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. Yucca schidigera is an herbaceous plant of the lily family, native to the deserts of the south-western United States and northern Mexico.
This plant was used in traditional medicine by Native Americans to treat a variety of ailments including arthritis. Yucca products are currently used in a number of applications.
Yucca powder and yucca extract are used as animal feed additives, as discussed in detail by Cheeke and Otero [ 1 ]. Beneficial effects in livestock and poultry production include: increased growth rate and improved feed conversion efficiency, reduction in atmospheric ammonia in confinement animal and poultry facilities, anti-protozoal and nematocidal activity, modification of ruminal microbe populations, inhibition of Gram-positive bacteria, reductions in stillbirths in swine, reduction in egg and tissue cholesterol contents, and anti-arthritic activity in horses and dogs.
Other applications include the use of yucca extract as a foaming agent in beverages, and use in crop production as nematode and fungi-control agents, as a soil wetting agent, and crop growth stimulant. Yucca contains a number of phytochemicals which contribute to these effects. The best known are the steroidal saponins. Saponins are natural detergents [ 2 ] that form stable foams.
Saponins contain a lipophilic nucleus the sapogenin and one or more side chains of hydrophilic carbohydrate Fig. Thus the intact saponin molecule is a surfactant, with both fat-soluble and water-soluble moities. It has been known for many years [ 3 ] that saponins form insoluble complexes with cholesterol. The hydrophobic portion of the saponin the aglycone or sapongenin associates lipophilic bonding with the hydrophobic sterol nucleus of cholesterol in a stacked micellar aggregation [ 4 ].
Chemical structures of saponins identified in Yucca schidigera bark [17]. Compounds 1—4 represent monodesmosidic and 6—7 bidesmosidic structures. Interactions of saponins with cholesterol and other sterols account for many of their biological effects, particularly those involving membrane activity.
It was demonstrated more than 45 years ago that dietary saponin reduces blood cholesterol levels [ 5 , 6 ]. This effect is a result of the saponins binding to cholesterol excreted in bile, thus inhibiting entero-hepatic cholesterol recycling. Dietary yucca extracts lower total and LDL cholesterol levels in hypercholesterolemic humans [ 7 ].
Saponins affect the permeability of intestinal cells by forming complexes with cholesterol in mucosal cell membranes [ 8 ]. In a similar manner, saponins have anti-protozoal activity by complexing with cholesterol in protozoal cell membranes, causing damage to the integrity of the membrane, and cell lysis. This has been well demonstrated with rumen protozoa in vivo [ 9 - 11 ]; and in vitro [ 12 , 13 ]. The antiprotozoal cholesterol-binding activity requires the intact saponin structure with both nucleus and side chain present.
Protozoal diseases in which part of the life cycle occurs in the gastrointestinal tract respond to the anti-protozoal activity of saponins. For example, yucca saponins are as effective as the drug metronidazole in killing tropozoites of Giardia lamblia in the intestine [ 14 ]. Acid hydrolysed fractions of yucca contain both furostanol and spirostanol aglycones.
These include sarsapogenin, markogenin, smilagenin, samogenin, gitogenin and neogitogenin [ 15 ]. In the plant they can be found in a multi-component mixture of glycosides [ 16 , 17 ].
They can be found both as monodesmosides with one sugar chain attached at 3- O - and bidesmosides with two sugar chains at 3- O - and O - positions Fig. Tanaka and co-workers identified as many as 13 structurally different saponins, but all of them were monodesmosides, given trivial names YS-I-XIII [ 16 ].
In the work of Oleszek and co-workers, eight individual saponins were isolated and identified out of which five were known spirostanol and three new furostanol structures [ 17 ]. Recently it has been recognized that yucca contains other physiologically-active constituents, particularly polyphenols. Two stilbenes, including trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and trans-3,4',5-tetraxydroxystilbene resveratrol were identified in yucca bark.
Also, some unique compounds with spiro confirmation were isolated and characterized. These included the spirobiflavonoid, larixinol, biosynthesized by combining two C 15 units of flavonoid origin, previously identified in Larix gmelini and a number of novel spirostructures, which were given trivial names of yuccaols A-E [ 18 , 19 ] Fig.
Resveratrol makes up the stilbenic portion of yuccaols A and B and trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene is the stilbene in yuccaols C, D and E. By the analogy to the biosynthesis of larixinol it was presumed that most probably these compounds are synthesized by the attachment of the stilbenic derivative to the carbocationic intermediate occurring during the oxidation of flavanone to flavanol and subsequent rearrangement of this intermediate.
