The present invention provides a method of inhibiting the formation of pseudorabies particles in a host cell. The method involves administering an effective amount of a poly-hydroxylated stilbene, particularly resveratrol, to a herpes virus infected host cell. The present invention also provides a method of reducing or inhibiting the growth of Neisseria gonorrhea and Neisseria meningiditis in vitro and in vivo. The method comprises administering a composition comprising a therapeutically effective amount of a tri-hydroxylated stilbene to a growth surface which has come into contact or could come into contact with the bacterium.

SUMMARY OF THE INVENTION

The present invention provides a new method of inhibiting the formation of infectious pseudorabies virus particles, in a host cell. The method involves administering a poly-hydroxylated stilbene, particularly resveratrol, or a derivative thereof to a pseudorabies virus infected host cell. The poly-hydroxylated stilbene is administered to the host cell in an amount sufficient to inhibit replication of the virus in the virus-infected host cell. Such method is useful for preventing the spread of pseudorabies virus from a virus-infected host cell to a non-infected host cell. Such method is also useful for establishing a model system for studying the molecular events that occur during replication of pseudorabies virus. In vivo, the method involves administering a composition comprising a poly-hydroxylated stilbene, preferably a tri-hydroxylated stilbene, or a derivative thereof to a non-human animal prior to or shortly after exposure of the animal to the virus. Such method is useful for reducing the cytopathic effect of a pseudorabies virus infection.

The present invention also provides a method of inhibiting replication of the gram negative bacteria belonging to the genus Neisseria, particularly Neisseria gonorrhea and Neisseria meningiditis. Such method involves contacting the bacterium with a composition containing a tri-hydroxylated stilbene or derivative thereof. In vivo, such method can be used to treat an individual who has come in contact with, e.g., a carrier, or an individual who is expected to come into contact with the bacterium, i.e., an individual who may be exposed to the carrier. In vivo, such method comprises administering a composition comprising a therapeutically effective amount of a tri-hydroxylated stilbene, particularly resveratrol, or a derivative thereof to said subject.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, it has been discovered that tri-hydroxylated stilbenes, particularly resveratrol has an antimicrobial effect on select pathogenic microorganisms including pseudorabies virus, Neisseria gonorrhea, and Neisseria meningiditis.

In accordance with the present invention, it has also been shown that resveratrol at concentrations ranging from 1 μg/ml to 200 μg/ml of solution does not inhibit the growth of Eschericia coli, Staphylococcu aureus, Group A beta-hemolytic Streptococcus, Pseudomonas aeruginosa or Candida albicans.

Tri-Hydroxylated Stilbenes

The structural skeleton of the compound employed in the present methods, i.e., the polyhydroxylated stilbene, comprises two aromatic rings joined by an ethylene bridge. Preferably, the compound is a tri-hydroxystilbene, more preferably 3,5,4′-trihdyroxystilbene, which is also known as resveratrol, or a derivative thereof. Resveratrol in either the cis form or trans form is suitable. Derivatives of resveratrol as used herein refers to compounds in which one or two of the hydroxyl functions of resveratrol are replaced with other moieties such as, for example, pterostilbene in which the hydroxyl functions at positions 3 and 5 on the disubstituted aromatic ring are methoxylated. Another example is β-glucoside derivative polydatin or piceid, in which one of the hydroxyl functions on the disubstituted aromatic ring is replaced with glucose; as well as polymers of the parent compound resveratrol. Such polymers have been given the name viniferins. Methods for producing the hydroxylated stilbenes are described in Moreana-Manas, M. et al, Anal Quim (1985) 81:157-161; Jeandet, P. et al, Am J. Enol Vitic (1991) 42:41-6; Goldberg DM et al. Anal Chem (1994) 66:3959-63, Murakami, S et al, Biochem Pharmacol. (1992) 44:1947-51; and Thakkar, K et al, J. Med Chem (1993) 36:2650-51, which are incorporated herein by reference. Resveratrol and 3,3′,4,5′-tetrahydroxy-trans-stilbene, known as piceatoannol, are also available commercially from Sigma Chemical Co., St. Louis, Mo.

