Combined administration of silymarin and vitamin C stalls acetaminophen-mediated hepatic oxidative insults in Wistar rats

The Antioxidant and Hepatoprotective Potential of Berberine and Silymarin on Acetaminophen Induced Toxicity in Cyprinus carpio L

Berberine (BBR) and silymarin (SM) are natural compounds extracted from plants known for their antioxidant and chemoprotective effects on the liver. The present study aimed to investigate the beneficial properties of BBR and SM and the association of BBR with SM on liver function using fish as "in vivo" models. Moreover, the study investigated their hepatoprotective role after acetaminophen (APAP) exposure. For this purpose, the fish (N = 360; 118.4 ± 11.09 g) were fed with control or experimental diets for 9 weeks. In the experimental diets, the feed was supplemented with either SM (1 g/kg feed), BBR (100 and 200 mg/kg feed), or a combination of BBR with SM (SM 1 g/kg feed + BBR 100 mg/kg feed and, respectively, SM 1 g/kg feed + BBR 200 mg/kg feed). After the feeding trial, seven fish from each tank were randomly selected and exposed to a single APAP dose. The selected serum biochemical markers, oxidative stress markers, and lysozyme activity were used to evaluate the efficiency of the supplements on carp's health profile, particularly regarding the hepatopancreas function. Our results showed that the inclusion of SM and BBR (either as a single or in combination) reduced the serum contents of total cholesterol, triglyceride, and alanine transaminase. An increase in the high-density cholesterol was observed after the administration of BBR or BBR in association with SM. Both supplements showed hepatoprotective activity against APAP-induced hepatotoxicity, especially BBR. The ameliorative effects of SM (1 g) in association with BBR (100 mg) were highlighted by the modulation of the nonspecific immune system and oxidative stress alleviation after APAP exposure.

Effects of swimming exercise combined with silymarin and vitamin C supplementation on hepatic inflammation, oxidative stress, and histopathology in elderly rats with high-fat diet-induced liver damage

OBJECTIVES

The aim of this study was to demonstrate that swimming exercise combined with silymarin and vitamin C supplementation improves hepatic inflammation, oxidative stress, and liver histopathology in elderly rats with high-fat diet-induced liver damage.

METHODS

Forty elderly male Wistar rats were randomly assigned to five groups (n = 8 in each): a normal diet (control), a high-fat diet (HFD), HFD + silymarin and vitamin C supplementation (HFD+Sup), HFD + swimming exercise (HFD+Exe), and HFD+Sup+Exe group (HFD+Sup+Exe). The non-alcoholic fatty liver model was induced for 6 wk in the HFD groups. After 6 wk of consuming an HFD, a daily supplemental gavage was administered to rats as an intervention along with HFD in the supplement groups for 8 wk. Moreover, rats in the exercise groups were subjected to swimming exercise training 5 d/wk for the same period.

RESULTS

The combination of swimming training and supplementation caused significant decreases in liver inflammatory biomarkers tumor necrosis factor-α and interleukin-1β while increasing total antioxidant capacity and peroxisome proliferator-activated receptor α (P < 0.05).

CONCLUSION

In elderly rats with liver injury caused by an HFD, the combination of exercise and silymarin with vitamin C supplementation effectively reduced oxidative stress, liver inflammation, fat accumulation, and regulated liver enzymes.

Ascorbic Acid Ameliorates Cardiac and Hepatic Toxicity Induced by Azithromycin-Etoricoxib Drug Interaction

The complexity of prescribing safe and effective drug therapy is still challenging. Due to the increased number of medications taken by patients, the potential for drug-drug interactions has clinically important consequences. This study focuses on the potential drug-drug interaction between azithromycin and etoricoxib and the possibility of counteracting this adverse reaction by giving ascorbic acid intraperitoneally to male albino rats. Sixty adult male albino rats weighing 150–180 g were used. The rats were allocated into six equal groups. One group was a control, and the others were given azithromycin, etoricoxib, either alone or combination, with one group treated with ascorbic acid and the last group treated with the drug combination and ascorbic acid. Blood samples were collected for measuring AST, ALT, LDH, CK-MB, and troponin alongside antioxidant enzymes and histopathological examination for both liver and heart tissue. The results showed both hepatic and cardiac damage in azithromycin and etoricoxib groups represented by increasing levels of heaptoc enzymes (ALT, AST, LDH, CK-MB, and troponin) with declining antioxidant enzymes and elevation of malondialdehyde and the appearance of hepatic and cardiac toxicities. Upon administration, ascorbic acid ameliorated all the mentioned biochemical parameters. In conclusion, ascorbic acid has great antioxidant capacities and hepatic and cardiac ameliorative effects and can alleviate drug interaction toxicity.