Resveratrol was identified previously in grapes and is believed to be a phytoalexin produced by the plant to fight fungal colonization [ 20 ]. Since yucca bark is a component of commercially available yucca powder, these compounds are present exclusively in this product; they are not present in yucca extract obtained by mechanical extraction. The chemistry and bioactivity of yucca saponins and phenolics have recently been reviewed by Piacente et al.
Yucca products have been used for many years for reputed anti-arthritic effects, both by Native Americans and more recently by the nutraceutical industry. Whole yucca plant powder in tablet form is a common nutraceutical. The only direct studies of anti-arthritic effects of yucca are those of Bingham [ 22 - 24 ], who reported that symptoms of pain and swelling in arthritic human patients were relieved by consumption of yucca tablets.
Bingham's work was reported in an obscure journal, and has apparently not been recognized as valid by the arthritis research community.
Nevertheless, Bingham's reports have led to the widespread use of yucca products for treatment and prevention of arthritis not only in humans but also in horses and dogs. Bingham [ 22 ] proposed that yucca saponins have anti-protozoal activity, which suppresses protozoal infection of the intestine. Bingham [ 22 ] reported that R. Wyburn-Mason had observed a free-living protozoan, Naegleria , universally present in the joints of arthritic patients [ 25 ].
Tropozoites of the organism reportedly were found in the intestine. Support for this theory was provided by the effectiveness of metronidazole, an anti-protozoal drug, in arthritis treatment.
Saponins are also effective anti-protozoal agents. Yucca saponins are as effective as metronidazole in killing giardia tropozoites in the intestine [ 14 ]. Thus, if the protozoal theory of causation of arthritis has any merit, a role of yucca in arthritis treatment can be advanced on the basis of the anti-protozoal activity of yucca saponins. There are well-known interactions between rheumatoid arthritis, chronic inflammatory disease, and food and nutrition [ 26 , 27 ].
Of particular importance are nutrients that stimulate the formation of oxidants and peroxides e. Yucca compounds may have roles in these effects. Yucca polyphenols are potent antioxidants [ 18 , 21 , 28 ]. Yucca saponins are known to reduce iron absorption [ 29 ] and may reduce fatty acid absorption by sequestering bile acids necessary for micelle formation and fat absorption [ 4 ].
Cordain [ 30 ] stated, "Despite the almost universal clinical observation that inflammation of the gut is frequently associated with inflammation of the joints and vice-versa, the nature of the relationship remains elusive. Yucca saponins have antibacterial properties [ 31 , 32 ], although Lactobacillus spp. Thus, a beneficial effect of yucca on arthritis could involve anti-protozoal, anti-oxidant and anti-bacterial activities. As previously mentioned, the drug metronidazole attenuates gastrointestinal inflammation and can prevent activation of arthritis in animal models [ 30 ].
Yucca saponins are as effective as metronidazole in control of intestinal protozoa [ 14 ]. Recent research suggests another possible mode of action of yucca in preventing arthritis by anti-inflammatory activity. Yucca contains anti-inflammatory polyphenolics such as resveratrol and yuccaols A, B, C, D and E [ 18 , 19 ]. Marzocco [ 34 ] demonstrated that yuccaols inhibit inducible nitric oxide synthase iNOS expression Fig.
Nitric oxide is an inflammatory agent, and its content in tissues increases during inflammatory responses. Resveratrol and yucca phenolics strongly inhibit NFkB [ 34 ]. Yuccaol C is particularly effective Fig. Thus, whole plant yucca powder has powerful anti-inflammatory activity, mediated via inhibition of NFkB activation.
Representative blot of iNOS expression a. Densitometric analysis of concentration-dependent effect of Yuccaol C 0. A1 macrophages b. Yuccaol C was added 1 h before and simultaneously with LPS challenge. Effect of yuccaol C 0. A1 macrophages. The generation of reactive oxygen species free radicals is an important factor in the development and maintenance of rheumatoid arthritis in humans and animal models [ 35 ]. One source of free radicals is nitric oxide produced within the synoviocytes and chondrocytes, giving rise to the highly toxic radical peroxynitrite [ 35 ].