Methods of Inhibiting Formation of Infectious Pseudorabies Viral Particles

In one aspect, the present invention provides a method of inhibiting formation of infectious pseudorabies viral particles in a host cell. The method comprises administering a polyhydroxylated stilbene, preferably a tri-hydroxylated stilbene, or a derivative thereof to the host cell. The polyhydroxylated stilbene is administered in an amount sufficient to or effective to inhibit replication of the pseudorabis virus within the infected cell. Preferably, the polyhydroxylated stilbene or derivative thereof is administered to the host cell either prior to infection of the host cell with the virus or preferably, within six hours after infection of the host cell with the virus.

Preferably, the tri-hydroxylated stilbene or derivative thereof is administered to the host cell by contacting the host cell with or exposing the host cell to a composition comprising the tri-hydroxylated stilbene or derivative thereof. For example, in vitro, the method comprises adding a tri-hydroxylated stilbene to the culture medium of pseudorabies virus-infected host cells. In the case of cultured cells, the tri-hydroxylated stilbene is added to the medium, preferably before the host cells are infected with the virus or within six hours after the host cells are infected with the virus. Good results have been obtained by exposing cultured host cells to the tri-hydroxylated stilbene, resveratrol, at a concentration which is greater than 1 μg/ml and less than 200 μg/ml of culture medium.

It has been determined that treatment of cultured cells in accordance with the present method is non-toxic to cells and blocks replication of pseudorabies virus at some early stage in it replicative cycle. It has also been determined that the effect of resveratrol on pseudorabies virus replication is reversible. Typical of the herpes viruses, pseudorabies replication occurs in phases, with each phase being dependent on the successful completion of the prior phase. The "immediate early phase" occurs at 1-3 hours after infection and is associated with regulatory and synthetic events. The "early phase" occurs 3-6 hours after infection and is also associated with regulatory and synthetic events, particularly the synthesis of virus DNA. The "late phase" occurs 6-10 hours after infection and is associated with final synthetic events and assembly of viral components into infections virions. Such method is useful for establishing model systems for studying the molecular events that occur during replication of pseudorabies virus. For example, mammalian cell cultures incubated in the presence and absence of resveratrol may be used to identify cellular factors that are involved in regulating pseudorabies virus synthetic events. Such cell cultures may also be employed to characterize the role of psuedorabies virus gene products in the replication of infectious virus, particularly those proteins and factors whose function are currently unknown.

In vivo, the method is used to inhibit the development of or to reduce the severity of a pseudorabies infection in a mammalian subject, particularly a non-human mammalian subject. Such method comprises administering a therapeutically effective amount of the tri-hydroxylated stilbene or derivative thereof to a mammalian subject prior to or shortly after exposure to the virus. Such method is particularly useful for reducing the severity of infection in a pig and, in some cases, preventing the animal from becoming a carrier. Since transmission among pigs is typically due to nose to nose contact, it is preferred that the tri-hydroxylated stilbene be administered in a composition which enters the pig through the nose or the oropharynx. For example, the tri-hydroxylated stilbene may be added to the drinking water or the feed of animals that may have come into contact with or could come into contact with the virus. In addition, the tri-hydroxylated stilbene may be incorporated into an aerosolizable solution or suspension which is then misted into the nurseries of newborn piglets.

Method of Inhibiting Growth of Neisseria gonorrheae or Neisseria meningiditis

In another aspect, the present invention provides a method of inhibiting the growth of Neisseria gonnorhea and Neisseria meningiditis. The method comprises administering a tri-hydroxylated stilbene, preferably resveratrol, or a derivative thereof to a surface which has come in contact with or could come in contact with the organism. In vivo, the method, which comprises administering the tri-hydroxylated stilbene to a mucous membrane of a human subject, may be used to prevent or reduce the symptoms of gonnococcal or meningococcal disease in the human subject. The tri-hydoxylated stilbene or derivative thereof may be incorporated into a pharmaceutical composition which is applied to the mucous membrane of a carrier of the bacterium or a person who could come into contact with the carrier.

