Ameliorative effect of methanol extract of Rumex vesicarius on CCl4-induced liver damage in Wistar albino rats

Abstract

Context: Rumex vesicarius L. (Polygonaceae), an edible plant, is reported to have many bioactive phytochemicals, especially flavonoids and anthraquinones with antioxidant and detoxifying properties.

Objective: This study evaluated the methanolic extract of R. vasicarius (MERV) for hepatoprotective activity in rats against CCl₄-induced liver damage.

Materials and methods: The whole plant extract was prepared and investigated for its hepatoprotective activity. Rats were pretreated with MERV (100 and 200?mg/kg, p.o.) for 7?d prior to the induction of liver damage by CCl₄. Animals were then sacrificed 24?h after CCl₄ administration for the biochemical (AST, ALT, and ALP activity in serum; lipid peroxidation (LPO) and glutathione (GSH) levels in liver tissue) and histological analyses.

Results: CCl₄-induced hepatotoxicity was confirmed by an increase (p?<?0.05) in serum AST (4.55-fold), ALT (3.51-fold), and ALP (1.82-fold) activities. CCl₄-induced hepatotoxicity was also manifested by an increase (p?<?0.05) in LPO (3.88-fold) and depletion of reduced glutathione (3.14-fold) activity in liver tissue. The multiple dose MERV administration at 200?mg/kg showed promising hepatoprotective activity as evident from significant decrease levels of serum AST (230.01?±?13.21), serum ALT (82.15?±?5.01), serum ALP (504.75?±?19.72), hepatic LPO (3.38?±?0.33), and increased levels of hepatic glutathione (0.34?±?0.04) towards near normal. Further, biochemical results were confirmed by histopathological changes as compared with CCl₄-intoxicated rats.

Discussion and conclusion: The results obtained from this study indicate hepatoprotective activity of Rumex plant against CCl₄-induced liver toxicity; hence, it can be used as a hepatoprotective agent.     

Antifatigue properties of tanshinone IIA in mice subjected to the forced swimming test

Context: Tanshinone IIA (Tan IIA) is a constituent of Danshen Salvia miltiorrhiza Bunge (Lamiaceae); however, its antifatigue activity remains unclear.

Objective: To study the antifatigue properties of Tan IIA and its underlying mechanisms.

Materials and methods: In program I, three mouse groups were separately subjected to three gavages with 0, 1 and 6?mg/kg Tan IIA and forced swimming test (FST) weekly for 8 weeks; in program II, one gavage with 0, 2 and 10?mg/kg Tan IIA was administered plus FST weekly for 4 weeks. Serum glucose, lactate, superoxide dismutase (SOD), malondialdehyde (MDA) and blood urea nitrogen (BUN) were determined after final FST.

Results: Tan IIA significantly prolonged swimming durations in program I but not in program II. Swimming times were 3208?±?1054 and 2443?±?1054?s for the 1 and 6?mg/kg treatments and 856?±?292?s for the vehicle control. The two doses significantly reduced serum glucose levels (40.3?±?8.5 and 60.0 1?±?11.8?mg/kg) and lactate levels (61.3?±?27.5 and 68.8?±?8.5?mg/kg) in treated mice compared with those in control mice (137.5?±?38.6?mg/kg and 122.7?±?18.2?mg/kg, respectively). However, no significant differences were observed regarding SOD, MDA or BUN levels.

Discussion and conclusions: Tan IIA has antifatigue activity and is associated with reductions in serum glucose and lactate levels. Further studies should assess muscle hypertrophy and efficient aerobic glycolysis caused by Tan IIA. Tan IIA has potential as a pharmacological agent for fatigue resistance.     

Recombinant bovine pancreatic trypsin inhibitor protects the liver from carbon tetrachloride-induced chronic injury in rats

Abstract

Context: Bovine pancreatic trypsin inhibitor (BPTI) has been reported to relieve liver ischemia-reperfusion-induced injury in rats.

Objective: This study was designed to determine whether the recombinant BPTI (rBPTI) can prevent the chronic liver injury induced by CCl₄ in rats.

Materials and methods: Fifty male Wistar rats were divided into five groups. Rats were treated with 40% CCl₄ at a dose of 2?ml/kg body weight twice a week subcutaneously for 12 weeks. In the 8th week, they were administered intraperitoneally with rBPTI (80 MU/kg), BPTI (80 MU/kg) or hepatocyte growth-promoting factor (pHGF; 100?mg/kg) daily for the next 4 weeks.

