Protective effect of flavonoids from Passiflora edulis Sims on diabetic complications in rats.

OBJECTIVES: This study was carried out to evaluate the effects of flavonoids present in leaves of Passiflora edulis fruit on complications induced by diabetes in rats. METHODS: The extract of P. edulis leaf was obtained by 70% ethanol maceration. From the dry extract, the fractions were obtained by consecutive liquid-liquid partition with hexane, ethyl acetate and n-butanol. The content of isoorientin of ethyl acetate and n-butanol fractions was determined by ultra-performance liquid chromatography coupled with electrospray and triple quadrupole ionization (TQD) analysis in tandem mass spectrometry (UPLC-ESI-Tq-MS). Only Fr-BuOH was used to treat diabetic or not Wistar rats. Biochemical parameters, platelet aggregation and production of reactive species were evaluated. KEY FINDINGS: The UPLC-ESI-Tq-MS analysis revealed the presence of several flavonoids, among which we identified five possible flavonoids c-heterosides (luteolin-7-O-pyranosyl-3-O-glucoside, apigenin-6-8-di-C-glycoside, apigenin-6-C-arabinoside-8-C-glycoside, isoorientin, isovitexin). The diabetic rats (treated intraperitoneally with alloxan, 150 mg/kg) treated with Fr-BuOH (20 mg/kg/day for 90 days) presented improvement in blood glucose, serum levels of fructosamine, lipid profile and urea. Furthermore, the Fr-BuOH reduced both platelet aggregation and the production of oxidant species in diabetic animals. CONCLUSIONS: These results suggested that flavonoid C-glycosides present in the Fr-BuOH may be beneficial for the diabetic state, preventing complications induced by diabetes.

Dereplication and evaluation of the antinociceptive and anti-inflammatory activity of hydroethanolic extract of leaves from Campomanesia xanthocarpa O. Berg.

Campomanesia xanthocarpa popularly known as gabiroba is used as a medicinal plant for the treatment of inflammatory diseases, ulcers, among other uses, requiring studies to assist in proving these activities. In this study, the extract of leaves from C. xanthocarpa (CxHE) was submitted to assays of formalin-induced paw-licking, peritonitis induced by lipopolysaccharide and carrageenan-induced mechanical hyperalgesia tests. In chemical analysis, a preliminary phytochemical screening and the determination of phenol and flavonoid content were carried out, in addition to analysis by ESI-MS/MS system and HPLC-DAD system. The CxHE presented compounds such as tannins, triterpenoids, steroids and saponins and content of phenols (35.9 ± 1.3 GAE/g extract) and flavonoids (23.3 ± 2.1 mg EQ/g extract). Protocatechuic acid, gallic acid, ethyl gallate, quercetin, and 3-methyl epigallocatechin gallate, alpha and beta-amyrins were identified. CxHE at doses of 10-1000 mg/kg p.o. demonstrated anti-inflammatory and antinociceptive effects in all in vivo assays employed in this study. [Figure: see text].

Exploring the bioactivity potential of Leonotis nepetifolia: phytochemical composition, antimicrobial and antileishmanial activities of extracts from different anatomical parts.

Leonotis nepetifolia (L.) Br. (Lamiaceae) is an African shrub popularly known as 'cordão-de-frade' in Brazil, traditionally used to treat infectious diseases, among other uses. This study aimed to investigate the phytochemical composition of hydroethanolic extracts from L. nepetifolia prepared from stems, leaves, roots and glomerulus, as well as their cytotoxicity, antileishmanial and antimicrobial activities. The chemical composition of the extracts was assessed by UPLC-ESI-MS/MS, whereas the antileishmanial activity was evaluated against promastigote and amastigote forms of Leishmania amazonensis. Cytotoxicity was tested on murine macrophages and the antimicrobial activity was investigated by a microdilution assay against several strains of fungi, Gram-positive and Gram-negative bacteria. The flavonoids apigenin, cirsiliol apigenin-7-O-glucoside, luteolin, luteolin-4'-O-glucoside, luteolin-4'-O- glucuronide and luteolin-7-O-glucoside were identified in all tested extracts. Extracts from leaves and roots showed more potent antileishmanial activity (IC50 32.90 µg mL-1 and 57.70 µg mL-1, respectively) against amastigotes forms in comparison to the other extracts. The leaf extract inhibited Bacillus cereus and Staphylococcus aureus growth (125 µg mL-1 and 100 µg mL-1, respectively), and also showed anti-Candida activity (10-125 µg mL-1). The biological effect can be related to the identified flavonoids. Our findings disclose the potential of L. nepetifolia as a source of bioactive compounds for the development of new therapeutic options for treating infectious diseases, especially flavonoids.

