Star role for bacteria in controlling flu pandemic?

Based on CiteSpace Insights into Illicium verum Hook. f. Current Hotspots and Emerging Trends and China Resources Distribution

Illicium verum Hook. f. is a globally significant spice, which is recognized in China as a food-medicine homolog and extensively utilized across the pharmaceutical, food, and spice industries. China boasts the world's leading resources of I. verum, yet its comprehensive utilization remains relatively underexplored. Through a resource survey of I. verum and the application of bibliometric visualization using CiteSpace, this study analyzed 324 papers published in the Web of Science Core Collection (WOSCC) from 1962 to 2023 and 353 core documents from China's three major databases (CNKI, Wanfang Database, and VIP Database). I. verum from Guangxi province towards various southern provinces in China, with autumn fruits exhibited superior quality and market value over their spring fruits. Literature in WOSCC emerged earlier, with a research emphasis on food science technology and pharmacology pharmacy domains. WOSCC research on I. verum could be divided into two phases: an embryonic period (1962-2001) and a growth period (2002-2023), showing an overall upward trend in publication. The three major Chinese databases contain a larger number of publications, with a focus on the food sector, which could be categorized into three stages: an embryonic period (1990-1999), a growth period (2000-2010), and a stable period (2011-2023), with an overall downward trend in publication. Both Chinese and international research hotspots converge on the medical applications of I. verum, with antioxidant bioactivity research emerging as a prevailing trend. This study delineated the resource distribution of I. verum across China and identified the research hotspots and trends both in China and internationally. The findings are beneficial for guiding researchers in swiftly establishing their research focus and furnishing decision-makers with a comprehensive reference for industry information.

The effect of sourdough, turnips, and butternut squash on the physicochemical and nutritional properties of Doowina functional food during fermentation

The dairy-cereal-based food, known as Doowina, is one of the traditional fermented foods in Iran. We aimed to improve the health-promoting properties of Doowina by using turnips, butternut squash, and sourdough as a new functional food with high nutritional value and antioxidant activity. Therefore, the physicochemical, microbial, and sensory properties of samples with nutritional supplements (8% turnip and 8% butternut squash) and different concentrations of sourdough (0, 0.5, and 1%) were studied during 0, 3, 6, and 9 days of fermentation time. The results showed that there was no significant difference (p < .05) in the moisture and ash content between the different formulations of Doowina. There was also no significant difference (p < .05) in the phenolic compound content and antioxidant activity of the Doowina samples during the fermentation period. However, the number of lactic acid bacteria (LAB) increased significantly (p < .05) until the 6th day of fermentation, and the protein content decreased significantly (p < .05) in all samples during the fermentation period. According to the results, the samples with butternut squash and sourdough had the highest total phenolic content, the highest antioxidant activity, the highest linoleic acid content, and the highest sensory rating of all samples.

Antioxidant associated chemoprophylaxis effect of natural spice and green vegetable on hepatotoxicity

This is a case control and cohort study, conducted at Department of Biochemistry in FUAST, compressing 24 number of albino Wistar rats. Illicium verum (star anise) natural spice and green vegetable broccoli are used for chemo-preventive herbal treatment in relation with vitamin C antioxidant activity. Hepatotoxicity was induced in liver of model rats by giving interperitoneally single injection of 200 mg/kg bod weight (B.W) of N-nitrosodiethylamine and orally giving 1 mg/kg BW phenobarbital for 14 days during disease prorogation period. The vitamin C analysis from Illicium verum (star anise), green broccoli, orange juice, orange peel and orange pulp was done by iodometric quantitative and qualitative titration method. Rats were given compound according to their bodyweight as 1 mg/kg B.W. After 14 days (Disease Promotion and Propagation Period) and 28 days (Disease cure period) of treatment behavioral activity was monitored by locomotors activity in open field experiment, stimulatory activity in home cage and anxiolytic effects observed in light and dark apparatus and also in T maze. Behavioral activity were significantly increased in Illicium verum and green broccoli treated rats. Hematological study including hemoglobin (Hb), white blood cells (WBC), red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW) and Platelets was done by abbot laboratory analyzer cell. The value of Hb and RBC was also significantly increased in star anise and broccoli treated rats, showed proper function of RBC in microcirculation. WBC was also in normal range revealed that no disease regards to bone marrow and leukemia's. The biochemical activity of rats including urea, creatinine, total protein, albumin, globulin, A/G ratio, amylase and calcium in blood serum were analyzed while, liver health or performance was also determined by LFT (liver function test). Behavioral and laboratorial variables were analyzed by using SPSS v. 20 and p-value < 0.05 was considered statistically significant. The study report noticeable significant effect of Illicium verum and broccoli on hepatotoxicity of experimental model. Recent experimental study statistical outcomes show reciprocal relationship between the consumption of vegetable diet and natural spice with the risk of Hepatotoxicity. Thus, the aim of the study is to enhance the function of star anise or illicium verum natural spice and green vegetable broccoli as an anticancer or chemoprophylaxis agent.

