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: Upon pretreatment with mangiferin ( 100 mg / kg body weight suspended in 2 ml of dimethyl sulphoxide ) given intraperitoneally for 28 days to MI rats protected the above - mentioned parameters to fall from the normal levels .
### Output Text:
Upon pretreatment with <span class="chemical">mangiferin</span> ( 100 mg / kg body weight suspended in 2 ml of <span class="chemical">dimethyl sulphoxide</span> ) given intraperitoneally for 28 days to MI rats protected the above - mentioned parameters to fall from the normal levels . 