The reduced immunohaemolysis was found to be due to inhibition of C3-convertase of the classical complement pathway.
A further target of BEs and BAs in the immune system is the complement system where inhibiton of C3-convertase was reported.
Anticomplementary activity of Boswellia acids--an inhibitor of C3-convertase of the classical complement pathway.
The C4b fragment (product of C4 cleavage) binds to the pathogen surface and associates with C2a to form the C3-convertase (C4b2a, similar to the C3-convertase of the classical pathway) (see Figure 1).
The enzyme MASP-2 has been shown to play a fundamental role in lectin pathway activation by cleaving C2 and C4, which in turn generate the C3-convertase C4b2a [6, 45].
Since C2 is required for C3-convertase formation by the classical and lectin pathways, but not for the alternative pathway, the alternative pathway is inefficiently activated by T.
Briefly, we can reinforce that the main mechanism to complement evasion is to inhibit the progression of the complement cascade to prevent the C3-convertase formation.
Some authors  demonstrated the complement inhibition before C3-convertase formation.
C3b binding to GP63 results in its conversion to iC3b (inactive C3b) to prevent the C3-convertase formation on the parasite surface .