Identification of Salicylates in Willow Bark (<i>Salix</i> Cortex) for Targeting Peripheral Inflammation
<i>Salix</i> cortex-containing medicine is used against pain conditions, fever, headaches, and inflammation, which are partly mediated via arachidonic acid-derived prostaglandins (PGs). We used an activity-guided fractionation strategy, followed by structure elucidation experiments using...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-10-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/20/11138 |
| Summary: | <i>Salix</i> cortex-containing medicine is used against pain conditions, fever, headaches, and inflammation, which are partly mediated via arachidonic acid-derived prostaglandins (PGs). We used an activity-guided fractionation strategy, followed by structure elucidation experiments using LC-MS/MS, CD-spectroscopy, and 1D/2D NMR techniques, to identify the compounds relevant for the inhibition of PGE<sub>2</sub> release from activated human peripheral blood mononuclear cells. Subsequent compound purification by means of preparative and semipreparative HPLC revealed 2<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>′</mo></msup></semantics></math></inline-formula>-<i>O</i>-acetylsalicortin (<b>1</b>), 3<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>′</mo></msup></semantics></math></inline-formula>-<i>O</i>-acetylsalicortin (<b>2</b>), 2<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>′</mo></msup></semantics></math></inline-formula>-<i>O</i>-acetylsalicin (<b>3</b>), 2<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>′</mo></msup></semantics></math></inline-formula>,6<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mo>′</mo></msup></semantics></math></inline-formula>-<i>O</i>-diacetylsalicortin (<b>4</b>), lasiandrin (<b>5</b>), tremulacin (<b>6</b>), and cinnamrutinose A (<b>7</b>). In contrast to <b>3</b> and <b>7</b>, compounds <b>1</b>, <b>2</b>, <b>4</b>, <b>5</b>, and <b>6</b> showed inhibitory activity against PGE<sub>2</sub> release with different potencies. Polyphenols were not relevant for the bioactivity of the <i>Salix</i> extract but salicylates, which degrade to, e.g., catechol, salicylic acid, salicin, and/or 1-hydroxy-6-oxo-2-cycohexenecarboxylate. Inflammation presents an important therapeutic target for pharmacological interventions; thus, the identification of relevant key drugs in <i>Salix</i> could provide new prospects for the improvement and standardization of existing clinical medicine. |
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| ISSN: | 1661-6596 1422-0067 |