Combination of Vitamin C and Curcumin Safeguards Against Methotrexate-Induced Acute Liver Injury in Mice by Synergistic Antioxidant Effects

Methotrexate (MTX), an antineoplastic and immunosuppressive drug, widely used in the treatment of different types of cancers and the management of chronic inflammatory diseases. However, its use is associated with hepatotoxicity. Vitamin C (VC) and curcumin (CUR) exhibit anti-inflammatory and antioxidant effects. Thus, we aimed to investigate the potential hepatoprotective effects of VC and CUR pretreatment alone and in combination against MTX-induced hepatotoxicity. Albino mice were randomly divided into 7 groups: the control group, which received only normal saline; MTX group; VC group, pretreated with VC (100 or 200 mg/kg/day orally) for 10 days; CUR group, pretreated with CUR (10 or 20 mg/kg/day orally); and combination group, which received VC (100 mg/kg) and CUR (10 mg/kg). MTX was administered (20 mg/kg, intraperitoneally) to all the groups on the tenth day to induce hepatotoxicity. Forty eight hours after MTX administration, the mice were anesthetized. Blood samples were collected, the liver was removed for biochemical analysis, and a part of the tissue was preserved in formalin for histopathological analysis. The results indicated that pretreatment with a combination of VC and CUR induced a more significant decrease in the serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, and lactic dehydrogenase and a significant increase in the tissue level of superoxide dismutase and glutathione; furthermore, it induced a significant decrease in malondialdehyde levels and improvement in histopathological changes in the liver tissues, confirming the potential hepatoprotective effects of the combination therapy on MTX-induced liver injury. To conclude, MTX-induced hepatotoxicity is mediated by induction of oxidative stress as evident by increased lipid peroxidation and reduction of antioxidant enzyme activity. Pretreatment with VC, CUR or their combination reduces the MTX-induced hepatotoxicity by antioxidant and anti-inflammatory effects. However, the combined effect of VC and CUR provided a synergistic hepatoprotective effect that surpasses pretreatment with CUR alone but seems to be similar to that of VC 200 mg/kg/day. Therefore, VC and CUR combination or a large dose of VC could be effective against MTX-induced hepatotoxicity. In this regard, further studies are warranted to confirm the combined hepatoprotective effect of VC and CUR against MTX-induced hepatotoxicity.

Ameliorative effect of ethanolic extract of Limnophila rugosa (Scrophulariaceae) in paracetamol- and carbon tetrachloride-induced hepatotoxicity in rats

Background

Limnophila rugosa (Scrophulariaceae) is a perennial aquatic plant used as a diuretic and digestive tonic as well as in the treatment of diarrhea, dysentery, dyspepsia and urinary ailments. Genus Limnophila has been reported as hepatoprotective. The present study was undertaken to evaluate the hepatoprotective activity of the ethanolic extract of L. rugosa aerial part in paracetamol- and carbon tetrachloride-induced (CCl4) hepatotoxicity in albino Wistar rats. Ethanolic extract was subjected to high-performance liquid chromatography (HPLC) analysis for the estimation of phenolic and flavonoid compounds and gas chromatography–mass spectrometry (GC–MS) analysis for phytochemical analysis. The in vitro antioxidant activity was carried out by 2,2-diphenyl-1-picrylhydrazyl, nitric oxide radical and hydrogen peroxide assay. Hepatoprotective potential of L. rugosa was studied in paracetamol (750 mg/mg)- and CCl4 (1.25 ml/kg)-induced liver damage in albino rats at dose 200 and 300 mg/kg using silymarin (100 mg/kg) as standard. Lipid peroxidation, superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) were determined in liver tissue homogenate. Serum biochemical and histopathological examination was performed. Molecular docking analysis was performed to understand the molecular mechanism of hepatoprotective activity.

Results

HPLC analysis revealed predominance of rutin. GC–MS analysis revealed camphor as principal component. Ethanolic extract exhibited significant concentration-dependent scavenging efficacy. The altered biochemical chemical parameters: aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, bilirubin, cholesterol, albumin, globulin and total protein, were significantly improved at 200 and 300 mg/kg in experimental rats. Extract signified hepatoprotective by decreasing lipid peroxidation and upregulating SOD, CAT and GSH. The findings were well supported by histological analysis. 2-Butyl-2, 7-octadien-1-ol (-5.8) and camphor (-4.8) gave the highest docking score on the transforming growth factor-β1.

