Malva sylvestris L. extract suppresses desferrioxamine‐induced PGE₂ and PGD₂ release in differentiated U937 cells: the development and validation of an LC‐MS/MS method for prostaglandin quantification

Abstract

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 PGE₂ and PGD₂ 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 PGE₂ and PGD₂) and quantification (1.0 ng/mL for PGE₂ and PGD₂) 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 PGE2 and PGD2 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.

Anti-Inflammatory Effect of Malva sylvestris, Sida cordifolia, and Pelargonium graveolens Is Related to Inhibition of Prostanoid Production

“…Complementary to the results observed for leaves, crude extracts of flowers showed statistically ( p < 0.05) lower values at 50 µg/mL for PGE 2 , PGD 2 , and PGF 2α , showing that leaves and flowers together are able to inhibit all the prostanoids tested. Similar findings were observed in the literature for M. sylvestris in the U937-d cell line [ 25 ]. Inhibition higher than 30% was observed for at least one mediator for all extracts or fractions.…”

“…Analysis of the extract showed the main compounds present on it are scopoletin, quercetin and malvidin 3-glucoside, but the authors attributed the observed effect to malvidin 3-glucoside. Leaf extract of M. sylvestris showed in vitro anti-inflammatory activity, demonstrated the presence of the compounds scopoletin, caffeic acid and ferulic acid [ 25 ].…”

“…In a literature survey, some studies evaluated the mechanism of the anti-inflammatory action of M. sylvestris [ 11 , 24 , 25 , 37 ] and S. cordifolia , [ 38 ], while no studies dedicated to determining the anti-inflammatory mechanism of action of P. graveolens or comparing these three species were found. Since they all can be found as Malva, comparing their different extracts and fractions is important since many compounds can be related to the final pharmacological effect in different ways.…”

Malva species: Insights on its chemical composition towards pharmacological applications

“…Later, it was confirmed that malvidin 3‐glucoside appears to be the main responsible bioactive compound for the antiinflammatory effect (Prudente et al, ). Also, Martins et al suggested that M. sylvestris extracts antiinflammatory effects seem to be related to special antiinflammatory mediators induction—prostaglandins PGE 2 and PGD 2 (Martins et al, ). Besides, several studies documented wound healing effects to M. sylvestris .…”

Protective effect of Malva sylvestris L. extract in ischemia-reperfusion induced acute kidney and remote liver injury

“…Many studies have examined mallow and proposed numerous properties for this herb. Extracts from mallow leaves show anti-complementary properties [ 15 ], suppress release of pro-inflammatory mediators PGE2 and PGD2 [ 16 ], and have anti-inflammatory properties [ 17 – 21 ].…”