Fig. 4: Trigonelline supplementation enhances mitochondrial activity and muscle function in aged mice.
a, Mitochondrial complex I activity normalized to citrate synthase activity (UCI × UCS−1) in gastrocnemius muscle of aged mice (20 months) after a 5-day dietary supplementation of trigonelline (unpaired, two-tailed Student’s t-test, n = 7–8 biological replicates per group). b, Mitochondrial complex I (NDUFB8) protein levels in the same samples as in a (unpaired, two-tailed Student’s t-test, n = 6 biological replicates per group). c, Succinate dehydrogenase (SDH) activity in the quadriceps muscle of the same groups as in a (unpaired, two-tailed Student’s t-test, n = 7 biological replicates per group). d, Mitochondrial complex II (succinate dehydrogenase [ubiquinone] iron-sulphur subunit, mitochondrial (SDHE)) protein levels in the same samples as in a (unpaired, two-tailed Student’s t-test, n = 6 biological replicates per group). e, Plasma trigonelline levels measured in aged mice (22–24 months) after 12 weeks of trigonelline supplementation (unpaired, two-tailed Student’s t-test, n = 13 and 15 biological replicates per group). f, LC–HRMS measurement of trigonelline levels in gastrocnemius muscle and liver of the same mice groups as in e (unpaired, two-tailed Student’s t-test; gastrocnemius: n = 5 and 6, liver: n = 13 and 16 biological replicates per group); <LOQ, below the level of quantification. g, Lean mass normalized to body weight of aged mice after 12 weeks of treatment as in e (unpaired, two-tailed Student’s t-test, n = 13 and 15 biological replicates per group). h, Tibialis anterior muscle mass of aged mice after 12 weeks of treatment as in e (unpaired, two-tailed Student’s t-test, n = 13 and 15 biological replicates per group). i, Grip strength of aged mice after 12 weeks of treatment as in e (unpaired, two-tailed Student’s t-test, n = 13 and 15 biological replicates per group). j, In situ muscle contractility normalized to initial force after supramaximal stimulation of the tibialis anterior muscle in young controls and aged mice after 12 weeks of treatment as in e (two-way ANOVA followed by uncorrected Fisher’s least significant difference tests; n = 11–14 biological replicates per group). All data are expressed as the mean ± s.e.m. with *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Individual P values are reported in Fig. 4 of the Source data.
