Dr. Ron’s Research Review – September 21, 2011

This week’s research review: The Common Cold 2011 – Part 2.

Echinacea

Standardized Echinacea purpurea extract has anti-viral properties and a mode of action of against highly pathogenic avian influenza virus (H5N1, H7N7) and swine-origin H1N1 (S-OIV) (Pleschka, Stein et al. 2009)

Interestingly, another recent article showed that E. purpurea alters the clinical course of influenza infection in mice through modulation of cytokines and not direct antiviral activity. (Fusco, Liu et al. 2010)

Elderberry

A standardized elderberry liquid extract was shown to have inhibitory activity of against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses (Krawitz, Mraheil et al. 2011)

Green Tea Catechins

A randomized controlled trial showed that green tea catechins and theanine prevented influenza infection among healthcare workers. (Matsumoto, Yamada et al. 2011)

An older prospective clinical study showed that gargling with tea catechin extracts prevented influenza infection in elderly nursing home residents. (Yamada, Takuma et al. 2006)

Dr. Ron


Articles

Echinacea purpurea aerial extract alters course of influenza infection in mice

            (Fusco, Liu et al. 2010) Download

Influenza infection is a major clinical problem and Echinacea purpurea, a widely consumed botanical product, is purported to alter the course of respiratory infections including influenza. Mice infected with WSN influenza A and treated with E. purpurea polysaccharide extract had less weight loss than untreated mice but similar pulmonary viral titers. Echinacea-treated mice had lower systemic and pulmonary KC and IL-10 levels and lower systemic IFN-gamma levels following influenza infection. These suggest that E. purpurea alters the clinical course of influenza infection in mice through modulation of cytokines and not direct antiviral activity.

Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses

         (Krawitz, Mraheil et al. 2011) Download

BACKGROUND: Black elderberries (Sambucus nigra L.) are well known as supportive agents against common cold and influenza. It is further known that bacterial super-infection during an influenza virus (IV) infection can lead to severe pneumonia. We have analyzed a standardized elderberry extract (Rubini, BerryPharma AG) for its antimicrobial and antiviral activity using the microtitre broth micro-dilution assay against three Gram-positive bacteria and one Gram-negative bacteria responsible for infections of the upper respiratory tract, as well as cell culture experiments for two different strains of influenza virus. METHODS: The antimicrobial activity of the elderberry extract was determined by bacterial growth experiments in liquid cultures using the extract at concentrations of 5%, 10%, 15% and 20%. The inhibitory effects were determined by plating the bacteria on agar plates. In addition, the inhibitory potential of the extract on the propagation of human pathogenic H5N1-type influenza A virus isolated from a patient and an influenza B virus strain was investigated using MTT and focus assays. RESULTS: For the first time, it was shown that a standardized elderberry liquid extract possesses antimicrobial activity against both Gram-positive bacteria of Streptococcus pyogenes and group C and G Streptococci, and the Gram-negative bacterium Branhamella catarrhalis in liquid cultures. The liquid extract also displays an inhibitory effect on the propagation of human pathogenic influenza viruses. CONCLUSION: Rubini elderberry liquid extract is active against human pathogenic bacteria as well as influenza viruses. The activities shown suggest that additional and alternative approaches to combat infections might be provided by this natural product.

Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial

            (Matsumoto, Yamada et al. 2011) Download

BACKGROUND: Experimental studies have revealed that green tea catechins and theanine prevent influenza infection, while the clinical evidence has been inconclusive. This study was conducted to determine whether taking green tea catechins and theanine can clinically prevent influenza infection. METHODS: DESIGN, SETTING, AND PARTICIPANTS: A randomized, double-blind, placebo-controlled trial of 200 healthcare workers conducted for 5 months from November 9, 2009 to April 8, 2010 in three healthcare facilities for the elderly in Higashimurayama, Japan. INTERVENTIONS: The catechin/theanine group received capsules including green tea catechins (378 mg/day) and theanine (210 mg/day). The control group received placebo. MAIN OUTCOME MEASURES: The primary outcome was the incidence of clinically defined influenza infection. Secondary outcomes were (1) laboratory-confirmed influenza with viral antigen measured by immunochromatographic assay and (2) the time for which the patient was free from clinically defined influenza infection, i.e., the period between the start of intervention and the first diagnosis of influenza infection, based on clinically defined influenza infection. RESULTS: Eligible healthcare workers (n = 197) were enrolled and randomly assigned to an intervention; 98 were allocated to receive catechin/theanine capsules and 99 to placebo. The incidence of clinically defined influenza infection was significantly lower in the catechin/theanine group (4 participants; 4.1%) compared with the placebo group (13 participants; 13.1%) (adjusted OR, 0.25; 95% CI, 0.07 to 0.76, P = 0.022). The incidence of laboratory-confirmed influenza infection was also lower in the catechin/theanine group (1 participant; 1.0%) than in the placebo group (5 participants; 5.1%), but this difference was not significant (adjusted OR, 0.17; 95% CI, 0.01 to 1.10; P = 0.112). The time for which the patient was free from clinically defined influenza infection was significantly different between the two groups (adjusted HR, 0.27; 95% CI, 0.09 to 0.84; P = 0.023). CONCLUSIONS: Among healthcare workers for the elderly, taking green tea catechins and theanine may be effective prophylaxis for influenza infection. TRIAL REGISTRATION: ClinicalTrials (NCT): NCT01008020.

