Promising Antiviral Activity of Agrimonia pilosa Phytochemicals against Severe Acute Respiratory Syndrome Coronavirus 2 Supported with In Vivo Mice Study

Studying the effects of secondary metabolites isolated from Cycas thouarsii R.Br. leaves on MDA-MB-231 breast cancer cells

The various therapeutic drugs that are currently utilized for the management of cancer, especially breast cancer, are greatly challenged by the augmented resistance that is either acquired or de novo by the cancer cells owing to the long treatment periods. So, this study aimed at elucidating the possible anticancer potential of four compounds 7, 4', 7'', 4'''-tetra-O-methyl amentoflavone, hesperidin, ferulic acid, and chlorogenic acid that are isolated from Cycas thouarsii leaves n-butanol fraction for the first time. The MTT assay evaluated the cytotoxic action of four isolated compounds against MDA-MB-231 breast cancer cells and oral epithelial cells. Interestingly, ferulic acid revealed the lowest IC50 of 12.52 µg/mL against MDA-MB-231 cells and a high IC50 of 80.2 µg/mL against oral epithelial cells. Also, using an inverted microscope, the influence of ferulic acid was studied on the MDA-MB-231, which revealed the appearance of apoptosis characteristics like shrinkage of the cells and blebbing of the cell membrane. In addition, the flow cytometric analysis showed that the MDA-MB-231 cells stained with Annexin V/PI had a rise in the count of the cells in the early and late apoptosis stages. Moreover, gel electrophoresis detected DNA fragmentation in the ferulic acid-treated cells. Finally, the effect of the compound was tested at the molecular level by qRT-PCR. An upregulation of the pro-apoptotic genes (BAX and P53) and a downregulation of the anti-apoptotic gene (BCL-2) were observed. Consequently, our study demonstrated that these isolated compounds, especially ferulic acid, may be vital anticancer agents, particularly for breast cancer, through its induction of apoptosis through the P53-dependent pathway.

Repurposing simvastatin for treatment of Klebsiella pneumoniae infections: in vitro and in vivo study

Simvastatin had minimum inhibitory concentrations of 32 to 128 µg/mL against Klebsiella pneumoniae isolates and hindered the biofilm-formation ability of 58.54% of the isolates. It considerably diminished the bacterial cell counts in the biofilms as revealed by scanning electron microscope. Also, qRT-PCR revealed a downregulation of the biofilm genes (bcsA, wza, and luxS) by simvastatin in 48.78% of the isolates. Moreover, simvastatin has significantly improved the survival of mice and decreased the burden of bacteria in the infected lungs. Also, the histological architecture was substantially improved in the simvastatin-treated group, as the alveolar sacs and bronchioles appeared normal with minimal collagen fiber deposition. The immunohistochemical studies exposed that the TNF-α, NF-kβ, and COX-2 immunostaining considerably declined in the simvastatin-treated group. Furthermore, ELISA exposed that both IL-1β and IL-6 were considerably diminished in the lungs of the simvastatin-treated group.

COVID-19-Associated Sepsis: Potential Role of Phytochemicals as Functional Foods and Nutraceuticals

The acute manifestations of coronavirus disease 2019 (COVID-19) exhibit the hallmarks of sepsis-associated complications that reflect multiple organ failure. The inflammatory cytokine storm accompanied by an imbalance in the pro-inflammatory and anti-inflammatory host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to severe and critical septic shock. The sepsis signature in severely afflicted COVID-19 patients includes cellular reprogramming and organ dysfunction that leads to high mortality rates, emphasizing the importance of improved clinical care and advanced therapeutic interventions for sepsis associated with COVID-19. Phytochemicals of functional foods and nutraceutical importance have an incredible impact on the healthcare system, which includes the prevention and/or treatment of chronic diseases. Hence, in the present review, we aim to explore the pathogenesis of sepsis associated with COVID-19 that disrupts the physiological homeostasis of the body, resulting in severe organ damage. Furthermore, we have summarized the diverse pharmacological properties of some potent phytochemicals, which can be used as functional foods as well as nutraceuticals against sepsis-associated complications of SARS-CoV-2 infection. The phytochemicals explored in this article include quercetin, curcumin, luteolin, apigenin, resveratrol, and naringenin, which are the major phytoconstituents of our daily food intake. We have compiled the findings from various studies, including clinical trials in humans, to explore more into the therapeutic potential of each phytochemical against sepsis and COVID-19, which highlights their possible importance in sepsis-associated COVID-19 pathogenesis. We conclude that our review will open a new research avenue for exploring phytochemical-derived therapeutic agents for preventing or treating the life-threatening complications of sepsis associated with COVID-19.

Dioon rzedowskii: An antioxidant, antibacterial and anticancer plant extract with multi-faceted effects on cell growth and molecular signaling

This study investigated the antioxidant, anticancer, antibacterial properties of Dioon rzedowskii extract, which had not been previously explored. We aimed to determine the extract's effect on liver and breast cancer cell lines and on solid Ehrlich carcinoma (SEC) mouse model to investigate the underlying molecular mechanisms. Three female albino mice groups were established: a tumor control group, a group treated with 100 mg/kg of the extract (D100), and a group treated with 200 mg/kg of the extract (D200) for 16 days after tumor development. Results showed that the D. rzedowskii extract inhibited cell growth in both MCF-7 and HepG2 cells in a concentration-dependent manner. This was achieved by suppressing the cell proliferation and inducing apoptosis. The extract also improved liver, heart, and kidney functions compared to the tumor control. Furthermore, oral administration of the extract reduced tumor volume and alleviated oxidative stress in tumor tissue. The anticancer effects were associated with overexpression of p53 and Bax and downregulation of cyclin D1 expression, which was attributed to decreased phosphorylated MAPK kinases. Additionally, D. rzedowskii exhibited antibacterial activity against K. pneumoniae isolated from cancer patients. The extract inhibited bacterial growth and reduced the membrane integrity. The study suggests that D. rzedowskii has promising potential as an adjunctive therapy for cancer treatment. Further investigations are needed to explore its combined anticancer efficacy. These results emphasize the value of natural products in developing compounds with potential anticancer activity and support a paradigm shift in cancer management to improve patients' quality of life.

