Antimutagenic, antioxidant and antimicrobial properties of Maytenus krukovii 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.

Phytochemical analysis and Evaluation of hepatoprotective effect of Maytenus royleanus leaves extract against anti-tuberculosis drug induced liver injury in mice

BACKGROUND

Myrin®-p Forte is an anti-tuberclosis agent that can cause hepatic injuries in clinical settings. Maytenus royleanus (Celastraceae) is a medicinal plant, possesses antioxidant and anticancer activities. The hepatoprotective effect of the methanol extract of Maytenus royleanus leaves (MEM) against Myrin®-p Forte induced hepatotoxicity in mice was investigated.

METHODS

Mice were randomly parted into six groups (n = 6). Fixed-dose combination of Myrin®-p Forte (13.5 mg/kg Rifampicin, 6.75 mg/kg Isoniazid, 36.0 mg/kg Pyrazinamide and 24.8 mg/kg Ethambutol; RIPE] was administered for 15 days to induce liver injury. In treatment groups MEM (200 mg/kg and 400 mg/kg doses) and Vitamin B6 (180mg/kg) were administered prior to RIPE. Control group received 2% DMSO. Serum liver function tests, DNA damage, tissue antioxidant enzymes and histopathological alterations were studied. HPLC analysis was performed to determine the chemical composition using standard compounds.

RESULTS

The quercitin, gallic acid, luteolin, viteixin, apigenin, kaempherol, hyperoside and myricetin contents of all samples were determined by reverse-phase HPLC. Quercetin (0.217 mg/g dry weight) and luteolin (0.141 mg/g dry weight) were the major flavonoids identified in MEM. Myrin®-p Forte markedly (p < 0.05) deteriorated lipid profile and upregulated the concentration of LDH, AST, ALP, ALT and γ-GT in serum along with DNA fragmentation (37.13 ± 0.47%) and histopathological injuries in hepatic tissues of mice compared with the control group. Myrin®-p Forte increased (p < 0.001) lipid peroxidation and H₂O₂ while decreased (p < 0.001) the activity level of CAT, SOD, POD, GPx, GST, GSR, γ-GT and GSH. Co-administration of MEM (200 mg/kg; 400 mg/kg) or the vitamin B6 (180 mg/kg) to Myrin®-p Forte administered mice significantly ameliorated LDL, cholesterol, HDL and triglyceride content. Furthermore, MEM dose dependently corrected serum liver function tests, decrease % DNA fragmentation (17.82 ± 0.35 and 7.21 ± 0.32 respectively), DNA damage. MEM treated protect RIPE induced oxidative damage by enhancing antioxidants to oxidants balance. Histological examination comprehends biochemical findings.

CONCLUSION

The antioxidant effects of MEM exerted the hepatoprotective potential against the Myrin®-p Forte induced hepatotoxicity in mice.

Metabolite profiling of polyphenols in a Terminalia chebula Retzius ayurvedic decoction and evaluation of its chemopreventive activity

ETHNOPHARMACOLOGICAL RELEVANCE

The decoction of Terminalia chebula fruit is an ayurvedic remedy whose prolonged oral administration is prized as a generic intestinal and hepatic detoxifying agent. Its administration is suggested also under the perspective of a reduced risk of cancer, metabolic and cardiovascular diseases.

AIM OF THE STUDY

To evaluate the phytochemical profile and the chemopreventive potential of Terminalia chebula fruit decoction prepared according to the ayurvedic decoction recipe.

MATERIALS AND METHODS

The quali- and quantitative metabolite profiling of polyphenols was obtained using HPLC-UV/DAD and HPLC-ESI-MS. The crude decoction and purified compounds were tested for their capability to interact with the EphA2-ephrin-A1 system and for their antimutagenic properties against dietary and environmental mutagens (AA, 2-NF, NaN3, and heterocyclic amines IQ, MeIQ, MeIQx, Glu-P1, Glu-P2,) in the Ames-Salmonella/microsome assay, with and without enzymatic induction.

RESULTS

The decoction was found to contain 3,4,6-tri-O-galloyl-d-glucose (55.87 mg/g), chebulic acid (54.03 mg/g), β-punicalagin (41.25mg/g), corilagin (40.31 mg/g), α-punicalagin (35.55 mg/g), chebulagic acid (29.09 mg/g), gallic acid (27.96 mg/g) 1,3,4,6-tri-O-galloyl-β-d-glucose (24.25mg/g) chebulinic acid (20.23 mg/g), 1,2,3,4,6-penta-O-galloyl-d-glucose (13.53 mg/g), ellagic acid (8.00 mg/g), 1,6-di-O-galloyl-d-glucose (4.16 mg/g). An inhibitory effect was recorded in both Salmonella typhimurium TA98 and TA100 strains against the mutagenic activity of heterocyclic amines (22-61%), promutagen AA (91-97%) and directly acting mutagen 2-NF (52%) with but not against NaN3 (7%). Galloyl derivatives allowed an inhibition of mutagenicity induced by MeIQ above 80% at 0.01 mol/plate. Both decoction and purified compounds were able to modulate the EphA2-ephrinA1 system, suggesting a potential multiple chemopreventive mechanism.