Plant callus-derived shikimic acid regenerates human skin through converting human dermal fibroblasts into multipotent skin-derived precursor cells

Background

The human skin-derived precursors (SKPs) are a good cell source for regeneration. However, the isolation of SKP from human skin is limited. To overcome this drawback, we hypothesized that the component of plant stem cells could convert human fibroblasts to SKPs.

Methods

Human dermal fibroblasts were treated with shikimic acid, a major component of Sequoiadendron giganteum callus extract. The characteristics of these reprogrammed cells were analyzed by qPCR, western blot, colony-forming assay, and immunofluorescence staining. Artificial human skin was used for CO₂ laser-induced wound experiments. Human tissues were analyzed by immunohistochemistry.

Results

The reprogrammed cells expressed nestin (a neural precursor-specific protein), fibronectin, and vimentin and could differentiate into the ectodermal and mesodermal lineage. Nestin expression was induced by shikimic acid through the mannose receptor and subsequent MYD88 activation, leading to P38 phosphorylation and then CREB binding to the nestin gene promoter. Finally, we confirmed that shikimic acid facilitated the healing of cut injury and enhanced dermal reconstruction in a human artificial skin model. Moreover, in a clinical study with healthy volunteers, plant callus extracts increased the expression of stem cell markers in the basal layer of the epidermis and collagen deposit in the dermis.

Conclusions

These results indicate that shikimic acid is an effective agent for tissue regeneration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02409-3.

Coronavirus Disease 2019 and Herbal Therapy: Pertinent Issues Relating to Toxicity and Standardization of Phytopharmaceuticals

Coronavirus disease 2019 (COVID-19) is a virulent viral disease that has now become a public health emergency of global significance and still without an approved treatment regimen or cure. In the absence of curative drugs and with vaccines development still in progress, alternative approaches to stem the tide of the pandemic are being considered. The potential of a phytotherapeutic approach in the management of the dreaded disease has gained attention, especially in developing countries, with several claims of the development of anti-COVID-19 herbal formulations. This is a plausible approach especially with the increasing acceptance of herbal medicine in both alternative and orthodox medical practices worldwide. Also, the established efficacy of herbal remedies in the treatment of numerous viral diseases including those caused by coronaviruses, as well as diseases with symptoms associated with COVID-19, presents a valid case for serious consideration of herbal medicine in the treatment of COVID-19. However, there are legitimate concerns and daunting challenges with the use of herbs and herbal products. These include issues of quality control, unethical production practice, inadequate information on the composition, use and mechanisms, weak regulatory policies, herb-drug interactions and adverse reactions, and the tendency for abuse. This review discusses the feasibility of intervention with herbal medicine in the COVID-19 pandemic and the need to take proactive measures to protect public health by improving the quality and safety of herbal medicine deployed to combat the disease. Graphical abstract.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43450-021-00132-x.

Treating a Global Health Crisis with a Dose of Synthetic Chemistry

The SARS-CoV-2 pandemic has prompted scientists from many disciplines to work collaboratively toward an effective response. As academic synthetic chemists, we examine how best to contribute to this ongoing effort.

Virucidal Action Against Avian Influenza H5N1 Virus and Immunomodulatory Effects of Nanoformulations Consisting of Mesoporous Silica Nanoparticles Loaded with Natural Prodrugs

Background

Combating infectious diseases caused by influenza virus is a major challenge due to its resistance to available drugs and vaccines, side effects, and cost of treatment. Nanomedicines are being developed to allow targeted delivery of drugs to attack specific cells or viruses.

Materials and Methods

In this study, mesoporous silica nanoparticles (MSNs) functionalized with amino groups and loaded with natural prodrugs of shikimic acid (SH), quercetin (QR) or both were explored as a novel antiviral nanoformulations targeting the highly pathogenic avian influenza H5N1 virus. Also, the immunomodulatory effects were investigated in vitro tests and anti-inflammatory activity was determined in vivo using the acute carrageenan-induced paw edema rat model.

