There has been new interest in finding active herbal antivirals as more patients are found to be resistant to conventional antiviral medication. This is of particular concern for patients with herpes who have poor immune function, as a result of cancer treatments, surgery or other medical conditions.
Researchers have conducted studies in vitro to establish levels of toxicity and then whether the herbal extract (usually in ethanol) has an antiviral affect on HSV-1 infected cells grown in culture. A number of studies have identified potential new herbal treatments that can be confirmed by further research with patients. There are four potential new candidates for herpes treatment – Bidens pilosa, black tea extract, Gymura procumbens and Quercus persica.
Bidens pilosa is an American native of the aster family, it has spread widely across other regions and is now considered to be a weed. In laboratory research it has been found to have remarkable antiviral activity, reducing viral replication. A recent study has shown that its antiviral action comes from blocking the virus binding to the host cell and then stopping the virus entering the cell. It was found to improve the survival rates of herpes infected mice and reduced the number or blisters on their skin (Nakama et al 2012).
Black tea extract is another strong contender for a new herbal treatment for herpes. In a study designed to find out if theaflavins, the flavanol compounds present in black tea extract, could inhibit herpes infection researchers found it was indeed effective in blocking the production of HSV-1 virus in cell culture. The researchers found it had the ability to interfere with the attachment of the virus to the cell, penetrate the cell as well HSV-1’s ability to replicate itself (Canatore et al 2013).
Gymura procumbens has been found to have many positive health effects including anti-inflammatory properties. Recent research has sought to find out if it has any antiviral properties(Jarikasem et al 2013). Using ethanol extracts of the plant the researchers conducted a double blind randomised control trial with patients with recurrent cold sores. They found a significant reduction in the viral load of patients in the experimental group (those who received Gymura) and concluded that gymura may indeed have an antiviral role to play in herpes treatment. Finally, researchers in Iran (Kamiri et al 2013) have found that an oak species, Quercus persica, also has antiviral properties and may be a candidate for further research as a treatment for herpes.
Existing known herbal treatments that have a role in treating herpes simplex include olive leaf, Echinacea, lemon balm (Melissa officionalis) which is also effective as an essential oil (see mind body), reishi (a fungus), astragalus and resveratrol a compound extracted from Japanese knotweed. Research has shown that resveratrol suppresses viral activity by interfering with viral replication and has the ability to impair expression of essential HSV genes and the creation of viral DNA (Faith et al 2006).
Jarikasem. antiherpetic Effects of Gynura procumbens. Evid Based Complement Alternat Med Sep 2013.
Cantatore. Effect of black tea extract on herpes simplex virus infection of cultured cells. BMC Complement Alternat Med Jun 2013.
Nakama et al. Efficacy of Bidens pilosa extract against Herpes Simplex virus infection in Vitro and In Vivo. Evid Based Complement Alternat Med. Feb 2012
Karimi et al. antiviral activity of Quercus persica L: High efficacy and low toxicity. Adv Biomed Res. 2013.
Chen et al. Inhibition of herpes simplex virus infection by oligomeric stilbenoids through ROS generation. antiviral Res Jul 2012.
Faith, SA et al. Resveratrol suppresses nuclear factor-kappaB in herpes simplex virus infected cells Antiviral Res. 2006 Dec
Schneider S et al. Anti-herpetic properties of hydroalcoholic extracts and pressed juice from Echinacea pallid. Planta Med 2010 Feb