Anti-Inflammatory, Antimicrobial and Stability Studies of Poly-Herbal Mouthwashes against Streptococcus mutans

Abstract

Methanol extracts of Moringa oleifera stem, twigs of Breynia nivosa, Azadirachta indica, and Psidium guajava were evaluated for antibacterial activity against Streptococcus mutans. Qualitative and quantitative phytochemical components of each plant extract were determined. Three batches of mouthwash were formulated based on the multiples of minimum inhibitory concentrations of each plant extracts. The batches were evaluated for antibacterial and anti-inflammatory activities, which were compared with those of a standard marketed mouthwash (Minty Brett ®) and anti-inflammatory agent (Volterene®). The stability of the batches was also determined. The methanol extract of each plant presented appreciable antibacterial activity (with minimum inhibitory concentrations of 25.12 mg/ml, 6.31 mg/ml, 39.8 mg/ml and 12.5 mg/ml for M. oleifera, B. nivosa, A. indica, and P. guajava respectively) against S. mutans. Tannins, saponins, triterpenoids, steroids, alkaloids and cardiac glycosides were present in all the plant extracts. Proteins and phlobatannins were present in B. nivosa. Batch 2 of the mouthwash preparation demonstrated a better antibacterial activity with inhibition zone diameter of 14.2 mm and average kill time of 25 min, while batch 3 had the best anti-inflammatory activity (65.1% inhibition). The batches stored on the shelf and in the refrigerator were stable during 3 months of observation. Defined combination of different herbal extracts lead to synergy, better activity and stability. The poly-herbal mouthwash formulation demonstrated better antibacterial and anti-inflammatory activities than standard marketed mouthwash (Minty Brett®).