Background: The dosage of herb ultrafine particle (UFP) depended on the increased level of its dissolution, toxicity, and efficacy. Objective: The dissolution, antibacterial activity, and cytotoxicity of Coptidis rhizoma (CR) UFP were compared with those of traditional decoction (TD). Materials and Methods: The dissolution of berberine (BBR) of CR TD and UFP was determined by high-performance liquid chromatography. The antibacterial activity of CR extract was assayed by plate-hole diffusion and broth dilution method; the inhibitory effect of rat serums against bacteria growth was evaluated after orally given CR UFP or TD extract. The cytotoxicity of CR extract was evaluated by 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide assay. Results: The dissolution amount of BBR from CR UFP increased 6-8-folds in comparison to TD at 2 min, the accumulative amount of BBR in both UFP and TD group increased in a time-dependent manner. The minimal inhibitory concentrations and minimal bactericidal concentrations of CR UFP extract decreased to 1/2~1/4 of those of TD extract. The inhibitory effect of rat serums against bacteria growth decreased time-dependently, and no statistical difference was observed between two groups at each time point. The 50% cytotoxic concentrations of UFP extract increased 1.66~1.97 fold than those of TD. Conclusions: The antibacterial activity and cytotoxicity of CR UFP increased in a dissolution-effect manner in vitro, the increased level of cytotoxicity was lower than that of antibacterial activity, and the inhibitory effect of rat serums containing drugs of UFP group did not improve.

Background: Medicinal plants have been used to prevent and treat various health problems. Aim: The present study was conducted to evaluate the antibacterial and antioxidant activities of aqueous and solvent extracts of some selected medicinal plants. Materials and Methods: The disc diffusion method was employed for the determination of antimicrobial activity, and antioxidant activity was evaluated by 2, 2-diphenyl-1-picrylhydrazyl radical scavenging, hydrogen peroxide reducing and β- carotene/linoleic acid bleaching inhibition assays. Folin-Ciocalteu reagent method was employed for the determination of total phenolic contents. Results: Aqueous and solvent extracts of Acacia catechu, A. ferruginea, Adenanthera pavonina, Albizia odoratissima, Anogeissus latifolia, Breynia vitis-idaea, Salacia oblonga, Senna spectabilis and Solanum indicum showed significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus and Streptococcus faecalis, and promising antioxidant properties. The antioxidant activities were positively correlated with total phenolic contents. Discussion and Conclusion: The promising antibacterial and antioxidant activities of these plants validated their traditional use in various herbal preparations to treat various ailments associated with pathogenic microbes and oxidative stress. Further investigations such as isolation of active principles and toxicological studies to ascertain the safety, and in vivo experimentations on suitable models are required to explore the therapeutic usage of these plants on humans.

Delonix elata , Enicostemma axillare, Merremia tridentata, Mollugo cerviana and Solanum incanum are medicinal plants used in traditional Indian medicine for the treatment of various ailments. These plants were selected to evaluate their potential antibacterial activity. To determine antibacterial activity and phytochemicals in the crude extracts of five medicinal plants used in traditional Indian medicine for the treatment of various ailments like rheumatism, piles fever, skin diseases and snake bite. The antibacterial activity of organic solvent extracts of these plants were determined by disc diffusion and broth dilution techniques against gram-positive bacterial strains (Bacillus subtilis, Staphylococcus aureus) and gram-negative bacterial strains (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa). Results revealed that the chloroform and methanol extracts of D. elata and methanol extracts of M. cerviana exhibited significant antibacterial activity against gram-positive and gram-negative strains with minimum bactericidal concentration (MBC) ranging from 1.5 to 100 mg/ml. Methanol extracts of M. tridentata exhibited activity only against gram-positive bacterial strains with MBC ranging from 12.5 to 100 mg/ml. Extracts of E. axillare and S. incanum showed activity only against B. subtilis and were not bactericidal at 100 mg/ml. The most susceptible organism to the organic extracts from all the studied plants was B. subtilis and the most resistant organism was P. aeruginosa. The presence of phytochemicals such as alkaloids, tannins, triterpenoids, steroids and glycosides in the extracts of these plants supports their traditional uses as medicinal plants for the treatment of various ailments. The present study reveals potential use of these plants for developing new antibacterial compounds against pathogenic microorganisms.

