Histological study of the effect of hydroxychloroquine sulfate on the retina and the possible protective role of propolis in adult male albino rats

Abstract

Background Hydroxychloroquine sulfate (HCS) is a widely used antimalarial drug. Recently, it garnered attention about its possible effect against COVID-19. Retinopathy is one of its dangerous side effects which may be untreated. Propolis is a substance made by honeybees and has a neuroprotective effect. Aim The study aimed to assess the impact of HCS on the retina and the possible ameliorative role of propolis in adult male albino rats. Materials and methods In all, 32 adult male albino rats were separated into four groups; group (I): the control group, group II: rats had received 100 mg/kg propolis for 12 weeks, group III: the HCS dose of 55 mg/kg/day had been administered to the rats for a period of 10 days, group IV: rats had received 55 mg/kg/day of HCS concomitant with 100 mg/kg propolis for 10 days and then propolis was continued to complete 12 weeks. Retinal specimens were obtained and processed for histological and morphometric analyses. Results Group III revealed vacuolations of photoreceptors; nuclei are widely separated in the outer and inner nuclear layers Also nuclei are darkly pigmented in the inner nuclear layer and the ganglion cell layer. Statistical analysis showed that there was a significant drop in the average number of ganglion cells when contrasted with the control group. These changes were markedly ameliorated in group HCS and propolis-treated group. Conclusion Hydroxychloroquine sulfate induced damaging effects on the rat retina and receiving propolis could attenuate these effects.