Results: rBPTI significantly prevented the disruption of liver function of alanine aminotransferase (ALT; 172.7?±?18.16 versus 141.2?±?15.28, p?=?0.003), aspartate aminotransferase (AST; 225.10?±?36.54 versus 170.06?±?27.14, p?=?0.007) and hydroxyproline (Hyp; 1.14?±?0.27 versus 0.62?±?0.17, p?=?0.001). rBPTI significantly decreased the level of thiobarbituric acid reactive substances (TBARS; 1.15?±?0.16 versus 0.87?±?0.15, p?=?0.003) and increased the activities of superoxide dismutase (SOD; 6.07?±?0.95 versus 7.75?±?1.12, p?=?0.007). rBPTI reduced the production of cytokines of IL-1β and TGF-β. The hepatocyte necrosis, fibrosis, fatty degeneration and inflammatory cell infiltration were ameliorated by rBPTI administration.

Conclusion: This study demonstrated that rBPTI exerted a hepatoprotective effect on chronic liver fibrosis induced by CCl₄, which suggests that rBPTI may have the potential application for chronic liver injury induced by drugs metabolism and toxic substances.     

Crataegus songarica methanolic extract accelerates enzymatic status in kidney and heart tissue damage in albino rats and its in vitro cytotoxic activity

Context: Crataegus songarica K. Koch (Rosaceae) has been used in folk medicine to treat various diseases.

Objective: This study evaluates the effect of C. songarica methanol extract on the kidney and heart tissue damage of albino rats, and to determine cytotoxic activity of various extracts of songarica on various human cancer cell lines.

Materials and methods: Rats were divided into six groups, Group I received water only; Group II received CCl₄ (1?mL/kg b wt) intraperitoneal; C. songarica extract (at doses of 100, 200 and 300?mg/kg b wt) orally for 15 days. Cytotoxic activity was determined by SRB method using MCF-7, HeLa, HepG2, SF-295, SW480 and IMR-32 cell lines.

Results: Compared with CCl₄ group, administration of C. songarica extract at the dose of 300?mg/kg b wt, significantly decreases serum creatinine (59.74%), urea (40.23%) and cholesterol (54?mg/dL), MDA (0.007?nmol/mg protein) in kidney and (0.025?nmol/mg protein) in heart tissue, along with evaluation of GSH (209.79?±?54.6), GR (111.45?±?2.84), GPx (94.01?±?14.80), GST (201.71) in kidney tissue and GSH (51.47?±?1.47), GR (45.42?±?6.69), GPx (77.19?±?10.94), GST (49.89) in heart tissue. In addition, methanol, ethanol and ethyl acetate extracts exhibited potent anticancer activity on six cancer cell lines with IC₅₀ values ranging from 28.57 to 85.106?µg/mL.

Discussion and conclusion: Crataegus songarica methanol extract has a potential antioxidant effect as it protects the kidney and heart tissue against CCl₄-induced toxicity, prevents DNA damage and showed strong anticancer activity.     

Protective effect and antioxidant role of sweetgum (Liquidambar orientalis) oil against carbon tetrachloride-induced hepatotoxicity and oxidative stress in rats

Context: Sweetgum oil (SO) obtained from the Liquidambar orientalis Mill (Hamamelidaceae) tree has been used in Turkish folk medicine for centuries as an antiulcerigenic. Some studies have reported the antibacterial and antioxidant activities of SO; however, its effect on hepatic and oxidative stress complications is still unexplored.

Objective: This study investigates the hepatoprotective effect and the antioxidant role of SO against carbon tetrachloride (CCl₄) toxicity.

Materials and methods: The experiment included control, CCl₄, SO, and CCl₄?+?SO treatment groups. Control and SO group rats were fed a diet without CCl₄. CCl₄ and CCl₄?+?SO treatment groups received 0.5?mL/kg CCl₄ diluted in olive oil (1:1 dilution) intraperitonally injection twice per week. The CCl₄?+?SO group also received 1000?mg/kg SO-supplemented feed for 50?d. Blood and tissue samples were used for the determination of hepatic damage serum biomarkers (HDSBs) levels, antioxidant defense system constituents (ADSCs), and malondialdehyde (MDA) contents. In addition, the liver was evaluated for histopathological changes.

