phyllanthin and Chemical-and-Drug-Induced-Liver-Injury

Hepatic fibrosis is an important outcome of chronic liver injury and results in excess synthesis and accumulation of extracellular matrix (ECM) components. Phyllanthin (PLN) isolated from Phyllanthus amarus exhibits strong antioxidative property and protects HepG2 cells from carbon tetrachloride (CCl4)-induced experimental toxicity. The present study reports the antifibrotic potential of PLN. The in vivo inhibitory effect of PLN on CCl4-mediated lipid peroxidation and important profibrotic mediator transforming growth factor β1 and on predominant ECM components collagen and fibronectin were also studied. The results show that PLN acts by suppressing the expression of inflammatory cytokine tumor necrosis factor-α and prevents activation of nuclear factor-κB in hepatic tissue. Our study highlights the molecular mechanism responsible for the antifibrotic efficacy of PLN.

Topics: Animals; Antioxidants; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Down-Regulation; Female; Hep G2 Cells; Humans; Lignans; Lipid Peroxidation; Liver; Liver Cirrhosis; Mice; NF-kappa B; Oxidative Stress; Phyllanthus; Plant Extracts; Protective Agents; RNA, Messenger; Signal Transduction; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Phyllanthin, a sparingly water-soluble hepatoprotective lignin obtained from Phyllanthus amarus Schum. et Thonn. (Euphorbiaceae) possesses low bioavailability. Phyllanthin along with piperine (a nutraceutical bioenhancer) was formulated as a mixed micellar lipid formulation (MMLF) in the present study and investigated to resolve the low bioavailability and enhance hepatoprotective effects on oral administration. Hepatoprotective, antioxidant and bioavailability studies of MMLF, a complex phosphatidylcholine formulation of phyllanthin (CP-PC), phyllanthin + piperine (CP-P-PC) and its corresponding non-formulated phyllanthin have been carried out. Phyllanthin (30 mg kg(-1) p.o.), CP-PC (30 mg kg(-1) p.o.), CP-P-PC (30 mg kg(-1) p.o.) and the reference drug silymarin (100 mg kg(-1), p.o.) were administered daily to rats for 10 days, followed by liver damage by administering a 1 : 1 (v/v) mixture of CCl4 and olive oil (1 ml kg(-1), i.p.) for 7 days from day 4 to day 10. The degree of protection was evaluated by determining the level of marker enzymes (SGOT and SGPT), bilirubin (TB) and total proteins (TP). Further, the effects of MMLF on lipid peroxidation (LPO), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) were estimated in liver homogenates to evaluate the antioxidant activity. Finally the concentration of phyllanthin was evaluated in plasma. EC50 values for the in vitro antioxidant assay with DPPH were found to be 19.99, 15.94 and 13.5 for phyllanthin, CP-PC and CP-P-PC, respectively. CP-P-PC (30 mg kg(-1) p.o.) showed significant (p < 0.05) hepatoprotective effect by reducing the levels of serum marker enzymes (SGOT, SGPT, and TB), whereas, elevated the levels of depleted total protein (TP), lipid peroxidation and antioxidant marker enzyme activities such as, GSH, SOD, CAT, GPX, and GR. The complex MMLF normalized adverse conditions of rat livers more efficiently than the non-formulated phyllanthin. The present findings indicate that the MMLF is helpful in solving the problem of low bioavailability of phyllanthin.

Topics: Administration, Oral; Alkaloids; Animals; Antioxidants; Benzodioxoles; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Chemistry, Pharmaceutical; Cytochrome P-450 Enzyme Inhibitors; Glutathione; Glutathione Peroxidase; Lignans; Lipid Peroxidation; Lipids; Liver; Male; Piperidines; Plant Extracts; Polyunsaturated Alkamides; Protective Agents; Rats; Rats, Wistar; Silymarin

Chronic injury to liver triggers synthesis of extracellular matrix components resulting in progressive fibrosis and eventually cirrhosis. Transforming growth factor-β1 (TGF-β1) transduces its signal by binding to TGF-β type 1 receptor kinase or activin like kinase (ALK5) receptor and mediates hepatic fibrosis by increasing the transcription of downstream entities such as collagen via Smad2 and Smad3. The present study was carried out to investigate the mechanism by which phyllanthin, a hepatoprotective lignin isolated from the plant Phyllanthus amarus (P. amarus) exerts its anti-fibrotic effect. The inhibitory role of phyllanthin on ALK5 was first analyzed using molecular docking experiments. Phyllanthin was found to effectively bind to serine (Ser) 280 at the active site of ALK5 by forming hydrogen bonds. The in vivo protective effect of phyllanthin against carbon tetrachloride (CCl4)-induced hepatic fibrosis was established by studying the protein expressions of TGF-β1, ALK5 and Smad2 and 3 and by determining various biochemical and histopathological parameters. Phyllanthin was found to exert its anti-fibrotic effect by down-regulating TGF signaling pathway via ALK5 and Smad2 and 3 inhibition.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Collagen; Female; Lignans; Liver Cirrhosis; Liver Function Tests; Mice; Molecular Docking Simulation; Phyllanthus; Protective Agents; Protein Binding; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta1

The present study was an attempt to investigate the hepatoprotective and antioxidative property of Phyllanthus amarus (P. amarus) extract and phyllanthin. Phyllanthin, one of the active lignin present in this plant species was isolated from the aerial parts, by silica gel column chromatography employing gradient elution with hexane-ethyl acetate solvent mixture. It was obtained in high yields (1.23%), compared to reported procedures and the purity was ascertained by HPTLC and reversed-phase HPLC analysis. Characterization of phyllanthin was done by mp, UV-Visible spectrophotometry, elemental analysis, FT-IR, 1H NMR, 13C NMR and mass spectral analysis. Free radical scavenging activity of P. amarus extract and phyllanthin was also examined using DPPH assay. The protective effect of P. amarus extract and phyllanthin was studied on CCl4-induced toxicity in human hepatoma HepG2 cell line. The results indicated that CCl4 treatment caused a significant decrease in cell viability. In addition, the toxin treatment initiated lipid peroxidation (LPO), caused leakage of enzymes like alanine transaminase (ALT) and lactate dehydrogenase (LDH) with a significant decrease in glutathione (GSH) levels. It was observed that phyllanthin effectively alleviated the changes induced by CCl4 in a concentration-dependent manner, with much smaller strengths as compared to P. amarus extract.

Topics: Antioxidants; Carbon Tetrachloride Poisoning; Cell Line; Chemical and Drug Induced Liver Injury; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Humans; Lignans; Lipid Peroxidation; Magnetic Resonance Spectroscopy; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared

Among phyllanthin, hypophyllanthin, triacontanal and tricontanol isolated from a hexane extract of Phyllanthus niruri, phyllanthin and hypophyllanthin protected against carbon tetrachloride- and galactosamine-induced cytotoxicity in primary cultured rat hepatocytes, while triacontanal was protective only against galactosamine-induced toxicity.

Topics: Animals; Carbon Tetrachloride Poisoning; Cell Survival; Cells, Cultured; Chemical and Drug Induced Liver Injury; Galactosamine; Lignans; Plant Extracts; Plants, Medicinal; Rats