Pharmaceutical compositions used in the present methods comprise a therapeutically effective amount of a tri-hydroxylated stilbene preferably resveratrol or a derivative thereof, and a pharmaceutically acceptable carrier. Preferably, the composition comprises a relatively inert carrier. Many such carriers are routinely used and can be identified by reference to pharmaceutical texts. Examples include polyethylene glycols, polypropylene copolymers, and some water soluble gels. Such a composition may also contain diluents, fillers, salts, buffers, stabilizers, solubilizers, and other pharmaceutically acceptable materials well known in the art. The term "pharmaceutically acceptable" means a non-toxic material that does not interfere with the effectiveness of the anti-microbial activity of the tri-hydroxylated stilbene or derivative thereof.

In practicing the present method, a pharmaceutical composition comprising a therapeutically effective amount of the hydroxylated stilbene, preferably resveratrol, is applied to a potential or actual site of infection in the host subject before or after the host subject is exposed to the bacterium. Such composition may be used prophylactically to prevent or reduce the severity of infections of the eye, nose, mouth, throat, oropharynx, genitalia, and rectum. In the case of oral administration, dentrifices, mouthwashes, tooth paste or gels, or mouth sprays are used. Vaginal or rectal administration may be by the usual carriers such as douches, foams, creams, ointments, jellies, and suppositories, the longer lasting forms being preferred. Ocular administration is preferably by ophthalmic ointments or solutions.

The pharmaceutical composition may further contain other agents which either enhance the activity of the tri-hydroxylated stilbene or complement its activity or use in inhibiting growth of the gonoccocus or meningococcus. Such additional factors and/or agents may be included in the pharmaceutical composition to produce a synergistic effect with the tri-hydroxylated stilbene, or to minimize side effects.

Preferably the pharmaceutical composition comprises a solvent for the tri-hydroxylated stilbene or derivative thereof, such as, for example, an alcohol. A liquid carrier such as water, petroleum, oils of animal or plant origin such as peanut oil, mineral oil, soybean oil, or sesame oil, corn oil, or synthetic oils may be added. The liquid form of the pharmaceutical composition may further contain a physiological saline solution, dextrose or other saccharide solution, or glycols such as ethylene glycol, propylene glycol or polyethylene glycol. The preparation of such pharmaceutical composition having suitable pH, isotonicity, and stability, is within the skill in the art.

Administration of the pharmaceutical composition to an uninfected subject is via local administration to a site which has been or may be contacted with the pathogenic organism. It is preferred that the pharmaceutical composition be applied prior to exposure to the targeted pathogen or preferably within 1-24 hours, more preferably within 1-12 hours after exposure of the uninfected subject to the pathogenic organsim.

Administration of the pharmaceutical composition to a carrier of Neisseria meningiditis is via local administration to the upper respiratory tract, i.e. ororpharynx. Administration of the pharmaceutical composition to a carrier of Neisseria gonorrhea is via local administration to the genitalia, rectum, or oropharynx.

Dosage

The tri-hydroxylated stilbene, preferably resveratrol or a derivative thereof is administered to the host subject in a therapeutically effective amount. As used herein, the term "therapeutically effective amount" means the total amount of the tri-hydroxylated stilbene that is sufficient to show a meaningful benefit, i.e., prevention or reduction in the extent of infection by the targeted pathogen or a reduction in the severity of the symptoms that result from infection with the targeted pathogen. The dosages of the tri-hydroxylated stilbene, particularly resveratrol, which can prevent or reduce the severity of an infection with pseudorabies virus, Neisseria gonorrhea or Neisseria meningididtis can be determined in view of this disclosure by one of ordinary skill in the art by running routine trials with appropriate controls. Comparison of the appropriate treatment groups to the controls will indicate whether a particular dosage is effective in preventing or reducing the severity of the infection at the levels used in a controlled challenge.

It is contemplated that the various compositions used to practice the method of the present invention should contain about 0.01 μg to about 10 μg, more preferably about 0.1 μg to about 1 mg, of the tri-hydroxylated stilbene, most preferably from about 10 μg to about 100 μg of resveratrol per/ml of the composition. Although a single administration of the composition may be sufficient to ameliorate the pathological effects of the virus or bacteria, it is expected that multiple doses will be preferred.
 

Claim 1 of 10 Claims

1. A method of treating a subject with a Neisseria gonorrhea or a Neisseria meningiditis infection of the eye, said method comprising administering 3,5,4′-trihydroxystilbene to the eye of the subject.

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