The Research Of Antibacterial Activities Of Ornidazole And Tea Polyphenols Against Main Periodontal Pathogen In Vitro

Backgroud Periodontitis is one of the familiar dental diseases and itis the main reason which leads to tooth loss. Bacterial infection and the hostimmune response are the dominant factor to determine periodontaldisease.The plaque micro-organisms and their products are the initiatingfactor which lead to periodontitis. The major putative periodontal pathogensincluding:P.gingivalis(Pg),A.actinomycetemitans(Aa),F.nucleatum(Fn),P.nigrescens(Pn), P.intermedia(Pi) and others. This class of bacterium damagesthe periodontal tissue with their direct action (their toxicity) and indirectaction (trigger the host immune response and inflammatory reaction).So, removing the pathogenic factors is the key for the periodontaltreatment. In addition to periodontal machinery treatment, drug therapyplays an important role in periodontal therapy to control pathogenicmicroorganisms, adjust the host defense functions, and promote the tissuehealing.The periodontitis is caused by multi-bacterium and multiple factors.So the combination of antibacterial for periodontitis is advocated. Tea polyphenols refers to a tea and it is the mixture of differentpolyphenols and its derivatives with complex molecular structure. Some ofit’s ingredients, except the antibacterial, are effective in resistance to allergy,scavenging free radicals and periodontal tissue repair.Following metronidazole and tinidazole, ornidazole is the thirdgeneration nitroimidazole medicament drugs, which has stronger actionagainst anaerobic bacteria and less side effects. Clinical and bacteriologicalresearch shows it is effective in periodontal treatment.Objective The agar dilution method was used to measure theantibacterial activities of6kinds of Chinese herbal medicines against10suspected periodontal pathogens in vitro. Then to explore the feasibility ofthe tea polyphenols combined with ornidazole through the compatiblestability experiment and drug sensitivity test.Materials and Methods1. Using the agar dilution method, theMIC and MBC of ornidazole and six Chinese herbs on9kinds ofperiodontal pathogenic bacterium were detected.2. At the0,1st,2nd,3rd,4th hour after mixing tea polyphenols andornidazole, to observe any physic change in this solution by the naked eyesand measure the changes of PH value in this solution. Then the ultravioletspectrophotometer with ferrous tartrate colorimetric measurement was usedto observe the absorption value and absorption curve changes of thissolution combined with tea polyphenols and ornidazole. 3. Using the agar dilution method board, and with the FIC (fractionalinhibitory concentration) value index, to detect the antibacterial effect ofthis solution combined with tea polyphenols and ornidazole against9different periodontal pathogen.Results1. Found by agar dilution method: among the six kinds ofChinese herb extracts, tea polyphenols has the strongest antibacterial activity,followed by：honokiol, gall, emodin, berberine, and yellow baicalin.2. Observe the solution with tea polyphenols and ornidazole each hourin the first4hours after they are mixed. both the appearance and PH valuehas no obvious change. No obvious change has been found about theabsorption value and the absorption curve by the ultravioletspectrophotometer measures.3. Using the agar dilution method board, the FIC0.508~1.000of thesolution with tea polyphenols and ornidazole was counted.Conclusions (1)In the6kinds of Chinese herb extracts, teapolyphenols has the strong bacteriostasis function to putative periodontalpathogens, ornidazole also has a strong inhibitory effect on periodontalpathogenic anaerobic bacteria.(2) There is no incompatibility between tea polyphenols and ornidazole.(3)When tea polyphenols and ornidazole have been soluted together, theyshow additive effects on periodontal pathogen.