Antimicrobial evaluation of extracts of Psidium guajva and Syzgium cumini against oral pathogens

Lubna Tahir, . (2015) Antimicrobial evaluation of extracts of Psidium guajva and Syzgium cumini against oral pathogens. Doctoral thesis, Quaid-i-Azam University, Islamabad.

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The search for bioactive compounds from plants has always been of great interest for scientists who are looking for new drugs from natural resources as according to WHO survey 80% of world population still rely on traditional medicines. Keeping this in mind the present research was conducted with a focus on isolation of some bioactive fractions from medicinal plants with strong antibacterial activities against dental caries causing pathogens. Eight plants were selected on the basis of their traditional uses, literature survey and ethnobotanical importance, Gaff (Diospyros blancoi), Grapes (Vitis vinifera), Jamaun (Syzygium cumuni), Gauva (Psidium guajava), Mango (Mangifera indica), Litchi (Litchi chinensis), Dates (Phoenix dactylifera) and Mulberry (Morus nigra). Extracts of all these plants in different solvents i.e. n-hexane, ethyl acetate, chloroform, methanol and water were tested for antibacterial activities against six oral bacteria (Streptococcus mitis, Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa). Two plants i.e. Jamaun (Syzygium cumuni), Gauva (Psidium guajava)) were selected on the basis of antibacterial activity and preliminary phytochemical analysis. Tablets were formulated form the crude extracts of the selected plants Syzygium cumuni and Psidium guajava and their efficacy was clinically tested. The in-vivo studies revealed the efficacy of dental caries tablets equal to 54%. Bioassay guided purification of the crude extracts of the two plants were carried out using different chromatotographic techniques (flash, column and thin layer chromatography). Out of 60 fractions obtained as a result of different chromatographic techniques, total of 5 fractions having bioactive compounds were further selected from both the plants. The anti-biofilm assay revealed the biofilm inhibition of almost between 90-95%. The FT-IR analysis revealed the presences of nitrile and aromatic groups in the bioactive fractions owing to the anti-caries activity of the extract. Scanning electron microscopic studies of cells after treatment with active fractions of extracts revealed that the extracts affected the integrity of the cell wall to considerable extent. Hence, it can be safely concluded that the inhibition of the dental caries causing bacteria by crude and partially purified extracts of Psidium guajava and Syzygium cumini was due to presences of various active compounds that act in synergy to cause biological effect which might not be recapitulated using single entities. Different combinations of ethyl acetate extracts of these plants will prove helpful in treating dental caries in a more natural and safe way in this world of searching for discovery of safe drug.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: Antimicrobial,evaluation,extracts,Psidium guajva ,Syzgium ,cumini ,oral pathogens
Subjects: Q Science > Q Science (General)
Depositing User: Unnamed user with email
Date Deposited: 27 Oct 2017 03:41
Last Modified: 27 Oct 2017 03:41

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