Trigonelline is an NAD+ precursor that improves muscle function during ageing and is reduced in human sarcopenia

In the paper

“Mitochondrial dysfunction and low nicotinamide adenine dinucleotide (NAD+) levels are hallmarks of skeletal muscle ageing and sarcopenia1–3”

What the sources say

• Partly supported

  The Results sections on aging and nuclear NAD+ report declining mitochondrial function and lower NAD+ in the skeletal muscle of older mice. The paper does not establish that both are hallmarks of sarcopenia; its reported observations are about skeletal-muscle aging in mice. (LLM, conf=0.87)

  cites [1] Gomes, A. P. et al. Declining NAD+ induces a pseudohypoxic state disrupting nuclear-mitochondrial communication during aging. Cell 155, 1624–1638 (2013). sourceExperimental — accuracy not yet measured
• Supported

  The Discussion (page not provided) reports lower NAD+ and mitochondrial oxidative capacity in sarcopenic older men than in age-matched controls. It also reports lower skeletal-muscle NAD+ with aging and an association between NAD+ abundance and mitochondrial function, supporting the broad characterization in the claim. (LLM, conf=0.89)

  cites [2] Janssens, G. E. et al. Healthy aging and muscle function are positively associated with NAD+ abundance in humans. Nat. Aging 2, 254–263 (2022). source
• Partly supported

  The Results (‘NAD+ levels are low in human sarcopenic muscle’; page not supplied) report mitochondrial deficits and 32% lower muscle NAD+ in people with sarcopenia. The Introduction describes declining mitochondrial function in ageing skeletal muscle, but the Discussion says evidence for NAD+ decline during ageing comes from preclinical models and human skin and brain; it does not establish low NAD+ as a hallmark of human skeletal muscle ageing generally. (LLM, conf=0.85)

  cites [3] Migliavacca, E. et al. Mitochondrial oxidative capacity and NAD+ biosynthesis are reduced in human sarcopenia across ethnicities. Nat. Commun. 10, 5808 (2019). sourceExperimental — accuracy not yet measured

In the paper

“Treating primary myotubes from different donors with sarcopenia and aged-matched healthy controls35 raised cellular NAD+ (Fig. 1g) with comparable efficiency between groups (Extended Data Fig. 1j).”

What the sources say

• Partly supported

  The citation is attached to the donor description, not the reported NAD+ result. The Discussion (page not available) describes muscle biopsies from older participants, supporting the study as a source of muscle tissue. It does not establish that the donors were divided into sarcopenia and age-matched healthy-control groups or that primary myotubes were derived from them; it also does not report trigonelline treatment or comparable NAD+ responses. (LLM, conf=0.78)

  cites [35] Patel, H. P. et al. Hertfordshire sarcopenia study: design and methods. BMC Geriatr. 10, 43 (2010). sourceExperimental — accuracy not yet measured

In the paper

“In C. elegans, trigonelline improves mitochondrial respiration and biogenesis, reduces age-related muscle wasting and increases lifespan and mobility through an NAD+-dependent mechanism requiring sirtuin.”

In the paper

“fully rescued NAD+ deficiency in FK866-treated cells (EC50 = 110 µM) (Fig. 1f)”

In the paper

“When compared to other NAD+ precursors in primary human muscle cells, trigonelline and the salvage precursor NAM induced NAD+ by approximately 50% while the NRK pathway precursors NR and NMN33 increased NAD+ levels approximately twofold (Extended Data Fig. 1f).”

What the sources say

• Not checked yetcites [33] Bogan, K. L. & Brenner, C. Nicotinic acid, nicotinamide, and nicotinamide riboside: a molecular evaluation of NAD+ precursor vitamins in human nutrition. Annu. Rev. Nutr. 28, 115–130 (2008). source

In the paper

“while all precursors had similar efficacy in renal proximal tubular epithelial cells (PTECs) (Extended Data Fig. 1h).”

In the paper

“and were largely cleared after an overnight wash-out (Extended Data Fig. 2a).”

In the paper

“After trigonelline gavage, Nampt and Nrk1 expression was downregulated in the liver, while Nrk1 and Nrk2 were upregulated in muscle in both treatment groups (Extended Data Fig. 2o).”

