Discovery of steroidal alkaloid metabolites and their accumulation in pigs after short-term tomato consumption

Scope: Whole tomato consumption has been shown to be more effective than lycopene alone against chronic disease risks, suggesting other phytochemicals play a role in the health properties of tomato-rich diets. Recently, metabolites of tomato steroidal alkaloids, an understudied class of secondary plant compounds, have been found in plasma, tissues, and urine. However, a comprehensive, targeted analysis to determine which steroidal alkaloid metabolites are present after tomato consumption is lacking. This study profiles and quantifies tomato steroidal alkaloids in blood for the first time. Methods and results: In a two-week parallel-arm study, piglets (n = 20) were fed diets containing 10% tomato powder or a macronutrient-matched control. Steroidal alkaloids were extracted from plasma and quantified using LC-MS. Tomatidine and alpha-tomatine were detected in plasma and confirmed with standards, while mass fragmentation spectra aided in identifying 31 additional metabolites representing 9 unique masses. Concentrations averaged to 107.7 nmol/L plasma, comprising of phase I (66%) and phase II (4.5%) metabolites. Conclusion: These results describe the profile and concentration of steroidal alkaloid metabolites in pig plasma after short-term tomato consumption. Our methodology and findings allow for future investigations of tomato steroidal alkaloid bioactivity using physiologically appropriate levels. ### Competing Interest Statement The authors have declared no competing interest.