Superoxide dismutase 3 prevents early stage diabetic retinopathy in streptozotocin-induced diabetic rat model

Purpose To identify the effects of superoxide dismutase (SOD)3 on diabetes mellitus (DM)-induced retinal changes in a diabetic rat model. Methods Diabetic models were established by a single intraperitoneal injection of streptozotocin (STZ) in Sprague-Dawley rats. After purification of the recombinant SOD3, intravitreal injection of SOD3 was performed at the time of STZ injection, and 1 and 2 weeks following STZ injection. Scotopic and photopic electroretinography (ERG) were recorded. Immunofluorescence staining with ɑ-smooth muscle actin (SMA), glial fibrillary acidic protein (GFAP), pigment epithelium-derived factor (PEDF), Flt1, recoverin, parvalbumin, extracellular superoxide dismutase (SOD3), 8-Hydroxy-2’deoxyguanosine (8-OHdG) and tumor necrosis factor-ɑ (TNF-ɑ) were evaluated. Results In the scotopic ERG, the diabetic group showed reduced a- and b-wave amplitudes compared with the control group. In the photopic ERG, b-wave amplitude showed significant (p < 0.0005) reduction at 8 weeks following DM induction. However, the trend of a- and b-wave reduction was not evident in the SOD3 treated group. GFAP, Flt1, 8-OHdG and TNF-ɑ immunoreactivity were increased, and ɑ-SMA, PEDF and SOD3 immunoreactivity were decreased in the diabetic retina. The immunoreactivity of these markers was partially recovered in the SOD3 treated group. Parvalbumin expression was not decreased in the SOD3 treated group. In the diabetic retinas, the immunoreactivity of recoverin was weakly detected in both of the inner nuclear layer and inner plexiform layer compared to the control group but not in the SOD3 treated group. Conclusions SOD3 treatment attenuated the loss of a/b-wave amplitudes in the diabetic rats, which was consistent with the immunohistochemical evaluation. We also suggest that in rod-dominant rodents, the use of blue on green photopic negative response (PhNR) is effective in measuring the inner retinal function in animal models of diabetic retinopathy. SOD3 treatment ameliorated the retinal Müller cell activation in diabetic rats and pericyte dysfunction. These results suggested that SOD3 exerted protective effects on the development of diabetic retinopathy.

Morphological and histological kidney structure in diabetic rats model treated with ethanol extracts of jengkol fruit peel (Archidendron pauciflorum)

In a long term, diabetes mellitus (DM) leads to nephropathy due to glomerular hyperfiltration. One of the plant used as a diabetic drug by the community in Karangwangi Village, Cianjur Regency, West Java is the fruit peel of jengkol. Therefore, this study aims to determine the effect of the ethanolic extract of Jengkol fruit peel (EEJFP) toward the morphological and histological structure on the kidney of the diabetic rat model. The method adopted was the Randomized Design (CRD) with 6 treatments namely NC (Carboxyl Methyl Cellulose (CMC) 0.5%), PC (CMC 0.5%), Pb (Glibenclamide 5 mg/kg BW), P1, P2, and P3 (EEJFP 385; 770; and 1,540 mg/kg BW) with 4 replications for 14 consecutive days. Furthermore, the induction of diabetes with streptozotocin dose of 60 mg/Kg BW was performed intravenously in experimental animals except for the NC group. The parameters observed include relative weight, morphological, and histological structure of kidney which include glomerular diameter, Bowman space distance, and percentage of proximal tubular cell necrosis. The non-parametric and parametric data were tested by Kruskal Wallis and ANOVA test as well as Duncan's follow-up test, respectively. The results showed that there was no significant difference in the morphological structure of the kidney between treatment groups. Furthermore, the relative weights of kidney in the PC, Pb, P1, and P3 groups were larger and significantly different compared to NC and P2 also, the histological structure showed that the glomerular diameter (65.43 ± 0.7 m), Bowman space distance (4.19 ± 1.7 µm), and the percentage of proximal tubular cell necrosis (24.6 ± 5.5%) at P2 were not significantly different from NC. Based on this results, it was concluded that EEJFP has no effect on the kidney’s morphological structure, however, it decreases its relative weight and repair the kidney’s histological damage of the diabetic rat model with the optimum dose of 770 mg/kg BW.

Protective effects of umbilical cord mesenchymal stem cell exosomes in a diabetic rat model through live retinal imaging

AIM: To assess the protective effect of human umbilical cord mesenchymal stem cell exosomes (hucMSC-Exs) in a diabetic rat model by using a variety of retinal bioassays. METHODS: hucMSCs were subjected to differential ultracentrifugation for the collection of exosomes, and transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) using a NanoSight analysis system and Western blotting (WB) were used to analyze the expression of surface marker proteins such as CD63, CD9 and Calnexin. Streptozotocin (STZ) was injected into the intraperitoneal cavity to establish a diabetic model. Rats were divided into a normal group, diabetic group and hucMSC-Ex group. Fundus fluorescein angiography (FFA), optical coherence tomography (OCT) and other live imaging methods were used to observe the fundus of the rats. Finally, the eyeballs of rats from each group were collected for hematoxylin-eosin (HE) staining to further analyze the retinal structure. RESULTS: Through TEM, NTA and WB, we successfully isolated hucMSC-Exs. Subsequent FFA and OCT confirmed that hucMSC-Exs effectively prevented early retinal vascular damage and thickening of the retina. Finally, HE staining of rat retinal sections revealed that exosomes effectively alleviated retinal structure disruption caused by diabetes. CONCLUSION: hucMSC-Exs have a protective effect on the retina in diabetic rat through FFA, OCT and HE staining.

Histopathological Profiles of Rats (Rattus norvegicus) Induced with Streptozotocin and Treated with Aqueous Root Extracts of Ruellia tuberosa L.

Diabetes mellitus (DM) is a serious worldwide health threat since the number of people with DM is forecasted to grow annually. Thus, effective and affordable treatment is urgently needed. Our previous studies used n-hexane and hydroethanolic root extracts of Ruellia tuberosa L. which significantly affected diabetic rats. In this study, aqueous R. tuberosa L. root extracts were used as treatments for the diabetic rat model and their effects were evaluated. Diabetes was generated by the administration of streptozotocin (STZ) at 20 mg/kg within 5 sequential days. Male Wistar rats were orally treated with the extracts and standard drug (metformin 200 mg/kg) and vehicle every day for 4 weeks. Hypoglycemic effects were assessed for normal, diabetic control, standard, and extract-treated groups. Histopathology was also carried out for the pancreatic, hepatic, and kidney tissues. The progression of diabetes was considerably diminished after extract treatment. In treated rats, the highest dose of extract induced a decline in blood glucose and serum malondialdehyde (MDA) levels at 25% and 35%, respectively. Furthermore, aqueous extract of R. tuberosa L. treatment decreased MDA levels in the pancreas by 12%. Histologic examination of the organ tissues of diabetic rats showed deteriorating alterations. After treatment, histopathological damages to the tissues and cells were reversed. The results of the experiments recommend that aqueous extract of R. tuberosa L. has antidiabetic effects on STZ-induced diabetic rats; nevertheless, a higher dose of the aqueous extracts is needed to achieve more significant results.