Molecular and Antioxidant Characterization of Opuntia robusta Fruit Extract and Its Protective Effect against Diclofenac-Induced Acute Liver Injury in an In Vivo Rat Model.

A molecular characterization of the main phytochemicals and antioxidant activity of Opuntia robusta (OR) fruit extract was carried out, as well as an evaluation of its hepatoprotective effect against diclofenac (DF)-induced acute liver injury was evaluated. Phenols, flavonoids and betalains were quantified, and antioxidant characterization was performed by means of the ABTS•+, DPPH and FRAP assays. UPLC-QTOF-MS/MS was used to identify the main biocompounds present in OR fruit extract was carried out via. In the in vivo model, groups of rats were treated prophylactically with the OR fruit extract, betanin and N-acteylcysteine followed by a single dose of DF. Biochemical markers of oxidative stress (MDA and GSH) and relative gene expression of the inducible antioxidant response (Nrf2, Sod2, Hmox1, Nqo1 and Gclc), cell death (Casp3) and DNA repair (Gadd45a) were analyzed. Western blot analysis was performed to measure protein levels of Nrf2 and immunohistochemical analysis was used to assess caspase-3 activity in the experimental groups. In our study, the OR fruit extract showed strong antioxidant and cytoprotective capacity due to the presence of bioactive compounds, such as betalain and phenols. We conclude that OR fruit extract or selected components can be used clinically to support patients with acute liver injury.

Hepatoprotective Effect of Opuntia robusta Fruit Biocomponents in a Rat Model of Thioacetamide-Induced Liver Fibrosis.

Liver fibrosis is a chronic disease associated with oxidative stress that has a great impact on the population mortality. Due to their antioxidant capacity, we evaluated the protective effect of Opuntia robusta fruit (Or) on liver fibrosis. A nutraceutical characterization of Or was performed and a model of fibrosis was induced with thioacetamide (TAA) in Wistar rats. Aminotransferases, reduced glutathione (GSH) and histopathology were evaluated. Or contained 436.5 ± 57 mg of Betacyanins equivalents/L., 793 mg of catechin equivalents (CAE)/100 g for flavonoids, 1118 mg of gallic acid equivalents (GAE)/100 g for total phenols, 141.14 mg/100 g for vitamin C and 429.9 µg/100 g for vitamin E. The antioxidant capacity of Or was: 2.27 mmol of Trolox® equivalents (TE)/L (DPPH), 62.2 ± 5.0 µmol TE/g (ABTS•+), 80.2 ± 11.7 µmol TE/g (FRAP), 247.9 ± 15.6 µmol TE/g (AAPH) and 15.0% of H2O2 elimination. An increase (p < 0.05) of aminotransferases and a decrease (p < 0.05) of hepatic GSH was observed in the TAA group compared to the control and the concomitant groups. Histopathology showed changes in the normal architecture of the liver treated with TAA compared to the concomitant treatments. Or contains bioactive components with antioxidant capacity, which can reduce fibrotic liver damage.

Betacyanins, major components in Opuntia red-purple fruits, protect against acetaminophen-induced acute liver failure.

Acetaminophen (APAP) misuse or overdose is the most important cause of drug-induced acute liver failure. Overdoses of acetaminophen induce oxidative stress and liver injury by the electrophilic metabolite N-acetyl-p-benzoquinone imine (NAPQI). Plant-based medicine has been used for centuries against diseases or intoxications due to their biological activities. The aim of this study was to evaluate the therapeutic value of Opuntia robusta and Opuntia streptacantha fruit extracts against acetaminophen-induced liver damage and to identify the major biocomponents on them. Opuntia fruit extracts were obtained by peeling and squeezing each specie, followed by lyophilization. HPLC was used to characterize the extracts. The effect of the extracts against acetaminophen-induced acute liver injury was evaluated both in vivo and in vitro using biochemical, molecular and histological determinations. The results showed that betacyanins are the main components in the analyzed Opuntia fruit extracts, with betanin as the highest concentration. Therapeutic treatments with Opuntia extracts reduced biochemical, molecular and histological markers of liver (in vivo) and hepatocyte (in vitro) injury. Opuntia extracts reduced the APAP-increased expression of the stress-related gene Gadd45b. Furthermore, Opuntia extracts exerted diverse effects on the antioxidant related genes Sod2, Gclc and Hmox1, independent of their ROS-scavenging ability. Therefore, betacyanins as betanin from Opuntia robusta and Opuntia streptacantha fruits are promising nutraceutical compounds against oxidative liver damage.

Morphological changes during the formation of amoebic liver abscess in vagotomized hamsters.

Amoebic liver abscess (ALA) is the main extra-intestinal complication caused by Entamoeba histolytica. Given the histological features of ALA in hamsters and the importance of the vagus nerve in the immune response, the aim of this study was to identify and analyze the major changes in ALA that are caused by a vagotomy. The changes found are related to inflammatory foci and abscess size, the type of collagen formed, and the number of trophozoites in lesions. Male hamsters were divided into three groups: Intact animals (IA) and those undergoing a false operation (SHAM) or a subdiaphragmatic vagotomy (VAG). In each group, E. histolytica trophozoites or culture medium (CM) were inoculated in hamsters by the intrahepatic route, and then euthanized at 6h, 12h, 24h, 48h, 4d or 7d post-infection. Initially the growth of the abscess was more rapid in the VAG group, but at day 7 it was faster in the IA and SHAM groups. VAG animals showed a higher quantity of type III collagen than the IA and SHAM groups. A larger number of amoebic trophozoites/mm² was observed up to day 4 in VAG hamsters (23.3±2.19) compared to IA (14.6±0.23) and SHAM (6.13±0.87) animals. This parameter decreased by day 7 in VAG (13.4±0.87) with respect to IA (24.7±1.47) and SHAM (21.7±1.48). The results show that a subdiaphragmatic vagotomy influenced the development of ALA in hamsters, suggesting a modification of the morphological structure of damaged hepatic tissue.