Hepatoprotective and antioxidant activities of Dicranopteris linearis leaf extract against paracetamol-induced liver intoxication in rats

Context: Dicranopteris linearis L. (Gleicheniaceae) leaves have been reported to exert hepatoprotective activity.Objective: The hepatoprotective and antioxidant effects of ethyl acetate partition of D. linearis (EADL) are investigated.Materials and methods: EADL was subjected to antioxidant and anti-inflammatory studies, and phytochemical analyses. In vivo study involved six groups (n = 6) of overnight fasted Sprague Dawley rats. The test solutions [10% DMSO (normal), 10% DMSO (negative), 200 mg/kg silymarin (positive) or EADL (50, 250 or 500 mg/kg)] were administered orally once daily for 7 consecutive days followed by oral vehicle (only for normal) or hepatotoxic induction using 3 g/kg paracetamol (PCM).Results: EADL exerted ≈ 90% radical scavenging effects based on the DPPH and superoxide anion radical scavenging assays, high antioxidant capacity in the oxygen radical absorbance capacity assay (≈ 555,000 units), high total phenolic content (≈ 350 mg GAE/100 g extract) (p < 0.05), but low anti-inflammatory effect. EADL also attenuated PCM-induced liver intoxication as indicated by reduced level of serum liver enzymes; increased activity of endogenous enzymatic antioxidant (superoxide dismutase - 8.3 vs. 4.0 U/g tissue; catalase - 119 vs. 52 U/g tissue) and; reduced level of lipid peroxidation marker (2.7 vs. 5.0 µM). Preliminary screening of EADL revealed the presence of saponins, tannins and flavonoids with further HPLC analysis demonstrating the presence of rutin and quercetin.Discussion and conclusion: EADL exerted hepatoprotective and antioxidant activities; thus, these data support the potential use of D. linearis as a new source for future hepatoprotective drug development.

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.

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.

Antiulcer activity of methanol extract of Melastoma malabathricum leaves in rats

OBJECTIVE

To determine the potential antiulcer activity of methanol extract of Melastoma malabathricum leaves (MEMM) using various established rat models.

MATERIALS AND METHODS

Ten groups of rats were used and orally administered 10% DMSO (negative control), 100 mg/kg ranitidine (positive control) or MEMM (50, 250 and 500 mg/kg) followed by gastric ulcer induction either using ethanol or indomethacin. The stomachs were collected and subjected to macroscopic and microscopic analyses.

RESULTS

MEMM exhibited significant (p < 0.05) antiulcer activity in the ethanol, but not in the indomethacin-induced gastric ulcer model. The percentage of antiulcer activity for 50-500 mg/kg MEMM ranged between 3 and 75%, respectively. The gross observations were supported by histological findings. MEMM also aggravated the indomethacin-induced gastric ulcer, leading to an increase in ulcer area formation and ulcer score.

CONCLUSION

The M. malabathricum leaves showed antiulcer activity, which could be attributed to their antioxidant and anti-inflammatory activities. This requires further in-depth studies.