Quinoa (Chenopodium quinoa Willd.) Saponins and Their Pharmaceutical Potential: A Review

This review provides an updated and comprehensive assessment of the current literature on quinoa (Chenopodium quinoa Willd.) saponins, with particular emphasis on pharmacological effects. Quinoa (Chenopodium quinoa Willd.) is an annual plant native to South America. Quinoa seeds are characterized by high nutritional value and are rich in proteins, lipids, carbohydrates, minerals, and saponins. Saponins are found in quinoa seeds and impart a bitter taste, which is why they are typically removed before seed consumption. Saponins have been characterized as antinutritional agents, but in recent years they have been investigated for their pharmaceutical applications. Protocols have been developed for the extraction of saponins from seeds, such as conventional solid–liquid extraction (maceration), ultrasound-assisted extraction, microwave-assisted extraction, enzyme-assisted extraction, and pressurized liquid extraction. Ultrasound-assisted extraction and microwave-assisted extraction are considered the most suitable methods for quinoa saponins. Quinoa saponins have shown promise as vaccine adjuvants. Furthermore, they have demonstrated direct anticancer activity, inducing apoptosis and inhibiting the proliferation of breast and colon cancer cells. In general, saponins can induce hemolysis at high concentrations through membrane disruption, primarily via lipid solubilization or pore formation. However, hemolytic activity varies significantly among different saponins and depends on their chemical structure and concentration. In vivo, they have not recorded adverse side effects at doses below 50 mg/kg body weight per day. More than 40 triterpenoid saponins, mainly derived from oleanolic acid, ederagenin, phytolaccagenic acid, and sergianic acid, have been identified in quinoa. Overall, although quinoa saponins have traditionally been considered antinutritional compounds, accumulating evidence indicates that they possess promising pharmacological properties, particularly as anticancer agents.