Different parts of Annona crassiflora Mart., a native species from Brazilian savanna, were traditionally used for the treatment of a wide variety of ailments including
arthritis. Thus, this study aimed to investigate the possible antinociceptive and anti-inflammatory properties of a
polyphenol-enriched fraction of the fruit peel of A. crassiflora, named here as EtOAc, in mice. Pro-inflammatory
cytokines and
nitric oxide (NO) production were evaluated in LPS-activated macrophages. Then, EtOAc fraction was administered by oral route in male C57BL/6/J mice, and the animals were submitted to
glutamate-induced nociception and complete
Freund's adjuvant (CFA)-induced monoarthritis tests to assess nociception (mechanical, spontaneous and cold
pain) and
inflammation (
edema and neutrophil infiltration), and to the open-field and rotarod tests for motor performance analysis. EtOAc fraction inhibited the production of
IL-6 and NO in the LPS-induced macrophages, and reduced spontaneous nociception induced by
glutamate, without altering the animals' locomotor activity. In addition, the
polyphenol-enriched fraction was able to revert the early and late
hyperalgesia induced by CFA, as well as
edema at the acute phase. Reduction of
myeloperoxidase activity and inflammatory cell infiltration was observed in the paw tissue of mice injected with CFA and treated with EtOAc fraction. Together, our results support the antinociceptive and anti-inflammatory effects of the
polyphenol-enriched fraction of A. crassiflora fruit peel and suggest that these effects are triggered, at least in part, by suppressing pro-inflammatory
cytokines and neutrophils infiltration.