METHODOLOGY: The experimental set included different animal groups. Specifically, four groups with gastric mucosal lesions were receiving either a) Ulcer control group treated with absolute ethanol (5 ml/kg), b) 20 mg/kg of omeprazole as reference group, c) 25 of biochanin A, d) 50 mg/kg of biochanin A. Histopathological sectioning followed by immunohistochemistry staining were undertaken to evaluate the influence of the different treatments on gastric wall mucosal layer. The gastric secretions were collected in the form of homogenate and exposed to superoxide dismutase (SOD) and nitric oxide enzyme (NO) and the level of malondialdehyde (MDA) and protein content were measured. Ulceration and patchy haemorrhage were clearly observed by light microscopy. The morphology of the gastric wall as confirmed by immunohistochemistry and fluorescent microscopic observations, exhibited sever deformity with notable thickness, oedematous and complete loss of the mucosal coverage however the biochanin-pretreated animals, similar to the omeprazole-pretreated animals, showed less damage compared to the ulcer control group. Moreover, up-regulation of Hsp70 protein and down-regulation of Bax protein were detected in the biochanin A pre-treated groups and the gastric glandular mucosa was positively stained with Periodic Acid Schiff (PAS) staining and the Leucocytes infiltration was commonly seen. Biochanin A displayed a great increase in SOD and NO levels and decreased the release of MDA.

METHODOLOGY/PRINCIPAL FINDINGS: Rats were divided into 7 groups. Groups 1 and 2 were orally administered with Tween 20 (10% v/v). Group 3 was orally administered with 20 mg/kg omeprazole (10% Tween 20). Groups 4-7 received 10, 20, 40, and 80 mg/kg of the complex (10% Tween 20), respectively. Tween 20 (10% v/v) was given orally to group 1 and absolute ethanol was given orally to groups 2-7, respectively. Rats were sacrificed after 1 h. Group 2 exhibited severe superficial hemorrhagic mucosal lesions. Gastric wall mucus was significantly preserved by the pre-treatment complex. The results showed a significant increase in glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO), and Prostaglandin E2 (PGE(2)) activities and a decrease in malondialdehyde (MDA) level. Histology showed marked reduction of hemorrhagic mucosal lesions in groups 4-7. Immunohistochemical staining showed up-regulation of Hsp70 and down-regulation of Bax proteins. PAS staining of groups 4-7 showed intense stain uptake of gastric mucosa. The acute toxicity revealed the non-toxic nature of the compound.

METHODS: In the Nrf2 induction study, mice were divided into control, 2000 mg/kg TRF and diethyl maleate treated groups. After acute treatment, mice were sacrificed at specific time points. Liver nuclear extracts were prepared and Nrf2 nuclear translocation was detected through Western blotting. To determine the effect of increasing doses of TRF on the extent of liver nuclear Nrf2 translocation and its implication on the expression levels of several Nrf2-regulated genes, mice were divided into 5 groups (control, 200, 500 and 1000 mg/kg TRF, and butylated hydroxyanisole-treated groups). After 14 days, mice were sacrificed and liver RNA was extracted for qPCR assay.

RESULTS: 2000 mg/kg TRF administration initiated Nrf2 nuclear translocation within 30 min, reached a maximum level of around 1 h and dropped to half-maximal levels by 24 h. Incremental doses of TRF resulted in dose-dependent increases in liver Nrf2 nuclear levels, along with concomitant dosedependent increases in the expressions of Nrf2-regulated genes.

METHODS: A group of mice (n = 5) treated orally with a single dose (5000 mg/kg) of MEDL was first subjected to the acute toxicity study using the OECD 420 model. In the hepatoprotective study, six groups of rats (n = 6) were used and each received as follows: Group 1 (normal control; pretreated with 10% DMSO (extract's vehicle) followed by treatment with 10% DMSO (hepatotoxin's vehicle) (10% DMSO +10% DMSO)), Group 2 (hepatotoxic control; 10% DMSO +3 g/kg APAP (hepatotoxin)), Group 3 (positive control; 200 mg/kg silymarin +3 g/kg APAP), Group 4 (50 mg/kg MEDL +3 g/kg APAP), Group 5 (250 mg/kg MEDL +3 g/kg APAP) or Group 6 (500 mg/kg MEDL +3 g/kg APAP). The test solutions pre-treatment were made orally once daily for 7 consecutive days, and 1 h after the last test solutions administration (on Day 7th), the rats were treated with vehicle or APAP. Blood were collected from those treated rats for biochemical analyses, which were then euthanized to collect their liver for endogenous antioxidant enzymes determination and histopathological examination. The extract was also subjected to in vitro anti-inflammatory investigation and, HPLC and GCMS analyses.

METHODS: Thirty-six male rabbits of New Zealand strain were randomly assigned to six groups. Rabbits were fed either a standard pellet (group NC) or a high-cholesterol diet (groups HC, PC, WF, SK and PL). Groups WF, SK and PL were also given 1 ml/kg/day B. angulata WF, SK and PL juices, respectively.