Glycerine addition in Cashew stembark extract mouthwash influence the inhibition of bacterial growth

The part of cashew plant (Anacardium Occidentale Linn) can be utilized as an ingredient in herbal medicine. Alkaloids, tannins, and flavonoids found in cashew stembark exhibit broad-spectrum antibacterial activity, making them appropriate as an active ingredient in mouthwash. On the other hand, one of the key ingredients in mouthwash formulas is glycerin. It is also frequently used as humectant. This study aims to prove the effect of glycerin on the cashew stembark extract mouthwash on its antibacterial activity. This study used 4 formulas consisted of 7% concentration of cashew stembark extract added with 1% sorbitol, 1.5% peppermint, distilled water as solvent, and various concentration of glycerin for each formula. The clarity, color change, and taste were assessed at day 7. The growth inhibition of both gram positive (S. aureus) and gram negative (P. aeruginosa) bacteria was measured. The data obtained were tested using one-way ANOVA and LSD (α=0.05). All of the 4 formulas of the mouthwashes found to be relatively stable. Based on the results of the inhibition test, it can be concluded that the addition of glycerin affects the inhibition of S. aureus and P. aeruginosa bacteria. Glycerin had significant effect on bacterial growth inhibition at 15% (Formula III).