Results

Prodrugs alone or the MSNs displayed weaker antiviral effects as evidenced by virus titers and plaque formation compared to nanoformulations. The MSNs-NH₂-SH and MSNs-NH₂-SH-QR2 nanoformulations displayed a strong virucidal by inactivating the H5N1 virus. They induced also strong immunomodulatory effects: they inhibited cytokines (TNF-α, IL-1β) and nitric oxide production by approximately 50% for MSNs-NH₂-SH-QR2 (containing both SH and QR). Remarkable anti-inflammatory effects were observed during in vivo tests in an acute carrageenan-induced rat model.

Conclusion

Our preliminary findings show the potential of nanotechnology for the application of natural prodrug substances to produce a novel safe, effective, and affordable antiviral drug.

Star anise (Illicium verum): Chemical compounds, antiviral properties, and clinical relevance

Medicinal herbs are one of the imperative sources of drugs all over the world. Star anise (Illicium verum), an evergreen, medium-sized tree with star-shaped fruit, is an important herb with wide distribution throughout southwestern parts of the Asian continent. Besides its use as spice in culinary, star anise is one of the vital ingredients of the Chinese medicinal herbs and is widely known for its antiviral effects. It is also the source of the precursor molecule, shikimic acid, which is used in the manufacture of oseltamivir (Tamiflu®), an antiviral medication for influenza A and influenza B. Besides, several other molecules with numerous biological benefits including the antiviral effects have been reported from the same plant. Except the antiviral potential, star anise possesses a number of other potentials such as antioxidant, antimicrobial, antifungal, anthelmintic, insecticidal, secretolytic, antinociceptive, anti-inflammatory, gastroprotective, sedative properties, expectorant and spasmolytic, and estrogenic effects. This review aimed to integrate the information on the customary attributes of the plant star anise with a specific prominence on its antiviral properties and the phytochemical constituents along with its clinical aptness.

Turnip (Brassica Rapus L.): a natural health tonic

Abstract In addition to basic nutrition, plant-based foods provide substantial amounts of bioactive compounds which deliver desirable health benefits. During the last decade, secondary metabolites, also known as phytochemicals, obtained from plants, have aroused special attention by researchers. Amongst such plants, the turnip contains a few valuable components which not only endorse health benefits but also provide healing properties. Various bioactive components, for example peroxidase, kaempferol, phenolic compounds, sulforaphane, organic acids, vitamin K, glucosinolates etc are highlighted in this manuscript. Likewise, numerous minerals, such as copper, manganese and calcium, and organic acids, such as sinapic and ferulic acids and their derivatives, found in different amounts in fresh greens and turnip roots, are also discussed briefly. The current paper is focused on the phenolic compounds, which act as beneficial compounds for human health and can be isolated from plant foods, especially turnip. Due to the presence of bioactive constituents, turnip imparts a positive role with respect to the hepatic injury caused by diabetes, high antioxidant activity and a good hepatoprotective role. The impact of environmental conditions and processing mechanisms on the phenolic compound composition of Brassica vegetables, with special reference to turnip, was also briefly discussed.

Shikimic acid inhibits LPS-induced cellular pro-inflammatory cytokines and attenuates mechanical hyperalgesia in mice

BACKGROUND AND AIMS

Shikimic acid (SA) is present in a wide variety of plants and microorganisms used in traditional and folk medicine and also is an essential starting material for the synthesis of the antiviral drug Oseltamivir (Tamiflu®). Some pharmacological actions observed in SA-enriched products include antioxidant and anti-inflammatory activities. Here, we investigated the anti-inflammatory and antinociceptive actions of isolated SA.

METHODS

RAW 264.7 macrophage cells were treated with bacterial LPS (1μg/mL) and the effect of SA on the modulation of cell viability, nitric oxide (NO) production, TNF-α, and IL-1β content and MAPK (ERK1/2 and p38) activation was evaluated. Besides, the anti-hyperalgesic actions of SA on in vivo model of mechanical hyperalgesia induced by carrageenan (CG), dopamine (DA), TNF-α and prostaglandin (PGE2) were assessed.

RESULTS

In RAW 264.7 cells, SA suppressed LPS-induced decrease in cell viability and nitrite accumulation to control values and inhibited up-regulation of TNF-α (65%) and IL-1β (39%). These effects may be mediated at least in part by inhibition of LPS-induced ERK 1/2 (22%) and p38 (17%) phosphorylation. In mice, SA at 50, 100, and 200mg/kg decreased formalin-induced nociceptive behavior (around 50%) and inhibited the inflammatory nociception induced by TNF-α and PGE2 (50 to 75% each). Moreover, SA (100 and 200mg/kg) significantly attenuated the mechanical hyperalgesia induced by CG and DA (25 to 40% each).

