Fermented maize slurry (Ogi) and its supernatant (Omidun) mitigate elevated intraocular pressure by modulating BDNF expression and glial plasticity in the retina-gut axis of glaucomatous rats

Abstract

Objectives Growing interest has been reported on the health benefits of fermented foods, which includes cognition enhancement and inflammation attenuation. BDNF is a known protectant against retinal degeneration, however, therapies that target this neurotrophic factor has been limited. Therefore, we assessed the reaction of BDNF and glial cells in glaucomatous rats and their response to treatment with fermented maize products. Methods Thirty male adult rats were either injected via the episcleral vein with hypertonic saline to elevate intraocular pressure (IOP) or treated with fermented maize slurry (Ogi) or its supernatant (Omidun). Following sacrifice, the retina and duodenum were studied by immunohistochemical analysis using antibodies directed against GFAP, AIF-1 and BDNF. Results Hypertonic saline injection produced hypertrophy of the Müller cells and increased GFAP and AIF-1 expression in the retina and gut when compared to the control. Treatment with Ogi and Omidun produced varying degrees of reduction of gliosis, protection against hypertonic saline-induced retinal ganglion cell loss, and reduced intraocular pressure. BDNF expression was downregulated following the hypertonic saline assault, while Omidun and Ogi treatment abrogated its reduction following the hypertonic saline assault. Conclusions Collectively, our findings suggest that acute elevation of IOP alters crosstalk between gut and retina with consequent aberrant activation of glial cells; and that probiotic bacteria like the lactic acid bacteria rich in fermented foods including Ogi and Omidun may offer neuroprotection to the ganglionic cells by attenuating the retinal glial reaction and improving BDNF activity.

Caffeine Improves Elevated IOP by modulating Oxido-inflammatory responses in Rat Models of Glaucoma

“…Group PHS (post hypertonic saline) received 50µL injection of hypertonic saline, followed by an intraperitoneal injection of 20 mg/kg of caffeine. Group CAF (Caffeine) received an intraperitoneal injection of 20 mg/kg of caffeine (Jing et al, 2017;Fafure et al, 2021;Adekeye et al, 2021).…”

“…Five sections (5-µm widths) of the retina in each animal were analyzed. A non-destructive grid of lines was set to avoid counting the same cells twice (Fafure et al, 2021).…”

“…The average eye pressures are about 21 mmHg (millimeters of mercury) or 2.8 kPa (Kilopascal), and higher pressures lead to greater risk (Ferri et al,2010;Mantravadi et al, 2015;Vadhar et al, 2015). The retinal ganglion cells (RGCs), which transmit visual information to the brain, degenerate in glaucoma; once damaged, they do not regenerate (Fafure AA et al, 2021). However, in some cases, some may have elevated ocular pressure for years and never develop optic nerve damage (Mantravadi et al, 2015;Vadhar et al, 2015).…”

New strategies for neuro protection in glaucoma

“…In animal models of glaucoma, various diet-related treatments were found as non-IOP-related neuroprotective mechanisms. High VitK1 intake ( Deng et al, 2020 ) , Coenzyme Q10 + Vitamin E ( Zhang et al, 2017 ; Ekicier Acar et al, 2020 ), Nicotinamide riboside of the vitamin B3 family ( Zhang X. et al, 2021 ), probiotic bacteria ( Fafure et al, 2021 ) and other dietary supplementation ( Cammalleri et al, 2020 ) were proved to attenuate the loss of RGCs by regulating glia-mediated neuroinflammatory or BDNF activity, etc.…”

T Cell-Mediated Autoimmunity in Glaucoma Neurodegeneration

“…Recently, modulation of the gut microbiota to reshape the systemic immune response has become an emerging therapy for glaucoma. A study found the beneficial roles of fermented maize slurry and its supernatant rich in probiotic bacteria to reshape gut microbiota in rats in the modulation of retinal immune reaction and protection of RGCs ( 57 ). Further studies, especially clinical trials, to illuminate the crosstalk between the retina and gut may provide more valuable information on the pathogenesis of glaucoma and explore the possible intervention methods.…”