In the paper

“Acute dosing of trigonelline in wild-type (WT) and Naprt KO mice40 (Fig. 2k and Extended Data Fig. 2j) equally increased trigonelline in tissues (Extended Data Fig. 2k), distal NAD+ metabolite fluxes in the liver and blood (Extended Data Fig. 2l,m) and tissue NAD+ levels (Extended Data Fig. 2l–n).”

What the sources say

• Not checked yetcites [40] Yaku, K. et al. BST1 regulates nicotinamide riboside metabolism via its glycohydrolase and base-exchange activities. Nat. Commun. 12, 6767 (2021). source

In the paper

“However, in Naprt KO mice treated with trigonelline, NA accumulated in the blood and liver (Fig. 2l), while NAMN was strongly downregulated (Fig. 2m)”

In the paper

“LC–HRMS analysis also confirmed that 2-OHNA blocks increased NAD+ after trigonelline treatment (Fig. 2g), without affecting cellular trigonelline levels in the treated groups (Extended Data Fig. 2h).”

In the paper

“Administration of isotopically labelled trigonelline in mice was highly bioavailable with high levels of the parent trigonelline molecule detected in the liver, gastrocnemius muscle, kidney, blood and urine 2 h after oral intake”

In the paper

“After trigonelline treatment, the Preiss–Handler pathway-related metabolites nicotinic acid adenine dinucleotide (NAAD) and NAMN downstream of NAPRT6,33 were increased and blocked by NAPRT inhibition with 2-OHNA (Fig. 2h,i)”

What the sources say

• Not checked yetcites [6] Ruggieri, S., Orsomando, G., Sorci, L. & Raffaelli, N. Regulation of NAD biosynthetic enzymes modulates NAD-sensing processes to shape mammalian cell physiology under varying biological cues. Biochim. Biophys. Acta 1854, 1138–1149 (2015). source
• Not checked yetcites [33] Bogan, K. L. & Brenner, C. Nicotinic acid, nicotinamide, and nicotinamide riboside: a molecular evaluation of NAD+ precursor vitamins in human nutrition. Annu. Rev. Nutr. 28, 115–130 (2008). source

In the paper

“Like the 24-h treatment (Extended Data Fig. 2g), trigonelline boosted NAD+ and this effect was blocked by NAPRT inhibition with 2-OHNA (Fig. 2o)”

In the paper

“while 2-OHNA abolished the effects of trigonelline but not NR (Fig. 2p).”

In the paper

“Conversely, various levels of cellular NAD+ depletion by blocking NAD+ salvage with FK866 for 24 h were rescued by trigonelline (Fig. 1f and Extended Data Fig. 2f), but not when co-treating with 2-OHNA (Extended Data Fig. 2g).”

In the paper

“activated the expression of genes linked to mitochondrial respiration and proteostasis (Fig. 3e), similar to NR (Extended Data Fig. 3c and14,43)”

In the paper

“trigonelline raised NAD+ levels in aged nematodes (Fig. 3c); its NAD+-boosting effects were comparable to NA and NAM, and partially lower than NR and NMN (Extended Data Fig. 3b).”

In the paper

“Trigonelline significantly extended the lifespan, with comparable effects to equimolar levels of NR (Fig. 3b and Extended Data Fig. 3a).”

In the paper

“Knockdown of nprt-1 or sir-2.1 (Extended Data Fig. 3j), the predominant sirtuin in N2 worms (Extended Data Fig. 3k), both blunted the lifespan-extending effects and mobility benefits of trigonelline (Fig. 3l–n)”

In the paper

“In contrast, NR was still able to bypass NAPRT inhibition and increase respiration (Fig. 2q).”

In the paper

“which was also rescued by trigonelline but blocked when trigonelline was co-treated with 2-OHNA (Fig. 2q).”

In the paper

“Finally, respirometry performed with mitochondrial complex inhibitors revealed higher levels of complex II-driven and complex IV-driven respiration in trigonelline-treated cells, again dependent on NAPRT (Extended Data Fig. 2q).”

In the paper

“Body composition was not impacted by the treatment, with no changes in lean and fat mass distribution in trigonelline-treated mice (Fig. 4g and Extended Data Fig. 4e)”

In the paper

“Trigonelline treatment in aged mice increased different domains of muscle performance that mobilize both leg and arm muscles by improving both muscle fatigue and grip strength”

In the paper

“we showed that trigonelline is metabolized via the Preiss–Handler pathway and requires NAPRT to boost NAD+, stimulate mitochondrial metabolism and increase mobility and lifespan during ageing.”

