Antioxidant activity of Maytenus ilicifolia root bark

Characterization of the chemical profile and the effects of ethanolic extracts of Maytenus ilicifolia Mart. ex Reissek on glucose metabolism in normal hyperglycemic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Maytenus ilicifolia Mart. ex Reissek, Celastraceae, is popularly known as "espinheira-santa" and used to treat pathologies related to the stomach. However, in popular culture, this species has also been used to treat other disorders such as diabetes, but without scientific evidence, requiring more phytochemical and pharmacological studies on the plant.

AIM OF THE STUDY

This work aims to investigate the anti-hyperglycemic potential of ethanolic extracts obtained from leaves from two different accessions of Maytenus ilicifolia (MIA and MIB) in normal hyperglycemic rats.

MATERIALS AND METHODS

The animals were divided into different experimental groups: normal hyperglycemic (negative control); MIA (treatment of Maytenus ilicifolia extract from access 116); MIB (treatment with Maytenus ilicifolia extract from access 122; and glipizide (positive control). At 30 min after treatment, all animals received glucose overload orally. Blood collection occurred at different periods for the assessment of blood glucose (0, 60, 90 and 210 min after treatment) and at the end of the experiment blood was collected through cardiac puncture and the liver, muscle, pancreas and intestine were dissected for further analysis.

RESULTS

Chromatographic analysis identified oleic and palmitic acid as the most common constituents, and both extracts of Maytenus ilicifolia caused a reduction in blood glucose levels within 60 min after administration of glucose overload when compared to the normal hyperglycemic group. No significant changes were observed in hepatic and muscular glycogen levels, plasma insulin concentration and disaccharidases activity with none of the extracts in the model employed. However, hyperglycemic rats treated with the extracts showed a marked increase in triglyceride and HDL cholesterol levels.

CONCLUSIONS

Our data suggest that Maytenus ilicifolia extracts from different locations showed differences in chemical composition which did not reflect significant differences in the results of biological tests. In addition, it was possible to conclude that the treatment with Maytenus ilicifolia had a discreet anti-hyperglycemic effect; however, it was not possible to identify the responsible mechanism, being necessary, therefore, new studies using different technologies in order to determine the possible mechanisms of action of the extract.

NiO nanoparticles induce cytotoxicity mediated through ROS generation and impairing the antioxidant defense in the human lung epithelial cells (A549): Preventive effect of Pistacia lentiscus essential oil

Nickel oxide nanoparticles (NiO NPs) have attracted increasing attention owing to potential capacity to penetrate to several human cell systems and exert a toxic effect. Elsewhere, the use of medicinal plants today is the form of the most widespread medicine worldwide. Utilizing aromatic plants as interesting source of phytochemicals constitute one of the largest scientific concerns. Thus this study was focused to investigate antioxidant and cytoprotective effects of essential oil of a Mediterranean plant P. lentiscus (PLEO) on NiO NPs induced cytotoxicity and oxidative stress in human lung epithelial cells (A549). The obtained results showed that cell viability was reduced by NiO NPs, who's also found to induce oxidative stress in dose-dependent manner indicated by induction of reactive oxygen species and reduction of antioxidant enzymes activities. Our results also demonstrated that PLEO contains high amounts in terpinen-4-ol (11.49%), germacrene D (8.64%), α-pinene (5.97%), sabinene (5.19%), caryophyllene (5.10%) and δ-Cadinene (4.86%). PLEO exhibited a potent antioxidant capacity by cell viability improving, ROS scavenging and enhancing the endogenous antioxidant system against NiO NPs in this model of cells. The present work demonstrated, for the first time, the protective activity of PLEO against cell oxidative damage induced by NiO NPs. It was suggested that this plant essential oil could be use as a cells protector.

Ethyl acetate fraction of Cymbopogon citratus as a potential source of antioxidant compounds

New fraction from a lemongrass acidic aqueous phase as a source of compounds with remarkable antioxidant properties by different in vitro mechanisms.

Chemical, enzymatic and cellular antioxidant activity studies of Agaricus blazei Murrill

Mushrooms possess nutritional and medicinal properties that have long been used for human health preservation and that have been considered by researchers as possible sources of free radical scavengers. In this work, the antioxidant properties of water extracts from Agaricus blazei Murill, produced by maceration and decoction, are demonstrated in vitro. Resistance to oxidation is demonstrated through three mechanisms: i) inhibition of enzymatic oxidative process, with 100% inhibition of HRP (horseradish peroxidase) and MPO (myeloperoxidase); ii) inhibition of cellular oxidative stress, with 80% inhibition of the oxidative burst of polymorphonuclear neutrophils (PMNs); and iii) direct action over reactive species, with 62% and 87% suppression of HOCl and superoxide anion radical (O2• -), respectively. From the data, it was concluded that the aqueous extract of A. blazei has significant antioxidant activity, indicating its possible application for nutraceutical and medicinal purposes.