Results: According to the results, the HDSBs levels of the CCl₄ group were significantly (p?<?0.05) increased compared with the control, whereas the HDSB levels of the CCl₄?+?SO group resulted in marked decreases (p?<?0.05) compared with the CCl₄ group. In addition, the results showed that SO-supplemented diet restored the CCl₄-induced MDA and ADS towards to control. Hepatoprotection of SO is further substantiated by the almost normal histologic findings in the CCl₄?+?SO group against degenerative changes in the CCl₄ group.

Discussion and conclusion: It was concluded that SO has a hepatoprotective effect and antioxidant capacity against CCl₄ toxicity.     

Effect of Purified Saponin Mixture from Astragalus corniculatus on Toxicity Models in Isolated Rat Hepatocytes

A purified saponin mixture (PSM) isolated from Astragalus corniculatus Bieb. (Fabaceae) was investigated for its protective effect in two models of toxicity, carbon tetrachloride (CCl₄) and tert-butyl hydroperoxide (t-BuOOH), using isolated rat hepatocytes. CCl₄ undergoes dehalogenation in the liver endoplasmic reticulum. This process leads to trichlormethyl radical (CCl₃) formation, initiation of lipid peroxidation, and measurable toxic effects on the hepatocytes. Oxidative damage is widely recognized as being involved in the development of many pathological conditions. In our experiment, t-BuOOH was used as a model of oxidative stress. The hepatocytes were incubated with the PSM alone (0.01–100 μ M) and along with CCl₄ (86 μ M) and t-BuOOH (75 μ M). As a sign of cytotoxicity, cell viability was used. CCl₄ and t-BuOOH significantly decreased hepatocyte viability. Our data indicate that PSM showed lower toxic effects compared to CCl₄ and t-BuOOH and in combination exerted statistically significant protection of cell viability against the toxic agents.     

Hydroxysafflor yellow A suppresses liver fibrosis induced by carbon tetrachloride with high-fat diet by regulating PPAR-γ/p38 MAPK signaling

Context: One approach to protect against liver fibrosis is the use of herb-derived natural compounds, such as hydroxysafflor yellow A (HSYA). The antifibrosis effect of HYSA against liver fibrosis has been investigated; however, its mechanisms have not yet been entirely revealed.

Objectives: To study the protective effects of HSYA on liver fibrosis induced by carbon tetrachloride (CCl₄) and a high-fat diet (HFD), and to determine the mechanism of action of HSYA.

Materials and methods: CCl₄ and HFD were used to mimic liver fibrosis in rats, and serum biochemical indicators were determined. The antifibrosis effects of HSYA were evaluated and its mechanisms were investigated by histopathological analysis, immunohistochemical staining, enzyme-linked immunosorbent assays, real-time-PCR, and western blotting.

Results: HSYA reduced CCl₄- and HFD-mediated liver fibrosis and ameliorated serum biochemical indicator, downregulated the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) (0.31?±?0.03 protein, 0.59?±?0.02 mRNA) and transformin growth factor-β1 (TGF-β1) (0.81?±?0.02 protein, 0.58?±?0.04 mRNA), and upregulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) (1.57?±?0.13 protein, 2.48?±?0.19 mRNA) and matrix metallopeptidases-2 (MMP-2) (2.31?±?0.16 protein, 2.79?±?0.22 mRNA) (p?Discussion and conclusion: These data demonstrate a novel role for HSYA in inhibiting CCl₄- and HFD-mediated liver fibrosis, and reveal that PPAR-γ and p38 MAPK signaling play pivotal roles in the prevention of liver fibrosis induced by CCl₄ and HFD.     