CONCLUSIONS

These results indicate that SA presents anti-inflammatory actions with potential for development of drugs to treat pro-inflammatory and painful conditions.

Sweetgum: An ancient source of beneficial compounds with modern benefits

Sweetgum trees are large, deciduous trees found in Asia and North America. Sweetgum trees are important resources for medicinal and other beneficial compounds. Many of the medicinal properties of sweetgum are derived from the resinous sap that exudes when the outer bark of the tree has been damaged. The sap, known as storax, has been used for centuries to treat common ailments such as skin problems, coughs, and ulcers. More recently, storax has proven to be a strong antimicrobial agent even against multidrug resistant bacteria such as methicillin-resistant Staphylococcus aureus. In addition to the sap, the leaves, bark, and seeds of sweetgum also possess beneficial compounds such as shikimic acid, a precursor to the production of oseltamivir phosphate, the active ingredient in Tamiflu®–an antiviral drug effective against several influenza viruses. Other extracts derived from sweetgum trees have shown potential as antioxidants, anti-inflammatory agents, and chemopreventive agents. The compounds found in the extracts derived from sweetgum sap suppress hypertension in mice. Extracts from sweetgum seeds have anticonvulsant effects, which may make them suitable in the treatment of epilepsy. In addition to the potential medicinal uses of sweetgum extracts, the extracts of the sap possess antifungal activity against various phytopathogenic fungi and have been effective treatments for reducing nematodes and the yellow mosquito, Aedes aegypti, populations thus highlighting the potential of these extracts as environment-friendly pesticides and antifungal agents. The list of value-added products derived from sweetgum trees can be increased by continued research of this abundantly occurring tree.

Shikimic acid, a base compound for the formulation of swine/avian flu drug: statistical optimization, fed-batch and scale up studies along with its application as an antibacterial agent

The sudden outbreak of swine flu has increased the global demand of shikimic acid which is an industrially interesting compound, as it is used as a key starting material for the synthesis of a neuraminidase inhibitor Tamiflu(®), for the treatment of antiviral infections such as swine flu. Statistical optimization and evaluation of medium components for the production of shikimic acid by Citrobacter freundii is addressed in the present investigation. Plackett-Burman design was applied for the screening of the most significant variables affecting shikimic acid production, where glucose, asparagine, KH2PO4, CaCO3 and agitation rate were the most significant factors. Response surface methodology was also employed to study the interaction among the most significant variables through which shikimic acid production increased to 12.76 g/L. Further, fed-batch studies resulted in the production of 22.32 g/L of shikimic acid. The scalability of the process was also confirmed by running 14 L bioreactor (7.5 L production medium) where 20.12 g/L of shikimic acid was produced. In addition the antibacterial activity of the shikimic acid produced was analysed against four Gram positive and four Gram negative bacteria and it was found to have a greater inhibition effect against the Gram negative bacteria.

Metabolic flux responses to genetic modification for shikimic acid production by Bacillus subtilis strains

BACKGROUND

Shikimic acid (SA) is a key chiral starting molecule for the synthesis of the neuramidase inhibitor GS4104 against viral influenza. Microbial production of SA has been extensively investigated in Escherichia coli, and to a less extent in Bacillus subtilis. However, metabolic flux of the high SA-producing strains has not been explored. In this study, we constructed with genetic manipulation and further determined metabolic flux with 13C-labeling test of high SA-producing B. subtilis strains.

RESULTS

B. subtilis 1A474 had a mutation in SA kinase gene (aroI) and accumulated 1.5 g/L of SA. Overexpression of plasmid-encoded aroA, aroB, aroC or aroD in B. subtilis revealed that aroD had the most significantly positive effects on SA production. Simultaneous overexpression of genes for 3-deoxy-D-arabinoheptulosonate-7-phosphate synthase (aroA) and SA dehydrogenase (aroD) in B. subtilis BSSA/pSAAroA/pDGSAAroD resulted in SA production of 3.2 g/L. 13C-Metabolic flux assay (MFA) on the two strains BSSA/pHCMC04/pDG148-stu and BSSA/pSAAroA/pDGSAAroD indicated the carbon flux from glucose to SA increased to 4.6% in BSSA/pSAAroA/pDGSAAroD from 1.9% in strain BSSA/pHCMC04/pDG148-stu. The carbon flux through tricarboxylic acid cycle significantly reduced, while responses of the pentose phosphate pathway and the glycolysis to high SA production were rather weak, in the strain BSSA/pSAAroA/pDGSAAroD. Based on the results from MFA, two potential targets for further optimization of SA production were identified. Experiments on genetic deletion of phosphoenoylpyruvate kinase gene confirmed its positive influence on SA production, while the overexpression of the transketolase gene did not lead to increase in SA production.

