Metformin Shows Partial Senomorphic Activity But Fails to Alleviate Cisplatin-Induced Neuropathy in Preclinical Models

Preclinical research demonstrates that while metformin exhibits partial senomorphic activity by reducing cellular senescence markers, it does not prevent functional sensory deficits in a rat model of cisplatin-induced peripheral neuropathy.

Researchers investigated the senomorphic potential of metformin in counteracting cisplatin-induced therapy-induced senescence (TIS) using human induced pluripotent stem cell-derived motor neurons (iPSC-MNs) and a rat model of chemotherapy-induced peripheral neuropathy (CIPN).

In human iPSC-MNs, metformin attenuated the transcript expression of key senescence markers, including CDKN2A and the SASP component CXCL8, but did not significantly reduce SA-β-gal activity or restore cellular viability.

In vivo, Sprague-Dawley rats administered a cumulative cisplatin dose of 23 mg/kg exhibited mechanical allodynia, thermal hyperalgesia, and elevated senescence markers in the dorsal root ganglia on day 8 post-treatment.

Metformin pre-treatment reversed the upregulation of cdkn1a, cdkn2a, and Il6 in the dorsal root ganglia but failed to prevent or alleviate the functional sensory deficits induced by cisplatin.

Therapy-induced senescence is a recognized contributor to chemotherapy-associated neurotoxicity, and safer alternatives to toxic senolytics (such as senomorphics like metformin) are highly sought after.

The study establishes a critical disconnect between molecular senomorphic effects (the downregulation of SASP and senescence transcripts) and functional clinical endpoints (sensory hypersensitivity).

These findings suggest that partial modulation of the senescent phenotype without clearance of the senescent cells may be therapeutically insufficient for resolving complex neuropathic symptoms.

The failure of metformin to resolve functional sensory hypersensitivity despite reducing molecular biomarkers of senescence highlights the limitations of using metformin as a repurposed monotherapy for chemotherapy-induced peripheral neuropathy.

This insight suggests that developers targeting senescence-mediated neurotoxicity may need to focus on robust senolytic clearance mechanisms rather than milder senomorphic suppression to achieve meaningful therapeutic outcomes.

Preclinical studies comparing the functional neuroprotective efficacy of strict senolytic agents against senomorphic drugs in chemotherapy-induced neuropathy models.