In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Chronic administration of LF strongly reduced the blood pressure and production of ROS and improved antioxidant capacity in Dex - induced hypertension , suggesting the role of inhibition of oxidative stress as another mechanism of antihypertensive action of LF .
### Output Text:
Chronic administration of LF strongly reduced the blood pressure and production of ROS and improved antioxidant capacity in <span class="chemical">Dex</span> - induced hypertension , suggesting the role of inhibition of oxidative stress as another mechanism of antihypertensive action of LF . 