons are intact in healthy human brains.

Ethanolic Extract of Melia Fructus Has Anti-influenza A Virus Activity by Affecting Viral Entry and Viral RNA Polymerase

Meliae Fructus (MF) is the dried ripe fruit of Melia toosendan Siebold et Zuccarini, Meliaceae family. MF is widely used in traditional medicine to treat inflammation and helminthic infection and has anti-bacterial, anti-oxidant, anti-cancer, anti-inflammatory, and analgesic activities. However, potential anti-influenza properties of MF have yet to be investigated. We determined whether an ethanolic extract of MF (EMF) has anti-viral activity via an EMF pre-, co-, and post-treatment assay, using the Influenza A/PR/8/34 and H3N2 virus on Madin-Darby canine kidney (MDCK) cells. The EMF had anti-influenza virus activity in pre- and co-treated cells in a dose-dependent manner, but not in post-treated cell. EMF inhibited the activity of hemagglutinin (HA) and neuraminidase (NA) of influenza virus. EMF inhibited viral HA, nucleoprotein (NP), matrix protein 2 (M2), non-structural protein 1 (NS1), polymerase acidic protein (PA), polymerase basic protein 1 (PB1), and polymerase basic protein 2 (PB2) mRNA synthesis at 5 h post infection (hpi), however, the levels of PA, PB1, and PB2 mRNA were increased in pre- and co-EMF treated cells compared with control virus-infected and EMF post-treated cells at 18 hpi. The level of M2 protein expression was also decreased upon pre- and co-treatment with EMF. The PA protein was accumulated and localized in not only the nucleus but also the cytoplasm of virus-infected MDCK cells at 18 hpi. Pre-EMF treatment inhibited the expression of pAKT, which is induced by influenza virus infection, at the stage of virus entry. We also found that treatment of EMF up-regulated the antiviral protein Mx1, which may play a partial role in inhibiting influenza virus infection in pre- and co-EMF treated MDCK cells. In summary, these results strongly suggested that an ethanolic extract of Meliae Fructus inhibited influenza A virus infection by affecting viral entry, PA proteins of the RNA polymerase complex, and Mx1 induction and may be a potential and novel anti-influenza agent.

Anti-influenza virus activity of extracts from the stems of Jatropha multifida Linn. collected in Myanmar

Background

To contribute to the development of novel anti-influenza drugs, we investigated the anti-influenza activity of crude extracts from 118 medicinal plants collected in Myanmar. We discovered that extract from the stems of Jatropha multifida Linn. showed anti-influenza activity. J. multifida has been used in traditional medicine for the treatment of various diseases, and the stem has been reported to possess antimicrobial, antimalarial, and antitumor activities. However, the anti-influenza activity of this extract has not yet been investigated.

Methods

We prepared water (H₂O), ethyl acetate (EtOAc), n-hexane (Hex), and chloroform (CHCl₃) extracts from the stems of J. multifida collected in Myanmar, and examined the survival of Madin-Darby canine kidney (MDCK) cells infected with the influenza A (H1N1) virus, and the inhibitory effects of these crude extracts on influenza A viral infection and growth in MDCK cells.

Results

The H₂O extracts from the stems of J. multifida promoted the survival of MDCK cells infected with the influenza A H1N1 virus. The EtOAc and CHCl₃ extracts resulted in similar, but weaker, effects. The H₂O, EtOAc, and CHCl₃ extracts from the stems of J. multifida inhibited influenza A virus H1N1 infection; the H₂O extract possessed the strongest inhibitory effect on influenza infection in MDCK cells. The EtOAc, Hex, and CHCl₃ extracts all inhibited the growth of influenza A H1N1 virus, and the CHCl₃ extract demonstrated the strongest activity in MDCK cells.

Conclusion

The H₂O or CHCl₃ extracts from the stems of J. multifida collected in Myanmar demonstrated the strongest inhibition of influenza A H1N1 viral infection or growth in MDCK cells, respectively. These results indicated that the stems of J. multifida could be regarded as an anti-influenza herbal medicine as well as a potential crude drug source for the development of anti-influenza compounds.

In vitro Anti-viral Activity of Psoraleae Semen Water Extract against Influenza A Viruses

Influenza causes respiratory infections and poses health risks to humans and animals; its effects are complicated by increasing resistance to existing anti-influenza viral agents. Therefore, novel therapeutic approaches against influenza virus infection are required. Psoraleae semen has been widely used in traditional medicine in Korea, Taiwan, China, and Japan for treating and preventing various diseases. In this study, we examined the anti-viral activities and mechanism of action of the water extract of Psoraleae semen (WPS) using RAW 264.7 and MDCK cells. We found that pre- and post-treatment with 100 μg/mL WPS markedly inhibited influenza A virus replication as assessed using a green fluorescent protein reporter virus, reduced viral protein expression (NS-1, PA, HA, PB-1, M1, and M2), and inhibited NA and HA activities. Mechanism studies revealed that WPS induced type I interferon cytokine secretion and subsequent stimulation of an anti-viral state in RAW 264.7 cells. Further, WPS exerted inhibitory effects on neuraminidase in influenza virus strains H1N1 and H3N2. Meanwhile, WPS exhibited inhibitory effects on hemagglutination in H3N2 but not in H1N1. Based on these results, WPS serves as an immunomodulator and inhibitor of influenza hemagglutinin and neuraminidase. Our results suggest that WPS is a promising source of novel anti-influenza drug candidates.

Quantitative Analysis of Psoralea corylifolia Linne and its Neuroprotective and Anti-Neuroinflammatory Effects in HT22 Hippocampal Cells and BV-2 Microglia

The seeds of Psoralea corylifolia L. (P. corylifolia), also known as “Bo-Gol-Zhee” in Korea, are used in a traditional herbal medicine for treating various skin diseases. In the present study, we performed quantitative analyses of the seven standard components of P. corylifolia: psoralen, angelicin, neobavaisoflavone, psoralidin, isobavachalcone, bavachinin, and bakuchiol, using high-performance liquid chromatography. We also investigated the neuroprotective and anti-neuroinflammation effects of P. corylifolia and its standard components in the hippocampal cell line HT22 and microglia cell line BV-2. A 70% ethanol extract of P. corylifolia was prepared and the seven standard components were separated using C-18 analytical columns by gradient solvents with acetonitrile and water, and ultraviolet detection at 215, 225 and 275 nm. The analytical method showed high linearity, with a correlation coefficient of ≥0.9999. The amounts of the standard components ranged from 0.74 to 11.71 mg/g. Among the components, bakuchiol (11.71 mg/g) was the most potent phytochemical component of P. corylifolia. Furthermore, we analyzed the inhibitory effects of the components from P. corylifolia to determine the bioactive compound needed to regulate neuronal cell changes. Angelicin, isobavachalcone, and bakuchiol suppressed lipopolysaccharide (LPS)-stimulated nitric oxide production in LPS-treated BV-2 microglia more significantly than did the other components. In HT22 hippocampal cells, neobavaisoflavone and bakuchiol had more potent inhibitory activity against hydrogen peroxide-induced cell death. Taken together of the quantification and efficacy analyses, bakuchiol appeared to be the most potent bioactive phytochemical component of P. corylifolia for the potential treatment of neurodegenerative diseases.