Next-generation probiotics: the upcoming biotherapeutics

Recent and continuing advances in gut microbiome research have pointed out the role of the gut microbiota as an unexplored source of potentially beneficial probiotic microbes. Along the lines of these advances, both public awareness and acceptance of probiotics are increasing. That's why; academic and industrial research is dedicated to identifying and investigating new microbial strains for the development of next-generation probiotics (NGPs). At this time, there is a growing interest in NGPs as biotherapeutics that alter the gut microbiome and affect various diseases development. In this work, we have focused on some emergent and promising NGPs, specifically Eubacterium hallii, Faecalibacterium prausnitzii, Roseburia spp., Akkermansia muciniphila, and Bacteroides fragilis, as their presence in the gut can have an impact on the development of various diseases. Emerging studies point out the beneficial roles of these NGPs and open up novel promising therapeutic options. Interestingly, these NGPs were found to enhance gastrointestinal immunity, enhance immunotherapy efficacy in cancer patients, retain the intestinal barrier integrity, generate valuable metabolites, especially short-chain fatty acids, and decrease complications of chemotherapy and radiotherapy. Although many of these NGPs are considered promising for the prevention and treatment of several chronic diseases, research on humans is still lacking. Therefore, approval of these microbes from regulatory agencies is rare. Besides, some issues limit their wide use in the market, such as suitable methods for the culture and storage of these oxygen-sensitive microbes. The present review goes over the main points related to NGPs and gives a viewpoint on the key issues that still hinder their wide application. Furthermore, we have focused on the advancement in NGPs and human healthiness investigations by clarifying the limitations of traditional probiotic microorganisms, discussing the characteristics of emerging NGPs and defining their role in the management of certain ailments. Future research should emphasize the isolation, mechanisms of action of these probiotics, safety, and clinical efficacy in humans.

Irisin/PGC-1α/FNDC5 pathway in Parkinson's disease: truth under the throes

Parkinson's disease (PD) is considered one of the most common neurodegenerative brain diseases which involves the deposition of α-synuclein. Irisin hormone, a newly discovered adipokine, has a valuable role in diverse neurodegenerative diseases. Therefore, this review aims to elucidate the possible role of the irisin hormone in PD neuropathology. Irisin hormone has a neuroprotective effect against the development and progression of various neurodegenerative disorders by increasing the expression of brain-derived neurotrophic factor (BDNF). Irisin hormone has anti-inflammatory, anti-apoptotic, and anti-oxidative impacts, thereby reducing the expression of the pro-inflammatory cytokines and the progression of neuroinflammation. Irisin-induced PGC-1α could potentially prevent α-synuclein-induced dopaminergic injury, neuroinflammation, and neurotoxicity in PD. Inhibition of NF-κB by irisin improves PGC-1α and FNDC5 signaling pathway with subsequent attenuation of PD neuropathology. Therefore, the irisin/PGC-1α/FNDC5 pathway could prevent dopaminergic neuronal injury. In conclusion, the irisin hormone has a neuroprotective effect through its anti-inflammatory and antioxidant impacts with the amelioration of brain BDNF levels. Further preclinical and clinical studies are recommended in this regard.

Rosuvastatin and diosmetin inhibited the HSP70/TLR4 /NF-κB p65/NLRP3 signaling pathways and switched macrophage to M2 phenotype in a rat model of acute kidney injury induced by cisplatin

Numerous efforts to manage acute kidney injury (AKI) were unsuccessful because its pathophysiology is still poorly understood. Thus, our research hotspot was to explore the possible renoprotective effects of rosuvastatin (Ros) and diosmetin (D) on macrophage polarization and the role of HSP70/TLR4/MyD88/NF-κB p65/NLRP3/STAT3 signaling in cis-induced AKI and study the activity of D against uropathogenic bacteria. Fifty-four albino male rats were randomized into 9 groups equally: Control, Ros, D20, D40, untreated Cis, and Cis groups cotreated with Ros, D20, D40 and Ros+D40 for 10 days. Our results indicated that Ros and D, in a dose-dependent manner, markedly restored body weight, systolic blood pressure, and renal histological architecture besides significantly upregulated SOD levels, expression of anti-inflammatory CD163 macrophages, arginase1levels, IL-10 levels,STAT3 and PCNA immunoreactivity. Also, they significantly downregulated renal index, serum urea, serum creatinine, serum cystatin c, inflammatory biomarkers (C reactive protein, IL1β & TNF-α), MDA levels, HSP70/TLR4/MyD88/NF-κB p65/NLRP3 expressions, proinflammatory CD68 macrophages and caspase-3 immunoreactivity, resulting in a reversal of cis-induced renal damage. These findings were further confirmed by molecular docking that showed the binding affinity of Ros and D towards TLR4 and NLRP3. Furthermore, D had antibacterial action with a minimum inhibitory concentration ranging from 128 to 256 µg/mL and caused a delay in the growth of the tested isolates, and negatively affected the membrane integrity. In conclusion, Ros and D had antioxidant, anti-inflammatory and antiapoptotic properties and switched macrophage from proinflammatory CD68 to anti-inflammatory CD163. Additionally, the targeting of HSP70/TLR4/MyD88/NF-κB p65/NLRP3/STAT3 signals are effective therapeutic strategy in AKI.