Conclusions

The ameliorative effect of L. rugosa in the rat model of hepatotoxicity could be attributed to its antioxidant potential and bioactive principles such as betulin, 5-hydroxy-6,7,4′-trimethoxyflavone (salvigenin), betulinic acid, ursolic acid, 3-octanol, acetophenone, anisylacetone, caryophyllene, cis-anethole and the compounds camphor and 2-butyl-2,7-octadien-1-ol identified from GC–MS analysis.

Hepatoprotective effect of silymarin on fructose induced nonalcoholic fatty liver disease in male albino wistar rats

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in the Western world, and it's likely to parallel the increasing prevalence of type 2 diabetes, obesity, and other components of metabolic syndrome. However, optimal treatment for NAFLD has not been established yet. Therefore, this study investigated the hepatoprotective effect of silymarin on fructose-induced nonalcoholic fatty liver disease in rats.

METHODS

Thirty male Wistar rats were randomly divided into five groups; normal control group that consumed tap water, silymarin control group that consumed tap water and silymarin (400 mg/kg/day), fructose control group that consumed 20% fructose solution, treatment group that consumed 20% fructose solution and silymarin (200 mg/kg/day), and another treatment group that consumed 20% fructose solution and silymarin (400 mg/kg/day). Hepatic triglyceride, serum lipid profile, lipid peroxidation, antioxidant level, morphological features, and histopathological changes were investigated. The data were analyzed using one-way analysis of variance (ANOVA) followed by Tukey multiple comparison test. Statistical significance was determined at p < 0.05.

RESULTS

This study showed that the fructose control group had a significantly high value in the stage of steatosis grade, hepatic triglyceride, serum triglyceride, total cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and hepatic malondialdehyde concentration as compared to the normal control. However, significantly low values of reduced glutathione and plasma total antioxidant capacity were found. The altered parameters due to fructose drastic effect were ameliorated by silymarin treatment.

CONCLUSIONS

The fructose control group developed dyslipidemia, oxidative stress, and mild steatosis that are the characteristics features of NAFLD. However, silymarin-treated groups showed amelioration in oxidative stress, dyslipidemia, and steatosis.

Protective role of Chlorella vulgaris with Thiamine against Paracetamol induced toxic effects on haematological, biochemical, oxidative stress parameters and histopathological changes in Wistar rats

Paracetamol is extensively consumed as an analgesic and antipyretic drug, but at a high dose level, it leads to deleterious side effects, such as hepatic and nephrotoxicity. This research aimed to estimate the prophylactic efficacy of Chlorella vulgaris and/or thiamine against paracetamol (P) induced hepatorenal and cardiac toxicity. Forty-eight female Wistar rats were randomly divided into eight equal groups (n = 6 rats). Group 1, normal control group. Group 2, Paracetamol group. Groups 3, 4 and 5 were treated with Silymarin drug, Chlorella vulgaris alga, Chlorella vulgaris alga supplemented with thiamine, respectively daily for 7 successive days, then all were administered Paracetamol (2gm/kg. bwt.). While, Groups 6, 7 and 8 were treated by Silymarin, Chlorella vulgaris alga, Chlorella vulgaris supplemented with thiamine, respectively daily for 7 successive days without paracetamol administration. Our results clarified that Paracetamol toxicity caused significant adverse effects on hematological, serum biochemical parameters, and oxidant -antioxidant status as well as histopathological picture of heart, liver, and kidney. However, in the Paracetamol intoxicated groups pretreatment either with Chlorella vulgaris alone or plus thiamine successfully improved the undesirable deleterious effects of paracetamol, and restored almost all variables to near their control levels. This study has finished to that oxidative stress participates in the pathogenesis of paracetamol-induced toxicity in rats and using Chlorella vulgaris alga either alone or plus thiamine alongside their health benefits can protect against oxidative harmful effects induced by paracetamol through their free radical scavenging and powerful antioxidant effects, and they can be used as propylactic agents against paracetamol-induced toxicity.