CONCLUSIONS

The traditional ayurvedic decoction of Terminalia chebula may harbour a potential as a safe and low-cost chemopreventive agent at the intestinal level, if administered according to the ayurvedic specifications. Moreover, its recourse may enhance the presence of some polyphenolic constituents.

trans-Resveratrol in nutraceuticals: issues in retail quality and effectiveness

Fourteen brands of resveratrol-containing nutraceuticals were evaluated in order to verify their actual resveratrol content and to control if their health-promoting properties are related to manufacturing quality. Products included pure resveratrol capsules or multi-ingredient formulations with standardized amounts of resveratrol and other phytochemicals. Samples were analyzed for total trans-resveratrol, flavonoids, procyanidin, polyphenol content and the results were compared with the content declared on-label. Only five out of 14 brands had near label values, compliant with Good Manufacturing Practices (GMP) requirements (95–105% content of active constituent), four products were slightly out of this range (83–111%) and three were in the 8–64% range. Two samples were below the limit of detection. The greater the difference between actual and labeled resveratrol content, the lower was the antioxidant and antiproliferative activity strength. Dietary supplements containing pure trans-resveratrol exhibited a greater induction of differentiation towards human leukemic K562 cells when compared to multicomponent products. Great differences currently exist among resveratrol food supplements commercially available and GMP-grade quality should not be taken for granted. On the other side, dosages suggested by most “pure”, “high-dosage” supplements may allow a supplementation level adequate to obtain some of the purported health benefits.

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.

Operculina turpethum attenuates N-nitrosodimethylamine induced toxic liver injury and clastogenicity in rats

The root extract of Operculina turpethum (OTE) has been used as an anti-inflammatory, purgative, and hepato-protective agent. N-Nitrosodimethylamine (NDMA) is a potent hepatotoxin that induces fibrosis of the liver. In the present study, we examined the therapeutic effects of OTE root extract against NDMA-induced hepatotoxicity and clastogenicity in rats. Hepatic fibrosis was induced in adult male albino rats through serial intraperitoneal administrations of NDMA at a concentration of 10mg/kg body weight on three consecutive days of each week over a period of three weeks. A group of rats received OTE orally in doses of 75, 150 and 200mg/kg body weight at 5h after the administration of NDMA. The controls and treated animals were sacrificed on days-7, 14 and 21 after the start of the administration of NDMA. The progression of hepatic fibrosis as well as the amelioration effect of OTE was evaluated through histopathologically as well as by immunohistochemical staining for the activation of hepatic stellate cells. Alterations in serum and liver biochemical parameters and LDH isoenzymes were also studied. Serial administration of NDMA resulted in well formed fibrosis in the liver and induction of micronuclei in the bone marrow cells. Staining of alpha-SMA demonstrated activated stellate cells from day-7 onwards which was dramatically increased on day-21. An elevation of micronuclei count, liver function enzymes, serum hydroxyproline levels and LDH isoenzymes 4 and 5 were also observed. All these changes were remarkably reduced in OTE administered animals and fibrogenesis was completely absent. Our results suggest that OTE has hepatoprotective and anti-clastogenic effects against NDMA-induced hepatic fibrosis. Therefore OTE may be used as a hepatoprotective agent against various liver diseases including toxic liver injury.

Influence of dietary feeding of low monomer content grape seed extract on vitellogenin production and cholesterol levels in goldfish, Carassius auratus

Grape seed extract (GSE) is a source of naturally occurring compounds known as proanthocyanidins and flavan-3-ols, which are recognized to exert a protective effect on human health, so GSE is widely used mainly as a nutritional supplement. However, polyphenols may have, in some cases, estrogenic effects or may interfere with the endocrine system. For that reason, it was considered of interest to investigate the beneficial or detrimental effects induced by low monomer content grape seed extract (LMC-GSE) in a teleost experimental model, the juvenile goldfish (Carassius auratus); therefore, biomarkers of estrogenic exposure together with cholesterol titers were assessed in both plasma and tissue samples taken from fish fed with different doses of LMC-GSE for 4 weeks. Dietary LMC-GSE (71 or 35 mg/g diet) did not affect vitellogenin (VTG) synthesis; on the contrary, VTG production was exclusively induced in fish fed with an estradiol-17beta (E2)-incorporated diet. In addition, it was found that both plasma E2 levels and hepatic total cholesterol were not affected by LMC-GSE dietary regimens.

Antioxidant and antimutagenic effects of the crude foliar extract and the alkaloid brachycerine of Psychotria brachyceras

The monoterpene indole alkaloid brachycerine from Psychotria brachyceras has been shown to be induced by UV and to have in vitro antioxidant activity, indicating a possible protective role against the secondary effects of this radiation. In this work, we have studied the antioxidant properties of brachycerine and a crude foliar extract from P. brachyceras by using Saccharomyces cerevisiae strains proficient and deficient in antioxidant defenses. The mutagenic and antimutagenic potential of these substances were assayed in S.cerevisiae N123 strain in the presence and absence of H2O2. In addition, we tested the antioxidant capacity of brachycerine and a crude foliar extract from P. brachyceras on hydroxyl radicals (OH) using the hypoxanthine/xanthine oxidase assay. The results show that brachycerine and the crude foliar extract of P. brachyceras have antioxidant and antimutagenic effects in yeast and probably this action is mainly due to the scavenging of OH radicals.