Hepatoprotective activities of two Ethiopian medicinal plants

The present study evaluated the in vivo hepatoprotective activity of two medicinal plants, namely, Justicia schimperiana (Hochst. ex Nees) (Acanthaceae) and Verbascum sinaiticum Benth. (Scrophulariaceae) used in Ethiopian traditional medical practices for the treatment of liver diseases. The levels of hepatic marker enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were used to assess their hepatoprotective activity against carbon tetrachloride (CCl₄)-induced hepatotoxicity in Swiss albino mice. The results revealed that pretreating mice with the hydro-alcoholic extracts of both plants significantly suppressed the plasma AST ((P?<?0.01) J. schimperiana; (P?<?0.05) V. Sinaiticum) and ALT ((P?<?0.05) J. schimperiana) activity when compared with the CCl₄ intoxicated control. Among the Soxhlet extracts of each of the plants, the methanol extract of J. schimperiana showed significant hepatoprotective activity. Further fractionation of this extract using solid phase extraction and testing them for bioactivity indicated that the fractions did not significantly reverse liver toxicity caused by CCl₄. However, the percentage hepatoprotection of the distilled water fraction was comparable with that of the standard drug silymarin at the same dose (50?mg/kg) as evidenced by biochemical parameters. Histopathological studies also supported these results. In vitro DPPH assay conducted on the water fraction of J. schimperiana and the Soxhlet methanol fraction of V. sinaiticum showed that they possess moderate radical scavenging activity (IC₅₀?=?51.2 and 41.7 μg/mL, respectively) which led to the conclusion that the hepatoprotective activity of the plants could be in part through their antioxidant action.     

Hepatoprotective effect of Stachys pilifera ethanol extract in carbon tetrachloride-induce hepatotoxicity in rats

Context: Stachys pilifera Benth (Lamiaceae) has long been used to treat infectious diseases, respiratory and rheumatoid disorders in Iranian folk medicine. Antitumor and antioxidant activity of the plant have been reported.

Objective: The study was designed to assess the hepatoprotective activity of ethanol extract of Stachys pilifera in carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats.

Materials and methods: The rats were randomly divided into six equal groups (n?=?7). Group I was treated with normal saline; Group II received CCl₄ (1?mL/kg. i.p., twice a week) for 60 consecutive days; Groups III, IV and V were given CCl₄ plus Stachys pilifera (100, 200 and 400?mg/kg/d,p.o.); Group VI received the extract (400?mg/kg/d, p.o.). Histopathological analysis and measurement of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), malondialdehyde (MDA), total protein (TP) and albumin (ALB) were performed.

Results: CCl₄ caused a significant increase in the serum levels of AST, ALT, ALP and MDA as well as decreased ALB, and TP serum levels (p?4-elevated levels of ALT, AST, ALP and MDA (p?4 group (p4.

Discussion: The results revealed that the Stachys pilifera extract could provide considerable protection against CCl₄ hepatotoxicity in rats that may be related to its antioxidant properties.     

Hepatoprotective and antioxidant activity of Melaleuca styphelioides on carbon tetrachloride-induced hepatotoxicity in mice

Context: Liver disease is a serious problem. Polyphenolic compounds have marked antioxidant effect and can prevent the liver damage caused by free radicals. In vitro studies have revealed the strong antioxidant activity of an ellagitannin-rich plant, namely, Melaleuca styphelioides Sm. (Myrtaceae).

Objective: In view of the limited therapeutic options available for the treatment of liver diseases, the hepatoprotective potential of the methanol extract of M. styphelioides leaves (MSE) was investigated against CCl₄-induced liver injury in mice.

Materials and methods: MSE was administered (500 and 1000?mg/kg/d p.o.) along with CCl₄ for 6 weeks. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were determined in the serum. Glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione transferase (GST), and malondialdehyde (MDA) were estimated in the liver homogenate. The bioactive components of MSE were identified by NMR, UV and HRESI-MS/MS data.

Results: MSE treatment (500 and 1000?mg/kg/d) markedly inhibited the CCl₄-induced increase in the levels of AST (31 and 38%), ALT (29 and 32%), ALP (13 and 19%), and MDA (22 and 37%) at the tested doses, respectively. MSE treatment markedly increased the levels of GSH (29 and 57%) and antioxidant enzymes compared with the CCl₄-treated group. MSE was more effective than silymarin in restoring the liver architecture and reducing the fatty changes, central vein congestion, Kupffer cell hyperplasia, inflammatory infiltration, and necrosis induced by CCl₄. The LD₅₀ of MSE was more than 5000?mg/kg.

Conclusion: MSE confers potent antioxidant and hepatoprotective effects against CCl₄-induced toxicity.     