Passiflora edulis Leaf Extract: Evidence of Antidiabetic and Antiplatelet Effects in Rats.

Different Passiflora species have been appointed as a promising herbal medicine due to antioxidant properties; however, their effect on oxidative process induced by diabetes is still controversial. We aimed to evaluate effects of hydroethanolic extract 70% from P. edulis leaf on biochemical blood markers, collagen glycation, production of oxidant species and platelet aggregation in diabetic rats. The phytochemical analysis of the extract was performed by dereplication using LC coupled to the Photodiode Array Detector and Mass Spectrometer detector. Male Wistar rats were assigned to the control group and groups treated with alloxan (150 mg/kg) intraperitoneally, extract (200 mg/kg/d, for 90 d) and combination of alloxan and extract. The phytochemical analysis suggested the presence of flavonoids C-glycosides in the extract. The diabetic animals treated with the extract presented improvement in glycaemic control, reduced glycation collagen, levels of non-high density lipoprotein (non-HDL) cholesterol, total cholesterol and creatinine, production of oxidant species and aggregation in platelet in relation to diabetic animals non-treated. Our results showed that P. edulis leaf extract presents a health benefit to the diabetic state, preventing the appearance of its complications. Its effect can be associated with flavonoids, among which is the flavonoid C-glycoside isoorientin.

The Anti-Inflammatory Potential of Mimosa caesalpiniifolia Following Experimental Colitis: Role of COX-2 and TNF-Alpha Expression.

The aim of this study was to evaluate the preventive and/or protective action of Mimosa caesalpiniifolia (M. caesalpiniifolia) following experimental colitis in rats. The rats were randomized into ten groups (n=10 per group), as follows: G1 - Sham group:; G2 - TNBS group; G3, G4 -colitis and treated with hydroalcoholic extract of M. caesalpiniifolia 250 mg/kg/day after and before/after inducing colitis, respectively; G5, G6 - colitis and treated with hydroalcoholic extract of M. caesalpiniifolia at 125 mg/kg/day after and before/after inducing colitis respectively; G7,G8 - colitis and treated with ethylacetate fraction of M. caesalpiniifolia at 50 mg/kg/day after and before/after inducing colitis, respectively; G9,G10 - colitis and treated with ethylacetate fraction of M. caesalpiniifolia at 50 mg/kg/day after and before/after inducing colitis, respectively. Rats treated with hydroalcoholic extract of M. caesalpiniifolia for both doses showed lower tissue damage in the distal colon. Ethylacetate fraction was effective at the highest dose only when administrated after inducing colitis. A downregulation of COX-2 was detected to rats suffering colitis and treated with M. caesalpiniifolia at high dose. On the other hand, TNF-alpha immunoexpression decreased in groups treated with M. caesalpiniifolia at low dose after inducing colitis. In summary, our results suggest that M. caesalpiniifolia attenuated the lesions of the colon, reduced inflammation, and modulates the expression of COX-2 and TNF-α during chronic colitis induced by TNBS when using for therapeutic purposes on a dose-dependent manner.

Mimosa (Mimosa caesalpiniifolia) prevents oxidative DNA damage induced by cadmium exposure in Wistar rats.

The Mimosa (Mimosa caesalpiniifolia) is a plant native from South America; it is used in the traditional medicine systems for treating bacterial, fungal, parasitic and inflammatory conditions. The aim of this study was to evaluate the antigenotoxic and antioxidant activities induced by mimosa (M. caesalpiniifolia) in multiple rodent organs subjected to intoxication with cadmium chloride. A total of 40 Wistar rats (8 weeks old, 250 g) were distributed into eight groups (n = 5), as follows: Control group (non-treated group, CTRL); Cadmium exposed group (Cd); cadmium exposure and treated with extract at 62.5 mg/kg/day; cadmium exposure and treated with extract at 125 mg/kg/day; cadmium exposure and treated with extract at 250 mg/kg/day; cadmium exposure and treated with ethyl acetate fraction at 62.5 mg/kg/day. For evaluating the toxicogenetic potential of mimosa, two groups were included in the study being treated with extract at 250 mg/kg/day and acetate fraction of mimosa at 62 mg/kg/day, only. Extract of mimosa at concentrations of 62.5 and 125 mg decreased DNA damage in animals intoxicated with cadmium when compared to cadmium group. In a similar manner, treatment with ethyl acetate fraction of mimosa at 62.5 mg concentration in animals previously exposed to cadmium reduced genetic damage in peripheral blood cells. In a similar manner, the treatment with ethyl acetate fraction reduced DNA damage in liver cells. Oxidative DNA damage was reduced to animals exposed to cadmium and treated with 125 mg of extract as well as those intoxicated to cadmium and treated with 62.5 of acetate fraction of mimosa. Taken together, our results indicate that mimosa prevents genotoxicity induced by cadmium exposure in liver and peripheral blood cells of rats as a result of antioxidant activity.