 


Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian influenza virus (H5N1, H7N7) and swine-origin H1N1 (S-OIV)

            (Pleschka, Stein et al. 2009) Download

BACKGROUND: Influenza virus (IV) infections are a major threat to human welfare and animal health worldwide. Anti-viral therapy includes vaccines and a few anti-viral drugs. However vaccines are not always available in time, as demonstrated by the emergence of the new 2009 H1N1-type pandemic strain of swine origin (S-OIV) in April 2009, and the acquisition of resistance to neuraminidase inhibitors such as Tamiflu (oseltamivir) is a potential problem. Therefore the prospects for the control of IV by existing anti-viral drugs are limited. As an alternative approach to the common anti-virals we studied in more detail a commercial standardized extract of the widely used herb Echinacea purpurea (Echinaforce, EF) in order to elucidate the nature of its anti-IV activity. RESULTS: Human H1N1-type IV, highly pathogenic avian IV (HPAIV) of the H5- and H7-types, as well as swine origin IV (S-OIV, H1N1), were all inactivated in cell culture assays by the EF preparation at concentrations ranging from the recommended dose for oral consumption to several orders of magnitude lower. Detailed studies with the H5N1 HPAIV strain indicated that direct contact between EF and virus was required, prior to infection, in order to obtain maximum inhibition in virus replication. Hemagglutination assays showed that the extract inhibited the receptor binding activity of the virus, suggesting that the extract interferes with the viral entry into cells. In sequential passage studies under treatment in cell culture with the H5N1 virus no EF-resistant variants emerged, in contrast to Tamiflu, which produced resistant viruses upon passaging. Furthermore, the Tamiflu-resistant virus was just as susceptible to EF as the wild type virus. CONCLUSION: As a result of these investigations, we believe that this standard Echinacea preparation, used at the recommended dose for oral consumption, could be a useful, readily available and affordable addition to existing control options for IV replication and dissemination.

Gargling with tea catechin extracts for the prevention of influenza infection in elderly nursing home residents: a prospective clinical study

         (Yamada, Takuma et al. 2006) Download

OBJECTIVES: To evaluate the effects of gargling tea catechin extracts on the prevention of influenza infection in elderly nursing home residents. DESIGN: A prospective study conducted for 3 months from January to March 2005. SETTINGS/LOCATION: A nursing home in Japan. SUBJECTS: A total of 124 elderly residents of at least 65 years of age were enrolled in the study. Seventy-six residents (83 +/-8.2 years, mean +/-standard deviation; 24 men, 52 women) gargled with tea catechin extract (catechin group) and were compared with 48 age- and sex-matched residents who gargled without tea catechin extracts (control group). All the residents were vaccinated with an influenza vaccine until early December 2004. INTERVENTIONS: catechin group: gargling with the tea catechin extract solution (200 microg/mL catechins, 60% of catechins comprise epigallocatechin gallate); control group: gargling without the catechin extract solution. In both groups, gargling was performed three times daily for 3 months. OUTCOME MEASURES: The incidence of influenza infection during the study was compared between the two groups. A safety evaluation was conducted to observe adverse events during the study. RESULTS: The incidence of influenza infection was significantly lower in the catechin group (1.3%, one resident) than in the control group (10%, five residents) calculated by multivariate logistic regression analysis (p = 0.028; odds ratio, 15.711; 95% confidence interval, 1.883-399.658). No adverse events, such as respiratory tract irritation, an obstruction, or allergic bronchial spasm, were observed during the study. CONCLUSIONS: This prospective study demonstrating the effect of catechin gargling on the prevention of influenza infection in the elderly is the first to be reported in the literature. Further randomized, controlled studies are needed to confirm the effects of catechin gargling on the prevention of influenza infection.


References

Fusco, D., X. Liu, et al. (2010). "Echinacea purpurea aerial extract alters course of influenza infection in mice." Vaccine 28(23): 3956-62.

Krawitz, C., M. A. Mraheil, et al. (2011). "Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses." BMC Complement Altern Med 11: 16.

Matsumoto, K., H. Yamada, et al. (2011). "Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial." BMC Complement Altern Med 11: 15.

Pleschka, S., M. Stein, et al. (2009). "Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian influenza virus (H5N1, H7N7) and swine-origin H1N1 (S-OIV)." Virol J 6: 197.

Yamada, H., N. Takuma, et al. (2006). "Gargling with tea catechin extracts for the prevention of influenza infection in elderly nursing home residents: a prospective clinical study." J Altern Complement Med 12(7): 669-72.