Increasing prevalence of allergic diseases with an inadequate variety of treatment drives forward search for new alternative drugs.
Fatty acids, abundant in nature, are regarded as important bioactive compounds and powerful nutrients playing an important role in
lipid homeostasis and
inflammation.
Phytochemical study on Typhonium blumei Nicolson and Sivadasan (Araceae), a folk anti-
cancer and anti-inflammatory medicine, yielded four oxygenated
fatty acids, 12R-hydroxyoctadec-9Z,13E-dienoic
acid methyl
ester (1) and 10R-hydroxyoctadec-8E,12Z-dienoic
acid methyl
ester (2), 9R-hydroxy-10E-octadecenoic
acid methyl
ester (3), and 12R*-hydroxy-10E-
octadecenoic acid methyl
ester (4). Isolated compounds were identified by spectroscopic methods along with GC-MS analysis. Isolated
fatty acids together with a series of saturated, unsaturated and oxygenated
fatty acids were evaluated for their anti-inflammatory and
anti-allergic activities in vitro. Unsaturated (including docosahexaenoic and eicosapentaenoic
acids) as well as hydroxylated
unsaturated fatty acids exerted strong anti-inflammatory activity in
superoxide anion generation (IC50 2.14-3.73 μM) and
elastase release (IC50 1.26-4.57 μM) assays. On the other hand, in the
anti-allergic assays, the
unsaturated fatty acids were inactive, while hydroxylated
fatty acids showed promising inhibitory activity in A23187- and
antigen-induced degranulation assays (e.g., 9S-hydroxy-10E,12Z-
octadecadienoic acid, IC50 92.4 and 49.7 μM, respectively). According to our results, the presence of a hydroxy group in the long chain did not influence the potent anti-inflammatory activity of free unsaturated
acids. Nevertheless, hydroxylation of
fatty acids (or their methyl
esters) seems to be a key factor for the
anti-allergic activity observed in the current study. Moreover, ChemGPS-NP was explored to predict the structure-activity relationship of
fatty acids. The
anti-allergic fatty acids formed different cluster distant from clinically used drugs. The bioactivity of T. blumei, which is historically utilized in
folk medicine, might be related to the content of
fatty acids and their metabolites.