CONCLUSION

Of the genes involved in shikimate pathway in B. subtilis, aroD exerted most significant influence on SA accumulation. Overexpression of plasmid-encoded aroA and aroD doubled SA production than its parent strain. MFA revealed metabolic flux redistribution among phosphate pentose pathway, glycolysis, TCA cycle in the low and high SA-producing B. subtilis strains. The high SA producing strain BSSA/pSAAroA/pDGSAAroD had increased carbon flux into shikimate pathway and reduced flux into TCA cycle.

Fermentative production of shikimic acid: a paradigm shift of production concept from plant route to microbial route

Different physiological and nutritional parameters affect the fermentative production of shikimic acid. In our study, Citrobacter freundii initially produced 0.62 g/L of shikimic acid in 72 h. However, when process optimization was employed, 5.11 g/L of shikimic acid was produced in the production medium consisting of glucose (5.0 %), asparagine (4.5 %), CaCO3 (2.0 %), at pH 6.0, when inoculated with 6 % inoculum and incubated at 30 ± 1 °C, 200 rpm for 60 h. Preliminary fed-batch studies have resulted in the production of 9.11 g/L of shikimic acid on feeding the production medium by 20 g/L of glucose at 24 h of the fermentation run. Production of similar amount of shikimic acid was observed when the optimized conditions were employed in a 10-L bioreactor as obtained in shake flask conditions. A total of 9.11 g/L of shikimic acid was produced in 60 h. This is approximately 14.69-fold increase in shikimic acid production when compared to the initial un-optimized production conditions. This has also resulted in the reduction of the production time. The present study provides useful information to the industrialists seeking environmentally benign technology for the production of bulk biomolecules through manipulation of various chemical parameters.

Pandemism of swine flu and its prospective drug therapy

Swine flu is a respiratory disease caused by influenza A H1N1 virus. The current pandemic of swine flu is most probably due to a mutation-more specifically, a re-assortment of four known strains of influenza A virus subtype H1N1. Antigenic variation of influenza viruses while circulating in the population is an important factor leading to difficulties in controlling influenza by vaccination. Due to the global effect of swine flu and its effect on humans, extensive investigations are being undertaken. In this context, Tamiflu is the only available drug used in the prophylaxis of this disease and is made from the compound shikimic acid. Due to the sudden increase in the demand of shikimic acid, its price has increased greatly. Thus, it is necessary to find an alternative approach for the treatment of swine flu. This review presents the overall information of swine flu, beginning from its emergence to the prevention and treatment of the disease, with a major emphasis on the alternative approach (bacterial fermentation process) for the treatment of swine flu. The alternative approach for the treatment of swine flu includes the production of shikimic acid from a fermentation process and it can be produced in large quantities without any time limitations.

Shikimic acid: review of its analytical, isolation, and purification techniques from plant and microbial sources

Shikimic acid properties and its available analytical techniques are discussed. Plants having the highest content of shikimic acid are shown. The existing isolation methods are analyzed and the most optimal approaches to extracting this acid from natural sources (plants and microorganisms) are considered.

Illicium verum: a review on its botany, traditional use, chemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The fruit of Illicium verum Hook. f. (Chinese star anise) has long been used in traditional Chinese medicine and food industry with the actions of dispelling cold, regulating the flow of Qi and relieving pain.

MATERIALS AND METHODS

A bibliographic investigation was carried out by analyzing recognized books including Chinese herbal classic, and worldwide accepted scientific databases (Pubmed, SciFinder, Scopus and Web of Science) were searched for the available information on I. verum.