Vitamin C, omega-3 and paracetamol pharmacokinetic interactions using saliva specimens as determiners

Background With its low side effects profile and availability as an over-the-counter drug, paracetamol has been utilized extensively worldwide as an antipyretic and analgesic agent for decades. This is associated with the increasing concern over its ease of access and/or unawareness of the consumers to this issue of paracetamol-induced hepatotoxicity. Paracetamol-induced liver injury today is a big problem where most of the researchers are interested in the possible role of the naturally available antioxidants to ameliorate hepatotoxicity through kinetic interference. So the present study was designed to evaluate the effect of vitamin C and omega-3 on the pharmacokinetic property of paracetamol. Methods Six young (average age 29) healthy volunteers participated in the study. The study included three consecutive periods, each of which preceded by overnight fasting and separated by 6 day washout periods. The first period involved the ingestion of a single paracetamol dose. The second one included the ingestion of paracetamol and vitamin C concomitantly, and the final period included paracetamol plus omega-3. Saliva samples were collected and prepared for High-performance liquid chromatography analysis. Results There was a significant increase in saliva paracetamol level after 30 min of administration when given concomitantly with vitamin C compared with the remaining groups. No significant differences in the paracetamol concentration profile between the subjects for each group were observed at 60, 90, 120 and 150 min in all treated groups. Conclusion Concurrent administration of vitamin C with paracetamol increases significantly the Cmax level (maximum measured concentration) in saliva and increases the extent of absorption and the possibility of drug-drug interaction and risk of side effects.

Hepatoprotective Actions of Ascorbic Acid, Alpha Lipoic Acid and Silymarin or Their Combination Against Acetaminophen-Induced Hepatotoxicity in Rats

Background and objectives: Ascorbic acid, alpha lipoic acid (ALA) and silymarin are well-known antioxidants that have hepatoprotective effects. This study aims to investigate the effects of these three compounds combined with attenuating drug-induced oxidative stress and cellular damage, taking acetaminophen (APAP)-induced toxicity in rats as a model both in vivo and in vitro. Materials and Methods: Freshly cultured primary rat hepatocytes were treated with ascorbic acid, ALA, silymarin and their combination, both with and without the addition of APAP to evaluate their in vitro impact on cell proliferation and mitochondrial activity. In vivo study was performed on rats supplemented with the test compounds or their combination for one week followed by two toxic doses of APAP. Results: Selected liver function tests and oxidative stress markers including superoxide dismutase (SOD), malondialdehyde (MDA) and oxidized glutathione (GSSG) were detected. The in vivo results showed that all three pretreatment compounds and their combination prevented elevation of SOD and GSSG serum levels indicating a diminished burden of oxidative stress. Moreover, ascorbic acid, ALA and silymarin in combination reduced serum levels of liver enzymes; however, silymarin markedly maintained levels of all parameters to normal ranges. Silymarin either alone or combined with ascorbic acid and ALA protected cultured rat hepatocytes and increased cellular metabolic activity. The subjected agents were capable of significantly inhibiting the presence of oxidative stress induced by APAP toxicity and the best result for protection was seen with the use of silymarin. Conclusions: The measured liver function tests may suggest an augmented hepatoprotection of the combination preparation than when compared individually.

Serum miR-122 and miR-192 as biomarkers of intrinsic and idiosyncratic acute hepatotoxicity: A quantitative real-time polymerase chain reaction study in adult albino rats

miR-122 and miR-192 were investigated as indicators of toxic liver injury caused by acetaminophen, but their role in idiosyncratic toxic liver injury remains controversial. So, this work aimed to assess and compare the expressions of miR-122 and miR-192 in two different types of toxic liver injury (intrinsic [acetaminophen] and idiosyncratic [diclofenac]). Forty male adult Wistar albino rats were divided into equal five groups, in which serum liver enzymes; microRNAs (miRNAs) expressions (miR-122 and miR-192) and histopathological findings were studied. The present study showed that (1) miR-122 and miR-192 are good serum biomarkers of toxic liver injury whatever its etiology, as their serum levels exhibited a significantly earlier increase and earlier return to normal baseline levels as compared to serum aminotransferase levels; (2) miR-122 is more specific than miR-192; and (3) both serum levels of miR-122 and miR-192 showed non-significant differences in relation to the type of toxic liver injury.

