Effect and mechanism of quercetin or quercetin-containing formulas against COVID-19: From bench to bedside.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global coronavirus disease 2019 (COVID-19) pandemic since 2019. Immunopathogenesis and thromboembolic events are central to its pathogenesis. Quercetin exhibits several beneficial activities against COVID-19, including antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antithrombotic effects. Although several reviews have been published, these reviews are incomplete from the viewpoint of translational medicine. The authors comprehensively evaluated the evidence of quercetin against COVID-19, both basically and clinically, to apply quercetin and/or its derivatives in the future. The authors searched the PubMed, Embase, and the Cochrane Library databases without any restrictions. The search terms included COVID-19, SARS-CoV-2, quercetin, antiviral, anti-inflammatory, immunomodulatory, thrombosis, embolism, oxidative, and microbiota. The references of relevant articles were also reviewed. All authors independently screened and reviewed the quality of each included manuscript. The Cochrane Risk of Bias Tool, version 2 (RoB 2) was used to assess the quality of the included randomized controlled trials (RCTs). All selected studies were discussed monthly. The effectiveness of quercetin against COVID-19 is not solid due to methodological flaws in the clinical trials. High-quality studies are also required for quercetin-containing traditional Chinese medicines. The low bioavailability and highly variable pharmacokinetics of quercetin hinder its clinical applications. Its positive impact on immunomodulation through reverting dysbiosis of gut microbiota still lacks robust evidence. Quercetin against COVID-19 does not have tough clinical evidence. Strategies to improve its bioavailability and/or to develop its effective derivatives are needed. Well-designed RCTs are also crucial to confirm their effectiveness in the future.

Content Analysis of Korean Videos Regarding Restless Legs Syndrome on YouTube.

OBJECTIVE: To evaluate the accuracy and quality of Korean videos associated with restless legs syndrome (RLS) on YouTube. METHODS: A YouTube search was performed on April 1, 2020 using the term "restless legs syndrome" in the Korean language. Two reviewers coded the source, content, and demographics of the included videos. Video quality was assessed using the modified DISCERN (mDISCERN) instrument. RESULTS: Among the 80 videos analyzed, 44 (55.0%) were reliable, and 36 (45.0%) were misleading. There was a trend toward a higher number of mean daily views in the misleading videos than in the reliable videos. Most of the misleading videos (72.2%) advocated complementary and alternative medicine as a primary treatment for RLS. Although the reliable videos had higher mDISCERN scores than the misleading videos, the overall quality of the reliable videos was low. CONCLUSION: Many Korean videos regarding RLS on YouTube involve a risk of exposure to misinformation and are of unsatisfactory quality.

Unraveling the Molecular Mechanism of Traditional Chinese Medicine: Formulas Against Acute Airway Viral Infections as Examples.

Herbal medicine, including traditional Chinese medicine (TCM), is widely used worldwide. Herbs and TCM formulas contain numerous active molecules. Basically, they are a kind of cocktail therapy. Herb-drug, herb-food, herb-herb, herb-microbiome, and herb-disease interactions are complex. There is potential for both benefit and harm, so only after understanding more of their mechanisms and clinical effects can herbal medicine and TCM be helpful to users. Many pharmacologic studies have been performed to unravel the molecular mechanisms; however, basic and clinical studies of good validity are still not enough to translate experimental results into clinical understanding and to provide tough evidence for better use of herbal medicines. There are still issues regarding the conflicting pharmacologic effects, pharmacokinetics, drug interactions, adverse and clinical effects of herbal medicine and TCM. Understanding study validation, pharmacologic effects, drug interactions, indications and clinical effects, adverse effects and limitations, can all help clinicians in providing adequate suggestions to patients. At present, it would be better to use herbs and TCM formulas according to their traditional indications matching the disease pathophysiology and their molecular mechanisms. To unravel the molecular mechanisms and understand the benefits and harms of herbal medicine and TCM, there is still much work to be done.

Optimal Regimen of N-Acetylcysteine on Chromium-Induced Renal Cell Damage.

