Search

The putative anticataractogenic efficacy of silver nanoparticles (AgNPs), biosynthesized with a Tabernaemontana divaricata (T. divaricata) extract, was evaluated in-vivo in four groups of Wistar rat pups: Group I (normal [control]); Group II (selenite-challenged [19 μmol/kg body weight], untreated); Group III (selenite-challenged, T. divaricata extract-treated [350 mg/kg body weight]); and Group IV (selenite-challenged, biosynthesized AgNPs-treated [200 mg/kg body weight]). Mean levels/activities of lenticular reduced glutathione (GSH), malondialdehyde (MDA), calcium, Ca2+ and Na+/K+-ATPase and total calpain were measured. The expression pattern of genes at mRNA transcript (by reverse transcription-PCR) and protein (by immunoblot analysis) levels for Ca2+ transporters, calpain isoforms and lenticular proteins (αA- and βB1-crystallins, and vimentin) were evaluated. In extract-treated and AgNPs-treated rats, relatively higher mean lenticular levels/activities of GSH, Ca2+ and Na+/K+-ATPase, total calpain, and higher mRNA transcript and protein levels of calpain isoforms and lenticular proteins were observed. However, relatively lower mean lenticular levels of MDA, calcium and also mRNA transcript and protein levels of plasma membrane Ca2+-ATPase-1 (PMCA-1) and sarco/endoplasmic reticulum Ca2+-ATPase-2 (SERCA-2) were recorded. The prevention of such lenticular alterations was more pronounced in AgNPs-treated rats than in plain extract-treated rats. These observations suggest that AgNPs biosynthesized with T. divaricata extract have the potential to prevent selenite-induced cataractogenesis in-vivo by maintaining normal lenticular calcium homeostasis and calpain cascade activities and by preventing alterations in key lenticular proteins.

The present study sought to determine whether topical voriconazole exerts antioxidative effects in experimental Aspergillus flavus keratitis. Three groups of five each young albino rabbits were used. Experimental keratitis was induced by application of Aspergillus flavus conidia to scarified cornea (right eye) of 10 rabbits (another 5 rabbits were negative controls [Group I]). Five days later, A. flavus-infected animals began receiving hourly topical saline (Group II) or voriconazole (10 mg/mL) (Group III). Twenty days post-inoculation, corneal lesions were graded; expression of interleukin-1beta (IL-1β) and tumor necrosis factor-α (TNF-α) genes, activities of three enzymatic antioxidants and reduced glutathione (GSH); malondialdehyde (MDA) levels were measured in corneal homogenates. Clinical, histopathological and microbiological scores suggested most severe keratitis in Group II and least severe in Group I rabbits. mRNA transcript levels of IL-1β and TNF-α were significantly higher in Group II than in Groups III and I rabbit corneal samples. Activities/levels of enzymatic antioxidants and of GSH were lowest in Group II and highest in Group I corneal samples, and MDA level was highest in Group II and least in Group I corneal samples. Corneal oxidative stress was more intense in A. flavus-challenged, saline-treated than in A. flavus-challenged, voriconazole-treated rabbits. Topical voriconazole notably reduced severity of keratitis and oxidative stress, although infection and inflammation did not completely resolve. Voriconazole thus exerts antioxidative effects, in addition to antifungal activity, in experimental A. flavus keratitis.

The present study highlights the putative anti-atherogenic, antioxidative and anti-inflammatory potential of Tabernaemontana divaricata extract (ethanolic) in a Wistar rat model of experimental hypercholesterolemia. The rats were divided into Group I (control), Group II (atherogenic diet-fed, saline-treated) and Group III (atherogenic diet-fed, T. divaricata extract-treated [200 mg/kg/b.wt]). The levels of lipid profile parameters (total cholesterol, triglycerides, high-density, low-density and very low-density lipoprotein cholesterol and atherogenic index) and C-reactive protein (CRP) were investigated in serum samples. The levels of enzymatic and non-enzymatic antioxidants, malondialdehyde and nitric oxide (NO), and gene and protein expression levels of CRP, inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) and gene expression levels of interleukin-1β (IL-1β) were determined in liver tissue samples. Rats of Group II showed significantly heightened mean concentrations of CRP, and lower mean levels of lipid profile parameters, except high-density lipoprotein cholesterol, than control rats; Rats of Group II also exhibited significantly lower mean activities/levels of enzymatic and non-enzymatic antioxidants and heightened mean malondialdehyde and NO content compared to control animals. However, in Group III rats, the values were significantly improved, in contrast to Group II rats. Significantly higher gene expression of IL-1β and significantly higher gene and protein expression of CRP, iNOS and TNF-α occurred in liver samples from hypercholesterolemic rats compared to control rats. In liver samples from Group III rats, gene and protein expression was not markedly elevated. The T. divaricata extract thus exhibited anti-atherogenic potential in hypercholesterolemic Wistar rats due to its hypocholesterolemic, antioxidant and anti-inflammatory effects.