**4. Conclusions**

The present review shows the richness of *Opuntia* species as producers of a wide variety of phenolic compounds, with an important role in the inflammatory process. The antiinflammatory studies conducted until now demonstrated the benefit of different species to reduce the oxidative stress occurring at the site of an injury, decreasing the amount of neutrophils' infiltration, as well as pro-inflammatory mediators' production, such as NO, TNF-α, and interleukins. These effects were correlated with the presence of flavonoids in the different tissues of cactus, namely, quercetin, isorhamnetin, and kaempferol derivates, as the important bioactive components. Even though the *Opuntia* genus regroups a lot of species throughout the world, the available studies are limited to a few of them, with *O. ficus-indica* being by far the most explored. Nevertheless, reports on cactus plants reveal their potential anti-inflammatory application in the pharmaceutical industry, supporting the traditional use of these species in folk medicine and enhancing their economic value worldwide and for local communities.

**Author Contributions:** Conceptualization, G.L.; methodology, G.L. and W.Z.; investigation, W.Z.; writing—original draft preparation, W.Z.; writing—review and editing, F.B., V.V., and G.L.; supervision, F.B. and G.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was partially funded by the strategic funding from UIDB/04423/2020 and UIDP/04423/2020 of CIIMAR.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** Graciliana Lopes thanks the Portuguese Foundation for Science and Technology (FCT) for the financial support for her work contract through the Scientific Employment Stimulus-Individual Call (CEECIND/01768/2021).

**Conflicts of Interest:** The authors declare no conflict of interest.
