Fifteen Aprila Fajrin1, Arief Nurrochmad2, Agung Endro Nugroho2, Rina Susilowati3
1Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, Universitas Gadjah Mada, Yogyakarta; Department of Clinical and Community Pharmacy, Faculty of Pharmacy, Jember University, Jember, Indonesia.
2Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, Universitas Gadjah Mada, Yogyakarta, Indonesia.
3Department of Histology and Cell Biology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.
Background: 6-Shogaol is one of the bioactive compounds from ginger (Zingiber officinale Roscoe.) that had been widely used in many diseases. This research was aim to investigate the effect of ginger extract and its pungent compound, 6-shogaol on pain behavior and sciatic nerve morphology in mice model of painful diabetic neuropathy. Materials and Methods: Seventy-two male BALB/c mice were divided into nine groups. Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ) 110 mg/kg body weight (BW). The mice were considered diabetic when the serum glucose level was at least 200 mg/dL. Thermal and mechanical hyperalgesia was measured using tail-flick latency and Randall–Selitto test once a week. Daily oral administration of 6-shogaol doses 5, 10, and 15 mg/kg BW, ginger extract doses 100, 200, and 400 mg/kg BW, or gabapentin dose 100 mg/kg BW was started at week 4. Diabetic mice without treatment and mice without STZ induction were used as controls. At week 7, the mice were euthanized, and paraffin sections of 1% osmium tetroxide-stained sciatic nerve samples were observed. Results: Ginger extract and 6-shogaol, but not gabapentin, produced dose-dependent lowering blood glucose effect. However, the mean of serum glucose level was not <200 mg/dL. After 4 weeks of hyperglycemia, the diabetic groups showed signs of hyperalgesia. The ginger extract, 6-shogaol, and gabapentin administration attenuated the hyperalgesic effect. The microstructure of sciatic nerves in diabetic mice that received ginger extract and 6-shogaol was less damaged compared to the diabetic control group. Conclusion: From this research, ginger extract and its pungent compound, 6-shogaol, showed anti-hyperalgesic and neuroprotective effects.
Keywords: 6-Shogaol, axon morphology, ginger extract, painful diabetic neuropathy, sciatic nerves, Zingiber officinale