As virucidal agents

Evidence of antiviral effects has especially been shown for St. John s Wort [2,3,10], Plant preparations with different chemical composition have been assayed against various viruses and both, hypericin and pseudohypericin, were found to be particularly effective as virucidal agents. The two compounds have been shown to be active against a broad range of viruses and retroviruses, such as herpes simplex virus types I and II, vesicular stomatitis and influenza viruses, cytomegalovyrus and human immunodeficiency virus-1 [2,3,10,91,92]. 

All essential oils from anise, hyssop, thyme, ginger, camomile and sandalwood possess virucidal activity against HSV-2 mainly before adsorption probably by interacting with the viral envelope (Koch et al. 2008). Camomile oil exhibited a high selectivity index and seems to be a promising candidate for topical therapeutic application as virucidal agents for treatment of herpes genitalis (Koch et al. 2008). 

Phenothiazines, such as methylene blue, were used as virucidal agents for more than 70 years, and they were investigated as agents to prevent the transfusion-mediated spread of hepatitis during the Korean War. In plasma, 5 to 6 log virus inactivation can be obtained. Further treatment inactivates clotting factors, particularly hbrinogen and Cl inactivator. 

If the biter is human immunodeficiency virus positive, the victim should have a baseline human immunodeficiency virus status determined and then repeated in 3 and 6 months. The bite should be thoroughly irrigated with a virucidal agent such as povidone-iodine. Victims may be offered antiretroviral chemoprophylaxis. 

Glutaraldehyde has a mode of action similar to formaldehyde but is less volatile and less toxic to people. It is a relatively powerfixl sporicidal agent and a virucidal agent effective against both lipophilic and hydrophilic viruses. It is frequently used in applications where the object to be disinfected will be used clinically, such as for sterilization of endoscopic equipment or for preparation of heart valves for surgical implants. Its effectiveness... 

Ohtake, S., Arakawa, T., Koyama, A.H., 2010. Arginine as a synergistic virucidal agent. Molecules 15,1408-1424. 

Viruses that contain hpid are inactivated by organic solvents such as chloroform and ether. Those without hpid are resistant to these agents. This distinction has been used to classify virases. Many of the chemical disinfectants used against bacteria, e.g. phenols, alcohols and quaternary ammonium compounds (Chapter 10), have minimal virucidal activity. The most generally active agents are chlorine, the hypochlorites, iodine, aldehydes and ethylene oxide. 

For assaying herpes virus, monolayers of baby hamster kidney (BHK) cells are used. Virus titre is expressed as the number of plaque-forming units (pfu) per millilitre before and after exposure to a disinfectant, so that the virucidal efficacy of the test agent can be determined. A diagrammatic representation is given in Fig. 11.7. 

Many 3-dialkylaminomethyl- and 5-dialkylaminoalkylaminothio-chroman-4-ones exhibit schistosomicidal activity,and a variety of other aminothiochromans are antiamebic. " The thiochroman ring is also found in antimicrobial agents,virucides, insecticides, and acaricides, and antiedemic and anti-inflammatory agents. Hexahydrothiochroman has been employed as a fuel additive, and several <-butyl thiochroman-4-ones have been studied for their... 

Key terms such as disinfection, sterilization and preservation are defined in Chapter 17 but other terms are often employed to describe the antimicrobial activity of agents. Hence, terms such as biocidal, bactericidal, virucidal and fungicidal describe a killing activity, whereas bacteriostatic and fungistatic refer to inhibition of growth of the organism... 

Early experiments on the viability of VACV in the presence of various reducing agents revealed ascorbic acid was strongly virucidal [73], Turner [114] reported quantities of ascorbic acid, as little as 62.5 pg/mL, completely inactivated VACV exposed for 2 h at 37°C under similar conditions, 100 pg/mL inactivated VACV in the span of 15 min. Moreover, in the presence of Cu2+ (5 pg/mL), a catalytic effect was observed the rate at which VACV inactivated significantly increased when exposed to ascorbic acid. 

Because of safety reasons, the in vivo methods mentioned above cannot be used for working with formulations where the safety of the chemical ingredients is unknown and/or with high-risk infectious agents such as HIV. To overcome this, we have developed ex vivo methods using either human skin removed during cosmetic surgery or pieces of human umbilical cord as detailed below and applied them to study the virucidal activity of topicals (Table 4). 

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