Bioactive Constituents of Lamium album L. as Inhibitors of Cytokine Secretion in Human Neutrophils

Abstract

The traditional role of Lamium album L. (white dead nettle, Lamiaceae) in providing relief from pain in rheumatism as well as vaginal and cervical inflammation was described. The aim of the study was to screen for the anti-inflammatory bioactivity of compounds isolated from aqueous-methanolic extract of Lamium album herb in human neutrophils (PMNs). The effect of the compounds on the inhibition of selected inflammatory markers released by neutrophils, such as cytokines (IL-8, TNF-α), was studied. The molecular masses and the purity of compounds were determined using high-performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MSn). The level of cytokines production after incubation with the compounds (1–25 µM) was measured by ELISA. Two derivatives of quercetin, not previously described, were isolated in this study. Phenylpropanoids (verbascoside and phlinoside D), as well as iridoids (lamalbid, and shanzhiside methyl ester), and flavonoids revealed to be more significant inhibitors of IL-8 secretion than TNF-α. The compounds at a concentration of 25 µM, except for shanzhiside methyl ester (6), inhibited secretion of IL-8 in the range from 29.1 to 50.0%. In conclusion, L. album might be a valuable source of bioactive compounds and may provide constituents to limit noninfectious inflammation associated with the aforementioned diseases.

Lamalbid, Chlorogenic Acid, and Verbascoside as Tools for Standardization of Lamium album Flowers—Development and Validation of HPLC–DAD Method

“…Despite singular exceptions (e.g., martynoside from the class of phenylpropanoids has been identified in Salvia officinalis), it was even concluded that phenylpropanoids might be considered the chemotaxonomic markers differentiating these two subfamilies [30]. In our previous study, we identified few phenylpropanoids including verbascoside (6), lamiusides A, B, D, and E in the herb of L. album [16,17]. According to previous data phenylpropanoids, such as verbascoside (6) and isoverbascoside, may reach up to 55% of the total phenolic content in a SPE-purified ethanolic extract [21].…”

“…In addition, it plays a role in a phylogenetic recognition and differentiation within Lamium genus [19], and its biological significance has been preliminary proved [16]. In addition to the interleukin 8 (IL-8) and tumor necrosis factor α (TNF-α) inhibitory activity in human neutrophils, lamalbid (1) has been reported to inhibit reactive oxygen species production and scavenge 2,2-diphenyl-1-picrylhydrazyl radical (66.56%) at a concentration of 100 µg mL −1 [16,32]. For this reason, the quantitation of lamalbid (1) might be also included in the assessment of Lamii albi flos quality.…”

“…The structures of compounds (UV-Vis and 1 H spectra), except for chlorogenic acid (3) and quercetin malonylhexoside (7), were described in our previous research. The molecular masses and the purity of compounds (>95%) were determined using high-performance liquid chromatography coupled with diode detector and mass spectrometer (HPLC-DAD-MS n ) method [16,17]. Lamalbid 1…”

“…In our previous study others phenylpropanoids, such as lamiusides B, C, and E, as well as phlinoside D, have been found in this species for the first time. We established that this class of compounds was likely to determine the potential role of white dead nettle preparations in cytokines related inflammation [16,17]. However, iridoids such as lamalbid (lamiridoside, 1), lamiol, and caryoptoside (2) seem to play a role of chemotaxonomic markers of species from the genus Lamium [18,19].…”

“…Their MS 2 fragmentation patterns showed signals at m/z 463 and 301 for rutin (4) and m/z 505, 463 and 301 for quercetin malonylhexoside (7) in the negative ionization mode. The MS data of tiliroside (8) showed peaks at m/z 593 [M − H] − , and fragmentary ions at m/z 447 and m/z 285[16,17].…”