Endogenous antioxidant and LOX-mediated systems contribute to the hepatoprotective activity of aqueous partition of methanol extract of Muntingia calabura L. leaves against paracetamol intoxication =

Methanol extract of Muntingia calabura L. (family Muntingiaceae) leaf has been reported to exert various pharmacological activities including hepatoprotection. The present study was carried out to identify the most effective hepatoprotective partition derived from the extract and to determine the mechanisms of action involved. The extract was partitioned using solvents with different polarity to yield petroleum ether (PEMC), ethyl acetate (EAMC), and aqueous (AQMC) extracts. Each extract, at 250 mg/kg, was subjected to the paracetamol (PCM)-induced hepatotoxic assay and several parameters such as liver weight, liver/body weight ratio, serum liver enzymes' level, and histopathological examinations were determined. Each partition was also tested for their antioxidant and anti-inflammatory potentials. The most effective extract (AQMC) was prepared in additional dose of 50 and 500 mg/kg, and then subjected to the same liver toxicity test in addition to the endogenous antioxidant enzymes assay. Moreover, AQMC was also subjected to the phytochemical screening and HPLC analysis. Overall, from the results obtained: AQMC exerted significant (p < 0.05): (i) antioxidant activity when assessed using the DPPH, SOD and ORAC assays with high TPC detected; (ii) anti-inflammatory activity via LOX, but not XO pathway; (iii) hepatoprotective activity indicated by its ability to reverse the effect of PCM on the liver weight and liver/body weight ratio, the level of serum liver enzymes (ALT, AST, and ALP), and activity of several endogenous antioxidant enzymes (SOD and CAT). Phytochemicals analyses demonstrated the presence of several flavonoid-based bioactive compounds such as gallic acid and quercetin, which were reported to possess hepatoprotective activity. In conclusion, AQMC exerts hepatoprotective activity against the PCM-induced toxicity possibly by having a remarkable antioxidant potential and ability to activate the endogenous antioxidant system possibly via the synergistic action of its phytoconstituents

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 NG-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 methanol extract of Dicranopteris linearis leaves against paracetamol- and carbon tetrachloride (CCl4)-induced liver toxicity in rats

The present study aimed to determine the hepatoprotective activity of methanol extract of Dicranopteris linearis leaves (MEDL) using two models of liver injury in r ats. Rats (n = 6) received 10% DMSO(negative control), 200 mg/kg silymarin (positive control) or MEDL (50, 250, and 500 mg/kg) orally once daily for 7 days and 3 hours after the last adminis tration of the test solutions, they were 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, all doses of MEDL significantly (P < 0.05) reduced the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in CCl4-induced hepatotoxic rats while only the 500 mg/kg MEDL caused significant (P < 0.05) reduction in the level of both enzymes in the PCM-induced liver toxicity model. The histological results obtained were in line with the biochemical analysis. In conclusion, the MEDL-induced hepatoprotective activity is attributed partly to its free radicals scavenging and antioxidant activities and high flav onoids content

Antiulcer activity of methanol-chloroform extract of Channa striatus fillet

Channa striatus (Haruan) is Malaysian freshwater fish that is traditionally used to treat ailments related to wound and also ulcers. The aimed of the present study was to determine the mechanisms of anti-ulcer activity of chloroform: methanol extract of C. striatus fillet (CMCS) in rats. The antiulcer profile of CMCS, given orally in the doses of 50, 250 and 500mg/kg, was assessed using the ethanol- and indomethacin-induced gastric ulcer models. The mechanisms of antiulcer of CMCS were determined as follows; i) the antisecretory activity of CMCS was measured using the pyloric ligation rat model, and; ii) the role of nitric oxide (NO) and sulfhydryl compounds in the modulation of CMCS antiulcer activity were determined by pre-treating the rats with L-NAME or NEM, respectively, followed by the pre-treatment of rats with CMCS before subjecting the animals to the ethanol-induced gastric ulcer model. From the results obtained, CMCS exerted significant (P<0.05) antiulcer activity in both models of gastric ulcer wherein the macroscopic and microscopic analysis of the stomach supported the antiulcer claim. With regard to its antisecretory effect, CMCS did not change the volume and pH, but reduce the total acidity only at the lower doses of the gastric juice. Moreover, CMCS demonstrated antiulcer activity was reversed by NEM, but not affected by L-NAME. In conclusion, CMCS shows antiulcer activity that is modulated via its cytoprotective, but not antisecretory effect, and in the presence of sulfhysryl compounds, but not NO

Amelioration of paracetamol-induced hepatotoxicity in rat by the administration of methanol extract of Muntingia calabura L. leaves

Muntingia calabura L. is a tropical plant species that belongs to the Elaeocarpaceae family. The present study is aimed at determining the hepatoprotective activity of methanol extract of M. calabura leaves (MEMC) using two models of liver injury in rats. Rats were divided into five groups (n = 6) and received 10% DMSO (negative control), 50 mg/kg N-acetylcysteine (NAC; positive control), or MEMC (50, 250, and 500 mg/kg) orally once daily for 7 days and on the 8th day were subjected to the hepatotoxic induction using paracetamol (PCM). The blood and liver tissues were collected and subjected to biochemical and microscopical analysis. The extract was also subjected to antioxidant study using the 2,2-diphenyl-1-picrylhydrazyl-(DPPH) and superoxide anion-radical scavenging assays. At the same time, oxygen radical antioxidant capacity (ORAC) and total phenolic content were also determined. From the histological observation, lymphocyte infiltration and marked necrosis were observed in PCM-treated groups (negative control), whereas maintenance of hepatic structure was observed in group pretreated with N-acetylcysteine and MEMC. Hepatotoxic rats pretreated with NAC or MEMC exhibited significant decrease (P < 0.05) in ALT and AST enzymes level. Moreover, the extract also exhibited good antioxidant activity. In conclusion, MEMC exerts potential hepatoprotective activity that could be partly attributed to its antioxidant activity and, thus warrants further investigations