Improvement of oral bioavailability of glycyrrhizin by sodium deoxycholate/phospholipid-mixed nanomicelles

Glycyrrhizin (GL), extracted from the Glycyrrhiza glabra L., is active triterpenoid saponin components. However, due to its impermeability across the gastrointestinal mucosa, oral bioavailability of the drug was relatively low. To improve its oral bioavailability, formulation of GL as sodium deoxycholate/phospholipid-mixed nanomicelles (SDC/PL-MMs) has been performed in this study. GL-SDC/PL-MMs were produced by a film dispersion method and then investigated using photon correlation spectroscopy (PCS), zeta potential measurement, as well as its physical stability after storage for 10, 20, 30, 60, 90 and 120 days. To verify the theoretical hypothesis, pharmacokinetics and pharmacodynamic studies based on carbon tetrachloride (CCl₄)-induced acute liver injury was investigated. Results showed that a narrow size distributed nanomicelles with a mean particle size of 82.99?±?7.5?nm and a zeta potential of ?32.23?±?1.05 mV was obtained. In the pharmacokinetics, GL-SDC/PL-MMs show a significant superiority in AUC_0–t, C_max and other pharmacokinetic parameters compared with the control group. In the pharmacodynamic studies, compared with the bifendate control group, GL-SDC/PL-MMs showed an equivalent effect in reducing alanine aminotransferase (ALT), aspartate aminotransferase (AST) and improving the pathological changes of liver tissue. These results revealed that SDC/PL-MMs could enhance GL absorption in gastrointestinal tract and pharmacodynamic effect in the treatment of acute liver injury caused by CCl₄, and SDC/PL-MMs might be a good choice for oral delivery of poor bioavailability drug like GL.     

Antioxidant and hepatoprotective effects of Solanum xanthocarpum leaf extracts against CCl4-induced liver injury in rats

Context: Solanum xanthocarpum Schard. and Wendl. (Solanaceae) has been used in traditional Indian medicines for its antioxidant, anti-inflammatory, and antiasthmatic properties.

Objective: The present study demonstrates the antioxidant and hepatoprotective effects of S. xanthocarpum. On the basis of in vitro antioxidant properties, the active fraction from column chromatography of the methanol extract of S. xanthocarpum leaves (SXAF) was chosen as the potent fraction and used for hepatoprotective studies in rats.

Materials and methods: The antioxidant activity was evaluated by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and reducing power assays. Rats were pre-treated with 100 and 200?mg/kg b.w. of SXAF for 14?d with a single dose of CCl₄ in the last day. Hepatoprotective properties were determined by serum biochemical enzymes, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), antioxidant enzymes (SOD, CAT, GSH, and GST), and histopathology studies.

Results: SXAF exhibited significant antioxidant activity in scavenging free radicals with IC₅₀ values of 11.72?µg (DPPH) and 17.99?µg (ABTS). Rats pre-treated with SXAF demonstrated significantly reduced levels of serum LDH (1.7-fold), ALP (1.6-fold), and AST (1.8-fold). Similarly, multiple dose SXAF administration at 200?mg/kg b.w. demonstrated significantly enhanced levels of SOD (1.78?±?0.13), CAT (34.63?±?1.98), GST (231.64?±?14.28), and GSH (8.23?±?0.48) in liver homogenates. Histopathological examination showed lowered liver damage in SXAF-treated groups.

Discussion and conclusion: These results demonstrate that SXAF possesses potent antioxidant properties as well as hepatoprotective effects against CCl₄-induced hepatotoxicity.     

Caffeic acid methyl and ethyl esters exert potential antidiabetic effects on glucose and lipid metabolism in cultured murine insulin-sensitive cells through mechanisms implicating activation of AMPK

Context: Caffeic acid methyl (CAME) and ethyl (CAEE) esters stimulate glucose uptake and AMP-activated protein kinase (AMPK) in C2C12 myocytes (ATCC^® CRL-1772^TM).

Objective: Effects of CAME and CAEE were now assessed on myocyte glucose transporter GLUT4 activity and expression, on hepatic gluconeogenesis and on adipogenesis as well as major underlying signaling pathways.

Materials and methods: GLUT4 protein translocation was studied in L6 GLUT4myc cells, glucose-6-phospatase (G6Pase) in H4IIE hepatocytes and adipogenesis in 3T3-L1 adipocytes. Key modulators were measured using western immunoblot. Cells were treated for 18?h with either CAME or CAEE at various concentrations (12.5–100?μM).

