الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
Abstract
Advanced fibrosis is generally considered an irreversible disease, even after removing the causative agent. However, fibrosis recovery is possible by remodeling of excess ECM proteins. Due to the side effects of the existing therapeutic drugs, there is an increasing interest in using herbal remedies in medicinal therapy in human and animal models. Therefore, the present study aimed to evaluate the antifibrotic activity of Prosopis juliflora leaves extract on TAA-induced alterations in fibrogenic, fibrolytic pathways, and cell death mediators.
To fulfill this aim, the physicochemical constituents of leaves extract were evaluated by RF-HPLC and LC-ESI-MS, followed by choosing the doses of treatment via determining LD50 and free radical scavenging activity for this extract. Eighty male Wistar rats were divided equally into 8 groups; normal control, PJLE1 (2 mg / Kg b.w./thrice weekly for 6 consecutive weeks), PJLE2 (4 mg / Kg b.w./ thrice weekly for 6 consecutive weeks), PJLE3 (8 mg / Kg b.w./ thrice weekly for 6 consecutive weeks); TAA-induced liver fibrosis, TAA+PJLE1, TAA+PJLE2, TAA+PJLE3.
The present study revealed the presence of high constituents of polyphenolic flavones in PJLE amounting to 19.57 mE quercetin/ mg and 64.21 mE gallic acid/mg. The LC-ESI-MS chromatogram identified the phytochemical constituents in PJLE as isorhamnetin 3-Orutinoside, isochatoside, isochatoside, rutin, chlorogenic, mesquitol, quercetin 3-O-hexoside, Quercetin 3-methyl ester, luteolin, apigenin, and Ferulic acid as polyphenolic compounds. Furthermore, it revealed the presence of several alkaloids; juliprosopine, prosopine, Julifloridine, and scoulerine. Other compounds also were tentatively identified as prosopidione and spermidine.
PJLE possessed an in vitro scavenging activity of DPPH free radical (IC50 of 123.5 μg/mL). PJLE exerted a strong cytotoxic effect against HepG2 cancer cell line with an IC50 value of 11.1 μg/ml. LD50 value of 44.4 mg/ Kg b.w. Based on the high antioxidant and cytotoxic activities of PJLE as well as the results of LD50, three doses from PJLE extract (2, 4, and 8 mg/ Kg b.w.) were chosen for evaluating its probable therapeutic effect against hepatic fibrosis induced in rats by TAA.
The histological examination of liver sections by H&E stain revealed that i.p. administration of PJLE to normal rats at the three different doses shows normal hepatocytes radiating from the normal central vein without any signs of inflammation,
apoptosis, necrosis, fibrosis. Intoxication of rats with TAA showed severe histological alterations in the liver tissues in the form of multilobular fibrosis (stage F3) with severe collagen deposition in association with inflammatory cells infiltration surrounding the degenerated hepatocytes (grade 3). In addition, TAA caused centrilobular coagulative necrosis (grade 3) in most of the hepatocytes. On the other hand, treatment of TAA-intoxicated rats with PJLE1 and PJLE3 improved significantly TAA histological alterations as evident by the presence of congestion in the blood vessels and necrosis in some hepatocytes (grade 2) with moderate fibrous septa (stage F2). Treatment of fibrotic rats with the intermediate dose of PJLE (4 mg/ Kg b.w.) improved TAA-induced histological disturbances,
since fine fibrous tissue (stage F1) was found to surround numerous normal hepatocytes with the presence of some necrotic hepatocytes (grade 1) in association with the presence of fine collagen deposition.
The safety of using PJLE at the three implicated doses was evoked in the present study by normal weights of rats as well as normal relative weights of liver, spleen, kidneys, and heart. In addition, revealed normal serum ALT activities and normal serum albumin concentrations as well as hepatic hydroxyproline contents were recorded in normal rats treated with in PJLE1, 2, and 3 groups. Furthermore, no significant alterations in the hepatic contents of TNF-α and IL-6 were reported in PJLE-administered rats. In the last, the hepatic relative expression of Bcl-2, Col1a1, Mmp-2, and Mmp-9 genes was not changed.
Severe hepatotoxic alterations were observed due to TAA intoxication including a significant reduction in the rat weight in association with significant elevations in the relative weights of liver, spleen, kidneys, and heart. TAA caused a significant elevation in serum ALT activity and a significant reduction in serum albumin concentration. Furthermore, TAA altered the balance between ECM accumulation and degradation in the form of a significant elevation in hepatic hydroxyproline content and a significant upregulation in the relative expression of hepatic Col1a1 gene. Also, the relative expression of hepatic Mmp-2 and Mmp-9 was down-regulated significantly. Moreover, TAA caused hepatocyte necrosis in the form of significant elevations in the hepatic contents of TNF-α and IL-6, compared to the normal levels, as well as a significant down-regulation in the relative expression of Bcl-2 gene.
Post-treatment of fibrotic rats with PJLE at the three implicated doses (PJLE1, PJLE2, and PJLE3) caused regain in the weight of rats to the normal level, while reduced significantly the relative liver weight, compared to the normal control group, but still higher than the normal relative weight. The studied therapeutic modalities ameliorated the relative weights of spleen, kidneys, and heart. Serum ALT activity returned to the normal level in TAA+PJLE1, TAA+PJLE2, and TAA+PJLE3 groups, while serum albumin concentration was raised significantly, compared to TAA group, but still less than the normal level.
The therapeutic modalities improved TAA-induced alterations in the balance between ECM accumulation and degradation in the form of significant reductions in the hepatic content of hydroxyproline, compared to TAA group, but were still significantly higher than the normal level. Treatment of fibrotic rats with PJLE2 returned the relative expression of Col1a1, Mmp-2, and Mmp-9 genes to the normal expression levels. While treatment with PJLE1 down-regulated significantly the relative expression of hepatic Col1a1, compared to TAA group, but was still higher than the normal expression level. In addition, PJLE1 posttherapy upregulated significantly the relative expression of hepatic Mmp-2, compared to TAA group, but was still less than the normal expression level. The relative expression level of hepatic Mmp-9 was not changed in TAA+PJLE1, compared to TAA group. Post-treatment with PJLE3 normalized the relative expression of hepatic Col1a1 with significant down-regulations in the expression levels of Mmp-2 and Mmp-9, compared to both TAA and normal control groups.
The therapeutic modalities showed more pronounced elevations in the hepatic content of TNF-α. Post-therapy with PJLE2 and PJLE3 produced more pronounced elevations in the hepatic content of IL-6, compared to TAA group. The relative expression of hepatic Bcl-2 gene was returned to the normal expression level in TAA+PJLE2 group, while treatment with PJLE1 upregulated the relative Bcl-2 expression, compared to TAA group, but was still less than the normal gene expression. Finally, PJLE3 posttreatment did not show any improvement in the relative Bcl-2 gene expression, compared to the normal expression level.
In conclusion, the present research reported that PJLE at a dose of 4 mg/ Kg b.w. reduced hepatic fibrosis induced by TAA not only by improving collagen deposition and turnover but also through decreasing hepatocyte necrosis. It is recommended to increase the therapeutic duration of more than 6 weeks for complete fibrosis recovery.