Application of Spray Drying Particle Engineering to a High-Functionality/Low-Solubility Milk Thistle Extract: Powders Production and Characterization

Many natural compounds having antioxidant and anti-inflammatory activity are a potential target for new therapies against chronic inflammatory syndromes. The oral administration of functional herbal supplements may become a prevention strategy or therapy adjuvant for susceptible patients. A case study is our milk thistle (Silybum marianum) extract rich in silymarin complex. A water-soluble microencapsulated powder system was developed by a spray drying technique to improve the poor silymarin bioactivity after oral administration. Sodium carboxymethylcellulose (NaCMC) was employed as coating/swelling polymer matrix and sodium lauryl sulfate (SLS) as the surfactant (1:1:0.05 w/w/w). A H₂O/EtOH/acetone (50/15/35 v/v/v) solvent system was used as liquid feed. The microsystems were capable of improving the in vitro dissolution and permeation rates, suggesting an enhancement of bioactivity after oral administration. The microsystems protect the antioxidant activity of silymarin after harsh storage conditions period and do not affect the anti-inflammatory properties of the raw extract (efficient already at lower concentrations of 0.312 mg/mL) to reduce dendritic cells (DCs) inflammatory cytokine secretion after lipopolysaccharide administration. This approach allows managing particle size, surface properties and release of bioactive agents improving the bioactivity of a herbal supplement and is also possibly applicable to many other similar natural products.

Hepatoprotective potential of Phyllanthus muellarianus leaf extract: studies on hepatic, oxidative stress and inflammatory biomarkers

CONTEXT

Leaves of Phyllanthus muellarianus (Kuntze) Exell. (Euphorbiacea) are widely used in the management of liver disorders in Nigeria. However, no there is no scientific validation to support this use.

OBJECTIVE

Hepatoprotective effect of Phyllanthus muellarianus aqueous leaf extract was investigated in acetaminophen-induced liver injury mice.

MATERIALS AND METHODS

Hepatoprotective effect of Phyllanthus muellarianus aqueous leaf extract was evaluated in acetaminophen-induced hepatic damage in Swiss albino mice using biomarkers of hepatocellular indices, oxidative stress, proinflammatory factors and lipid peroxidation. Mice received distilled water, 100, 200, or 400 mg/kg b.w of Phyllanthus muellarianus aqueous leaf extract, respectively, for seven days. Treatment groups were challenged with 300 mg/kg b.w of acetaminophen on the sixth day.

RESULTS

Oral administration of Phyllanthus muellarianus aqueous leaf extract significantly (p < 0.05) attenuates acetaminophen-mediated alterations in serum alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, albumin and total bilirubin by 76.56, 85.41, 89.39, 82.77 and 78.38%. Similarly, acetaminophen-mediated decrease in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase were significantly attenuated in the liver of mice by 85.10, 80.81, 80.45, 76.23 and 95.22%, respectively. Increased levels of conjugated dienes, lipid hydroperoxides, malondialdehyde, protein carbonyl, fragmented DNA, tumor necrosis factor-α, interleukin-6 and -8 were significantly lowered by Phyllanthus muellarianus aqueous leaf extract.

CONCLUSION

Overall, results of this study show that Phyllanthus muellarianus halted acetaminophen-mediated hepatotoxicity due to its capability to enhance antioxidant enzymes.

Zea mays, Stigma maydis prevents and extenuates acetaminophen-perturbed oxidative onslaughts in rat hepatocytes

CONTEXT

Zea mays L. (Poaceae) Stigma maydis is an underutilized product of corn cultivation finding therapeutic applications in oxidative stress-related disorders.

OBJECTIVES

This study investigated its aqueous extract against acetaminophen (APAP)-perturbed oxidative insults in rat hepatocytes.

MATERIALS AND METHODS

Hepatotoxic rats were orally pre- and post-treated with the extract (at 200 and 400 mg/kg body weight) and vitamin C (200 mg/kg body weight), respectively, for 14 days. Liver function, antioxidative and histological analyses were thereafter evaluated.

RESULTS

The APAP-induced marked (p < 0.05) increases in the activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase and the concentrations of bilirubin, oxidized glutathione, protein carbonyls, malondialdehyde, conjugated dienes, lipid hydroperoxides and fragmented DNA were dose-dependently extenuated in the extract-treated animals. The extract also significantly (p < 0.05) improved the reduced activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase as well as total protein, albumin and glutathione concentrations in the hepatotoxic rats. These improvements may be attributed to the bioactive constituents as revealed by the gas chromatography-mass spectrometric chromatogram of the extract. The observed effects compared favourably with vitamin C and are informative of hepatoprotective and antioxidative attributes of the extract and were further supported by the histological analysis.

CONCLUSION

The data from the present findings suggest that Stigma maydis aqueous extract is capable of preventing and ameliorating APAP-mediated oxidative hepatic damage via enhancement of antioxidant defence systems.