Results: Myocyte glucose uptake rose from 10.1?±?0.5 to 18.7?±?0.8 and 21.9?±?1.0?pmol/min/mg protein in DMSO-, CAME- and CAEE-stimulated cells, respectively, similar to insulin (17.7?±?1.2?pmol/min/mg protein), while GLUT4myc translocation increased significantly by 1.70?±?0.18, by 1.73?±?0.18- and by 1.95?±?0.30-fold (relative to DMSO), following insulin, CAME and CAEE stimulation, respectively. CAME and CAEE suppressed hepatocyte G6Pase by 62.0?±?6.9% and 62.7?±?6.0% with IC₅₀ of 45.93 and 22.64?μM, respectively, comparable to insulin (70.7?±?2.3% inhibition). Finally, CAME and CAEE almost abrogated adipogenesis (83.3?±?7.2% and 97.3?±?3.0% at 100?μM; IC₅₀ of 13.8 and 12.9?μM, respectively). The compounds inhibited adipogenic factors C/EBP-β and PPAR-γ and stimulated AMPK activity in the three cell-lines.

Discussion and conclusions: CAME and CAEE exerted antidiabetic activities in insulin-responsive cells through insulin-independent mechanisms involving AMPK and adipogenic factors.     

In vitro inhibition of UGT1A3, UGT1A4 by ursolic acid and oleanolic acid and drug–drug interaction risk prediction

1.?Ursolic acid (UA) and oleanolic acid (OA) may have important activity relevant to health and disease prevention. Thus, we studied the activity of UA and OA on UDP-glucuronosyltransferases (UGTs) and used trifluoperazine as a probe substrate to test UGT1A4 activity. Recombinant UGT-catalyzed 4-methylumbelliferone (4-MU) glucuronidation was used as a probe reaction for other UGT isoforms.

2.?UA and OA inhibited UGT1A3 and UGT1A4 activity but did not inhibit other tested UGT isoforms.

3.?UA-mediated inhibition of UGT1A3 catalyzed 4-MU-β-d-glucuronidation was via competitive inhibition (IC₅₀ 0.391?±?0.013?μM; K_i 0.185?±?0.015?μM). UA also competitively inhibited UGT1A4-mediated trifluoperazine-N-glucuronidation (IC₅₀ 2.651?±?0.201?μM; K_i 1.334?±?0.146?μM).

4.?OA offered mixed inhibition of UGT1A3-mediated 4-MU-β-d-glucuronidation (IC₅₀ 0.336?±?0.013?μM; K_i 0.176?±?0.007?μM) and competitively inhibited UGT1A4-mediated trifluoperazine-N-glucuronidation (IC₅₀ 5.468?±?0.697?μM; K_i 6.298?±?0.891?μM).

5.?Co-administering OA or UA with drugs or products that are substrates of UGT1A3 or UGT1A4 may produce drug-mediated side effects.     

Protection of carbon tetrachloride-induced hepatotoxicity by zinc: role of metallothionein

The dose-dependent release of alanine aminotransferase and aspartate aminotransferase into plasma 24 hr following various doses of CCl₄ (ip) was markedly lower in rats pretreated for 3 days with zinc chloride (150 μmol/kg/day) than in control rats. Although this dose of zinc produced a 34% decrease in hepatic concentration of cytochrome P-450 and a 50% decrease in binding of ¹⁴C derived from ¹⁴CCl₄ to hepatic microsomal protein and lipid in vitro, prior treatment with a single injection of zinc (250 μmol/kg) resulted in protection against CCl₄ toxicity without changing P-450 concentrations or ¹⁴C binding. Administration of a single dose (250 μmol/kg) of zinc or pretreatment on 3 consecutive days with 150 μmol/kg zinc produced a 700 or 1900% increase in hepatic concentration of metallothionein (MT), respectively. Following administration of ¹⁴CCl₄ to zinc-treated rats, radioactivity was present in the same elution volume as MT following gel filtration (G-75) of liver cytosol. This suggests that MT may protect against CCl₄-induced liver damage by sequestering reactive metabolites of CCl₄.     

