Betulinic acid, anti-inflammatory activity

In a comparative study on the anti-inflammatory activity of the Diospyros leucomelas (Ebenaceae) principles and other readily available triterpenoids administered at 100 mg/kg p.o., betulinic acid showed the highest activity (45% inhibition) 3h after carrageenan injection [47]. Erythrodiol had a more durable effect, inducing a 40% inhibition after 5 h [69]. After comparing the variable effects observed on this model, it was concluded that the presence of a primary alcohol or carboxylic acid function at C-27 or C-29 is clearly positive. 

In connection with the work on the relationship between chemical structure and anti-inflammatory activity, the effect of ursolic acid, betulin, betulinic acid and erythrodiol on a system of chronic dermal edema and cellular proliferation caused by repeated administration of TPA has recently been examined [89], This experimental model of chronic inflammation has considerable selectivity for corticosteroids and leukotriene synthesis inhibitors. Erythrodiol and ursolic acid were significantly effective and also reduced the neutrophil infiltration detected by MPO activity. The lupane derivatives, betulin and betulinic acid, despite their possible steroid-like mechanism of action [47], were not effective in the chronic model. This result could mean that a six-member E ring of the pentacyclic structure is necessary for the activity against a multiple dose of TPA. The data confirm that a hydroxyl group at the C-28 position is important for the activity, as is also true in the case of erythrodiol, and it may explain the anti-inflammatory effect of this compound in each of the methods. 

Ursolic and oleanolic acids have been early described to exert antiinflammatory and antihyperlipidemic activities. Betulinic acid has been reported to exhibit antiretroviral, antimalarial, and anti-inflammatory properties. Thumher and coworkers [183] have demonstrated its cytotoxic activity against a variety of tumor cells originating from the neural crest. It has also... 

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