Antibacterial and anti-Toxoplasma activities of Aspergillus niger endophytic fungus isolated from Ficus retusa: in vitro and in vivo approach

Emergent records propose that Aspergillus niger endophytic fungus is a vital source for various bioactive molecules possessing many biological properties. The current study was designed to inspect the antibacterial and anti-Toxoplasma potentials of Ficus retusa-derived endophytic fungi. After isolation and identification (using 18S rRNA gene sequencing) of A. niger endophytic fungus, LC/MS was utilized for identification and authentication of the chemical profile of the A. niger endophyte extract. Then, the fungal extract was assessed for its antibacterial and antibiofilm activities against Klebsiella pneumoniae clinical isolates. Additionally, its efficacy against Toxoplasma gondii was elucidated in vivo. The fungal extract displayed antibacterial activity against K. pneumoniae isolates with minimum inhibitory concentration values of 64-512 µg/mL. It also possessed a membrane potential dissipating effect using flow cytometry. Moreover, it formed distorted cells with rough surfaces and deformed shapes using a scanning electron microscope (SEM). Regarding its antibiofilm activity, it resulted in a dysregulation of the genes encoding biofilm formation (fimH, mrkA and mrkD) using qRT-PCR in nine K. pneumoniae isolates. The in vivo anti-Toxoplasma potential was demonstrated by decreasing the mortality rate of mice and reducing the tachyzoites' count in the peritoneal fluids and liver impression smears of mice. In addition, the deformities of the parasite decreased, as revealed by SEM and the inflammation in tissues diminished. Thus, A. niger endophytic fungi could be a valuable source of antibacterial and anti-Toxoplasma compounds.

Phytochemical investigation, antibacterial, and ameliorative potential effects of Tamarix nilotica on LPS-induced acute lung injury model in mice

Acute lung injury (ALI) is a serious illness with a high mortality rate of 40-60%. It is characterised by systemic inflammatory processes and oxidative stress. Gram-negative bacterial infections are the major cause of ALI, and lipopolysaccharide (LPS) is the major stimulus for the release of inflammatory mediators. Hence, there is an urgent need to develop new therapies which ameliorate ALI and prevent its serious consequences. The Middle Eastern native plant Tamarix nilotica (Ehrenb) Bunge belongs to the family Tamaricaceae, which exhibits strong anti-inflammatory and antioxidant effects. Thus, the current work aimed to ensure the plausible beneficial effects of T. nilotica different fractions on LPS-induced acute lung injury after elucidating their phytochemical constituents using LC/MS analysis. Mice were randomly allocated into six groups: Control saline, LPS group, and four groups treated with total extract, DCM, EtOAc and n-butanol fractions, respectively, intraperitoneal at 100 mg/kg doses 30 min before LPS injection. The lung expression of iNOS, TGF-β1, NOX-1, NOX-4 and GPX-1 levels were evaluated. Also, oxidative stress was assessed via measurements of MDA, SOD and Catalase activity, and histopathological and immunohistochemical investigation of TNF-α in lung tissues were performed. T. nilotica n-butanol fraction caused a significant downregulation in iNOS, TGF-β1, TNF-α, NOX-1, NOX-4, and MDA levels (p ˂ 0.05), and significantly elevated GPX-1 expression levels, SOD, and catalase activity (p ˂ 0.05), and alleviated all histopathological abnormalities confirming its advantageous role in ALI. The antibacterial activities of T. nilotica and its different fractions were investigated by agar well diffusion method and broth microdilution method. Interestingly, the n-butanol fraction exhibited the best antibacterial activity against Klebsiella pneumoniae clinical isolates. It also significantly reduced exopolysaccharide quantity, cell surface hydrophobicity, and biofilm formation.

Antiviral and antibacterial potential of electrosprayed PVA/PLGA nanoparticles loaded with chlorogenic acid for the management of coronavirus and Pseudomonas aeruginosa lung infection

Respiratory tract infections are a common cause of morbidity and mortality globally. The current paper aims to treat this respiratory disorder. Therefore, we elucidated the phytochemical profile of Euphorbia milii flowers and isolated chlorogenic acid (CGA) for the first time. The electrospraying technique was utilized to prepare CGA nanoparticles in polyvinyl alcohol (PVA)/PLGA polymeric matrix. Complete in vitro characterizations were performed to determine particle size, polydispersity index (PDI), zeta potential, loading efficiency (LE), scanning electron microscopy and in vitro release study. The optimum formula (F2) with a particle size (454.36 ± 36.74 nm), a surface charge (-4.56 ± 0.84 mV), % of LE (80.23 ± 5.74), an initial burst (29.46 ± 4.79) and % cumulative release (97.42 ± 4.72) were chosen for further activities. In the murine lung infection model, PVA/PLGA NPs loaded with CGA (F2) demonstrated in vivo antibacterial activity against Pseudomonas aeruginosa. Using a plaque assay, the in vitro antiviral activity was investigated. The F2 exhibited antiviral activity against coronavirus (HCoV-229E) and (Middle East respiratory syndrome coronavirus (MERS-CoV), NRCEHKU270). The IC₅₀ of F2 against HCoV-229E and MERS-CoV was 170 ± 1.1 and 223 ± 0.88 µg/mL, respectively. The values of IC₅₀ of F2 were significantly lower (p < .05) than that of free CGA. Therefore, the encapsulation of CGA into electrospray PVA/PLGA NPs would be a promising tool as an antimicrobial agent.