In the paper

“our correlation analyses did not detect an association between circulating trigonelline and dietary caffeine intake levels in a population from the Middle East, possibly because coffee consumption is low in this population.”

In the paper

“the dietary intake of folate and fibre was linked to circulating trigonelline levels.”

In the paper

“our comparative studies demonstrate that trigonelline has similar cellular and physiological benefits to NA and NR in cells or nematodes, most probably because of its higher stability than ribosylated precursors.”

In the paper

“However, patients with sarcopenia had lower circulating concentrations of trigonelline, a natural alkaloid found in plants4 and animals, including in humans29,30 (Fig. 1a).”

What the sources say

• Not checked yetcites [4] Ashihara, H. et al. Trigonelline and related nicotinic acid metabolites: occurrence, biosynthesis, taxonomic considerations, and their roles in planta and in human health. Phytochem. Rev. 14, 765–798 (2015). source
• Not checked yetcites [29] Barton, W. et al. The microbiome of professional athletes differs from that of more sedentary subjects in composition and particularly at the functional metabolic level. Gut 67, 625–633 (2018).
• Not checked yetcites [30] Calvani, R. et al. Gut microbiome-derived metabolites characterize a peculiar obese urinary metabotype. Int. J. Obes. 34, 1095–1098 (2010). source

In the paper

“Collectively, we identify nutritional supplementation of trigonelline as an NAD+-boosting strategy with therapeutic potential for age-associated muscle decline.”

In the paper

“Altogether, our in vitro and in vivo results indicate that trigonelline is metabolized through the Preiss–Handler pathway via NAPRT and promotes NAD+ biosynthesis via both direct and indirect mechanisms.”

In the paper

“Altogether, these results demonstrate that trigonelline is a bona fide NAD+ precursor that is directly incorporated in NAD+ in cells and multiple tissues.”

In the paper

“This suggests that trigonelline engages the Preiss–Handler pathway during first-pass metabolism and that secondary compensations through the NR–NMN–NRK pathway also contribute to NAD+ in Naprt KOs.”

In the paper

“with hepatic incorporation being faster probably because of a first-pass effect (Extended Data Fig. 2c).”

In the paper

“SHMT2 is unlikely to directly demethylate trigonelline because it is not a N-methyltransferase and is known to cross-talk with NAD+ metabolism indirectly37,38.”

What the sources say

• Not checked yetcites [37] Ye, J. et al. Serine catabolism regulates mitochondrial redox control during hypoxia. Cancer Discov. 4, 1406–1417 (2014). source
• Not checked yetcites [38] Zhang, Y. et al. SHMT2 promotes cell viability and inhibits ROS-dependent, mitochondrial-mediated apoptosis via the intrinsic signaling pathway in bladder cancer cells. Cancer Gene Ther. 29, 1514–1527 (2022). source

In the paper

“As expected, trigonelline increased NAD+ levels after sir-2.1 knockdown because sirtuins act as NAD+ sensors downstream of NAD+ biosynthesis and sir-2.1 knockdown did not change baseline NAD+ levels (Extended Data Fig. 3l).”

In the paper

“proteins (Fig. 4b,d and Extended Data Fig. 4p) were flattened in chronic versus acute exposure, probably because of long-term physiological compensation as observed in clinical studies in muscle with dietary administration of other NAD+ precursors46,47.”

What the sources say

• Not checked yetcites [46] Elhassan, Y. S. et al. Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome and induces transcriptomic and anti-inflammatory signatures. Cell Rep. 28, 1717–1728 (2019). source
• Not checked yetcites [47] Yoshino, M. et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science 372, 1224–1229 (2021). source

In the paper

“Our previous profiling of muscle biopsies from patients with sarcopenia versus age-matched healthy controls revealed that mitochondrial dysfunction and reduced NAD+, two well-established molecular hallmarks of organismal ageing11, are prominent features of pathological progression and sarcopenia3.”

What the sources say

• Not checked yetcites [3] Migliavacca, E. et al. Mitochondrial oxidative capacity and NAD+ biosynthesis are reduced in human sarcopenia across ethnicities. Nat. Commun. 10, 5808 (2019). source
• Not checked yetcites [11] López-Otín, C., Blasco, M. A., Partridge, L., Serrano, M. & Kroemer, G. Hallmarks of aging: an expanding universe. Cell 186, 243–278 (2023). source

In the paper

“Its synthesis from NA via methylation confers protective and adaptive functions4,48, without an established reutilization as a Preiss–Handler substrate49,50.”

