Clinical Study of Zuogui Jiangtang Shuluo Formula in Treating Diabetic Peripheral Neuropathy

Mechanistic Study of Zuogui Jiangtang Shuluo Formula in Regulating Lipid Metabolism and Inhibiting Ferroptosis for the Prevention and Treatment of Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of type 2 diabetes mellitus, affecting 35%-50% of diabetic patients. Its pathogenesis involves metabolic disorders induced by hyperglycemia and dyslipidemia, leading to irreversible damage to neurons and vascular endothelial cells. Distal symmetric polyneuropathy (DSPN) is the most representative form, characterized by distal pain, numbness, and sensory loss, which may progress to ulcers, gangrene, and even amputation in severe cases.

Current modern medical treatments for DPN primarily focus on nutritional nerve support, antioxidative stress, and microcirculation improvement, but these approaches are limited in variety and may carry side effects. Traditional Chinese Medicine (TCM) offers advantages including higher safety and diverse therapeutic options.

Based on long-term clinical observation, our research group proposes that the core pathogenesis of DPN is Qi-Yin deficiency with blood stasis obstructing collaterals. The treatment principle is to nourish Yin, supplement Qi, activate blood circulation, and unblock collaterals, with Zuogui Jiangtang Shuluo Formula (ZGJTSLF) as the primary prescription. Previous studies have shown that ZGJTSLF can improve TCSS scores and nerve conduction velocity in DPN patients compared with mecobalamin, but high-level evidence is still lacking.

This randomized, parallel-controlled trial aims to evaluate the clinical efficacy of ZGJTSLF in treating DPN, with TCSS score and nerve conduction velocity as primary outcomes. Metabolomics and lipidomics will be employed to compare metabolic profiles between healthy controls and DPN patients before and after ZGJTSLF treatment, aiming to identify potential biomarkers and explore the underlying mechanisms.

DSPN inclusion criteria:

1. Meet the diagnostic criteria for type 2 diabetes mellitus with distal symmetric polyneuropathy (DSPN) according to Western medicine standards.
2. Meet the TCM syndrome differentiation criteria for consumptive thirst complicated with arthromyodynia of the pattern of Qi-Yin deficiency with blood stasis.
3. Glycated hemoglobin (HbA1c) between 6.5% and 9.0% (inclusive).
4. Aged 35 to 75 years (inclusive) at the time of screening, regardless of gender.
5. Have not participated in any other clinical trial within 2 weeks prior to the start of treatment, and have not taken lipid-lowering agents, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), antidepressants, immunosuppressants, or other traditional Chinese medicines that may affect metabolomic and lipidomic profiles.
6. Willing to voluntarily participate in the trial and adhere to the 4-week traditional Chinese medicine treatment regimen.
7. Right-handed.
8. Provide written informed consent and are able to understand and comply with the study protocol requirements, including dietary and exercise recommendations and blood glucose monitoring.

DSPN exclusion criteria

1. Patients with type 1 diabetes mellitus or other specific types of diabetes mellitus.
2. Women who are pregnant, breastfeeding, planning pregnancy, or taking oral contraceptives long-term.
3. Neuropathies caused by other conditions, including but not limited to multiple sclerosis, Parkinson's disease, Guillain-Barré syndrome, epilepsy, spinal cord injury, cervical or lumbar spine lesions (nerve root compression, spinal stenosis, cervical or lumbar degenerative diseases), neuromuscular diseases, severe arterial or venous vascular diseases (venous thrombosis, lymphangitis, etc.), sequelae of cerebrovascular disease, or post-surgical status of lower extremity vasculature.
4. History of stroke, transient ischemic attack, unstable angina, or myocardial infarction within 3 months prior to study enrollment.
5. History of acute diabetic complications (diabetic ketoacidosis, lactic acidosis, or hyperosmolar hyperglycemic state) within 3 months prior to study enrollment.
6. Concomitant severe complications of diabetes, such as end-stage diabetic kidney disease, or proliferative diabetic retinopathy.
7. Concomitant severe diseases of the heart, liver, kidney, cerebrovascular system, or malignant tumors, defined as serum creatinine >200 μmol/L, blood urea nitrogen >1.5 times the upper limit of normal, or alanine aminotransferase or aspartate aminotransferase >3 times the upper limit of normal.
8. Any infection that, in the investigator's opinion, makes the patient unsuitable for participation prior to study enrollment, including but not limited to urinary tract infection, respiratory infection, or diabetic foot with infection requiring further treatment.
9. Patients with psychiatric disorders, cognitive impairment, or inability to cooperate with the study procedures; or individuals with a history of alcohol abuse or drug addiction.

Healthy volunteer inclusion criteria:

1. Aged 18 to 55 years (inclusive) at the time of screening, regardless of gender.
2. Body mass index (BMI) within the range of 19.0 to 26.0 kg/m² (inclusive). No severe diseases of the heart, liver, kidney, cerebrovascular system, or malignant tumors; routine laboratory tests, electrocardiogram, and chest X-ray are essentially within normal limits.
3. Have not participated in any other clinical trial within 2 weeks prior to the start of treatment, and have not taken lipid-lowering agents, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), antidepressants, immunosuppressants, or other traditional Chinese medicines that may affect metabolomic and lipidomic profiles.
4. Voluntarily sign the informed consent form and are willing and able to cooperate with the investigators to complete the clinical study.

Healthy volunteer exclusion criteria:

1. Women who are pregnant, breastfeeding, planning pregnancy, or taking oral contraceptives long-term.
2. Patients with psychiatric disorders, cognitive impairment, or inability to cooperate with the study procedures.
3. Individuals with a history of alcohol abuse or drug addiction.