Plausible Protective Role of Encephalartos villosus Extract in Acetic-Acid-Induced Ulcerative Colitis in Rats

Ulcerative colitis (UC) is an inflammatory ailment of the intestine associated with the upregulation of oxidative stress and pro-inflammatory cytokines. Here, we aimed to assess the consequences of Encephalartos villosus (EV) Lem extract on acetic acid (AA)-induced UC. Rats were randomly classified into five groups, as follows: control, AA, AA + mesalazine, AA + EV (50 mg/kg), and AA + EV (100 mg/kg) groups. EV (50 mg/kg and 100 mg/kg) and mesalzine (100 mg/kg) were administered orally for 14 days before the induction of UC. On the last day of the experiment, colitis was provoked via the intra-rectal delivery of 3% AA. Then, after 24 h, the rats were sacrificed and their colon tissues were isolated and inspected. Interestingly, EV pretreatment substantially (p < 0.05) reduced the elevated colon weight/length ratio and ulcer area and normalized the histological changes and immunohistochemical features. In addition, EV efficiently reduced the levels of myeloperoxidase (MPO) and increased the activity of glutathione peroxidase (GS-PX) and catalase (CAT). EV (100 mg/kg) resulted in a downregulation of toll-like receptor 4 (TLR-4) and upregulation of heme oxygenase 1 (HO-1) and occludin expression levels. Concerning the anti-inflammatory mechanisms, EV reduced the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nuclear transcription factor kappa B (NF-ĸB) and inhibited cyclooxygenase-2 (COX-2) expression levels. It also decreased caspase-3 levels. Our results indicate that the oral intake of EV improves AA-induced colitis in rats through its antioxidative effects and the modulation of pro-inflammatory cytokines, as well as the restoration of mucosal integrity. Consequently, EV may be an efficient therapeutic candidate for UC.

Extracts of Thesium chinense inhibit SARS-CoV-2 and inflammation in vitro

CONTEXT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading rapidly. Relevant research based on the antiviral effects of Thesium chinense Turcz (Santalaceae) was not found.

OBJECTIVE

To investigate the antiviral and anti-inflammatory effects of extracts of T. chinense.

MATERIALS AND METHODS

To investigate the anti-entry and replication effect of the ethanol extract of T. chinense (drug concentration 80, 160, 320, 640, 960 μg/mL) against the SARS-CoV-2. Remdesivir (20.74 μM) was used as positive control, and Vero cells were used as host cells to detect the expression level of nucleocapsid protein (NP) in the virus by real-time quantitative polymerase chain reaction (RT-PCR) and Western blotting. RAW264.7 cells were used as an anti-inflammatory experimental model under lipopolysaccharide (LPS) induction, and the expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The ethanol extract of T. chinense significantly inhibited the replication (half maximal effective concentration, EC50: 259.3 μg/mL) and entry (EC50: 359.1 μg/mL) of SARS-CoV-2 into Vero cells, and significantly reduced the levels of IL-6 and TNF-α produced by LPS-stimulated RAW264.7 cells. Petroleum ether (EC50: 163.6 μg/mL), ethyl acetate (EC50: 22.92 μg/mL) and n-butanol (EC50: 56.8 μg/mL) extracts showed weak inhibition of SARS-CoV-2 replication in Vero cells, and reduced the levels of IL-6 and TNF-α produced by LPS-stimulated RAW264.7 cells.

CONCLUSION

T. chinense can be a potential candidate to fight SARS-CoV-2, and is becoming a traditional Chinese medicine candidate for treating COVID-19.

Celecoxib-Loaded Cubosomal Nanoparticles as a Therapeutic Approach for Staphylococcus aureus In Vivo Infection

There is a great need for novel approaches to treating bacterial infections, due to the vast dissemination of resistance among pathogenic bacteria. Staphylococcus aureus are ubiquitous Gram-positive pathogenic bacteria and are rapidly acquiring antibiotic resistance. Here, celecoxib was encapsulated into cubosomal nanoparticles, and the particle morphology, size distribution, zeta potential, entrapment efficiency, and celecoxib release were evaluated in vitro. Also, a systemic infection model in mice elucidated the in vivo antibacterial action of the celecoxib cubosomes. Cubosomes are a nanotechnology-based delivery system which can adhere to the external peptidoglycan layers of Gram-positive bacteria and penetrate them. The size distribution investigation revealed that the prepared celecoxib-loaded cubosomes had a mean particle size of 128.15 ± 3.04 nm with a low polydispersity index of 0.235 ± 0.023. The zeta potential measurement showed that the prepared cubosomes had a negative surface charge of -17.50 ± 0.45, indicating a highly stable nanodispersion formation with little susceptibility to particle aggregation. The cubosomal dispersion exhibited an entrapment efficiency of 88.57 ± 2.36%. The transmission electron micrograph for the prepared celecoxib-loaded cubosomes showed a narrow size distribution for the cubosomal nanoparticles, which had a spherical shape and were non-aggregated. The tested cubosomes diminished the inflammation in the treated mice's liver and spleen tissues, as revealed by hematoxylin and eosin stain and Masson's trichrome stain. The immunostained tissues with nuclear factor kappa B and caspase-3 monoclonal antibodies revealed a marked decrease in these markers in the celecoxib-treated group, as it resulted in negative or weak immunostaining in liver and spleen that ranged from 4.54% to 17.43%. This indicates their inhibitory effect on the inflammatory pathway and apoptosis, respectively. Furthermore, they reduced the bacterial burden in the studied tissues. This is alongside a decrease in the inflammatory markers (interleukin-1 beta, interleukin-6, cyclooxygenase-2, and tumor necrosis factor-alpha) determined by ELISA and qRT-PCR. The IL-1β levels were 16.66 ± 0.5 pg/mg and 17 ± 0.9 pg/mg in liver and spleen, respectively. Also, IL-6 levels were 85 ± 3.2 pg/mg and 84 ± 2.4 pg/mg in liver and spleen, respectively. In conclusion, the current study introduced cubosomes as an approach for the formulation of celecoxib to enhance its in vivo antibacterial action by improving its oral bioavailability.