Chromium (Cr) is a well-known heavy metal that can cause renal damage. The production of reactive oxygen species (ROS) due to chromium-induced toxicity induces cell dysfunction, apoptosis, and death. N-acetylcysteine (NAC) is an antioxidant used as an antidote for chromium-induced toxicity. However, the optimal regimen and protective mechanisms of NAC are not fully understood in human renal cells. Our results showed that exposure to 10 µM K2Cr2O7, a toxic Cr(VI) compound, induced apoptosis and production of intracellular ROS in the human proximal tubular epithelial cell line HK-2. Supplements of 600 or 1000 µg/mL NAC inhibited intracellular ROS in HK-2 cells exposed to Cr(VI) and significantly increased cell viability within 2 h of Cr(VI)-induced cytotoxicity. Moreover, Cr(VI) induced the expression of apoptosis markers, including cleaved-caspase-3, cleaved-poly (ADP-ribose) polymerase, cleaved-caspase 8, and cleaved-caspase 9, and altered the expression ratio of Bax/Bcl-xL. Expression of apoptosis markers within 2 h of Cr(VI)-induced cytotoxicity in cells treated with 600 µg/mL NAC was significantly suppressed. However, delayed treatment with NAC at 4 h and 8 h after exposure to Cr did not suppress the activation of apoptotic pathways. In summary, our study reports the optimum timing and dose of NAC for the protection of human renal proximal tubular cells from Cr(VI)-induced cell death. The NAC treatment strategy described could be applied in clinical practice to suppress renal cell apoptosis, which in turn could rescue renal function.

Two-month breathing-based walking improves anxiety, depression, dyspnoea and quality of life in chronic obstructive pulmonary disease: A randomised controlled study.

AIMS AND OBJECTIVES: To examine the effects of the two-month breathing-based walking intervention and its follow-up on anxiety, depression, dyspnoea and quality of life in patients with chronic obstructive pulmonary disease. BACKGROUND: Mind-body-related exercises improve bio-psychological symptoms and quality of life in chronic diseases, but these improvements are not proven for chronic obstructive pulmonary disease. DESIGN: This was a randomised controlled study and applied the Consolidated Standards of Reporting Trials (CONSORT) statement. METHODS: Outpatients diagnosed with chronic obstructive pulmonary disease were recruited from a medical centre in Taiwan and randomly assigned to two groups. The walking group (n = 42) received breathing, meditation and walking for two months, and the control group (n = 42) did not. Data from the outcomes of anxiety, depression, dyspnoea and quality of life were collected at baseline and in Month 1, Month 2 and Month 3. Clinical trial registration was done (ClinicalTrials.gov.: NCT03388489). FINDINGS: The results showed significant changes in anxiety, depression, dyspnoea and quality of life in the walking group across three months, compared to those in the control group and at baseline. CONCLUSION: This breathing-based walking intervention is promising to achieve bio-psychological well-being for patients with chronic obstructive pulmonary disease. RELEVANCE TO CLINICAL PRACTICE: This breathing-based walking, as a mind-body exercise, could serve as an evidence-based nursing care that contributes to improving anxiety, depression, dyspnoea and quality of life in stable chronic obstructive pulmonary disease outpatients. The feasibility and acceptability of the breathing-based walking were met the requirement of the chronic obstructive pulmonary disease outpatients, which could be considered as home-based exercise.

Optimal dosage and early intervention of L-ascorbic acid inhibiting K2Cr2O7-induced renal tubular cell damage.

Chromium poisoning can cause renal failure and death. Chromium intoxication may be managed using L-ascorbic acid (vitamin C) therapy. However, the evidence supporting the effectiveness of this treatment is insufficient, and the mechanism of action has not been clarified in renal cells. In this study, our results showed that the optimal regimen of L-ascorbic acid therapy in human epithelial renal proximal tubule cells, HK-2 cells, was 30 µg/mL. Supplementation of L-ascorbic acid with 30 µg/mL and within 8 h of chromium intoxication (K2Cr2O7, Cr6+) was effective to inhibit renal tubular cell damage by blocking generation of free radicals, cell apoptosis, and autophagy. Intracellular chromium concentrations were estimated using electrothermal atomic absorption spectrometry. Treatment of L-ascorbic acid within 8 h of chromium intoxication significantly decreased the entry of chromium into the cells. Moreover, concomitant administration of L-ascorbic acid with repeatedly dosing at 8-hourly intervals had a better protective effect at lower concentration of L-ascorbic acid when compared to single dosing of L-ascorbic acid at an early time point of chromium intoxication. These findings might help physicians develop effective therapy strategies in renal failure.

Artemisia capillaris inhibited enterovirus 71-induced cell injury by preventing viral internalization.

