Hepatoprotective effect of aqueous extract of Aframomum melegueta on ethanol-induced toxicity in rats.
ABSTRACT In recent years there have been remarkable developments in the prevention of diseases, especially with regards to the role of free radicals and antioxidants. Ethanol-induced oxidative stress appears to be one mechanism by which ethanol causes liver injury. The protective effect of aqueous plant extract of Aframomum melegueta on ethanol-induced toxicity was investigated in male Wistar rats. The rats were treated with 45 % ethanol (4.8 g/kg b.w.t.) for 16 days to induce alcoholic diseases in the liver. The activities of alanine aminotransferase, aspartate aminotransferase and triglyceride were monitored and the histological changes in liver examined in order to evaluate the protective effects of the plant extract. Hepatic malondialdehyde and reduced glutathione, as well as superoxide dismutase and glutathione-S-transferase activities were determined for the antioxidant status. Chronic ethanol administration resulted in a statistically significant elevation of serum alanine aminotransferases and triglyceride levels, as well as a decrease in reduced glutathione and superoxide dismutase which was dramatically attenuated by the co-administration of the plant extract. Histological changes were related to these indices. Co-administration of the plant extract suppressed the elevation of lipid peroxidation, restored the reduced glutathion, and enhanced the superoxide dismutase activity. These results highlight the ability of Aframomum melegueta to ameliorate oxidative damage in the liver and the observed effects are associated with its antioxidant activities.
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ABSTRACT: The ethnobotanical use of Aframomum melegueta in the treatment of urinary tract and soft tissue infection suggested that the plant has antimicrobial activity. To substantiate the folkloric claims, an acetone, 50:50 acetone:methanol and 2:1 chloroform:methanol extracts were tested against E. coli K12; acetone extract and the fractions of acetone extracts were tested against L. monocytogenes. Bioassay-guided fractionation was performed on the extract using L. monocytogenes as the test organism to isolate the bioactive compounds which were then tested against all the other organisms. Four known labdane diterpenes (G3 and G5) were isolated for the first time from the rhizomes of A. melegueta and purified. These were tested against E. coli, L. monocytogenes, methicillin resistant Staphylococus aureus (MRSA) and Staphylococcus aureus to determine antibacterial activity. The result showed that two compounds G3 and G5 exhibited more potent antibacterial activity compared to the current clinically used antibiotics ampicillin, gentamicin and vancomycin and can be potential antibacterial lead compounds. The structure of the labdane diterpenes were elucidated using Nuclear Magnetic Resonance (NMR) spectroscopy and Mass spectrometry. A possible mode of action of the isolated compound G3 and its potential cytotoxicity towards mammalian cells were also discussed. The results confirmed the presence of antibacterial compounds in the rhizomes of A. melegueta with a favourable toxicity profile which could be further optimized as antibacterial lead compounds.Journal of ethnopharmacology 12/2013; 151(3). DOI:10.1016/j.jep.2013.12.035 · 2.94 Impact Factor
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ABSTRACT: Extracts from medicinal plants, many of which have been used for centuries, are increasingly tested in models of hepatotoxicity. One of the most popular models to evaluate the hepatoprotective potential of natural products is acetaminophen (APAP)-induced liver injury, although other hepatotoxicity models such as carbon tetrachloride, thioacetamide, ethanol and endotoxin are occasionally used. APAP overdose is a clinically relevant model of drug-induced liver injury. Critical mechanisms and signaling pathways, which trigger necrotic cell death and sterile inflammation, are discussed. Although there is increasing understanding of the pathophysiology of APAP-induced liver injury, the mechanism is complex and prone to misinterpretation, especially when unknown chemicals such as plant extracts are tested. This review discusses the fundamental aspects that need to be considered when using this model, such as selection of the animal species or in vitro system, timing and dose-responses of signaling events, metabolic activation and protein adduct formation, the role of lipid peroxidation and apoptotic versus necrotic cell death, and the impact of the ensuing sterile inflammatory response. The goal is to enable researchers to select the appropriate model and experimental conditions for testing of natural products that will yield clinically relevant results and allow valid interpretations of the pharmacological mechanisms.Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 01/2013; 55. DOI:10.1016/j.fct.2012.12.063 · 2.61 Impact Factor
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ABSTRACT: The present study is aimed at evaluating the protective effects of oils from Zingiber officinale (ginger) and Curcuma longa (turmeric) on acute ethanol-induced fatty liver in male Wistar rats. Ferric reducing antioxidant power activity and oxygen radical absorbance capacity of the oils were evaluated ex vivo. Rats were pretreated for 28 d with standard drug (Livolin Forte) and oils from Z. officinale and C. longa before they were exposed to 45% ethanol (4.8 g/kg) to induce acute fatty liver. Histological changes were observed and the degree of protection was measured by using biochemical parameters such as alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities. Serum triglyceride (TG) level, total cholesterol (TC) level and the effects of both oils on reduced gluthatione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD) and hepatic malondialdehyde (MDA) levels were estimated. Oils from Z. officinale and C. longa at a dose of 200 mg/kg showed hepatoprotection by decreasing the activities of serum enzymes, serum TG, serum TC and hepatic MDA, while they significantly restored the level of GSH as well as GST and SOD activities. Histological examination of rats tissues was related to the obtained results. From the results it may be concluded that oils from Z. officinale and C. longa (200 mg/kg) exhibited hepatoprotective activity in acute ethanol-induced fatty liver and Z. officinale oil was identified to have better effects than C. longa oil.01/2014; 12(1):59-65. DOI:10.1016/S2095-4964(14)60006-6