TNF-α production is modulated by Aloe vera gel extract and its fractions in Candida albicans infected macrophages

Background: Aloes have been used as medicinal plants for centuries. The immunomodulatory effect of Aloe vera has previouslybeen shown. Meanwhile, TNF-α, as an inflammatory cytokine, plays an essential role in defense against invading pathogen. Objectives: In the present study, the effects of A. vera extract gel and its fractions were investigated on the TNF-α production bymacrophages against Candida albicans as an opportunistic microorganism in humans. Materials and methods: TNF-α was measured using Enzyme-Linked Immunosorbent Assay according to the instructions of themanufacturer (Biosource, Switzerland). Results: The results showed that TNF-α level was increased by A. vera gel extract and some isolated fractions dose dependently.The A. vera gel extract in dilutions of 1:2, 1:5, 1:10 and 1:50 significantly increased the production of TNF-α. Likewise, R100 andR30 fractions of A. vera caused significant increase in TNF-α production. However, R10 and R5 fractions caused a reduction inTNF-α production as compared with that in control group. Conclusions: These results showed that A. vera gel extracts and its fractions induce both immunostimulating and immunosuprressiveeffects on the production of TNF-α against Candida albicans. The efficacy of immunomodulatory of this herb is dose-dependent