Effect of Aerva sanguinolenta (Lal bishalyakarani) plant extract on biofilm-induced human enamel demineralization: An in vitro study.

BACKGROUND: Controlling cariogenic biofilm formation by plant extracts could add to preventive strategies to dental caries. OBJECTIVE: To evaluate in vitro the role of Aerva Sanguinolenta ethanolic extract on biofilm-induced microbial human enamel demineralization. METHODOLOGY: The prepared enamel sections of study group (SG), positive control group (PCG), and negative control group (NCG) were immersed in 2 ml of 0.2% ethanolic extract of A. sanguinolenta, 0.12% chlorhexidine, and distilled water, respectively, for 2 min before subjecting to closed batch culture technique utilizing mono- or dual-species culture media of Streptococcus mutans and Lactobacillus acidophilus. Quantification of biofilm and demineralization of enamel was performed by crystal violet (CV) assay and scanning electron microscope (SEM) attached to energy-dispersive X-ray analysis, respectively. STATISTICAL ANALYSIS: Two-way ANOVA and Tukey's test were used for analysis. RESULTS: CV assay of biofilm recorded the highest and lowest optical absorbance value in NC3 (2.728660) and PC3 (0.364200), respectively. Thus, biofilm formation is highest in NCG and lowest among PCG. Surface roughness and porosity in enamel are greatest among NCG and lowest among SG as evident by SEM. Wt% of calcium (S3 47.7170) and phosphorus ion (S3 22.7330) was highest in SG, closely resembling that of B enamel (Ca = 41.9530, P = 19.6650). Wt% of oxygen is lowest in SG (S3 28.8920) and resembles baseline O2 (37.4950). Thus, the amount of biofilm formation is moderate and amount of demineralization of enamel is least among SGs. CONCLUSION: Enamel exposed to 2 ml of 0.2% solution of A. sanguinolenta for 2 min could fairly inhibit formation of biofilm and positively inhibit underlying demineralization in cariogenic environment.

Comparative evaluation of different probiotic products on salivary Streptococcus mutans and Lactobacillus level in caries risk population.

INTRODUCTION: Dental caries is a multifactorial disease with the main causative organism being Streptococcus mutans and Lactobacillus spp. "Probiotics" are defined as living microorganisms, principally bacteria, which are safe for human consumption and when ingested in sufficient quantities, have beneficial effects on human health, beyond basic nutrition. These can be used to replace the pathogenic strains of bacteria with the nonpathogenic type in the oral cavity thus can help prevent dental caries. AIMS: To evaluate and compare the role of probiotic milk and lozenges on S. mutans and Lactobacillus spp. count on patients who are exposed to probiotics continuously for 7 days. MATERIALS AND METHODS: Sixty volunteers who were prone to caries were divided into three equal groups. Experimental groups were given probiotics daily for 7 days. In Group A, patients were given milk without any probiotics (control); in Group B, probiotic milk is given; and in Group C, probiotic lozenges are given. Saliva samples were assessed on the 1st day and after 7 days of intervention. The collected saliva samples were inoculated on the selected culture media and estimation was done by measuring the colony-forming unit. STATISTICAL ANALYSIS USED: Statistical analysis was performed using Student's paired t-test and multiple comparisons by Tukey's honest significant difference test. RESULTS: There was a significant reduction in salivary S. mutans level in both experimental groups after 7 days (P < 0.05). However, there was no significant difference in Lactobacillus count before and after the intervention. CONCLUSIONS: Probiotics have a role in reducing salivary S. mutans count. Probiotics lozenges showed greater efficacy in reducing salivary S. mutans count than probiotic milk.

Comparative assessment of the effectiveness of different cleaning methods on the growth of Candida albicans over acrylic surface.

CONTEXT: This study evaluated the efficacy of denture adhesive, cleanser, chlorhexidine, and brushing against Candida albicans biofilm developed on an acrylic surface and predicted the most effective, simple, and inexpensive way to maintain denture health, thereby preventing denture stomatitis. AIMS: To find the best possible method for maintaining denture hygiene. SETTINGS AND DESIGN: This retrospective analysis was conducted in the Guru Nanak Institute of Dental Sciences and Research, Kolkata, and this in vitro study was designed to minimize denture stomatitis among denture wearing population. SUBJECTS AND METHODS: Sixty acrylic discs of equal dimensions after exposure to C. albicans were treated for a duration of 24 h with denture adhesive, cleanser, 0.2% chlorhexidine individually, or in combinations simulating clinical conditions dividing in six groups, ten samples each (n = 10). STATISTICAL ANALYSIS USED: After treatment, colony count was evaluated and statistically analyzed by post hoc Tukey's test and Dunnett's test to determine the most effective way of prevention. RESULTS: The statistical post hoc analysis (Tukey's test and Dunnett's test) showed high significance (P < 0.0001). The group treated with adhesive showed high fungal growth compared to the control group, whereas chlorhexidine showed high potency to prevent C. albicans, whereas adhesive increased the adhesion of C. albicans to acrylic surface. CONCLUSIONS: Denture adhesive increases the adherence of C. albicans to denture surface. Other cleaning chemicals such as cleanser and chlorhexidine decrease the adherence. Moreover, among the all denture cleaning protocol, chlorhexidine drastically inhibit the adherence, as well as growth of C. albicans over denture surface.

Participation of chlorobiumquinone in the transplasma membrane electron transport system of Leishmania donovani promastigote: effect of near-ultraviolet light on the redox reaction of plasma membrane.

The respiratory quinone composition of the parasitic protozoa Leishmania donovani promastigote was investigated. 1'-oxomenaquinone-7, a chlorobiumquinone was found to be the major isoprenoid quinone. Substantial level of ubiquinone-9 was also present. Isolation and identification of the quinone from the purified plasma membrane yielded mainly 1'-oxomenaquinone-7 and ubiquinone-9; menaquinone was not detected. Membrane bound 1'-oxomenaquinone-7 could be destroyed by near-ultraviolet irradiation, with a concomitant loss or stimulation of plasma membrane electron transport activities. The abilities of different quinones to restore alpha-lipoic acid and ferricyanide reductase activity in near UV-irradiated cell preparations were compared. The order was; conjugate of chlorobiumquinone and sphingosine base approximately conjugate of 2-methyl-3-(1'-oxooctadecyl)-1,4-napthoquinone and octadecylamine >> chlorobiumquinone approximately 2-methyl-3-(1'-oxooctadecyl)-1,4-napthoquinone > menaquinone-4 approximately ubiquinone-10. After irradiation with near-UV light, transmembrane alpha-lipoic acid reduction was inhibited, while transmembrane ferricyanide reduction was stimulated. The result obtained indicates that chlorobiumquinone mediates the plasma membrane electron transport between cytosolic reductant and oxygen as well as alpha-lipoic acid. UV-inactivation of chlorobiumquinone shuts down the plasma membrane oxygen uptake and diverts the electron flux towards ferricyanide reduction via ubiquinone-9. Chlorobiumquinone is the only example of a polyisoprenoid quinone containing a side chain carbonyl group from photosynthetic green-sulphur bacteria. Recent work has revealed numerous genes of trypanosomatid sharing common ancestry with plants and/or bacteria. These observations pose some fascinating questions about the evolutionary biology of this important group of parasitic protozoa.