Artemisia capillaris (A. capillaris) is a common herbal drug used for thousands years in ancient China. A. capillaris has been empirically used to manage hand-foot-mouth disease (HFMD), which is commonly caused by enterovirus 71 (EV71). EV71 can cause meningoencephalitis with mortality and neurologic sequelae without effective management. It is presently unknown whether A. capillaris is effective against EV71 infection. To test the hypothesis that it could protect cells from EV71-induced injury, a hot water extract of A. capillaris was tested in human foreskin fibroblast cells (CCFS-1/KMC) and human rhabdomyosarcoma cells (RD cells) by plaque reduction assay and flow cytometry. Inhibition of viral replication was examined by reverse quantitative RT-PCR (qRT-PCR). Its effect on translations of viral proteins (VP0, VP1, VP2, protease 2B and 3AB), and apoptotic proteins were examined by western blot. A. capillaris was dose-dependently effective against EV71 infection in both CCFS-1/KMC cells and RD cells by inhibiting viral internalization. However, A. capillaris was minimally effective on viral attachment, VP2 translation, and inhibition of virus-induced apoptosis. Further isolation of effective molecules is needed. In conclusion, A. capillaris has anti-EV71 activity mainly by inhibiting viral internalization. A. capillaris would be better to manage EV71 infection in combination with other agents.

Flos Farfarae Inhibits Enterovirus 71-Induced Cell Injury by Preventing Viral Replication and Structural Protein Expression.

Enterovirus 71 (EV71) infection can cause airway symptoms, brainstem encephalitis, neurogenic shock, and neurogenic pulmonary edema with high morbidity and mortality. There is no proven therapeutic modality. Flos Farfarae is the dried flower bud of Tussilago farfara L. that has been used to manage airway illnesses for thousands of years. It has neuro-protective activity and has been used to manage neuro-inflammatory diseases. However, it is unknown whether Flos Farfarae has activity against EV71-induced neuropathy. The current study used both human foreskin fibroblast (CCFS-1/KMC) and human rhabdomyosarcoma (RD) cell lines to test the hypothesis that a hot water extract of Flos Farfarae could effectively inhibit EV71 infection. The authenticity of Flos Farfarae was confirmed by HPLC-UV fingerprint. Through plaque reduction assays and flow cytometry, Flos Farfarae was found to inhibit EV71 infection ([Formula: see text]). Inhibition of viral replication and protein expression were further confirmed by reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR (qRT-PCR), and western blot, respectively. The estimated IC[Formula: see text]s were 106.3[Formula: see text][Formula: see text]g/mL in CCFS-1/KMC, and 15.0[Formula: see text][Formula: see text]g/mL in RD cells. Therefore, Flos Farfarae could be beneficial to inhibit EV71 infection by preventing viral replication and structural protein expression.

Gan-Lu-Siao-Du-yin, a prescription of traditional Chinese medicine, inhibited enterovirus 71 replication, translation, and virus-induced cell apoptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: Gan-Lu-Siao-Du-yin (GLSDY) is a prescription of traditional Chinese medicine. GLSDY contains 11 ingredients and is commonly used for endemic diseases. Enterovirus 71 (EV71) is an endemic disease that can cause meningoencephalitis with mortality and neurologic sequelae without any effective management. It is unknown whether GLSDY is effective against EV71 infection. AIM OF THE STUDY: To test the hypothesis that GLSDY can protect cell from EV71-induced injury. MATERIALS AND METHODS: Effects of a hot water extract of GLSDY on EV71 were tested in human foreskin fibroblast cells (CCFS-1/KMC) and human rhabdomyosarcoma cells (RD cells) by plaque reduction assay and flow cytometry respectively. Inhibition of viral replication was further examined by reverse quantitative RT-PCR (qRT-PCR). Its effect on viral protein translation and virus-induced apoptosis were examined by western blot. RESULTS: GLSDY was dose-dependently effective against EV71 infection (p<0.0001) in both CCFS-1/KMC cells and RD cells. GLSDY was highly effective when supplemented after viral inoculation (P<0.0001) with an IC50 of 8.7µg/mL. GLSDY inhibited viral RNA replication (P<0.0001), formation of viral structural proteins (VP0, VP1, VP2 and VP3) and non-structural proteins (protease 2B and 3AB). Furthermore, 300µg/mL GLSDY is effective to inhibit virus-induced apoptosis possibly through direct inhibition of caspase-8 and indirectly by inhibition of Bax. CONCLUSIONS: GLSDY is cheap and readily available to manage EV71 infection by inhibiting viral replication, viral protein formations, and EV71-induced apoptosis.