What the sources say

• Not checked yetcites [4] Ashihara, H. et al. Trigonelline and related nicotinic acid metabolites: occurrence, biosynthesis, taxonomic considerations, and their roles in planta and in human health. Phytochem. Rev. 14, 765–798 (2015). source
• Not checked yetcites [48] Ashihara, H., Ludwig, I.A. and Crozier, A. Physiological aspect and biotechnology of trigonelline. In Plant Nucleotide Metabolism: Biosynthesis, Degradation, and Alkaloid Formation (eds Ashihara, H., Ludwig, I. A. and Crozier, A.) 351–365 (John Wiley & Sons, 2020). source
• Not checked yetcites [49] Li, W. et al. A Novel N-methyltransferase in Arabidopsis appears to feed a conserved pathway for nicotinate detoxification among land plants and is associated with lignin biosynthesis. Plant Physiol. 174, 1492–1504 (2017). source
• Not checked yetcites [50] Wu, R. et al. MeNA, controlled by reversible methylation of nicotinate, is an NAD precursor that undergoes long-distance transport in Arabidopsis. Mol. Plant 11, 1264–1277 (2018). source

In the paper

“chronic trigonelline administration mitigates muscle decline during ageing by stimulating mitochondria and increasing muscle performance and resistance to fatigue during high-intensity contraction.”

In the paper

“probably because tetanic force relies on muscle mass and neuromuscular coupling, both of which were not affected by trigonelline.”

In the paper

“Collectively, these results demonstrate that trigonelline functionally rescues NAD+ deficiency and confirm that trigonelline requires NAPRT and a functional Preiss–Handler pathway for physiological activity on mitochondrial bioenergetics.”

In the paper

“Together, these results validate the physiological requirement of the Preiss–Handler pathway for longevity, mitochondrial and functional benefits of trigonelline in an in vivo model, and demonstrate that the observed benefits on ageing and health span require the NAD+-dependent sirtuin deacetylase.”

In the paper

“trigonelline is particularly abundant in plant-derived food products, such as coffee beans and fenugreek seeds, which have been reported to modulate endogenous trigonelline levels in humans4,51,52.”

What the sources say

• Not checked yetcites [4] Ashihara, H. et al. Trigonelline and related nicotinic acid metabolites: occurrence, biosynthesis, taxonomic considerations, and their roles in planta and in human health. Phytochem. Rev. 14, 765–798 (2015). source
• Not checked yetcites [51] Midttun, Ø., Ulvik, A., Nygård, O. & Ueland, P. M. Performance of plasma trigonelline as a marker of coffee consumption in an epidemiologic setting. Am. J. Clin. Nutr. 107, 941–947 (2018). source
• Not checked yetcites [52] Gadgil, M. D. et al. Diet patterns are associated with circulating metabolites and lipid profiles of South Asians in the United States. J. Nutr. 152, 2358–2366 (2022). source

In the paper

“the benefits of trigonelline on muscle performance did not arise from structural adaptations in the skeletal muscle architecture, such as myofibre cross-sectional area, vascularization and fibrosis, but were linked to functional improvements of the mitochondrial respiratory activity of complexes I and II.”

In the paper

“fatigue and grip strength are also well-established measures of sarcopenia and physical frailty54,55 and are commonly used to assess the pathological impairment of quality of life in older people in clinical practice.”

What the sources say

• Not checked yetcites [54] Cruz-Jentoft, A. J. et al. Sarcopenia: revised European consensus on definition and diagnosis. Age Ageing 48, 16–31 (2019). source
• Not checked yetcites [55] Fried, L. P. et al. Frailty in older adults: evidence for a phenotype. J. Gerontol. A Biol. Sci. Med. Sci. 56, M146–M156 (2001). source

In the paper

“Trigonelline was proposed as a biomarker of metabolic health or physical fitness because urinary trigonelline levels decrease during obesity and increase in professional athletes29,30.”

What the sources say

• Not checked yetcites [29] Barton, W. et al. The microbiome of professional athletes differs from that of more sedentary subjects in composition and particularly at the functional metabolic level. Gut 67, 625–633 (2018).
• Not checked yetcites [30] Calvani, R. et al. Gut microbiome-derived metabolites characterize a peculiar obese urinary metabotype. Int. J. Obes. 34, 1095–1098 (2010). source

In the paper

“we conclude that trigonelline cannot reverse all causes of sarcopenia and will have to be combined with other nutrients that support muscle mass, such as protein, vitamin D or omega 3 fatty acids, or for the nutritional management of sarcopenia7.”

