Hepatoprotective action of various partitions of methanol extract of Bauhinia purpurea leaves against paracetamol-induced liver toxicity: involvement of the antioxidant mechanisms.

BACKGROUND: Methanol extract of Bauhinia purpurea L. (family Fabaceae) (MEBP) possesses high antioxidant and anti-inflammatory activities and recently reported to exert hepatoprotection against paracetamol (PCM)-induced liver injury in rats. In an attempt to identify the hepatoprotective bioactive compounds in MEBP, the extract was prepared in different partitions and subjected to the PCM-induced liver injury model in rats. METHODS: Dried MEBP was partitioned successively to obtain petroleum ether (PEBP), ethylacetate (EABP) and aqueous (AQBP) partitions, respectively. All partitions were subjected to in vitro antioxidant (i.e. total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH)- and superoxide-radicals scavenging assay, and oxygen radical absorbance capacity (ORAC) assay) and anti-inflammatory (i.e. lipooxygenase (LOX) and xanthine oxidase (XO) assay) analysis. The partitions, prepared in the dose range of 50, 250 and 500 mg/kg, together with a vehicle (10 % DMSO) and standard drug (200 mg/kg silymarin) were administered orally for 7 consecutive days prior to subjection to the 3 mg/kg PCM-induced liver injury model in rats. Following the hepatic injury induction, blood samples and liver were collected for the respective biochemical parameter and histopathological studies. Body weight changes and liver weight were also recorded. The partitions were also subjected to the phytochemical screening and HPLC analysis. RESULTS: Of all partitions, EABP possessed high TPC value and demonstrated remarkable antioxidant activity when assessed using the DPPH- and superoxide-radical scavenging assay, as well as ORAC assay, which was followed by AQBP and PEBP. All partitions also showed low anti-inflammatory activity via the LOX and XO pathways. In the hepatoprotective study, the effectiveness of the partitions is in the order of EABP>AQBP>PEBP, which is supported by the microscopic analysis and histopathological scoring. In the biochemical analysis, EABP also exerted the most effective effect by reducing the serum level of alanine transaminase (ALT) and aspartate transaminase (AST) at all doses tested in comparison to the other partitions. Phytochemical screening and HPLC analysis suggested the presence of: flavonoids, condensed tannins and triterpenes in EABP; flavonoids, condensed tannins and saponins in PEBP and; only saponins in AQBP. CONCLUSION: EABP demonstrates the most effective hepatoprotection against PCM-induced liver injury in rats. This observation could be attributed to its remarkable antioxidant activity and the presence of flavonoids that might probably act synergistically with other biocompounds to cause the hepatoprotection.

Anti-ulcer activity of the aqueous extract of Melastoma malabathricum L. leaf in rats.

Melastoma malabathricum L. Smith (Melastomaceae) has been used in the Malay traditional culture to treat ulcer-based ailments.The objective of the present study was to investigate the potential anti-ulcer effect of aqueous extract of M. malabathricum leaves (AEMM) using ethanol- and indomethacin-induced gastric ulcer models in rats. Rats were divided into ten groups (n=6) and received DMSO (10%; negative group), ranitidine (100mg/kg; positive group) or AEMM (50, 250 and 500mg/kg) orally for 7 days and on the 8(th) day subjected to the respective gastric ulcer models. The stomachs were collected and subjected to macroscopic and microscopic analysis. At all groups tested, the AEMM exerted significant (p<0.05) anti-ulcer effect only against the ethanol-induced gastric ulcer model. The percentage of anti-ulcer for the 50-500mg/kg AEMM ranging between 50-82%, respectively. The macroscopic observations were supported by histological findings. In conclusion, AEMM exhibits potential anti-ulcer activity attributed to its previously proven high flavonoids content and antioxidant activity.

Gastroprotective activity of chloroform extract of Muntingia calabura and Melastoma malabathricum leaves.