Association of prescribed Chinese herbal medicine use with risk of end-stage renal disease in patients with chronic kidney disease.

The evidence on whether Chinese herbal medicines affect outcome in patients with chronic kidney disease (CKD) is limited. Here we retrospectively explored the association of prescribed Chinese herbal medicine use and the risk of end-stage renal disease (ESRD) in patients with CKD. Patients with newly diagnosed CKD in the Taiwan National Health Insurance Research Database from 2000 to 2005 were categorized into new use or nonuse of prescribed Chinese herbal medicine groups. These patients were followed until death, dialysis initiation, or till the end of 2008. Among the 24,971 study patients, 11,351 were new users of prescribed Chinese herbal medicine after CKD diagnosis. Overall, after adjustment for confounding variables, the use group exhibited a significant 60% reduced ESRD risk (cause-specific hazard ratio 0.41, 95% confidence interval 0.37-0.46) compared with the nonuse group. The change was significantly large among patients using wind dampness-dispelling formulas (0.63, 0.51-0.77) or harmonizing formulas (0.59, 0.46-0.74), suggesting an independent association between specific Chinese herbal medicines and reduced ESRD risk. The findings were confirmed using propensity score matching, stratified analyses, and three weighting methods. However, dampness-dispelling and purgative formulas were associated with increased ESRD risk. Thus, specific Chinese herbal medicines are associated with reduced or enhanced ESRD risk in patients with CKD.

Yakammaoto inhibits enterovirus 71 infection by reducing viral attachment, internalization, replication, and translation.

Enterovirus 71 (EV71) can cause central nervous system infections with mortality and neurologic sequelae. At present, there is no effective therapeutic modality for EV71 infection. The infection is more common in families with poor socioeconomic status. Therefore, finding a readily available, cost-effective therapeutic modality would be very helpful to these socioeconomically disadvantaged families. Yakammaoto is a cheap and readily available traditional prescription that is proven to have antiviral activity against coxsackievirus B4 (CVB4). CVB4 and EV71 are enteroviruses. In this study, we evaluated the antiviral activity of hot water extract of yakammaoto against EV71. The results of plaque reduction assay and flow cytometry demonstrated that yakammaoto dose dependently inhibited EV71 infection. In addition, reverse transcription-polymerase chain reaction (RT-PCR) and quantitative RT-PCR results showed that yakammaoto reduced viral replication. Western blotting analysis showed that yakammaoto can inhibit viral protein production. Thus, our results suggest that yakammaoto should be considered to manage EV71 infection in the future.

Yakammaoto inhibited human coxsackievirus B4 (CVB4)-induced airway and renal tubular injuries by preventing viral attachment, internalization, and replication.

ETHNOPHARMACOLOGICAL RELEVANCE: Yakammaoto is a prescription of traditional Chinese medicine (TCM) containing nine ingredients, including Ephedra sinica, Pinellia ternate, Zingiber officinale, Tussilago farfara, Aster tataricus, Ziziphus jujube, Belamcanda chinensis, Asarum sieboldii, and Schisandra chinensis. Yakammaoto has been used against flu-like symptoms for more than two thousand years in China and Japan. Coxsackievirus B4 (CVB4) causes not only flu-like symptoms but life-threatening diseases, such as pneumonia, acute kidney injury, and so forth with severe morbidity and mortality. There is no effective therapeutic modality against CVB4 infection. It is unknown whether yakammaoto is effective against CVB4 infection. We tested the hypothesis that yakammaoto can effectively inhibit CVB4-induced plaque formation in human airway and renal tubular cell lines by preventing viral attachment, internalization, and replication. MATERIALS AND METHODS: The fingerprint of yakammaoto was assessed by HPLC. Effects of yakammaoto on CVB4 infection were tested by plaque reduction assay, reverse transcription polymerase chain reaction (RT-PCR), and enzyme-linked immunosorbent assay (ELISA). RESULTS: Yakammaoto dose-dependently inhibited CVB4-induced plaque formation in HK-2, A549, and HEp-2 cells (p<0.0001). Yakammaoto was both effective when supplemented prior to and after viral inoculation (p<0.0001) by preventing viral attachment (p<0.0001), internalization (p<0.0001), and replication (p<0.0001). Yakammaoto could decrease NGAL secretion before cytolysis to protect against viral injury. CONCLUSIONS: Yakammaoto had antiviral activity against CVB4-induced cellular injuries in airway mucosa and renal tubular epithelia by preventing viral attachment, internalization, and replication. The current study provides a basic support of its potential use against CVB4-induced airway and concomitant renal injuries.

