Anti-inflammatory benzophenones from the barks of mango (Mangifera indica L.).

Mango (Mangifera indica L.), commonly known as the "king of fruits", has been cultivated in South Asia for thousands of years. Its barks are a rich source of naturally occurring phytochemicals, such as benzophenones, phenolic acids, and sterols. Meanwhile, mango has been commonly used as a traditional Chinese medicine for inflammation-related diseases. In this study, phytochemicals in the barks of mango have been carried out and twenty-two benzophenones, including eight undescribed compounds were isolated and purified. Their structures were elucidated through comprehensive spectroscopic method. Anti-neuroinflammatory effects of the isolated benzophenones were evaluated in BV-2 microglia cells stimulated by lipopolysaccharide (LPS). The benzophenones exhibited significant inhibitive effects on the production of nitric oxide (NO), IL-6 and IL-1β. Notably, compound 16 exhibited the strongest activity (IC50 = 12.93 ± 0.67 μM), outperforming minocycline (IC50 = 34.73 ± 4.06 μM). Further mechanistic studies on compounds 19 and 22 revealed they concentration-dependently suppressed of iNOS, COX-2, IL-1β, IL-6, and CCL2, alongside inhibition of NF-κB nuclear translocation, which suggested NF-κB pathway involvement. These results suggest that the benzophenones from mango barks might be explored as a healthy benefit agent to be used for neurodegenerative diseases.