RESULTS

I. verum is an aromatic evergreen tree of the family Illiciaceae. It is sometimes contaminated with highly toxic Japanese star anise (I. anisatum L.) and poisonous star anise (I. lanceolatum A. C. Smith), which contain several neurotoxic sesquiterpenes. Traditional uses of I. verum are recorded throughout Asia and Northern America, where it has been used for more than 10 types of disorders. Numerous compounds including volatiles, seco-prezizaane-type sesquiterpenes, phenylpropanoids, lignans, flavonoids and other constituents have been identified from I. verum. Modern pharmacology studies demonstrated that its crude extracts and active compounds possess wide pharmacological actions, especially in antimicrobial, antioxidant, insecticidal, analgesic, sedative and convulsive activities. In addition, it is the major source of shikimic acid, a primary ingredient in the antiflu drug (Tamiflu).

AIM OF THE REVIEW

This review summarizes the up-to-date and comprehensive information concerning the botany, traditional use, phytochemistry and pharmacology of I. verum together with the toxicology, and discusses the possible trend and scope for future research of I. verum.

Top-hits for H1N1pdm Identified by Virtual Screening Using Ensemble-based Docking

A list of 27 promising antiviral drugs is proposed for use against the H1N1pdm strain. Since the binding site of the H1N1pdm neuraminidase is similar to that of the bird flu H5N1, an effective means to quickly identify top candidates for use against H1N1pdm is to use known bird-flu drugs and the 27 compounds from the NCI diversity set which bind best to H5N1 neuraminidase. These compounds serve as viable candidates for docking against the H1N1pdm neuraminidase, using ensembles extracted from molecular dynamics simulations of the H1N1pdm system. The ranking order of these top candidates was found to be different from the previously published results for H5N1. The results indicated that the Oseltamivir (Tamiflu) and Peramivir drugs have higher ranking than Zanamivir (Relenza). However, six drug candidates were found to bind more effectively to H1N1pdm neuraminidase than Tamiflu. Detailed hydrogen bond network analysis for these six candidates is also provided.

Immunomodulatory activity of shikimic acid and quercitin in comparison with oseltamivir (Tamiflu) in an in vitro model

The risk of an avian influenza pandemic has put oseltamivir (Tamiflu) in the spotlight and has given rise to rumors that shikimic acid (SK), which is used for the synthesis of Tamiflu, possesses therapeutic activity. This study was undertaken to determine whether SK, either alone or in combination with quercitin (QT) is able to modulate the release of IL-6 and IL-8 from peripheral blood mononuclear cells (PBMCs). The experiments were conducted comparing the properties of SK, both alone and in combination, with those of Tamiflu. The incubation of PBMCs with 100 nM Tamiflu or SK at two concentrations (10 nM; 100 nM) did not produce any change in IL-6 and IL-8 baseline levels (data expressed as incremental change vs. baseline). On the contrary, incubation with SK and QT at both concentrations (10 and 100 nM) produced a significant increase in the release of IL-8 as compared to other groups (4.19 +/- 0.82, SK-QT 10 nM; 3.83 +/- 1.17 SK-QT 100 nM, P < 0.05 vs. baseline 1.00 +/- 0.10, Tamiflu 100 nM 1.35 +/- 0.16, SK 10 nM 1.68 +/- 0.15 and SK 100 nM 1.80 +/- 0.48). The SK-QT combination also proved to be effective in the upregulation of IL-6 (3.08 +/- 0.46, SK-QT 10 nM; 3.60 +/- 0.74 SK-QT 100 nM, P < 0.05 vs. baseline 1.00 +/- 0.26). According to these findings SK alone is not able to modulate innate immunity in antiviral terms. However, the data show that the SK + QT combination, even at low doses, may be effective for the modulation of innate immunity.

Les inhibiteurs de neuraminidase face au risque de grippe aviaire

Oseltamivir and zanamivir are highly potent inhibitors of influenza A and B neuraminidase and operate by inhibiting viral replication, and more specifically, the release and the movement of the virus through mucus. Neuraminidase inhibitors reduce the severity and duration of symptoms, and prevent clinical influenza as post-exposure and seasonal prophylaxis. Both have similar efficacy; oseltamivir has a more convenient route of administration, and zanamivir a more favourable resistance profile. Pending availability of effective vaccines, neuraminidase inhibitors are the only specific antiviral drugs which might be opposed to a possible pandemic that could emerge from the current highly pathogenic H5N1 virus. Although the effectiveness of oseltamivir and zanamivir for the therapy of clinical H5N1 influenza is questionable, simulation models suggest that a combination of targeted antiviral prophylaxis and quarantine might be able to contain an emerging influenza strain at the source. As a consequence, after an initial lack of commercial success probably related to the mild intensity of seasonal influenza during the last winters, neuraminidase inhibitors are now stockpiled by many countries to prepare for an outbreak.