Assessment of the antioxidant potential of Cnidoscolous chayamansa

The current study is an effort to investigate the chemical constituents and antioxidant potential of Cnidoscolous chayamansa McVaugh (Euphorbiacea) root on carbon tetrachloride-induced liver damage. Albino rats were grouped into four: A - D. Groups A and B received 1?mL/kg BW of olive oil and 1?mL/kg body weight (BW) of carbon tetrachloride (CCl₄), respectively, for 8 days while those in C and D received 1?mL/ kg BW each of CCl₄ and 500 and 1000?mg/kg BW of aqueous extract of C. chayamansa root, respectively, for the same period. Chemical analysis of the plant root revealed the presence of tannins, phenolics, flavonoids, saponins, Fe, Zn, Mg, Ca, vitamins A and C. Administration of CCl₄ resulted in significant increase (P?<0.05) in liver malondialdehyde concentration while the activities of liver alkaline phosphatase, superoxide dismutase, glutathione peroxidase and catalase were significantly reduced (P?<0.05). Simultaneous administration of CCl₄ and the plant extract at 500 and 1000?mg/kg BW produced values of these biochemical parameters that compared favourably with the control (P?>0.05) in addition to increasing superoxide dismutase activity in the liver (P?<0.05). We conclude that aqueous extract of C. chayamansa root possessed antioxidant activity and protected the hepatocyte against CCl₄-induced damage. The antioxidant activity of the plant may be due to its chemical constituents.     

Effect of T-2 toxin-injected shrimp muscle extracts on mouse macrophage cells (RAW264.7)

Following intramuscular injections of 0.1?mL, 3?mg?kg^?1?BW^?1(1/10 LD₅₀) T-2 toxin (T-2), the tissue concentration of T-2 in shrimp was quantitatively detected using LC-MS/MS. The biological half-time (t_1/2) of T-2 in blood was 40.47?±?0.24?min. The highest number of intramuscular T-2 shrimp could tolerate when given at blood t_1/2 intervals was 4. The shrimps which were injected 5 T-2 died. The T-2 toxin highest accumulation was 0.471?±?0.012?ng?g^?1?BW^?1. The effect of toxic shrimp muscle subjected to different processing conditions (high pressure, trifluoroacetic acid, acid and alkali digestions, artificial digestive juice [to simulate exposure to gastric and intestinal juices]) on mouse macrophage cells (RAW267.4) were evaluated by the MTT assay. The inhibition ratio of 2% muscle extract on RAW267.4 was 85.70?±?2.63%. The immunocytotoxicity of muscle extracts to RAW264.7 was highest in muscle extracts subjected to physical and chemical digestion (high pressure >?NaOH?> trifluoroacetic acid >?0.02 M HCl?>?0.2 M HCl?>?controls), and also artificial digestion (artificial intestinal juice >?artificial gastric juice >?N type intestinal juice >?N type gastric liquid >?controls). Results showed that high-pressure and artificial intestinal juice were most effective in the release of modified T-2 to free T-2 thus enhancing toxicity. These results can be interpreted as measurement of T-2 in food being of little value because of enhanced toxicity of T-2-contaminated food as they pass through the gastrointestinal tract.     

Hepatoprotective effects of Portulaca oleracea extract against CCl4-induced damage in rats

Abstract

Context: Purslane (Portulaca oleracea L., Portulacaceae) has been traditionally used in folk medicine to afford protection against liver injury, although its actual efficacy remains uncertain.

Objective: To evaluate purslane as a hepatoprotective agent, we investigated the protective effect of its ethanol extract against carbon tetrachloride (CCl₄)-induced hepatic toxicity in rats.

Materials and methods: A total of 108 male Wistar rats were randomly divided into 12 groups. The first group was maintained as normal control, whereas CCl₄ (0.5?ml/kg bw, 50% CCl₄ in olive oil, i.p.), purslane extract (0.005, 0.01, 0.05, 0.1, and 0.15?g/kg bw, intragastrically), and purslane extract (five doses as above) along with CCl₄ were administered to the Groups II, III–VII, and VIII–XII, respectively. The rats were sacrificed on the 30th day, and blood was withdrawn by cardiac puncture. Liver damage was assessed by measuring hepatic marker enzymes (ALT, AST, ALP, GGT, and SOD) and histopathological observation.

