Purpose: Diabetes accelerates peripheral, distal symmetric polyneuropathy, small fiber predominant neuropathy, radiculoplexopathy, and autonomic neuropathy. This study investigated the neuroprotective effects of gallic acid and myricetin-rich Labisia pumila extract in a diabetic neuropathy rat model and evaluated the neuropathy correlationship with serum inflammatory biomarkers.
Methods: Thirty male rats were divided into 5 groups (n = 6), namely: healthy control; non-treated diabetic control; and diabetic-rats treated with 200 mg/kg metformin; Labisia pumila ethanol extract (LP) at 150 mg/kg or 300 mg/kg doses. Diabetes was induced by 60 mg streptozotocin /kg intraperitoneal injection. Rats were orally treated daily for ten weeks. Their fasting blood glucose (FBG), neurological functions (hot plate and tail immersion; thermal hyperalgesia; cold allodynia; motor walking function), biomarkers for inflammation and oxidative stress, the neuro-histopathological changes, and brain somatic index were measured.
Results: The extract significantly prevented abnormal increases in FBG and decreases in body weight gain. It attenuated behavioral dysfunctions (hot plate and tail immersion; thermal hyperalgesia; cold allodynia; motor walking function), systemic inflammation (serum TNF-α, prostaglandin-E2) oxidative tension (malondialdehyde), histological brain and sciatic nerve injuries in the diabetic-rats, better than Metformin.
Conclusion: LP mitigated neural dysfunction better than metformin partly by amending diabetic systemic inflammation, oxidative tension, and diabetic abnormalities. The nerve injuries were strongly correlated to serum prostaglandin-E2, TNF-α levels, and walking functions. The motor function was correlated to sensory neuronal functions, inflammation, and oxidation. The sensory neuronal functions were more affected by TNF-α than prostaglandin-E2 or oxidation. Diabetic brain and sciatic nerve deteriorations were influenced by serum TNF-α, PGE2, and MDA levels.
Supplementary information: The online version contains supplementary material available at 10.1007/s40200-021-00905-0.
Keywords: Brain; Diabetic neuropathy; Labisia pumila; Metformin; Prostaglandin-E2; TNF-α.
© Springer Nature Switzerland AG 2021.