What the sources say

• Not checked yetcites [7] Cruz-Jentoft, A. J. & Sayer, A. A. Sarcopenia. Lancet 393, 2636–2646 (2019). source

In the paper

“sarcopenia is a multifactorial disease where both muscle mass and function decline beyond pathological thresholds7,8.”

What the sources say

• Not checked yetcites [7] Cruz-Jentoft, A. J. & Sayer, A. A. Sarcopenia. Lancet 393, 2636–2646 (2019). source
• Not checked yetcites [8] Cruz-Jentoft, A. J. et al. Sarcopenia: European consensus on definition and diagnosis: report of the European Working Group on Sarcopenia in Older People. Age Ageing 39, 412–423 (2010). source

In the paper

“suggests that trigonelline could cross-talk with the S-adenosyl-L-methionine-dependent methyltransferase activity of SHMT2 and folate/one-carbon metabolism”

In the paper

“demonstrates the benefits of its therapeutic dietary supplementation for mitochondrial function, muscle health and mobility during ageing.”

In the paper

“Although high coffee consumption has been associated with a lower prevalence of sarcopenia in some populations53”

What the sources say

• Not checked yetcites [53] Chung, H. et al. Association of coffee consumption with sarcopenia in Korean elderly men: analysis using the Korea National Health and Nutrition Examination Survey, 2008–2011. Korean J. Fam. Med. 38, 141–147 (2017). source

In the paper

“Equal protein load (20 µg per well) and consistent gel transfer was verified by Revert Total Protein Stain (LI-COR).”

In the paper

“Respiration rates were normalized to the number of worms in each well and averaged over five measurements.”

In the paper

“NAD+ levels were normalized on the protein content.”

In the paper

“trigonelline can protect from metabolic dysfunction and improve glucose tolerance both in mice and humans62,63.”

What the sources say

• Not checked yetcites [62] van Dijk, A. E. et al. Acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance. Diabetes Care 32, 1023–1025 (2009). source
• Not checked yetcites [63] Yoshinari, O. & Igarashi, K. Anti-diabetic effect of trigonelline and nicotinic acid, on KK-Ay mice. Curr. Med. Chem. 17, 2196–2202 (2010). source

In the paper

“Isotopically labelled internal standards, including fully labelled 13C yeast extract and nicotinamide-d4, were included for data normalization.”

• Also stated in: § Metabolomics analyses in cells and rodent tissues · plain

  “Additionally, isotopically labelled acyl-carnitines (NSK-B, Cambridge Isotope Laboratories) were added for normalization in cell metabolomics.”

In the paper

“Trigonelline concentrations were determined using calibration curves ranging from 10 µM to 1,000 µM.”

In the paper

“In vivo treatments were performed with trigonelline monohydrate (Laurus Labs) after internal quality control using MS, showing more than 99.9% purity”

In the paper

“Protein layers from cells, liver and muscle samples were quantified using a bicinchoninic acid assay (Thermo Fisher Scientific) for normalization.”

In the paper

“Our preclinical experiments demonstrated that trigonelline is an NAD+ precursor that optimizes mitochondrial function to improve muscle strength and prevent fatigue during ageing.”

In the paper

“The heterogeneity of NAD+ biosynthesis and metabolism also suggests that some physiological specificity may exist between different precursors across organs”

In the paper

“For worms, two housekeeping genes were used to normalize the expression data, that is, actin (act-1) and peroxisomal membrane protein 3 (pmp-3).”

In the paper

“The normality of each readout was assessed based on historical values of the laboratory for this readout.”

In the paper

“Because of its high bioavailability and serum stability, trigonelline can reach the brain and impact cognitive performance in mice with Alzheimer’s disease61”

What the sources say

• Not checked yetcites [61] Farid, M. M., Yang, X., Kuboyama, T. & Tohda, C. Trigonelline recovers memory function in Alzheimer’s disease model mice: evidence of brain penetration and target molecule. Sci. Rep. 10, 16424 (2020). source

In the paper

“Results are representative of data obtained from at least two independent experiments.”

In the paper

“Therefore, trigonelline is a nutritional geroprotector with therapeutic potential to manage sarcopenia and other age-related pathologies.”