Water extract of Pueraria lobata Ohwi has anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines.

Human respiratory syncytial virus (HRSV) infects all age groups and causes bronchiolitis, pneumonia, and acute respiratory distress syndrome with a significant mortality rate. To date, only ribavirin has been used to manage HRSV infection. However, ribavirin is expensive with an only modest effect. Furthermore, ribavirin has several side effects, which means it has limited clinical benefit. Pueraria lobata Ohwi (P. lobata) is a common ingredient of Ge-Gen-Tang (Kakkon-to) and Sheng-Ma-Ge-Gen-Tang (Shoma-kakkon-to), which are prescriptions of Chinese traditional medicine proven to have antiviral activity against HRSV. Therefore, it was hypothesized that P. lobata might be effective against HRSV. To find a cost-effective therapeutic modality, both human upper (HEp-2) and lower (A549) respiratory tract cell lines were used to test the hypothesis that P. lobata could inhibit HRSV-induced plaque formation. Results showed that the water extract of P. lobata was effective (p < 0.0001) against HRSV-induced plaque formation. P. lobata was more effective when given prior to viral inoculation (p < 0.0001) by inhibiting viral attachment (p < 0.0001) and penetration (p < 0.0001). However, supplementation with P. lobata could not stimulate interferon secretion after HRSV infection. In conclusion, P. lobata has antiviral activity against HRSV-induced plaque formation in airway mucosa mainly by inhibiting viral attachment and internalization. Further identification of effective constituents could contribute to the prevention of HRSV infection.

Anti-viral activity of water extract of Paeonia lactiflora pallas against human respiratory syncytial virus in human respiratory tract cell lines.

Paeonia lactiflora Pallas (P. lactiflora, Ranunculaceae) is a common ingredient of Sheng-Ma-Ge-Gen-Tang (SMGGT; Shoma-kakkon-to) and Ge-Gen-Tang (GGT; kakkon-to). SMGGT and GGT are different prescriptions of traditional Chinese medicine with different ingredients designed for airway symptoms. Both SMGGT and GGT have anti-viral activity against human respiratory syncytial virus (HRSV). Therefore, P. lactiflora was hypothesized to be the effective ingredient of both SMGGT and GGT against HRSV. However, P. lactiflora does not have any proven antiviral activity. This study used both human upper (Human larynx epidermoid carcinoma cell line, HEp-2) and lower (human lung carcinoma cell line, A549) respiratory tract cells to test the hypothesis that a hot water extract of P. lactiflora could effectively inhibit plaque formation induced by HRSV infection. The ability of P. lactiflora to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA). The results showed that P. lactiflora was time-dependently and dose-dependently effective against HRSV in HEp-2 and A549 cells, particularly supplemented before viral inoculation (p < 0.0001). 10 µg/ml P. lactiflora had a comparable anti-HRSV activity with 10 µg/ml ribavirin, a broad-spectrum antiviral agent. P. lactiflora was dose-dependently effective against viral attachment (p < 0.0001), with a better effect on A549 cells (p < 0.0001). P. lactiflora was time-dependently (p < 0.0001) and dose-dependently (p < 0.0001) effective against viral penetration. Moreover, P. lactiflora stimulated IFN-ß secretion without any effect on TNF-α secretion. Therefore, P. lactiflora could be beneficial at preventing HRSV infection by inhibiting viral attachment, internalization, and stimulating IFN secretion.

Xiao-Qing-Long-Tang (Sho-seiryu-to) inhibited cytopathic effect of human respiratory syncytial virus in cell lines of human respiratory tract.