The study of experimental arthritis in animals has demonstrated an increased activity of iNOS [ 36 , 37 ]. Thus the NFkB inhibitory and anti-oxidant effects of yucca polyphenolics may aid in prevention of reactive oxygen species ROS induction of arthritis by inhibiting the induction of iNOS.
Platelet aggregation is characteristic of inflammation. Yucca phenolics have inhibitory activity against platelet aggregation [ 38 - 40 ]. Yucca phenolics also have antioxidant activity [ 19 ] and free-radical scavenging effects [ 18 ]. Blood platelets participate in allergic inflammation responses [ 41 ]. Yuccaols inhibit the generation of free radicals in blood platelets [ 39 ]. One of the yucca phenolics, trans -3,3',5,5'-tetrahydroxymethoxystilbene, showed the highest anti-platelet action.
Another botanical product with anti-inflammatory activity is cat's claw [ 42 ]. As reviewed by Miller et al. The evidence presented in this review indicates that yucca has potential in vivo anti-inflammatory activity, and warrants more in-depth investigation.
Yucca schidigera is a medicinal plant which may have beneficial effects in the prevention and treatment of arthritis. Following an anti-inflammatory diet, like the Mediterranean diet, may help reduce body wide inflammation. Here's how to do it. Get involved with the arthritis community. Every gift to the Arthritis Foundation will help people with arthritis across the U. Join us and become a Champion of Yes. There are many volunteer opportunities available.
Take part to be among those changing lives today and changing the future of arthritis. Help millions of people live with less pain and fund groundbreaking research to discover a cure for this devastating disease. Please, make your urgently-needed donation to the Arthritis Foundation now! Honor a loved one with a meaningful donation to the Arthritis Foundation. We'll send a handwritten card to the honoree or their family notifying them of your thoughtful gift.
I want information on ways to remember the AF in my will, trust or other financial planning vehicles. The Arthritis Foundation is focused on finding a cure and championing the fight against arthritis with life-changing information, advocacy, science and community. We can only achieve these goals with your help. Strong, outspoken and engaged volunteers will help us conquer arthritis. By getting involved, you become a leader in our organization and help make a difference in the lives of millions.
Become a Volunteer More About Volunteering. By taking part in the Live Yes! And all it takes is just 10 minutes. Your shared experiences will help: - Lead to more effective treatments and outcomes - Develop programs to meet the needs of you and your community - Shape a powerful agenda that fights for you Now is the time to make your voice count, for yourself and the entire arthritis community. Currently this program is for the adult arthritis community. Since the needs of the juvenile arthritis JA community are unique, we are currently working with experts to develop a customized experience for JA families.
Get Started. As a partner, you will help the Arthritis Foundation provide life-changing resources, science, advocacy and community connections for people with arthritis, the nations leading cause of disability. Join us today and help lead the way as a Champion of Yes. Our Trailblazers are committed partners ready to lead the way, take action and fight for everyday victories. Our Visionary partners help us plan for a future that includes a cure for arthritis. Our Pioneers are always ready to explore and find new weapons in the fight against arthritis.
Our Pacesetters ensure that we can chart the course for a cure for those who live with arthritis. Our Signature partners make their mark by helping us identify new and meaningful resources for people with arthritis. Our Supporting partners are active champions who provide encouragement and assistance to the arthritis community. Anti-Inflammatory Diet Do's and Don'ts Following an anti-inflammatory diet, like the Mediterranean diet, may help reduce body wide inflammation.
Anti-Inflammatory Diet. While there is no specific diet that people with rheumatoid and other inflammatory forms of arthritis should follow, researchers have identified certain foods that may help control inflammation, which can lead to pain. Many of them are found in the so-called Mediterranean diet , which emphasizes fish, vegetables and olive oil, among other staples. Certain types of fish are rich in inflammation-fighting omega-3 fatty acids, which reduce C-reactive protein CRP and interleukin-6, two inflammatory proteins in your body.
How much: At least 3 to 4 ounces, twice a week Best sources: Salmon, tuna, sardines, anchovies and other cold-water fish. Try a Handful of Nuts or Seeds. How much: Eat 1. Beans have several antioxidant and anti-inflammatory compounds. How much: At least one cup, twice a week Best sources: Try pinto, black, red kidney and garbanzo beans. Olive oil contains heart-healthy monounsaturated fat, antioxidants and oleocanthal, a compound that can lower inflammation and pain.
How much: Two to three tablespoons per day for cooking or in salad dressings or other dishes Best sources: Extra virgin olive oil is less refined and processed.
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