Nacre extract derived from Pinctada fucata mitigates skeletal muscle aging by suppressing senescence-associated inflammation and preserving contractile features in naturally aged mice and C2C12 myotubes

Abstract

Objective: To investigate the effect of a water-soluble nacre extract derived from Pinctada fucata on skeletal muscle aging.

Methods: Naturally aged C57BL/6J mice received nacre extract mixed in chow for 12 weeks. Forelimb grip strength, hanging performance, and locomotor activity were assessed. Skeletal muscle remodeling and signaling were evaluated by histology and immunostaining for fibrosis, contractile-marker features, senescence- and DNA damage-associated markers, inflammatory signaling, and mitochondrial proteins. Oxidative status was assessed by determining antioxidant capacity, lipid peroxidation, and oxidative DNA damage. Transcriptomic profiling was also performed, and selected targets were validated by quantitative RT-PCR and immunostaining. In addition, differentiated C2C12 myotubes were exposed to doxorubicin and treated with nacre extract; senescence-associated β-galactosidase, DNA damage signaling, and cell viability were measured.

Results: Nacre extract increased forelimb grip strength and showed a positive trend in hanging performance without altering spontaneous locomotion. It also reduced collagen deposition, preserved contractile-marker immunoreactivity, attenuated senescence- and inflammation-associated signals, and increased mitochondrial protein immunoreactivity. Oxidative DNA damage was notably reduced by nacre extract. Transcriptomics indicated modulation of stress/redox programs and increased neurotrophic tyrosine kinase receptor type 2 expression, which were supported by tissue-level validation. In C2C12 myotubes, nacre extract suppressed doxorubicin-induced senescence-associated phenotypes without loss of cell viability.

Conclusions: Water-soluble nacre extract mitigates skeletal muscle aging through coordinated modulation of oxidative stress, inflammation, mitochondrial features, and cellular senescence.

Keywords

Sarcopenia / Cellular senescence / Skeletal muscle aging / Nacre extract / Pinctada fucata

Conflict of interest statement

The authors declare no conflict of interest.

Funding

This study received no extramural funding.

Data availability statement

The data supporting the findings of this study are available from the corresponding author upon request.

Authors’ contributions

SK contributed to the methodology, investigation, formal analysis, data curation, and writing of the original draft of the manuscript. MK was involved in the investigation, methodology, and data curation. HY contributed to the investigation and methodology. YH was responsible for conceptualization, supervision, project administration, review writing and editing.

Publisher’s note

The Publisher of the Journal remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Acknowledgments

We are grateful to Kaneko Pearl Farming Company Limited for supplying the pearl oyster shells used in this study. We also thank Dr. Takehito Sugasawa (University of Tsukuba) for support with RNA-seq analyses.

References

[1] Gustafsson T, Ulfhake B. Aging skeletal muscles: What are the mechanisms of age-related loss of strength and muscle mass, and can we impede its development and progression? Ini J Mol Sci 2024; 25(20). doi: 10.3390/ijms252010932.

[2] Marques A, Queirós C, Santy-Tomlinson J. Frailty and sarcopenia. In: Hertz K, Santy-Tomlinson J. (eds.) Fragility fracture and orthogeriatric nursing:Holistic care and management of the fragility fracture and orthogeriatric patient. Springer International Publishing: Cham; 2024, p. 35-52.

[3] Jimenez-Gutierrez GE, Martínez-Gómez LE, Martínez-Armenta C, Pineda C, Martínez-Nava GA, Lopez-Reyes A, et al. Molecular mechanisms of inflammation in sarcopenia: Diagnosis and therapeutic update. Cells 2022; 11(15). doi: 10.3390/cells11152359.

[4] Plekhova NG, Novikova PA, Voro AN, Korolev DV, Shumatov VB. Cellular senescence in skeletal muscle: Age, sarcopenia, therapy. J Evol Biochem Phys 2025; 61(3): 861-879.

[5] Sahu P, Satapathy T. Immunopharmacology of senescence: Targeting the senescence-associated secretory phenotype (SASP)—a mechanism-based review. Inflammopharmacol 2025; 33(8): 4291-4310.

[6] Stojanovic B, Jovanovic I, Stojanovic MD, Stojanovic BS, Kovacevic V, Radosavljevic I, et al. Oxidative stress-driven cellular senescence: Mechanistic crosstalk and therapeutic horizons. Antioxidants 2025; 14(8). doi: 10.3390/antiox14080987.

[7] Chhunchha B, Kubo E, Lehri D, Singh DP, Chhunchha B, Kubo E, et al. NLRP3 inflammasome and inflammatory response in aging disorders: The entanglement of redox modulation in different outcomes. Cells 2025; 14(13). doi: 10.3390/cells14130994.

[8] López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. The hallmarks of aging. Cell 2013; 153(6): 1194-1217.