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

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

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

Mechanism of hepatoprotective activity of methanolic extract of Melastoma malabathricum L. leaves

The objective of this study was to determine the hepatoprotective activity of methanolic extracts of Melastoma malabathricum leaves (MEMM) and its partitions using rats’ model, by evaluating the prophylactic effect of the plants extracts administered prior to the induction of liver toxicity using a hepatotoxic agent. The study were design as hepatoprotective potential of MEMM has never been reported. In an attempt to establish the pharmacological properties, the hepatoprotective potential of MEMM was investigated using carbon tetrachloride (CCl4)- and paracetamol (PCM)- induced hepatotoxicity in rats. Throughout this study, the animals were divided into 22 groups containing 6 rats each group. In the first stage of in vivo study, rats were divided into groups and administered orally once daily with 10 % dimethyl sulfoxide (DMSO) as negative control, 200 mg/kg silymarin as positive control, or MEMM (50, 250, 500 mg/kg) for 7 days, followed by hepatotoxicity induction using CCl4 or PCM. In the second stage, MEMM was partitioned into 3 fractions: petroleum ether extract (PEMM), ethyl acetate extract (EAMM), aqueous extract (AQMM). PEMM, EAMM and AQMM were then tested on PCM-induced hepatotoxicity in rats. Blood sample underwent biochemical analysis to evaluate alanine transferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels; the livers were subjected to microscopic analysis. All extracts (MEMM, PEMM, EAMM AQMM) underwent antioxidant study using oxygen radical absorbance capacity (ORAC) test, Total phenolic compound (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and superoxide scavenging assay, and anti-inflammatory evaluation via lipoxygenase (LOX) and xanthine oxidase (XO) assays. Total phenolic content (TPC), phytochemical screening and high-performance liquid chromatography (HPLC) evaluation were also performed. From the histological observation, lymphocyte infiltration and marked necrosis were observed in the DMSO-treated groups (negative control). MEMM showed encouraging activity for reducing the toxic effect of CCl4 or PCM on the liver by reducing the weight of the liver in a dose independent manner; histological observation demonstrated normalization of the histopathological changes, preserving hepatocyte structure, causing a significant decline in AST and ALT levels (p<0.05). PEMM, EAMM and AQMM which contains non-polar compounds, intermediate compounds and polar compounds, respectively, attenuated the liver enzyme levels in a dose-independent manner. Overall, EAMM had the best activity for attenuating the liver enzymes. MEMM had the highest TPC value, followed by AQMM, EAMM, and PEMM. All the extracts (MEMM, PEMM, EAMM, and AQMM) demonstrated potential free radical scavenging activity in SOD and DPPH assays. However, the different trend was showed by ORAC assay from that DPPH and SOD. EAMM and AQMM had high ORAC value, which determine the capacity of an extract to act as an antioxidant. In the anti-inflammatory assays, MEMM and EAMM showed the moderate inhibition in LOX activity, but weak anti-inflammatory activity in XO. Phytochemical screening showed that the extracts showed that MEMM, PEMM and EAMM contained flavonoids, triterpenes, tannins, saponins, polyphenolic compounds and steroids, but not alkaloids. In contrast, the AQMM extract contained fewer compounds. HPLC analysis demonstrated that four to eight peaks detected at different wavelengths of the chromatogram of MEMM, PEMM, EAMM and AQMM, which were suggested to be flavonoid-based compounds. In conclusions, MEMM exerted potential hepatoprotective activity that can be partly attributed to its antioxidant activity, and EAMM was considered to have the best activity among the fractions, which warrants further investigation

Hepatoprotective effects of methanol extract of Bauhinia purpurea leaves

The objective of the present study was to determine the hepatoprotective activity of methanol extract of Bauhinia purpurea L. leaves (MEBP ; family Fabaceae) using paracetamol and carbon tetrachloride induced liver toxicity models. The dried, ground leaves of B.purpurea (40g) were soaked with 800ml methanol (1:20 (w/v)) for 72h at room temperature, filtered and subjected to the rotary evaporation process. This processes were repeated three times. The vehicle (10% DMSO), 200mg/kg silymarin or MEBP (50, 250 and 500 mg/kg) were administered orally once daily for 7 consecutive days in rats (n=6). Hepatotoxicity was induced by administration of CC14- (0.15 ml/kg) or PCM (3g/kg) 3 hours after the last extract administration. On the 9th day, the animals were sacrificed and the liver was collected for histopathological examination. From the histological observation, hepatic steatosis, lymphocyte infiltration and marked necrosis was observed in CC14 and PCM-treated groups (negative control). Hepatotoxic with PCM pretreated with silymarin or 500 mg/kg MEBP exhibited significant (P<0.05) decreased in he mean of histological scoring compared to the negative control. On the other hand, only 500 mg/kg MEBP significantly (P<0.05) decreased the mean of scoring for CC14-induced hepatotoxicity study compared to the negative control group (P<0.05). In conclusion, the methanol extract of leaves of Bauhinia purpurea exerts potential hepatoprotective property that warrants further investigation