Anti-Inflammatory and Anti-Bacterial Potential of Mulberry Leaf Extract on Oral Microorganisms.

Mulberry leaves extract (Morus alba extracts; MAE) is known to have therapeutic potentials for numerous human diseases, including diabetes, neurological disorders, cardiovascular diseases, and cancers. However, there has not been sufficient research proving therapeutic effects on oral disease and its related oral risk factors. Thus, we investigated whether MAE has any anti-inflammatory and anti-bacterial effects on risk factors causing oral infectious diseases. To examine the anti-inflammatory response and bacterial inhibition of MAE, we measured intracellular reactive oxygen species (ROS) generation, production of pro-inflammatory cytokines, and the bacterial growth rate. Our study showed that MAE has anti-inflammatory activities, which inhibit the ROS generation and suppressed the production of pro-inflammatory cytokines (TNF-α and IL-6) in human monocyte THP-1 cells by stimulating lipopolysaccharide (LPS) and/or F. nucleatum, which are the virulent factors in periodontal diseases. Furthermore, MAE inhibited the bacterial growth on oral microorganisms (F. nucleatum and S. mutans) infected THP-1 cells. These findings suggested that MAE could be a potential natural source for therapeutic drugs in oral infectious disease.

Effect of burdock extracts upon inflammatory mediator production.

We investigated the burdock extract on the inhibitions of NO generation, COX-2 expression, and the generations of IL-6 and TNF-α , to find out its anti-inflammatory effect in this study. After the treatment of the burdock extract in the cells, we measured the amount of NO generated in the inflammatory cells developed by LPS and UVB, and confirmed the developments of inflammatory mediators by RT-PCR. Upon the results on the NO generation after the development of inflammation by LPS in Raw 264.7 cell, we found approximately 50% of inhibitory effect at 200 µg/ml concentrations of the burdock extract. It was confirmed that the expression levels of TNF-α, COX-2, and IL-6 were declined to the levels of control by LPS and UVB stimulated inflammation in HaCat cell. This means the anti-inflammatory effect of the burdock extract.