ETHNOPHARMACOLOGICAL RELEVANCE: Xiao-Qing-Long-Tang (XQLT, TJ-19, Sho-seiryu-to, so-cheong-ryong-tang) has been used against acute airway diseases for thousands of year in ancient China. Most of the acute airway illnesses are caused by virus. However, without activity against influenza virus, XQLT has been questioned to manage respiratory tract viral infection. Nevertheless, XQLT might be active against airway viruses other than influenza. Human respiratory syncytial virus (HRSV) is one of the most common respiratory viral pathogens without effective management. However, it is unknown whether XQLT has anti-HRSV activity. AIM OF THE STUDY: We tested the hypothesis that XQLT can effectively minimize HRSV-induced plaque formation in respiratory tract mucosal cell lines. MATERIALS AND METHODS: Anti-HRSV activity of a hot water extract of XQLT was examined by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Its effects on syncytial formation and viral fusion (F) protein were examined directly by microscopy and by western blot, respectively. Ability of XQLT to stimulate IFN-ß was evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: Hot water extract of XQLT dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cells (P<0.0001), particularly when given before viral inoculation (p<0.0001). XQLT inhibited viral attachment (p<0.0001) and internalization (p<0.0001). 300µg/ml XQLT could decrease both the number and the size of HRSV-induced syncytium without clear effect on the production of viral F protein. XQLT could stimulate epithelial cells to secrete IFN-ß before and after viral inoculation to counteract viral infection (p<0.0001). CONCLUSIONS: XQLT is effective against HRSV infection on airway epithelia by preventing viral attachment, internalization, syncytial formation, and by stimulating interferon secretion.

Water extract of Cinnamomum cassia Blume inhibited human respiratory syncytial virus by preventing viral attachment, internalization, and syncytium formation.

ETHNOPHARMACOLOGICAL RELEVANCE: Cinnamomum cassia Blume is a popular traditional Chinese herbal medicine that has been used to manage respiratory tract disease, including common cold and chronic bronchitis for thousand years. Human respiratory syncytial virus (HRSV) is one of the leading causes of severe lower respiratory tract illness worldwide. No effective therapeutic modality against HRSV infection has been proved. It is unknown whether Cinnamomum cassia is effective against HRSV. AIM OF THE STUDY: This study tested the hypothesis that Cinnamomum cassia can effectively decrease HRSV-induced plaque formation and syncytium formation in respiratory mucosal cell lines. MATERIALS AND METHODS: Antiviral activity of the hot water extract of Cinnamomum cassia against HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Its ability to inhibit the synthesis of viral fusion (F) protein was examined by Western blot assay. RESULTS: Cinnamomum cassia dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cell lines (p<0.0001). Cinnamomum cassia was more effective when given before viral infection (p<0.0001) mainly by inhibition of viral attachment (p<0.0001) and internalization (p<0.0001). Cinnamomum cassia could inhibit F protein production and syncytium formation to interfere with HRSV spreading. CONCLUSIONS: Cinnamomum cassia prevented airway epithelia from HRSV infection through inhibiting viral attachment, internalization and syncytium formation. Cinnamomum cassia could be a candidate to develop therapeutic modalities to manage HRSV infection in the future.

Fresh ginger (Zingiber officinale) has anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginger, Zingiber officinale Roscoe, is a common spice and also a widely used medicinal plant in ancient China. Ginger is an ingredient of Ge-Gen-Tang (Kakkon-to; GGT). GGT has been proved to have antiviral activity against human respiratory syncytial virus (HRSV). However, it is unknown whether ginger is effective against HRSV. AIM OF THE STUDY: To find a readily available agent to manage HRSV infection, the authors tested the hypothesis that ginger can effectively decrease HRSV-induced plaque formation in respiratory mucosal cell lines. MATERIALS AND METHODS: Effect of hot water extracts of fresh and dried gingers on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Ability of ginger to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: Fresh ginger dose-dependently inhibited HRSV-induced plaque formation in both HEp-2 and A549 cell lines (p<0.0001). In contrast, dried ginger didn't show any dose-dependent inhibition. 300 µg/ml fresh ginger could decrease the plaque counts to 19.7% (A549) and 27.0% (HEp-2) of that of the control group. Fresh ginger was more effective when given before viral inoculation (p<0.0001), particularly on A549 cells. 300 µg/ml fresh ginger could decrease the plaque formation to 12.9% when given before viral inoculation. Fresh ginger dose-dependently inhibited viral attachment (p<0.0001) and internalization (p<0.0001). Fresh ginger of high concentration could stimulate mucosal cells to secrete IFN-ß that possibly contributed to counteracting viral infection. CONCLUSIONS: Fresh, but not dried, ginger is effective against HRSV-induced plaque formation on airway epithelium by blocking viral attachment and internalization.

Antiviral effect of cimicifugin from Cimicifuga foetida against human respiratory syncytial virus.