Results: Treatment with CCl₄ resulted in increased serum activities of marker enzymes with a concomitant decrease in SOD. Histological alterations were also observed in the liver tissue upon CCl₄ treatment. Administration of purslane extract (0.01, 0.05, 0.1, and 0.15?g/kg b.w.) significantly showed a marked tendency towards normalization of all measured biochemical parameters in CCl₄-treated rats. Histopathological changes also paralleled the detected alteration in markers of liver function.

Discussion and conclusion: These results demonstrate that purslane exerts protective effects against CCl₄-induced damage in rat liver and supports a potential therapeutic use of purslane as an alternative for patients with liver diseases.     

Hepatoprotective effects of Flagellaria indica are mediated through the suppression of pro-inflammatory cytokines and oxidative stress markers in rats

Context The antioxidative properties of plants or plant derivative products are well known for their free radical scavenging effects. Flagellaria indica L. (Flagellariaceae) (FI) is a tropical medicinal plant used by the natives of Sabah as medication for semi-paralysis.

Objective This study evaluates the hepatoprotective mechanism of FI against carbon tetrachloride (CCl₄)-mediated liver damage.

Materials and methods Aqueous extract of FI leaves was orally administered to adult Sprague–Dawley rats once daily for 14 consecutive days at 300, 400, and 500?mg/kg b.w. prior to CCl₄ treatment (1.0?mL/kg b.w.) on the 13th and 14th days.

Results Total phenolic content in the aqueous extract of FI leaves was 65.88?±?1.84?mg gallic acid equivalent/g. IC₅₀ value for free radical scavenging activity of FI aqueous extract was reached at the concentration of 400?μg/mL. Biochemical studies show that the aqueous extract of FI was able to prevent the increase in levels of serum transaminases, alanine aminotransferase, and aspartate aminotransferase (38–74% recovery), and malondialdehyde formation (25–87% recovery) in a dose-dependent manner. Immunohistochemical results evidenced the suppression of oxidative stress markers (4-hydroxynonenal and 8-hydroxydeoxyguanosine) and pro-inflammatory markers (tumour necrosis factor-α, interleukin-6, prostaglandin E₂). Histopathological and hepatocyte ultrastructural alterations proved that there were protective effects in FI against CCl₄-mediated liver injury. Signs of toxicity were not present in rats treated with FI alone (500?mg/kg b.w.).

Discussion and conclusion It can be concluded that the presence of phenolic constituents and their antioxidative effects can be credited to the hepatoprotective activity of FI.     

Enantiospecific effects of chiral drugs on cytochrome P450 inhibition in vitro

1.?The aim of this work was to examine the differences in the inhibitory potency of individual enantiomers and racemic mixtures of selected chiral drugs on human liver microsomal cytochromes P450.

2.?The interaction of enantiomeric forms of six drugs (tamsulosin, tolterodine, citalopram, modafinil, zopiclone, ketoconazole) with nine cytochromes P450 (CYP3A4, CYP2E1, CYP2D6, CYP2C19, CYP2C9, CYP2C8, CYP2B6, CYP2A6, CYP1A2) was examined. HPLC methods were used to estimate the extent of the inhibition of specific activity in vitro.

3.?Tamsulosin (TAM) and tolterodine (TOL) inhibited CYP3A4 activity with an enantiospecific pattern. The inhibition of CYP3A4 activity differed for R-TAM (K_i 2.88?±?0.12?µM) and S-TAM (K_i 14.22?±?0.53?µM) as well as for S-TOL (K_i 1.71?±?0.03?µM) and R-TOL (K_i 4.78?±?0.17?µM). Also, the inhibition of CYP2C19 by ketoconazole (KET) cis-enantiomers exhibited enantioselective behavior: the (+)-KET (IC₅₀ 23.64?±?6.25?µM) was more potent than (?)-KET (IC₅₀ 66.12?±?12.6?µM). The inhibition of CYP2C19 by modafinil (MOD) enantiomers (R-MOD IC₅₀?=?51.79?±?8.58?µM, S-MOD IC₅₀?=?48.62?±?9.74?µM) and the inhibition of CYP2D6 by citalopram (CIT) enantiomers (R-CIT IC₅₀?=?68.17?±?5.70?µM, S-CIT IC₅₀?=?62.63?±?7.89?µM) was not enantiospecific.

4.?Although enantiospecific interactions were found (TAM, TOL, KET), they are probably not clinically relevant as the plasma levels are generally lower than the drug concentration needed for prominent inhibition (at least 50% of CYP activity).