Antibacterial Activity Of Amchur Extracts On Some Indigenous Oral Microbiota Causing Dental Caries

摘要

The antibacterial activity of amchur (dried pulp of unripe Mangifera indica) extract (50% ethanol) was tested against ten bacterial strains causing dental plaque by agar well diffusion method. The crude extract showed a broad spectrum of antibacterial activity inhibiting both the groups of Gram-positive & Gram-negative bacteria. The extract was most effective against Bacillus sp., followed by Staphylococcus mutans and Pseudomonas sp., whereas Halobacterium sp. was found to be the most resistant. Chlorhexidine (present in mouthwashes to prevent infection of dental caries) was used as a positive control. Natural extract of amchur was found to be more effective as compared to chlorhexidine. This study shows the potential of amchur in the treatment of dental caries. Introduction Dental caries is the localized destruction of the tissues of the tooth by acid produced from the bacterial degradation of fermentable sugars. Gnotobiotic animal studies showed that caries could be induced by specific bacteria, especially members of the mutans Streptococci- group (e.g Streptococcus mutans & Streptococcus sobrinus), but only when fed a cariogenic (high sucrose) diet. These studies also showed the potential for transmission from animal to animal, & that protection could be achieved by antimicrobial agents & vaccination. Advanced lesions often have a high proportion of lactobacilli, while dentinal lesions have a diverse microflora with many fastidious Gram positive (Actinomyces naeslundii, A. odontolyticus, Propionibacterium spp., Eubacterium spp.) and Gram negative (Fusobacterium spp., Capnocytophage spp., Veillonella spp.) bacteria.Many natural substances of plant origin are reported to be biologically active, endowed with antimicrobial, allelopathic and antioxidant properties (Beuchat and Golden, 1989).Amchur (dried pulp of unripe Mangifera indica) is used in Indian spices as a souring agent to provide the desired acidity in the various food recipes. Very limited literature is available on the antimicrobial activity of amchur extract. Mango is considered as a king of fruits in Indian delicacy. The roots and bark of mango Mangifera indica (Anacardiaceae) are astringent, acrid, anti-inflammatory, and constipating. The leaves and flowers are refrigerant, styptic, vulneray and constipating. Amchur (dried or dehydrated product of unripe mango flesh in the form of peeled slices or powder) is used as an acidulant or a souring agent for curries. Amchur is rich in citric acid. Very limited literature is available on the antimicrobial activity of amchur extract. In the present study, we have investigated the antibacterial activity of dried pulp of unripe Mangifera indica against dental caries for the first time. Materials And Methods Materials: All chemicals used were of analytical-reagent grade and obtained from E. Merck (Mumbai, India). Amchur (Mangifera indica) was collected from local market of Meerut (Uttar Pradesh, India). Dr. C.M Govil, Professor, Botany Department, C.C.S University, Meerut, India confirmed the species.Bacterial Strains: Ten bacterial strains (6 Gram positive and 4 Gram negative), involved in dental caries, were selected for the study. Gram positives were Streptococcus mutans, Streptococcus salivarius, Lactobacillus sp., Bacillus sp., Micrococcus sp., Staphylococcus aureus, Halobacterium sp., Veilonella sp., Pseudomonas aeruginosa, Pseudomonas sp. The bacterial stock cultures were obtained from the culture collection unit of Department of Microbiology, C.C.S University, Meerut, India. The viability tests for each isolate were carried out by resuscitating the organism in nutrient agar medium.The stock on nutrient agar medium (Hi Media, Mumbai, India) was incubated for 24h at 37°C following refrigeration storage at 4°C until required for sensitivity testing. Extraction: The pulp of unripe mango (Mangifera indica) was dried and powdered in milling machine (Inalsa Mixer Grinder) to obtain fine dry powder called amchur. The powder