Human respiratory syncytial virus (RSV) causes serious infection of the lower respiratory tract in children and an effective antiviral therapy against the viral pathogen remains unavailable. We previously demonstrated that the oriental medicinal plant, Cimicifuga foetida L. (C. foetida), possessed inhibitory activity against RSV. Since cimicifugin is a major constituent of C. foetida, we sought to examine in this study its anti-RSV effect on both the human upper (HEp-2) and lower (A549) respiratory tract cell lines. Results revealed that cimicifugin dose-dependently inhibited RSV-induced plaque formation in both HEp-2 and A549 cells (p < 0.0001), with a superior effect in the latter cell type (p < 0.0001). The antiviral activity of cimicifugin was time-dependent (p < 0.0001) and was most effective when cells were treated with the compound before viral inoculation. Additional experiments demonstrated that cimicifugin could inhibit viral attachment (p < 0.0001) and viral internalization (p < 0.0001). Furthermore, the drug could potentiate heparin's effect against attachment of RSV, particularly in A549 cells. Enzyme-linked immunosorbent assay (ELISA) analysis of antiviral cytokines induction revealed that cimicifugin could also stimulate epithelial cells to secrete IFN-ß to counteract viral infection. Taken together, these results indicate that cimicifugin is an efficient antiviral agent against RSV infection. We suggest that cimicifugin might be useful for the management of RSV pathogenesis.

Cimicifuga foetida L. inhibited human respiratory syncytial virus in HEp-2 and A549 cell lines.

Human respiratory syncytial virus (HRSV) causes serious pediatric infection of the lower respiratory tract without effective therapeutic modality. Sheng-Ma-Ge-Gen-Tang (SMGGT; Shoma-kakkon-to) has been proven to be effective at inhibiting HRSV-induced plaque formation, and Cimicifuga foetida is the major constituent of SMGGT. We tested the hypothesis that C. foetida effectively inhibited the cytopathic effects of HRSV by a plaque reduction assay in both human upper (HEp2) and lower (A549) respiratory tract cell lines. Its ability to stimulate anti-viral cytokines was evaluated by an enzyme-linked immunosorbent assay (ELISA). C. foetida dose-dependently inhibited HRSV-induced plaque formation (p < 0.0001) before and after viral inoculation, especially in A549 cells (p < 0.0001). C. foetida dose-dependently inhibited viral attachment (p < 0.0001) and could increase heparins effect on viral attachment. In addition, C. foetida time-dependently and dose-dependently (p < 0.0001) inhibited HRSV internalization. C. foetida could stimulate epithelial cells to secrete IFN-ß to counteract viral infection. However, C. foetida did not stimulate TNF-α secretion. Therefore, C. foetida could be useful in managing HRSV infection. This is the first evidence to support that C. foetida possesses antiviral activity.

Ge-Gen-Tang has anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE: Ge-Gen-Tang (GGT) has been used against adult respiratory tract infection for thousand years in ancient China. However, GGT is unable to inhibit influenza virus. The effect of GGT to manage respiratory tract viral infection has been questioned. Several ingredients of GGT and their constituents are able to inhibit various viruses. Therefore, GGT might have antiviral activity against other viruses causing respiratory tract illness. Human respiratory syncytial virus (HRSV) is one of the most important airway viruses. However, it is unknown whether GGT is effective against HRSV. AIM OF THE STUDY: HRSV contributes considerably to respiratory tract illness of the elderly and immunocompromised adults. There is no effective therapeutic modality for HRSV infection. In order to find a readily available agent to manage HRSV infection, the authors tested the hypothesis that GGT can effectively minimize airway pathology by preventing HRSV-induced plaque formation in respiratory mucosal cell lines. MATERIALS AND METHODS: Effect of the hot water extract of GGT on HRSV was tested by plaque reduction assay in both human upper (HEp-2) and low (A549) respiratory tract cell lines. Ability of GGT to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: GGT dose-dependently inhibited HRSV-induced plaque formation in both cell lines (p<0.0001), especially in A549 cells. GGT was more effective when given before viral infection (p<0.0001). GGT could dose-dependently inhibit viral attachment (p<0.0001) with or without heparin. GGT could further inhibit HRSV internalization time-dependently and dose-dependently (p<0.0001). GGT could stimulate mucosal cells to secrete IFN-ß to counteract viral infection before and after viral inoculation. CONCLUSIONS: GGT is effective against HRSV-induced plaque formation in airway epithelium.