Anti-inflammatory and anti-arthritic effects of Yucca schidigera: a review

Abstract

Yucca schidigera is a medicinal plant native to Mexico. According to folk medicine, yucca extracts have anti-arthritic and anti-inflammatory effects. The plant contains several physiologically active phytochemicals. It is a rich source of steroidal saponins, and is used commercially as a saponin source. Saponins have diverse biological effects, including anti-protozoal activity. It has been postulated that saponins may have anti-arthritic properties by suppressing intestinal protozoa which may have a role in joint inflammation. Yucca is also a rich source of polyphenolics, including resveratrol and a number of other stilbenes (yuccaols A, B, C, D and E). These phenolics have anti-inflammatory activity. They are inhibitors of the nuclear transcription factor NFkappaB. NFkB stimulates synthesis of inducible nitric oxide synthase (iNOS), which causes formation of the inflammatory agent nitric oxide. Yucca phenolics are also anti-oxidants and free-radical scavengers, which may aid in suppressing reactive oxygen species that stimulate inflammatory responses. Based on these findings, further studies on the anti-arthritic effects of Yucca schidigera are warranted.

Figure 1

Chemical structures of saponins identified in Yucca schidigera bark [17]. Compounds 1–4 represent monodesmosidic and 6–7 bidesmosidic structures.

Figure 2

Structures of yucca phenolics.

Figure 3

Representative blot of iNOS expression (a). Densitometric analysis of concentration-dependent effect of Yuccaol C (0.01–100 μM) on LPS-induced iNOS expression in J774.A1 macrophages (b). Yuccaol C was added 1 h before and simultaneously with LPS challenge. Values, mean ± s.e.m., are expressed as %inhibition of at least 6–9 independent experiments with 3 replicates each. Comparisons were made using one way ANOVA test. *P < 0.05, and **P < 0.01 [34]

Figure 4

Effect of yuccaol C (0.01–100 μM) on NF-kB in LPS-stimulated J774.A1 macrophages. Values, mean ± s.e.m., are expressed as optical density/mm² of at least 3 independent experiments with 3 replicates each. Comparisons were performed using one way ANOVA test. *P < 0.05, and **P < 0.01 [34]