Extract from Ascaris suum and N-acetyl-L-cysteine induces an immunosuppressant effect in model of autoimmune hepatitis

Abstract

Background: Extract of adult Ascaris suum (ASC) worms attenuated the liver damage in experimental autoimmune hepatitis (EAH) with induction of Th2 immune response, but fibrosis occurred. N-acetyl-L-cysteine (NAC) has protective effects against liver fibrosis.

Objectives: Evaluate the association ASC + NAC on the T- and B-cell activation, inflammation and fibrogenic markers in the liver in EAH.

Methods: Experimental autoimmune hepatitis was induced intravenously with concanavalin A in BALB/c mice. EAH + ASC+NAC group received NAC and ASC; EAH + ASC group received ASC; EAH group received PBS. Doubly labelled CD4⁺ T (CD28, CTLA-4, CD40L or IL-10) and CD45R⁺ B lymphocytes (IL-10) and CD4⁺ CD25⁺ FoxP3⁺ cells were evaluated, along with gene expression of Col1a1, α-SMA, Fizz1, Arg1 and PPAR-γ and histomorphometry.

Results: Experimental autoimmune hepatitis group showed high frequency of CD28⁺ and CD40L⁺ T lymphocytes, but not the EAH + ASC group. In relation to EAH group, the Fizz1 expression was lower in both groups treated, but Arg1 expression was lower in only EAH + ASC+NAC group. In the EAH + ASC+NAC group, there were higher frequencies of CD4⁺ IL-10⁺ and CD4⁺ CD25⁺ FoxP3⁺ cells, but not CD45R⁺ IL-10⁺ , along with mitigated inflammation and collagen production.

Conclusions: Ascaris suum favoured immunosuppression in EAH limiting the T cells activation. However, association ASC and NAC was necessary for attenuating the inflammatory process and collagen production.

Keywords: hepatitis; immunoregulation; parasite.