In Vitro Antiviral Effect and Potential Neuroprotection of Salvadora persica L. Stem Bark Extract against Lipopolysaccharides-Induced Neuroinflammation in Mice: LC-ESI-MS/MS Analysis of the Methanol Extract

Neuroinflammation is a serious immunomodulatory complex disorder that causes neurological and somatic ailments. The treatment of brain inflammation with new drugs derived from natural sources is a significant therapeutic goal. Utilizing LC-ESI-MS/MS analysis, the active constituents of Salvadora persica extract (SPE) were identified tentatively as exerting antioxidant and anti-inflammatory effects in natural medicine. Herein, we determined the antiviral potential of SPE against herpes simplex virus type 2 (HSV-2) using the plaque assay. HSV-2 is a neurotropic virus that can cause neurological diseases. SPE exhibited promising antiviral potential with a half-maximal cytotoxic concentration (CC50) of 185.960 ± 0.1 µg/mL and a half-maximal inhibitory concentration (IC50) of 8.946 ± 0.02 µg/mL. The in vivo study of the SPE impact against lipopolysaccharide (LPS)-induced neuroinflammation was performed using 42 mice divided into seven groups. All groups were administered LPS (0.25 mg/kg) intraperitoneally, except for the normal and SPE groups 1 and 2. Groups 5, 6, and 7 received 100, 200, and 300 mg/kg SPE. It was revealed that SPE inhibited acetylcholinesterase in the brain. It increased superoxide dismutase and catalase while decreasing malondialdehyde, which explains its antioxidative stress activity. SPE downregulated the gene expression of the inducible nitric oxide synthase, as well as the apoptotic markers (caspase-3 and c-Jun). In addition, it decreased the expression of the proinflammatory cytokines (interleukin-6 and tumor necrosis factor-alpha). Mice administered SPE (300 mg/kg) with LPS exhibited normal neurons in the cerebral cortices, hippocampus pyramidal layer, and cerebellum, as determined by the histopathological analysis. Therefore, using S. persica to prevent and treat neurodegeneration could be a promising new therapeutic strategy to be explored.

Cholinergic dysfunction in COVID-19: frantic search and hoping for the best

A novel coronavirus known as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a potential cause of acute respiratory infection called coronavirus disease 2019 (COVID-19). The binding of SARS-CoV-2 with angiotensin-converting enzyme 2 (ACE2) induces a series of inflammatory cellular events with cytopathic effects leading to cell injury and hyperinflammation. Severe SARS-CoV-2 infection may lead to dysautonomia and sympathetic storm due to dysfunction of the autonomic nervous system (ANS). Therefore, this review aimed to elucidate the critical role of the cholinergic system (CS) in SARS-CoV-2 infection. The CS forms a multi-faceted network performing diverse functions in the body due to its distribution in the neuronal and non-neuronal cells. Acetylcholine (ACh) acts on two main types of receptors which are nicotinic receptors (NRs) and muscarinic receptors (MRs). NRs induce T cell anergy with impairment of antigen-mediated signal transduction. Nicotine through activation of T cell NRs inhibits the expression and release of the pro-inflammatory cytokines. NRs play important anti-inflammatory effects while MRs promote inflammation by inducing the release of pro-inflammatory cytokines. SARS-CoV-2 infection can affect the morphological and functional stability of CS through the disruption of cholinergic receptors. SARS-CoV-2 spike protein is similar to neurotoxins, which can bind to nicotinic acetylcholine receptors (nAChR) in the ANS and brain. Therefore, cholinergic receptors mainly nAChR and related cholinergic agonists may affect the pathogenesis of SARS-CoV-2 infection. Cholinergic dysfunction in COVID-19 is due to dysregulation of nAChR by SARS-CoV-2 promoting the central sympathetic drive with the development of the sympathetic storm. As well, nAChR activators through interaction with diverse signaling pathways can reduce the risk of inflammatory disorders in COVID-19. In addition, nAChR activators may mitigate endothelial dysfunction (ED), oxidative stress (OS), and associated coagulopathy in COVID-19. Similarly, nAChR activators may improve OS, inflammatory changes, and cytokine storm in COVID-19. Therefore, nAChR activators like varenicline in virtue of its anti-inflammatory and anti-oxidant effects with direct anti-SARS-CoV-2 effect could be effective in the management of COVID-19.

Protective Potential of Saussurea costus (Falc.) Lipsch. Roots against Cyclophosphamide-Induced Pulmonary Injury in Rats and Its In Vitro Antiviral Effect

Diseases and infections of the respiratory tract are common global causes of morbidity and mortality. Our study attempts to elucidate a novel remedy for respiratory ailments, in addition to identifying and quantifying the metabolites of Saussurea costus root extract (SCRE) using HPLC. Then, in vitro antiviral and in vivo lung protective effects were elucidated. The in vitro antiviral potential of SCRE was analyzed via plaque assay against the low pathogenic human coronavirus (HCoV-229E) and human influenza virus (H1N1). The value of the half maximal inhibitory concentrations (IC50) of SCRE against HCoV-229E and H1N1 influenza virus were 23.21 ± 1.1 and 47.6 ± 2.3 µg/mL, respectively. SCRE showed a histological improvement, namely a decrease in inducible nitric oxide synthase (iNOS) and caspase-3 immunoexpression in in vivo cyclophosphamide (CP)-induced acute lung injury (ALI). Moreover, there was a considerable decline in microRNA-let-7a gene expression and a significant rise in heme oxygenase-1 (HO-1) gene expression, with a marked decrease in the malondialdehyde (MDA) level. Molecular docking studies revealed that the major constituents of SCRE have a good affinity for caspase-3, HO-1, and iNOS proteins. In conclusion, a traditional plant SCRE could be a promising source of novel therapeutic agents for treating and protecting respiratory tract diseases. More future investigations should be carried out to reveal its efficacy clinically.