[9] Heng Z, Yotsuya Y, Omachi T, Hasegawa Y. Nacre extract improves insulin resistance and cognitive functions in diabetic mice. Asian Pac J Trop Biomed 2025; 15(11): 454-464.

[10] Chaturvedi R, Singha PK, Dey S. Water soluble bioactives of nacre mediate antioxidant activity and osteoblast differentiation. PLoS One 2013; 8(12). doi: 10.1371/journal.pone.0084584.

[11] Loh XJ, Young DJ, Guo H, Tang L, Wu Y, Zhang G, et al. Pearl powder—An emerging material for biomedical applications: A review. Materials 2021; 14(11). doi: 10.3390/ma14112797.

[12] Yamamoto H, Shimomura N, Hasegawa Y. Oral administration of nacre extract from pearl oyster shells has anti-aging effects on skin and muscle, and extends the lifespan in SAMP8 mice. Pharmaceuticals 2024; 17(6): 713.

[13] Fuji T, Inoue T, Hasegawa Y. Nacre extract prevents scopolamine-induced memory deficits in rodents. Asian Pac J Trop Med 2018; 11(3). doi: 10.4103/1995-7645.228434.

[14] Yamagami H, Fuji T, Wako M, Hasegawa Y. Sulfated polysaccharide isolated from the nacre of pearl oyster improves scopolamine-induced memory impairment. Antioxidants 2021; 10(4). doi: 10.3390/antiox10040505.

[15] Hasegawa Y, Inoue T, Kawaminami S, Fujita M. Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity. Asian Pac J Trop Med 2016; 9(7): 662-667.

[16] Lattouf R, Younes R, Lutomski D, Naaman N, Godeau G, Senni K, et al. Picrosirius red staining: A useful tool to appraise collagen networks in normal and pathological tissues. J Histochem Cytochem 2014; 62(10): 751-758.

[17] Yotsuya Y, Hasegawa Y. Nacre extract from pearl oyster attenuates amyloid beta-induced memory impairment. J Nat Med 2022; 76(2): 419-434.

[18] Yan Z, Yotsuya Y, Hasegawa Y. Neuroprotective effect of marine-derived nacre extract against aβ-induced toxicity via preservation of mitochondrial function and biogenesis. Neurochem Res 2025; 51(1). doi: 10.1007/s11064-025-04624-3.

[19] Omachi T, Hasegawa Y. Effect of nacre extract from pearl oyster shells against behavioral and psychological symptoms of dementia in senescence-accelerated mouse P 8 (SAMP8). J Funct Foods 2024; 116. doi: 10.1016/j.jff.2024.106208.

[20] Jung S, Ahn B, Jung S, Ahn B. Filbertone reduces senescence in C2C12 myotubes treated with doxorubicin or H₂O₂ through MuRF1 and Myogenin. Nutrients 2024; 16(18). doi: 10.3390/nu16183177.

[21] Wohlgemuth RP, Sriram S, Henricson KE, Dinh DT, Brashear SE, Smith LR. Strain-dependent dynamic re-alignment of collagen fibers in skeletal muscle extracellular matrix. Acta Biomater 2024; 187: 227-241.

[22] Bertaggia E, Scabia G, Dalise S, Verso FL, Santini F, Vitti P, et al. Haptoglobin is required to prevent oxidative stress and muscle atrophy. PLoS One 2014; 9(6). doi: 10.1371/journal.pone.0100745.

[23] Ru Q, Li Y, Chen L, Wu Y, Min J, Wang F. Iron homeostasis and ferroptosis in human diseases: Mechanisms and therapeutic prospects. Signal Transduct Target Ther 2024; 9(1): 271. doi: 10.1038/s41392-024-01969-z.

[24] Kulakowski SA, Parker SD, Personius KE. Reduced TrkB expression results in precocious age-like changes in neuromuscular structure, neurotransmission, and muscle function. J Appl Physiol 2011; 111(3): 844-852.

[25] Li X, Li C, Zhang W, Wang Y, Qian P, Huang H. Inflammation and aging: Signaling pathways and intervention therapies. Signal Transduct Target Ther 2023; 8(1): 239. doi: 10.1038/s41392-023-01502-8.

[26] Chen H, Ren B, Wang J, Liu X, Yi X, Goltzman D, et al. Mesenchymal stem cell-specific Sirt1 overexpression prevents sarcopenia induced by 1,25-dihydroxyvitamin D deficiency. Aging 2025; 17(4): 1026-1042.

[27] Sun H, Li D, Wei C, Liu L, Xin Z, Gao H, et al. The relationship between SIRT1 and inflammation: A systematic review and meta-analysis. Front Immunol 2024; 15. doi: 10.3389/fimmu.2024.1465849.

[28] Marzetti E, Calvani R, Coelho-Junior HJ, Picca A. Mitochondrial pathways and sarcopenia in the geroscience era. J Nutr Health Aging 2024; 28(12). doi: 10.1016/j.jnha.2024.100397.