CONTEXT: Muntingia calabura L. (family Muntingiaceae) and Melastoma malabathricum L. (family Melastomaceae) are traditionally used to treat gastric ulcer. OBJECTIVE: The present study determines the mechanisms of gastroprotective activity of the chloroform extract of leaves obtained from both the plants using several in vitro and in vivo assays. MATERIALS AND METHODS: Phytochemical screening, HPLC analysis, and antioxidant activity of the respective extract were carried out. Gastroprotective activity was determined using ethanol-induced gastric ulcer assay while the mechanisms of gastroprotection were determined using the pyloric ligation assay. The test solutions [8% Tween-80 (vehicle), 20 mg/kg omeprazole, and different doses of extracts (50, 250, or 500 mg/kg] were administered orally once daily for 7 consecutive days before the animals were subjected to ethanol induced gastric ulcers. RESULTS: The chloroform-extracted M. calabura (CEMC) contains tannins, polyphenolics, triterpenes, and steroids while the chloroform-extracted M. malabathricum (CEMM) contains only triterpenes and steroids. CEMC, but not CEMM, exerted remarkably strong antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH)- (86% versus 16%) and superoxide- (73% versus 36%) radical scavenging assays. Both extracts demonstrated significant (p < 0.05) gastroprotection with the EC50 value recorded at 192.3 or 297.7 mg/kg, respectively. In the pylorus ligation assay, CEMC and CEMM significantly (p < 0.05) reduced the total and free acidity and volume; while increased the pH of gastric juice as well as the gastric wall mucus content in comparison with the vehicle-treated group. DISCUSSION AND CONCLUSION: CEMC and CEMM exert gastroprotective effects in animals with ethanol-induced gastric ulcers via antioxidant and anti-secretory effects.

Mechanisms of gastroprotection of methanol extract of Melastoma malabathricum leaves.

BACKGROUND: Melastoma malabathricum L. (Melastomaceae) is a small shrub with various medicinal uses. The present study was carried out to determine the gastroprotective mechanisms of methanol extract of M. malabathricum leaves (MEMM) in rats. METHODS: The extract's mechanisms of gastroprotection (50, 250, 500 mg/kg) were studied using the pylorus-ligation in rat model wherein volume, pH, free and total acidity of gastric juice, and gastric wall mucus content were determined. The involvement of endogenous nitric oxide (NO) and sulfhydryl (SH) compounds in the gastroprotective effect of MEMM were also measured. MEMM was subjected to the antioxidant, anti-inflammatory and phytochemical analysis and HPLC profiling. RESULTS: MEMM contained various phyto-constituents with quercitrin being identified as part of them. MEMM and quercitrin: i) significantly (p < 0.05) reduced the volume and acidity of gastric juice while increasing the pH and gastric wall mucus content.; ii) significantly (p < 0.05) increased the level of SOD, GTP and GTR while significantly (p < 0.05) reduced the level of CAT, MPO and TBARS activities.; iii) exerted gastroprotective activity when assessed using the ethanol-induced gastric ulcer assay, which was reversed by N(G)-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase) and N-ethylmaleimide (NEM; a sulfhydryl (SH) blocker). MEMM inhibited the lipoxygenase (LOX) and xanthine oxidase (XO) activities with the highest affinity for the former while quercitrin showed high affinity for XO activity. CONCLUSIONS: MEMM exhibited a gastroprotective activity due partly to the presence of quercitrin, its antioxidant and anti-inflammatory activities, and via the modulation of NO and SH groups.

Effect of aqueous extract of Dicranopteris linearis leaves against paracetamol and carbon tetrachloride-induced liver toxicity in rats.

The present study aimed to determine the hepatoprotective activity of Dicranopteris linearis L. (family Gleicheniaceae) leaf aqueous extract (DLAE) using two models of liver injury in rats. Rats were divided into ten groups (n=6) and received dH2O (negative control), 200 mg/kg silymarin (positive control) or DLAE (50, 250 and 500 mg/kg) orally once daily for 7 consecutive days and on the 8th day subjected to the hepatotoxic induction either using carbon tetrachloride (CCl4) or paracetamol (PCM). The bloods and livers were collected and subjected to biochemical and microscopical analysis. From the data obtained, only the highest dose of DLAE significantly (P<0.05) reduced the ALP, ALT and AST levels in CCl4-and PCM-induced hepatotoxic rats while the other doses caused significant (P<0.05) reduction only in the levels of ALT and AST. The histological results obtained were in line with the biochemical analysis wherein reduction in the CCl4- and PCM-induced tissue formation of necrosis, steatosis and inflammation occurred in a dose-dependent manner. In conclusion, the DLAE possesses hepatoprotective activity, which could be attributed to its free radicals scavenging and antioxidant activities, and high flavonoids content. Thus, in-depth studies regarding the hepatoprotective activity of DLAE are warranted.

