Malva sylvestris L. extract suppresses desferrioxamine‐induced PGE 2 and PGD 2 release in differentiated U937 cells: the development and validation of an LC‐MS/MS method for prostaglandin quantification

Malva sylvestris is a species used worldwide as an alternative to anti‐inflammatory therapies; however, its mechanism of action remains unknown. In this paper, the anti‐inflammatory effects of M . sylvestris alcoholic extracts were evaluated by measuring the pro‐inflammatory mediators PGE 2 and PGD 2 in desferrioxamine‐stimulated phorbol 12‐myristate 13‐acetate‐differentiated U937 cells. An HPLC‐DAD fingerprint of the M . sylvestris extract was performed and caffeic acid, ferulic acid and scopoletin were identified and quantified. An HPLC‐MS/MS method was developed and validated to separate and measure the prostaglandins. The lower limits of detection (~0.5 ng/mL for PGE 2 and PGD 2 ) and quantification (1.0 ng/mL for PGE 2 and PGD 2 ) indicated that the method is highly sensitive. The calibration curves showed excellent coefficients of correlation ( r  > 0.99) over the range of 1.0–500.0 ng/mL, and at different levels, the accuracy ranged from 96.4 to 106.4% with an RSD < 10.0% for the precision study. This method was successfully applied using U937‐d cells. A significant dose‐dependent reduction of PGE 2 and PGD 2 levels occurred using 10 µg/mL (10.74 ± 2.86 and 9.60 ± 6.89%) and 50 µg/mL of extract (48.37 ± 3.24 and 53.06 ± 6.15%), suggesting that the anti‐inflammatory mechanisms evoked by M . sylvestris may be related to modulation of these mediators. Copyright © 2014 John Wiley & Sons, Ltd.