The antibacterial activity of the leaves and bark of mangrove plants, Avicennia marina, A. officinalis, Bruguiera sexangula, Exoecaria agallocha, Lumnitzera racemosa, and Rhizophora apiculata was evaluated against antibiotic resistant pathogenic bacteria, Staphylococcus aureus and Proteus sp. Soxhlet extracts of petroleum ether, ethyl acetate, ethanol and water were prepared and evaluated the antibacterial activity using agar diffusion method. Most of the plant extracts showed promising antibacterial activity against both bacterial species. However, higher antibacterial activity was observed for Staphylococcus aureus than Proteus sp. The highest antibacterial activity was shown by ethyl acetate of mature leaf extracts of E. agallocha for Staphylococcus aureus. All ethyl acetate extracts showed higher inhibition against S. aureus while some extracts of chloroform, ethyl acetate and ethanol gave inhibition against Proteus sp. None of the petroleum ether and aqueous extracts showed inhibition against Proteus sp. All fresh plant materials did also show more antibacterial activity against both bacterial strains than did dried plant extracts. Antibacterial activity of fresh and dried plant materials reduced for both bacterial strains with time after extraction. Since L. racemosa and A. marina gave the best inhibition for bacterial species, they were used for further investigations. Charcoal treated plant extracts of L. racemosa and A. marina were able to inhibit both bacterial strains more than those of untreated plant extracts. Phytochemical screening of mature leaf, bark of L. racemosa and leaf extracts of A. marina has been carried out and revealed that leaf and bark contained alkaloids, steroids, triterpenoids and flavonoids. None of the above extracts indicate the presence of saponins and cardiac glycosides. Separated bands of extracts by TLC analysis showed antibacterial activity against S. aureus.

The purpose of present study was to investigate the antibacterial activity of three commercially available fluoride- and zinc-releasing glass ionomer cements on strains of mutans streptococci. Three glass ionomers (Fuji II Conventional, Fuji II Light Cure, and Fuji IX) were used. The antibacterial effect of glass ionomer cements were estimated by anaerobically growing mutans streptococci on a selective medium by inoculating human saliva and measuring the inhibition zones around the glass ionomer discs on the medium. Fluoride and zinc release were measured and compared with the antibacterial activity. The results, when statistically analyzed, showed a direct correlation between fluoride release and antibacterial activity, but there was no correlation between zinc release and antibacterial activity.

Aim: To evaluate and compare the antibacterial activity of newer dentin bonding agents on Streptococcus mutans using the direct contact test. Materials and Methods: Streptococcus mutans was used as test organism and a direct contact test was performed. The dentin bonding agents to be tested were grouped as Group I, Clearfil Protect Bond, Group II, Adper Easy One, and Group III, Prime and Bond NT. For the direct contact test, three microtiter plates consisting of 96 wells each were taken (288 wells). These wells were divided into three groups of 96 wells; 16 wells of a microtiter plate were utilized, of which four were designated as 'A' wells (with the dentin bonding agent and bacterial suspension), another four as 'B' wells (without the dentin bonding agent, but with the bacterial suspension), another four as the 'C' wells (with the tested material, but without bacteria, which served as the negative control), and the remaining four as the 'D' wells (without the dentin bonding agent, which served as the positive control). Each group was treated with their respective bonding agents as per the manufactures instructions. Broth of 15 mL was then transferred from the A wells into an adjacent set of B wells containing fresh medium (215 mL). This resulted in two sets of four wells for each tested material containing an equal volume of liquid medium, so that bacterial growth was monitored both in the presence and in the absence of the tested material. The plate was placed for incubation at 37°C in the microplate reader and the optical density in each well was measured at 600 nm. The readings were taken at regular intervals. (Every 30 minutes for 16 hours). Results: The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was least effective against Streptococcus mutans. Interpretation and Conclusion: The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was the least effective against Streptococcus mutans. Hence, the incorporation of antibacterial agents into the dentin bonding agents may become an essential factor in inhibiting residual bacteria in the cavity and secondary caries.

Context: Antibiotic resistance is a major problem with inadvertent usage. Thus, there is a need to search for new antimicrobial agents of herbal origin to combat antibiotic resistance. One such plant is Morus alba which has a long history of medicinal use in traditional Chinese medicine. Aim: To compare the antibacterial activity of ethanolic extract of M. alba leaves with chlorhexidine gluconate against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia. Settings and Design: Experimental in vitro study. Methodology: Crude extract from the leaves of M. alba were prepared by Soxhlet extraction method by using ethanol as a solvent. Minimum inhibitory concentration (MIC) of the extract was assessed against A. actinomycetemcomitans, P. gingivalis and T. forsythia, and compared with that of chlorhexidine gluconate by broth dilution method. Results: P. gingivalis was the most sensitive organism against the M. alba extract with an MIC value of 1.95 mg/ml; while T. forsythia and P. gingivalis both were most sensitive organisms against chlorhexidine gluconate with MIC values of 0.00781 mg/ml. Conclusion: M. alba possess good antibacterial activity against A. actinomycetemcomitans, P. gingivalis and T. forsythia and thus would be beneficial for the prevention and treatment of periodontal disease. However, chlorhexidine gluconate was found to be more effective when compared to M. alba.