Stress left mice showing signs of faster ageing
A year of unpredictable mild stress was accompanied by a broad pattern of ageing-like changes in mice, from poorer social novelty preference, spatial memory, motor performance and grip strength to greater frailty, mortality and a shorter healthy lifespan. The same experiment found that Bazi Bushen formula, or BZBS, improved several of these measures, with the higher dose performing better than the anti-ageing comparator NMN on reported frailty, death-rate and lifespan measures.
The main experiment used 125 female and 126 male specific-pathogen-free C57BL/6 mice aged 11 months, alongside six young male controls aged four months. After a one-week acclimation, the animals were assigned to control, stressed-model, NMN, high-dose BZBS or low-dose BZBS groups. The stress exposure rotated 10 mild stress methods each day for 12 months. NMN was given at 200 milligrams per kilogram per day, while the two BZBS doses were 2 or 1 gram per kilogram per day.
Stress was also associated with structural abnormalities across several organs. These included white-matter atrophy, changes in the intestine, muscle, fat and skin, kidney tubular changes, heart and lung damage, and inflammatory infiltration. BZBS and NMN attenuated structural abnormalities across multiple organs.
The immune system changed across tissues
To map the changes at cellular level, the researchers used single-cell RNA sequencing, a method that measures gene activity in individual cells. They profiled the brain, small intestine, kidney, lung and peripheral blood mononuclear cells. After quality control, the dataset contained 297,944 high-quality cellular transcriptome datasets covering 51 main cell types.
The stressed mice showed a clear shift in immune-cell composition. B, natural killer and T-cell populations were reduced, while myeloid populations increased by 19.11% in the kidney, 17.12% in the lung and 18.32% in peripheral blood mononuclear cells. The pattern extended beyond a single organ and pointed to a broader myeloid-lymphoid imbalance.
BZBS moved the immune profile back toward the control pattern. It restored the lymphocyte-myeloid balance, reduced M1 macrophages, increased M2 macrophages and B cells, and reduced the reported siAge immunosenescence signal.
Inflammatory and senescence markers also rose across tissues under chronic stress, including NF-kB, TNF-alpha, IL-6, P16, P21 and P53. Gene-activity scoring detected elevated inflammation in all samples and most cell types. High-dose BZBS suppressed these changes more strongly than the low dose or NMN.
The ageing signals were not the same in every tissue
The tissue profiles differed in important ways. Pulmonary and peripheral blood immune-cell populations had the highest counts of stress-related, pro-ageing differentially expressed genes, meaning genes whose activity differed between groups. Cerebral tissue had an ageing-related gene proportion of 86.7%, while kidney and peripheral blood immune-cell ageing scores were the highest. These were transcriptomic scores, not clinical measures of ageing.
The stress exposure was also associated with a redox imbalance, including peroxide accumulation, glutathione depletion and impaired superoxide dismutase activity. Lung macrophages showed higher mitochondrial reactive oxygen species, and the liver showed accelerated epigenetic ageing based on methylation patterns. BZBS attenuated the redox and mitochondrial changes and reversed the reported methylation-ageing phenotype.
The researchers then looked for compounds that might account for some of the laboratory effects. After oral BZBS, 23 chemical prototypes were detected in rat plasma and five in rat brain. In supporting astrocyte cell models, Osthole, Schisandrin and Schisandrin B showed dose-dependent reductions in mitochondrial dysfunction and mitochondrial reactive oxygen species, restored membrane potential, and, in the case of Osthole, improved respiratory capacity. These experiments are not direct evidence of human efficacy or in vivo therapeutic benefit.
Further tests suggested involvement of the AMPK-Sirtuin-PGC-1alpha pathway. In cell models, AMPK inhibition or knockdown weakened mitochondrial rescue. Binding assays reported interactions between selected compounds and AMPK-alpha1, AMPK-alpha2, SIRT1, SIRT3 and SIRT6, while cellular assays and tests in treated mouse lung tissue supported pathway activation. The results did not include myeloid-specific in vivo knockout validation.
The evidence stops short of a treatment
The findings remain preclinical. The mouse model cannot fully reproduce human ageing, only five major tissues were analysed, and candidate-gene mechanisms were not validated in vivo. The study included only one anti-ageing positive control, and the intervention was given during the stress exposure rather than after stress-related or ageing-related symptoms had appeared.
That distinction matters because the experiment identifies candidate mechanisms and compounds, but does not establish that BZBS prevents or treats ageing-related disease in people. The supporting rat and cell experiments likewise do not establish human safety or efficacy.
The paper reports support from national and regional Chinese research programmes, including traditional-medicine, Hebei, Shijiazhuang, talent and Yanzhao programmes. The authors declare no conflicts of interest.
Paper data and sources
Original title: Reversal of Chronic Stress‐Induced Inflammaging by Bazi Bushen Formula Through AMPK‐Sirtuins Axis Activation and Myeloid Reset
Authors: Li M, Chen Z, Wang L et al.
Journal/Repository: Exploration (Beijing, China)
Status: Peer-reviewed
First online: 2026-10-11
DOI: Not available
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