Integrated Proteomics and Metabolomics Analysis to Explore the Amelioration Mechanisms of Rosa roxburghii Tratt Fruit Polyphenols on Lipopolysaccharide-Induced Acute Lung Injury Mice

Acute lung injury (ALI) is the main cause of death for the elderly and children due to its high morbidity and mortality rates. Plant-derived functional foods are becoming increasingly important to the healthcare and food industries for adjunctive and alternative treatments of ALI. Polyphenols have been regarded to be beneficial to the prevention and amelioration of ALI. Rosa roxburghii Tratt fruit polyphenols (RRTP) has potential to prevent ALI, but mechanism remains unclear. This study was set up to systematically analyze the RRTP extract active ingredients, comprehensively evaluate its protective effects via lung histopathological examination, protein concentration, and cytokines production in ALI mice induced by lipopolysaccharide (LPS), and finally revealed alleviation mechanisms of the regulatory effects of RRTP by proteomics and metabolomics approach. The results demonstrated RRTP could synergistically exert significant preventive effects against ALI by notably ameliorating lung histopathological damage and pulmonary capillary permeability in ALI mice, inhibiting lung tissue inflammatory response and acute phase proteins and S-100 calcium binding proteins, suppressing excessive activation of complement and coagulation cascades, and regulating disordered lipids metabolism and amino acid metabolism. This study illustrated that RRTP has obvious advantages in ALI adjunctive therapy and revealed the complicated amelioration mechanisms, which provides a breakthrough for the development and demonstration of RRTP as a nutritional compound additive for complementary therapy of ALI.

Potential role of lipoxin in the management of COVID-19: a narrative review

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection leads to the development of coronavirus disease 2019 (COVID-19), which causes endothelial dysfunction (ED), oxidative stress (OS), and inflammatory disorders. These changes cause hypoxia and cytokine storm with the development of cardio-pulmonary complications. Bioactive lipids and other polyunsaturated fatty acids participate in a vital role in the SARS-CoV-2 infection process. One of these mediators is the anti-inflammatory compound, lipoxin (LX). LXs are produced from arachidonic acid (AA) by collaboration between 5-lipoxygenase (5-LO) and 12-15 LO during cell interactions. Thus, our goal was to review the probable role of LXs in COVID-19 regarding the effects of LXs on the inflammatory signaling pathways that are linked with COVID-19 pathogenesis and complications.

Is sitagliptin effective for SARS-CoV-2 infection: false or true prophecy?

Coronavirus disease 2019 (Covid-19) is caused by severe acute respiratory syndrome type 2 (SARS-CoV-2). Covid-19 is characterized by hyperinflammation, oxidative stress, and multi-organ injury (MOI) such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Covid-19 is mainly presented with respiratory manifestations; however, extra-pulmonary manifestations may also occur. Extra-pulmonary manifestations of Covid-19 are numerous including: neurological, cardiovascular, renal, endocrine, and hematological complications. Notably, a cluster of differentiation 26 (CD26) or dipeptidyl peptidase-4 (DPP-4) emerged as a new receptor for entry of SARS-CoV-2. Therefore, DPP-4 inhibitors like sitagliptin could be effective in treating Covid-19. Hence, we aimed in the present critical review to assess the potential role of sitagliptin in Covid-19. DPP-4 inhibitors are effective against the increased severity of SARS-CoV-2 infections. Moreover, DPP-4 inhibitors inhibit the interaction between DPP-4 and scaffolding proteins which are essential for endosome formation and replication of SARS-CoV-2. Therefore, sitagliptin through attenuation of the inflammatory signaling pathway and augmentation of stromal-derived factor-1 (SDF-1) may decrease the pathogenesis of SARS-CoV-2 infection and could be a possible therapeutic modality in treating Covid-19 patients. In conclusion, the DPP-4 receptor is regarded as a potential receptor for the binding and entry of SARS-CoV-2. Inhibition of these receptors by the DPP-4 inhibitor, sitagliptin, can reduce the pathogenesis of the infection caused by SARS-CoV-2 and their associated activation of the inflammatory signaling pathways.

The Effect of Nitazoxanide on the Clinical Outcomes in Patients with COVID-19: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

Nitazoxanide, a US Food and Drug Administration-approved antiparasitic agent, was reported to be effective in treating coronavirus disease 2019 (COVID-19). The lack of effective and precise treatments for COVID-19 infection earlier in the pandemic forced us to depend on symptomatic, empirical, and supportive therapy, which overburdened intensive care units and exhausted hospital resources. Therefore, the aim of this systematic review and meta-analysis was  to assess the efficacy and safety of nitazoxanide for COVID-19 treatment.

METHODS

A systematic review and meta-analysis synthesizing relevant randomized controlled trials from six databases (MedRxiv, WOS, SCOPUS, EMBASE, PubMed, and CENTRAL) until 17 May 2022 was conducted. Risk ratio (RR) for dichotomous outcomes was used and data with a 95% confidence interval (CI) are presented. The protocol was registered in PROSPERO with ID: CRD42022334658.

RESULTS

Six randomized controlled trials with 1412 patients were included in the analysis. Nitazoxanide was effective in accelerating viral clearance compared with placebo (RR: 1.30 with 95% CI 1.08, 1.56, p = 0.006) and reducing oxygen requirements (RR: 0.48 with 95% CI 0.39, 0.59, p = 0.00001), but we found no difference between nitazoxanide and placebo in improving clinical resolution (RR: 1.01 with 95% CI 0.94, 1.08, p = 0.88), reducing the mortality rate (RR: 0.88 with 95% CI 0.4, 1.91, p = 0.74), and intensive care unit admission (RR: 0.69 with 95% CI 0.43, 1.13, p = 0.14). Moreover, nitazoxanide was as safe as placebo (RR: 0.9 with 95% CI 0.72, 1.12, p = 0.34).

