Table of Contents
Clinical Overview
Use
Note: This monograph discusses yucca species, encompassing both yucca food sources and those used medicinally.
Historically, yucca has served various purposes, from being a fiber in rope, sandals, and cloth, to its purported benefits in treating conditions such as hypertension, arthritis, migraine headaches, and colitis. In vitro and animal studies suggest that yucca constituents exhibit anti-inflammatory, antimicrobial, antioxidant, antiplatelet, and cytotoxic properties. There is also evidence of positive effects on fertility in animals. However, clinical trials are lacking to substantiate these uses.
Dosing
Whole yucca plant powder is available in tablet form; nevertheless, there is a dearth of clinical trials to provide dosing recommendations.
Contraindications
Contraindications for yucca have not been established.
Pregnancy/Lactation
Avoid use. Information on safety and efficacy during pregnancy and lactation is insufficient.
Interactions
No well-documented interactions.
Adverse Reactions
Information is limited. Yucca powder and yucca extract from Yucca schidigera have obtained Generally Recognized as Safe (GRAS) status from the US Food and Drug Administration (FDA). Ornamental use of yucca plants is linked to a high frequency of allergic rhinitis. A case report describes contact urticaria and sensitization.
Toxicology
No available data.
Scientific Family
Agavaceae
Botany
The term “yucca” encompasses approximately 40 species of trees and shrubs primarily found in arid regions of North and Central America. Common names may refer to different species; for instance, Yucca aloifolia is known as Spanish bayonet, and Yucca whipplei as Our Lord’s candle. Yucca plants, characterized by rigid, evergreen, sword-shaped leaves on a stout trunk, are dependent on nocturnal yucca moths for pollination. Various species include Yucca schidigera (Mohave yucca), Yucca glauca (soapweed yucca), Yucca elephantipes or Yucca gigantea (spineless yucca), and Yucca brevifolia (Joshua tree). Yucca has a rich history of traditional uses among indigenous people for food, fiber, and rituals.
History
Yucca plants have been integral to indigenous cultures for centuries, utilized in diverse ways such as boiling and baking fruits, consuming blossoms, chewing raw leaves, and fermenting fruits for ritualistic beverages. Yucca fiber has been employed in crafting rope, sandals, and cloth. Saponins in yucca, known for their persistent soaping action, have found use in soaps and shampoos. Yucca has also been explored as a dietary supplement and is believed to have therapeutic applications in conditions like hypertension, arthritis, migraines, and colitis.
Chemistry
Yucca roots and flowers are rich in saponin steroidal glycosides, comprising sapogenins and sugars. Saponins, notable for their bitter taste and foaming ability, are present in most species and include compounds like sarsasapogenin, tigogenin, furostanol, and spirostanol. Phenolic compounds such as yuccaols and gloriosaols, along with spirostane aglycones, contribute to the diverse chemical profile. Yucca is also a source of tetrahydroxymethoxystilbene and resveratrol, compounds with antioxidant properties.
Uses and Pharmacology
Antidiabetic Activity
Animal Data: In diabetic rats, Yucca schidigera demonstrated reductions in glucose levels, increased insulin levels, elevated high-density lipoprotein cholesterol levels, and antioxidant effects.
Anti-Inflammatory Effects
In Vitro Data: The anti-inflammatory activity of yucca has been attributed to its saponin content. Phenols in yucca may also contribute to anti-inflammatory effects by inhibiting enzymes associated with inflammation.
Clinical Data: Despite its inclusion in equine joint supplements and historical use for arthritis in humans, no clinical trials support yucca’s anti-inflammatory properties. Some studies have suggested reductions in blood pressure and serum cholesterol levels, as well as a decrease in migraine headaches.
Antimicrobial Effects
Animal/In Vitro Data: Yucca leaf protein demonstrated inhibition of herpes simplex viruses and human cytomegalovirus. Steroidal saponin glycosides from yucca exhibited antifungal activity against various human pathogens. Yucca saponin-rich extracts showed antibacterial activity against Staphylococcus aureus.
Antiobesity Effects
Animal Data: A yucca extract attenuated some negative effects of a high-fat diet in mice, impacting hormones associated with obesity.
Antioxidant Activity
Animal/In Vitro Data: Yucca extracts displayed in vitro antioxidant activity greater than the reference quercetin. They also inhibited lipid peroxidation and nitrogen oxygen generation. In rats, yucca extract protected against nitrate-induced oxidative stress.
Antiplatelet Effects
In Vitro Data: Resveratrol and yuccaols reduced thrombin-induced platelet aggregation. Yucca bark caused reductions in platelet adhesion and aggregation, along with a decrease in radical generation.
Cytotoxic Effects
Animal/In Vitro Data: Yucca-derived compounds, including gloriosaols, demonstrated antiproliferative and apoptotic effects in tumor cell lines. Yucca extracts exhibited antitumor activity against melanoma in mice. Yuccaols inhibited proliferation and biosynthesis in Kaposi sarcoma cells.
Fertility Effects
Animal Data: Yucca powder extract in rabbits increased conception and kindling rates. Progesterone release was promoted, with no impact on testosterone or estradiol.
Dosing
Clinical trials for dosing recommendations are lacking for yucca. Whole yucca plant powder is available in tablet form.
Pregnancy/Lactation
Avoid yucca use during pregnancy and lactation due to insufficient safety and efficacy data.
Interactions
No well-documented interactions exist for yucca.
Adverse Reactions
Yucca powder and yucca extract from Yucca schidigera have received Generally Recognized as Safe (GRAS) status from the FDA. Ornamental use of yucca plants is linked to a high incidence of allergic rhinitis, and cases of contact urticaria and sensitization have been reported.
Toxicology
Data on yucca toxicity are not available.
Scientific Family
Agavaceae
Botany
The term “yucca” encompasses approximately 40 species of trees and shrubs primarily found in arid regions of North and Central America. Common names may refer to different species; for instance, Yucca aloifolia is known as Spanish bayonet, and Yucca whipplei as Our Lord’s candle. Yucca plants, characterized by rigid, evergreen, sword-shaped leaves on a stout trunk, are dependent on nocturnal yucca moths for pollination. Various species include Yucca schidigera (Mohave yucca), Y