Effect of Potassium Bromate on the Liver of Adult Male Albino Rat and A Possible Protective Role of Vitamin C: Histological, Immunohistochemical, and Biochemical Study

Potassium bromate (KBrO3 ) is a food additive which is used primarily as a maturing agent for flour. It is proved as a toxic agent with significant reduction in the activities of antioxidant capacity. The therapeutic efficacy of vitamin C as antioxidant may provide a possible solution to KBrO3 mediated oxidative damage. Twenty four adult male albino rats were used to evaluate the protective role of vitamin C against KBrO3 induced hepatotoxicity and divided into four groups; Group 1 (control), Group 2: received 30 mg/Kg/day vitamin C orally for 4 weeks, Group 3: received 20 mg/Kg/dose KBrO3 orally twice weekly for 4 weeks and Group 4: received both KBrO3 and vitamin C. Liver specimens were processed for histological study by light and electron microscopes and stained immunohistochemically to detect glial fibriller acidic protein (GFAP). Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were estimated as well as the levels of malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) activities in all dissected tissues were determined. KBrO3 induced histological alterations in the form of degeneration, cellular infiltration and significant increase in collagen deposition in portal tracts with a significant increase in immunoexpression of GFAP. Significant rise in serum levels of AST, ALT, and MDA in liver tissues were recorded. However, levels of GSH and SOD were significantly decreased. Most of these changes were improved by vitamin C treatment. In conclusion, vitamin C ameliorates the histological and biochemical alterations of the liver induced by KBrO3 . Anat Rec, 299:1256-1269, 2016. © 2016 Wiley Periodicals, Inc.

Kinetics of α-amylase and α-glucosidase inhibitory potential of Zea mays Linnaeus (Poaceae), Stigma maydis aqueous extract: An in vitro assessment

ETHNOPHARMACOLOGICAL RELEVANCE

Corn silk (Zea mays L., Stigma maydis) is an important herb used traditionally in many parts of the world to treat array of diseases including diabetes mellitus. Inhibitors of α-amylase and α-glucosidase offer an effective strategy to modulate levels of post prandial hyperglycaemia via control of starch metabolism.

AIM OF THE STUDY

This study evaluated α-amylase and α-glucosidase inhibitory potentials of corn silk aqueous extract. Active principles and antioxidant attributes of the extract were also analysed.

MATERIALS AND METHODS

The α-amylase inhibitory potential of the extract was investigated by reacting its different concentrations with α-amylase and starch solution, while α-glucosidase inhibition was determined by pre-incubating α-glucosidase with different concentrations of the extract followed by addition of p-nitrophenylglucopyranoside. The mode(s) of inhibition of the enzymes were determined using Lineweaver-Burke plot.

RESULTS

In vitro analysis of the extract showed that it exhibited potent and moderate inhibitory potential against α-amylase and α-glucosidase, respectively. The inhibition was concentration-dependent with respective half-maximal inhibitory concentration (IC50) values of 5.89 and 0.93mg/mL. Phytochemical analyses revealed the presence of alkaloids, flavonoids, phenols, saponins, tannins and phytosterols as probable inhibitory constituents. Furthermore, the extract remarkably scavenges reactive oxygen species like DPPH and nitric oxide radicals, elicited good reducing power and a significant metal chelating attributes.

CONCLUSION

Overall, the non-competitive and uncompetitive mechanism of action of corn silk extract is due to its inhibitory effects on α-amylase and α-glucosidase, respectively. Consequently, this will reduce the rate of starch hydrolysis, enhance palliated glucose levels, and thus, lending credence to hypoglycaemic candidature of corn silk.

Lophirones B and C Attenuate Acetaminophen-Induced Liver Damage in Mice: Studies on Hepatic, Oxidative Stress and Inflammatory Biomarkers

Lophirones B and C are chalcone dimers with proven chemopreventive activity. This study evaluates the hepatoprotective effect lophirones B and C in acetaminophen-induced hepatic damage in mice using biomarkers of hepatocellular indices, oxidative stress, proinflammatory factors and lipid peroxidation. Oral administrations of lophirones B and C significantly (p < 0.05) attenuated acetaminophen-mediated alterations in serum alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, albumin and total bilirubin. Similarly, acetaminophen-mediated decrease in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose 6- phosphate dehydrogenase were significantly attenuated in the liver of mice. Increased levels of conjugated dienes, lipid hydroperoxides, malondialdehyde, protein carbonyl and fragmented DNA were significantly lowered by lophirones B and C. Levels of tumour necrosis factor-α, interleukin-6 and 8 were significantly lowered in serum of acetaminophen treated mice by the chalcone dimers. Overall, results of this study show that lophirones B and C halted acetaminophen-mediated hepatotoxicity.