CONCLUSIONS

Compared with placebo, nitazoxanide was effective in expediting viral clearance and decreasing oxygen requirements. However, there was no difference between nitazoxanide and placebo regarding clinical response, all-cause mortality, and intensive care unit admission. Therefore, more large-scale studies are still needed to ascertain the clinical applicability of nitazoxanide in COVID-19.

The role of berberine in Covid-19: potential adjunct therapy

Coronavirus disease 2019 (Covid-19) is a global diastrophic disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Covid-19 leads to inflammatory, immunological, and oxidative changes, by which SARS-CoV-2 leads to endothelial dysfunction (ED), acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and multi-organ failure (MOF). Despite evidence illustrating that some drugs and vaccines effectively manage and prevent Covid-19, complementary herbal medicines are urgently needed to control this pandemic disease. One of the most used herbal medicines is berberine (BBR), which has anti-inflammatory, antioxidant, antiviral, and immune-regulatory effects; thus, BBR may be a prospective candidate against SARS-CoV-2 infection. This review found that BBR has anti-SARS-CoV-2 effects with mitigation of associated inflammatory changes. BBR also reduces the risk of ALI/ARDS in Covid-19 patients by inhibiting the release of pro-inflammatory cytokines and inflammatory signaling pathways. In conclusion, BBR has potent anti-inflammatory, antioxidant, and antiviral effects. Therefore, it can be utilized as a possible anti-SARS-CoV-2 agent. BBR inhibits the proliferation of SARS-CoV-2 and attenuates the associated inflammatory disorders linked by the activation of inflammatory signaling pathways. Indeed, BBR can alleviate ALI/ARDS in patients with severe Covid-19. In this sense, clinical trials and prospective studies are suggested to illustrate the potential role of BBR in treating Covid-19.

Nitazoxanide and COVID-19: A review

Coronavirus disease 2019 (COVID-19) is a current global illness triggered by severe acute respiratory coronavirus 2 (SARS-CoV-2) leading to acute viral pneumonia, acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and cytokine storm in severe cases. In the COVID-19 era, different unexpected old drugs are repurposed to find out effective and cheap therapies against SARS-CoV-2. One of these elected drugs is nitazoxanide (NTZ) which is an anti-parasitic drug with potent antiviral activity. It is effectively used in the treatment of protozoa and various types of helminths in addition to various viral infections. Thus, we aimed to elucidate the probable effect of NTZ on SARS-CoV-2 infections. Findings of the present study illustrated that NTZ can reduce SARS-CoV-2-induced inflammatory reactions through activation of interferon (IFN), restoration of innate immunity, inhibition of the release of pro-inflammatory cytokines, suppression of the mammalian target of rapamycin (mTOR), and induction of autophagic cell death. Moreover, it can inhibit the induction of oxidative stress which causes cytokine storm and is associated with ALI, ARDS, and multi-organ damage (MOD). This study concluded that NTZ has important anti-inflammatory and immunological properties that may mitigate SARS-CoV-2 infection-induced inflammatory disorders. Despite broad-spectrum antiviral properties of NTZ, the direct anti-SARS-CoV-2 effect was not evident and documented in recent studies. Then, in silico and in vitro studies in addition to clinical trials and prospective studies are needed to confirm the beneficial impact of NTZ on the pathogenesis of SARS-CoV-2 infection.

Ursolic acid and SARS-CoV-2 infection: a new horizon and perspective

SARS-CoV-2 (severe acute respiratory syndrome coronavirus type 2) has been identified as the source of a world coronavirus pandemic in 2019. Covid-19 is considered a main respiratory disease-causing viral pneumonia and, in severe cases, leads to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Although, extrapulmonary manifestations of Covid-19 like neurological, cardiovascular, and gastrointestinal have been confirmed. Exaggerated immune response and release of a high amount of pro-inflammatory cytokines may progress, causing a cytokine storm. Consequently, direct and indirect effects of SARS-CoV-2 infection can evolve into systemic complications due to the progression of hyper inflammation, oxidative stress and dysregulation of the renin-angiotensin system (RAS). Therefore, anti-inflammatory and antioxidant agents could be efficient in alleviating these disorders. Ursolic acid has anti-inflammatory, antioxidant, and antiviral effects; it reduces the release of pro-inflammatory cytokines, improves anti-inflammatory cytokines, and inhibits the production of reactive oxygen species (ROS). In virtue of its anti-inflammatory and antioxidant effects, ursolic acid may minimize SARS-CoV-2 infection-induced complications. Also, by regulating RAS and inflammatory signaling pathways, ursolic acid might effectively reduce the development of ALI in ARDS in Covid-19. In this state, this perspective discusses how ursolic acid can mitigate hyper inflammation and oxidative stress in Covid-19.

Traditional herbs against COVID-19: back to old weapons to combat the new pandemic

BACKGROUND

Recently, the coronavirus (COVID-19) pandemic is a chief public health disaster caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are no established effective preventive or therapeutic anti-COVID-19 drugs available except for some recently approved vaccines. Still, countless recent studies recommend various alternative and complementary approaches against COVID-19, which are medicinal herbs employed as traditional remedies to enhance immunity to struggle with viral infections. In addition, physicians worldwide are highly interested in vitamin and mineral supplements to help them combat COVID-19 either through protection or treatment. Dietary supplements specifically vitamin D, vitamin C, and zinc provide good prophylactic and therapeutic support to the presently available treatment regimens. In the present work, we have focused on plant-based remedies with promising anti-COVID-19 activities.