Effect of methanol extract of Dicranopteris linearis against carbon tetrachloride-induced acute liver injury in rats.

BACKGROUND: Dicranopteris linearis (family Gleicheniaceae) has been reported to possess anti-inflammatory and antioxidant activities but no attempt has been made to study its hepatoprotective potential. The aim of the present study was to determine the hepatoprotective effect of methanol extracts of D. linearis (MEDL) against carbon tetrachloride (CCl4)-induced acute liver injury in rats. METHODS: 6 groups (n = 6) of rats received oral test solutions: 10% dimethyl sulfoxide (DMSO), 200 mg/kg silymarin, or MEDL (50, 250, and 500 mg/kg), once daily for 7 consecutive days, followed by hepatotoxicity induction with CCl4. Blood and liver were collected for biochemical and microscopic analysis. The extract was also subjected to antioxidant studies (e.g. 2, 2-diphenyl-1-picrylhydrazyl (DPPH)- and superoxide anion-radical scavenging assays, oxygen radical absorbance capacity (ORAC) test and total phenolic content (TPC) determination), phytochemical screening and HPLC analysis. RESULTS: Pretreatment with MEDL and silymarin significantly (P < 0.05) reduced the serum levels of AST, ALT and ALP, which were increased significantly (P < 0.05) in DMSO-pretreated group following treatment with CCl4. Histological analysis of liver tissues in groups pretreated with MEDL and silymarin showed mild necrosis and inflammation of the hepatocytes compared to the DMSO-pretreated group (negative control group). The MEDL showed higher DPPH- and superoxide anion-radical scavenging activity as well as high TPC and ORAC values indicating high antioxidant activity. CONCLUSIONS: MEDL exerts hepatoprotective activity that could be partly contributed by its antioxidant activity and high phenolic content, and hence demands further investigation.

Methanol extract of Melastoma malabathricum leaves exerted antioxidant and liver protective activity in rats.

BACKGROUND: Melastoma malabathricum L. (Melastomaceae) is a small shrub with various medicinal uses. The present study was carried out to determine the hepatoprotective activity of methanol extract of M. malabathricum leaves (MEMM) against the paracetamol-induced liver toxicity in rats model. METHODS: The respective chemicals and herbal solutions (10% DMSO, 200 mg/kg silymarin or MEMM (50, 250 and 500 mg/kg)) were administered orally to rats once everyday for 7 days followed by the hepatotoxicity assay. The blood samples and livers were collected and subjected to biochemical and microscopical analysis. Prior to the hepatoprotective study, MEMM was subjected to determination of the total phenolic content (TPC) and the antioxidant properties using several standard assays (e.g. 2, 2-diphenyl-1-picrylhydrazyl- and superoxide anion- radical scavenging assay, and oxygen radical absorbance capacity assay). RESULTS: MEMM exerted significant (p < 0.05) and high antioxidant activity in which high TPC was recorded; while in the hepatotoxicity study, the extract exhibited significant hepatoprotective effects against the paracetamol-induced hepatotoxic model. The results observed for serum liver enzymes (ALT, ALP and AST) as well as the microscopic observations and microscopic scoring supported the hepatoprotective potential of MEMM. The phytochemical and HPLC analysis of MEMM demonstrated the presence of flavonoids as its major constituents. CONCLUSIONS: The MEMM-induced hepatoprotective activity could be allied partly to its antioxidant activity and the presence of flavonoids.

Hepatoprotective activity of methanol extract of Melastoma malabathricum leaf in rats.

The present study aimed to determine the hepatoprotective activity of a methanol extract of Melastoma malabathricum leaves (MEMM) using two established rat models. Ten groups of rats (n=6) were given a once-daily administration of 10% dimethyl sulfoxide (negative control), 200 mg/kg silymarin (positive control), or MEMM (50, 250, or 500 mg/kg) for 7 days followed by induction of hepatotoxicity either using paracetamol or carbon tetrachloride. Blood samples and livers were collected for biochemical and microscopic analysis. Based on the results obtained, MEMM exhibited a significant (p<0.05) hepatoprotective activity against both inducers, as indicated by an improvement in the liver function test. These observations were supported by the histologic findings. In conclusion, M. malabathricum leaves possessed hepatoprotective activity, which could be linked to their phytochemical constituents and antioxidant activity; this therefore requires further in-depth studies.