A study of antimicrobial activity, acute toxicity and cytoprotective effect of a polyherbal extract in a rat ethanol-HCl gastric ulcer model

Background

The decoction of the aerial parts of Rhynchosia recinosa (A.Rich.) Bak. [Fabaceae] is used in combination with the stem barks of Ozoroa insignis Del. (Anacardiaceae), Maytenus senegalensis (Lam.) Excell. [Celastraceae] Entada abyssinica Steud. ex A.Rich [Fabaceae] and Lannea schimperi (Hochst.)Engl. [Anacardiaceae] as a traditional remedy for managing peptic ulcers. However, the safety and efficacy of this polyherbal preparation has not been evaluated. This study reports on the phytochemical profile and some biological activities of the individual plant extracts and a combination of extracts of the five plants.

Methods

A mixture of 80% ethanol extracts of R. recinosa, O. insignis, M. senegalensis, E. abyssinica and L. schimperi at doses of 100, 200, 400 and 800 mg/kg body wt were evaluated for ability to protect Sprague Dawley rats from gastric ulceration by an ethanol-HCl mixture. Cytoprotective effect was assessed by comparison with a negative control group given 1% tween 80 in normal saline and a positive control group given 40 mg/kg body wt pantoprazole. The individual extracts and their combinations were also tested for antibacterial activity against four Gram negative bacteria; Escherichia coli (ATCC 25922), Salmonella typhi (NCTC 8385), Vibrio cholerae (clinical isolate), and Klebsiella pneumoniae (clinical isolate) using the microdilution method. In addition the extracts were evaluated for brine shrimp toxicity and acute toxicity in mice. Phytochemical tests were done using standard methods to determine the presence of tannins, saponins, steroids, cardiac glycosides, flavonoids, alkaloids and terpenoids in the individual plant extracts and in the mixed extract of the five plants.

Results

The combined ethanolic extracts of the 5 plants caused a dose-dependent protection against ethanol/HCl induced ulceration of rat gastric mucosa, reaching 81.7% mean protection as compared to 87.5% protection by 40 mg/kg body wt pantoprazole. Both the individual plant extracts and the mixed extracts of 5 plants exhibited weak to moderate antibacterial activity against four G-ve bacteria. Despite Ozoroa insignis being toxic to mice at doses above 1000 mg/kg body wt, the other plant extracts and the combined extract of the 5 plants were tolerated by mice up to 5000 mg/kg body wt. The brine shrimp test results showed the same pattern of toxicity with Ozoroa insignis being the most toxic (LC₅₀ = 10.63 μg/ml). Phytochemical tests showed that the combined extract of the five plants contained tannins, saponins, steroids, cardiac glycosides, flavonoids and terpenoids. Flavonoids, tannins and terpenoids are known to have antioxidant activity.

Conclusion

The combined extract of the five plants exhibited a dose-dependent protective activity in the rat ethanol-HCl gastric ulcer model. The extracts also exhibited weak antibacterial activity against four Gram negative bacteria and low acute toxicity in mice and brine shrimps. Although the results support claims by traditional healers who use a decoction of the five plants for treatment of peptic ulcers, more models of gastric ulceration and proper animal toxicity studies are needed to validate possible clinical use of the polyherbal extract. It is also evident that the doses of the crude extracts showing protection of the gastric mucosa are too large for realistic translation to direct clinical application, but further studies using bioassay guided fractionation are important to either identify more practical fractions or active compound/s.

CZE/PAD and HPLC-UV/PAD Profile of Flavonoids from Maytenus aquifolium and Maytenus ilicifolia “espinheira santa” Leaves Extracts

This paper describes the application of HPLC and CZE to analyze flavonoids in the leaves of Maytenus ilicifolia and Maytenus aquifolium, which are species widely used in Brazilian folk medicine. The two species showed different flavonoid profiles, but acidic hydrolysis of the Maytenus extracts confirmed that all these compounds are quercetin or kaempferol derivatives. A comparison of the CZE and HPLC profiles of Maytenus extracts showed numerous flavonoid peaks using HPLC. However, the advantages of CZE such as analysis without requiring clean-up and less generation of chemical waste than with HPLC point to the potential of the CZE technique for the quality control (routine analysis) of “espinheira santa” phytopharmaceuticals.

Evaluation of antioxidant capacity and synergistic associations of quinonemethide triterpenes and phenolic substances from Maytenus ilicifolia (Celastraceae)

This work describes the isolation of the secondary metabolites identified as the quinonemethides maytenin (1) and pristimerin (2) from Maytenus ilicifolia extracts obtained from root barks of adult plants and roots of seedlings and their quantification by high performance liquid chromatography coupled to a diode array detector. The electrochemical profiles obtained from cyclic voltammetry and a coulometric detector coupled to high-performance liquid chromatography contributed to the evaluation of their antioxidant capacity. The antioxidant properties of individual components and the crude extracts of the root barks of Maytenus ilicifolia were compared and the possible synergistic associations of quinonemethide triterpenes and phenolic substances were investigated by using rutin as a model phenolic compound.

