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Antioxidant Activity of an Aqueous Leaf Extract from Uncaria tomentosa and Its Major Alkaloids Mitraphylline and Isomitraphylline in Caenorhabditis elegans

Bruna C Azevedo, Mariana Roxo, Marcos C Borges, Herbenya Peixoto, Eduardo J Crevelin, Bianca W Bertoni, Silvia H T Contini, Adriana A Lopes, Suzelei C França, Ana M S Pereira, Michael Wink

Molecules. 2019 Sep 10;24(18):3299.

PMID: 31510078

Abstract:

Uncaria tomentosa (Rubiaceae) has a recognized therapeutic potential against various diseases associated with oxidative stress. The aim of this research was to evaluate the antioxidant potential of an aqueous leaf extract (ALE) from U. tomentosa, and its major alkaloids mitraphylline and isomitraphylline. The antioxidant activity of ALE was investigated in vitro using standard assays (DPPH, ABTS and FRAP), while the in vivo activity and mode of action were studied using Caenorhabditis elegans as a model organism. The purified alkaloids did not exhibit antioxidant effects in vivo. ALE reduced the accumulation of reactive oxygen species (ROS) in wild-type worms, and was able to rescue the worms from a lethal dose of the pro-oxidant juglone. The ALE treatment led to a decreased expression of the oxidative stress response related genes sod-3, gst-4, and hsp-16.2. The treatment of mutant worms lacking the DAF-16 transcription factor with ALE resulted in a significant reduction of ROS levels. Contrarily, the extract had a pro-oxidant effect in the worms lacking the SKN-1 transcription factor. Our results suggest that the antioxidant activity of ALE in C. elegans is independent of its alkaloid content, and that SKN-1 is required for ALE-mediated stress resistance.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP4963013 Isomitraphylline Isomitraphylline 4963-01-3 Price
AP509808 Mitraphylline Mitraphylline 509-80-8 Price
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