AIM

To enable investigators and researchers to identify potential herbal compounds with anti-COVID activity to be used as promising therapies to combat this pandemic.

MAIN BODY

This review highlights the recently published studies concerning natural traditional herbs, herbal bioactive metabolites, dietary supplements, and functional foods that could help prevent and/or treat COVID-19. Herein, we explored medicinal herbs as potential inhibitors of SARS-CoV-2 and discussed how these studies help form larger discussions of diet and disease. Moreover, by investigating the herbal bioactive components, we have outlined several medicinal herbs that can fight against COVID-19 by hindering SARS-CoV-2 replication and entry to its host cells, deterring the cytokine storm, and several other means. Finally, we have summarized various herbal products, functional foods, and dietary supplements with potent bioactive compounds which can inhibit and/or prevent COVID-19 disease progression.

CONCLUSIONS

Based on the studies reviewed in this work, it was concluded with no doubt that phytochemical components present in various herbs could have a starring role in the deterrence and cure of coronavirus contagion.

Silver Nanoparticles Prepared Using Encephalartos laurentianus De Wild Leaf Extract Have Inhibitory Activity against Candida albicans Clinical Isolates

Candida albicans is a major human opportunistic pathogen causing infections, which range from cutaneous to invasive systemic infections. Herein, the antifungal and anti-biofilm potential of silver nanoparticles (AgNPs) green synthesized in the presence of Encephalartos laurentianus leaf extract (ELLE) were investigated. The bioactive chemicals of ELLE, including phenolics, flavonoids, and glycosides were identified and quantified for the first time. AgNPs showed minimum inhibitory concentration (MIC) values against C. albicans clinical isolates ranging from 8 to 256 µg/mL. In addition, AgNPs significantly decreased biofilm formation. The impact of AgNPs on the expression of the genes encoding biofilm formation was assessed using qRT-PCR. AgNPs had a beneficial role in the macroscopic wound healing, and they resulted in complete epithelization without any granulation tissue or inflammation. Treatment with AgNPs resulted in negative immunostaining of tumor necrosis factor-α. The levels of the inflammation markers, interleukin-6 and interleukin-1β, significantly decreased (p < 0.05) in the AgNPs-treated group. There was also a pronounced increase in the gene expression of fibronectin and platelet-derived growth factor in the wound tissues. Thus, AgNPs synthesized using ELLE may be a promising antifungal and wound healing agent.

Dipyridamole and adenosinergic pathway in Covid-19: a juice or holy grail

Background

Coronavirus disease 2019 (Covid-19) is an infectious worldwide pandemic triggered by severe acute respiratory coronavirus 2 (SARS-CoV-2). This pandemic disease can lead to pro-inflammatory activation with associated acute lung injury and acute respiratory distress syndrome.

Main body of the abstract

SARS-CoV-2 infection is linked with inhibition of adenosine and activation of phosphodiesterase. Dipyridamole (DIP) is a nucleoside transport and phosphodiesterase inhibitor so that it may potentially affect SARS-CoV-2 infection and its accompanying inflammations. Therefore, the primary objective of this mini-review study was to elucidate the potential beneficial impacts of DIP on the adenosinergic pathway in Covid-19. A systemic search was done using online databases with relevant keywords. The findings of the present study illustrated that DIP directly or indirectly, through augmentation of adenosine and inhibition of phosphodiesterase, mitigates Covid-19 outcomes.

Conclusion

Our study concluded that DIP has a potential therapeutic effect in the management and treatment of Covid-19. This could be attained either directly, through anti-SARS-CoV-2, anti-inflammatory, and anti-platelets properties, or indirectly, through augmentation of extracellular adenosine, which has anti-inflammatory and immune-regulatory effects. However, extensive randomized clinical trials, and clinical and prospective research in this area are required to demonstrate the safety and therapeutic efficacy of DIP and adenosine modulators in the treatment of Covid-19.

Mechanistic Insights on the In Vitro Antibacterial Activity and In Vivo Hepatoprotective Effects of Salvinia auriculata Aubl against Methotrexate-Induced Liver Injury

Methotrexate (MTX) is widely used in the treatment of numerous malignancies; however, its use is associated with marked hepatotoxicity. Herein, we assessed the possible hepatoprotective effects of Salvinia auriculata methanol extract (SAME) against MTX-induced hepatotoxicity and elucidated the possible fundamental mechanisms that mediated such protective effects for the first time. Forty mice were randomly allocated into five groups (eight/group). Control saline, MTX, and MTX groups were pre-treated with SAME 10, 20, and 30 mg/kg. The results revealed that MTX caused a considerable increase in blood transaminase and lactate dehydrogenase levels, oxidative stress, significant activation of the Nod-like receptor-3 (NLPR3)/caspase-1 inflammasome axis, and its downstream inflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18). MTX also down-regulated nuclear factor erythroid 2-related factor 2 (Nrf2) expression. Additionally, it increased the immunostaining of nuclear factor kappa-B (NF-κB) and downstream inflammatory mediators. Furthermore, the hepatic cellular apoptosis was dramatically up-regulated in the MTX group. On the contrary, prior treatment with SAME significantly improved biochemical, histopathological, immunohistochemical alterations caused by MTX in a dose-dependent manner. The antibacterial activity of SAME has also been investigated against Acinetobacter baumannii clinical isolates. LC-ESI-MS/MS contributed to the authentication of the studied plant and identified 24 active constituents that can be accountable for the SAME-exhibited effects. Thus, our findings reveal new evidence of the hepatoprotective and antibacterial properties of SAME that need further future investigation.