Genetic diversity and conservation of native populations of Maytenus Ilicifolia Mart. ex Reiss

The aim of this work was to analyze genetic variability in 18 populations of Maytenus ilicifolia, and representatives of Maytenus aquifolia and Maytenus evonymoidis, collected in the states of Mato Grosso do Sul, Paraná, Santa Catarina and Rio Grande do Sul, using RAPD molecular markers. Considering total samples of the three species, 263 amplified fragments were identified, of which 72.2% showed to be polymorphous. The index of similarity (Jaccard coefficient) was on average 0.64 between M. ilicifolia and M. aquifolia; 0.47 between M. ilicifolia and M. evonymoidis; and 0.44 between M. aquifolia and M. evonymoidis. The analysis of groupings by the UPGMA algorithm allowed to clearly separate the three analyzed species. In determining the variability in M. ilicifolia, 222 bands were identified, on average 11.1 bands per primer, being 43.2% polymorphous. The index of similarity (Jaccard coefficient) in the bulks of each population in M. ilicifolia was, on average, 0.92 and the index of similarities among the populations was 0.83. The analysis of groupings with the UPGMA algorithm and the analysis of the main coordination (PCO), allowed the separation of the analyzed populations into three groups, the populations from the south of Rio Grande do Sul and the population from Mato Grosso do Sul standing out. A relation between the groupings found and the edaphoclimatic conditions of the collecting places was observed.

Muscarinic-dependent inhibition of gastric emptying and intestinal motility by fractions of Maytenus ilicifolia Mart ex. Reissek

ETHNOPHARMACOLOGICAL RELEVANCE

Maytenus ilicifolia Mart. ex. Reissek (Celastraceae) is widely used in Brazilian folk medicine to treat gastric disturbances.

AIM OF THE STUDY

This work intended to characterize the effects of Maytenus ilicifolia on gastrointestinal motility.

MATERIALS AND METHODS

Gastric emptying and intestinal transit were measured in the same animal. Mice received a semisolid marked with phenol red, half an hour after treatment with extracts. The amount of marker in the stomach and the distance reached in the intestine after 15 min were measured as index of gastrointestinal emptying and intestinal transit, respectively.

RESULTS

Intraperitoneal administration of a flavonoid-rich extract potently reduced the gastric emptying (ED(50)=89 mg/kg) and the intestinal transit (ED(50)=31 mg/kg) of mice. Bio-guided purification of the flavonoid-rich extract by chemical partition with solvents of decreasing polarity yielded fraction insF with about 12-14 times higher activity than the initial flavonoid extract in both the gastric emptying and the intestinal transit. The inhibitory effects of the insF (9.7 mg/kg, i.p.) on gastric emptying and intestinal transit were reversed by co-administration of bethanechol (10 mg/kg, s.c.) but not by co-administration of metoclopramide (30 mg/kg, p.o.) indicating muscarinic but not dopaminergic interaction of the compounds of Maytenus. Chemical investigation of the insF fraction by HPLC-MS allowed the identification of 4 free flavonoids (catechin, epicatechin, quercetin and kaempferol), 29 flavonol glycosides and 8 tannins. The flavonol glycosides ranged from 1 to 4 monosaccharide units, having mainly quercetin and kaempferol as aglycone moieties, and the tannins were composed by catechin/epicatechin and/or afzelechin/epiafzelechin.

CONCLUSIONS

Overall, the results indicate that the components of Maytenus ilicifolia have a potential use in the treatment of gastrointestinal motility disturbances such as diarrhea.

Antioxidant and Larvicidal Activities of Tephrosia Egregia Sandw against Aedes Aegypti

The antioxidant and larvicidal activities of Tephrosia egregia extracts and its major component, dehydrorotenone, were studied. High antioxidant activity was found for dehydrorotenone and methanol and ethyl acetate extracts from roots and stems, respectively. Among the tested extracts, the hexane extract from stems showed potent larvicidal activity (LC50 12.88 ± 0.64) while low activity was found for dehydrorotenone.

Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile

Reactive oxygen species (ROS) and free radical species have been implicated in initiating or accompanying many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Salacia species have long been used, in several countries, as traditional medicines against certain diseases and for their anti-inflammatory properties. In this study, Salacia campestris Walp (Hippocrateaceae) root bark ethanol extract (ScEtOH) was assessed for its ability to scavenge free radicals and reactive oxygen species; the results were expressed as percentage inhibition of the active species. ScEtOH was efficient against studied species: DPPH radical (obtained inhibition = 30%), ABTS•+ (IC50 = 1.8±0.8 μg/mL), HOCl (IC50 = 1.7 ± 0.1 μg/mL), O2•- (obtained inhibition = 32%), and NO• (obtained inhibition = 18 %). Peroxidase activity inhibition was evaluated through the guaiacol oxidation reaction catalyzed by hemin, HRP and myeloperoxidase (MPO); data showed that ScEtOH at 10 μg/mL led to 54 and 51% of inhibition, respectively, for the hemin and HRP systems. In the MPO system, ScEtOH promoted a 50% inhibition at 8.9 μg/mL, whereas quercetin, a powerful MPO inhibitor, inhibited this system at 1.35 μg/mL.