Cell experiment:

Retinas are collected at day 14 postoperatively, following treatment with normal saline (NS) or various doses of Gastrodin. The mRNA expression levels of TNF-α and iNOS are determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR)[1].

Animal experiment:

Adult female SD rats (age, 8 wk; weight, 200 to 250 g) are used. The rats are divided into 4 groups: 1) control group; 2) normal saline (NS) group who are exposed to acute ocular hypertension (AOH) and receive intraperitoneal injection of 0.9% NS; 3) G10 group who are exposed to AOH and receive intraperitoneal injection of 10 mg/kg Gastrodin; 4) G50 group who are exposed to AOH and receive intraperitoneal injection of 50 mg/kg Gastrodin. The loss of retinal ganglion cells (RGCs) and the number of Iba1-positive retina microglia are determined at 2 wk after rapid ocular hypertension[1].

Gastrodin, a main constituent of a Chinese herbal medicine Tianma, has been known to display anti-inflammatory effects. Gastrodin, has long been used for treating dizziness, epilepsy, stroke and dementia.

Gastrodin treatment reduces the mRNA expression levels of TNF-α and iNOS in the retinas of acute ocular hypertension[1].

Intraperitoneal injection with Gastrodin 10 mg/kg or 50 mg/kg once daily for 15 d significantly inhibits the loss of retinal ganglion cells (RGCs) because of acute ocular hypertension (AOH) damage. 2 wk after AOH, the number of Iba1 positive retinal microglia obviously reduces to 231.3±54.3 cells/mm2 and 201.9±43.1 cells/mm2 in the rats intraperitoneally injected with Gastrodin at 10 mg/kg and 50 mg/kg, respectively[1].

References:
[1]. Wang JW, et al. Gastrodin protects retinal ganglion cells through inhibiting microglial-mediated neuroinflammation in an acute ocular hypertension model. Int J Ophthalmol. 2017 Oct 18;10(10):1483-1489.