Estrogenic and chemopreventive activities of xanthones and flavones of Syngonanthus (Eriocaulaceae).

The possible benefits of some bioactive flavones and xanthones present in plants of the genus Syngonanthus prompted us to screen them for estrogenic activity. However, scientific research has shown that such substances may have undesirable properties, such as mutagenicity, carcinogenicity and toxicity, which restrict their use as therapeutic agents. Hence, the aim of this study was to assess the estrogenicity and mutagenic and antimutagenic properties. We used recombinant yeast assay (RYA), with the strain BY4741 of Saccharomyces cerevisiae, and Ames test, with strains TA100, TA98, TA97a and TA102 of Salmonella typhimirium, to evaluate estrogenicity, mutagenicity and antimutagenicity of methanolic extracts of Syngonanthus dealbatus (S.d.), Syngonanthus macrolepsis (S.m.), Syngonanthus nitens (S.n.) and Syngonanthus suberosus (S.s.), and of 9 compounds isolated from them (1=luteolin, 2=mix of A-1,3,6-trihydroxy-2-methoxyxanthone and B-1,3,6-trihydroxy-2,5-dimethoxyxanthone, 3=1,5,7-trihydroxy-3,6-dimethoxyxanthone, 4=1,3,6,8-tetrahydroxy-2,5-dimethoxyxanthone, 5=1,3,6,8-tetrahydroxy-5-methoxyxanthone, 6=7-methoxyluteolin-8-C-ß-glucopyranoside, 7=7-methoxyluteolin-6-C-ß-glucopyranoside, 8=7,3'-dimethoxyluteolin-6-C-ß-glucopyranoside and 9=6-hydroxyluteolin). The results indicated the estrogenic potential of the S. nitens methanol extract and four of its isolated xanthones, which exhibited, respectively, 14.74±1.63 nM; 19.54±6.61; 7.20±0.37; 6.71±1.02 e 10.01±4.26 nM of estradiol-equivalents (EEQ). None of the extracts or isolated compounds showed mutagenicity in any of the test strains and all of them showed antimutagenic potential, in particular preventing mutations caused by aflatoxin B1 (AFB1) and benzo[a]pyrene (B[a]P). The results show that the xanthones, only isolated from the methanol extract of S. nitens capitula, probably were the responsible for its estrogenic activity and could be useful as phytoestrogens, providing a new opportunity to develop hormonal agents. In addition, flavones and xanthones could also be used as a new antimutagenic agent. Since, the mutagens are involved in the initiation and promotion of several human diseases, including cancer, the significance of novel bioactive phytocompounds in counteracting these pro-mutagenic and carcinogenic effects is now gaining credence.

Effects of Rhizophora mangle on Experimental Colitis Induced by TNBS in Rats.

Male Unib-WH rats were pretreated for two weeks with butanolic (BuOH) and ethyl acetate (EtOAc) fractions. Colitis was induced by rectal administration of TNBS, the treatment continued, and animals were sacrificed on day 7 after the TNBS administration. Phytochemical studies were performed in order to provide the characterization of the tannins present in the bark of R. mangle. Results showed that EtOAc fraction increased the levels of IL-10 (∗∗P < 0.01) and diminished the levels of TNF-α (∗∗∗P < 0.001) and IL-6 (∗∗P < 0.01). BuOH fraction reduced the MPO activity (∗∗P < 0.01) and levels of TBARS (∗∗∗P < 0.001); it also increased COX-1 expression, diminished the levels of TNF-α (∗∗∗P < 0.001), and increased the levels of IL-12 (∗∗∗P < 0.001). Besides, both treatments augmented the levels of GSH (∗P < 0.05), the activity of GSH-Px (∗∗P < 0.01 for BuOH fraction and ∗∗∗P < 0.001 for EtOAc fraction), and CAT (∗∗P < 0.01). In conclusion, both treatments ameliorated the injury induced by TNBS through different mechanisms, probably by their chemical composition which directed its activity into an antioxidant or anti-inflammatory response, leading to an immune modulation.

Antioxidant action of mangrove polyphenols against gastric damage induced by absolute ethanol and ischemia-reperfusion in the rat.

Rhizophora mangle, the red mangrove, has long been known as a traditional medicine. Its bark has been used as astringent, antiseptic, hemostatic, with antifungic and antiulcerogenic properties. In this paper, we aimed to evaluate the antioxidant properties of a buthanolic fraction of the R. mangle bark extract (RM) against experimental gastric ulcer in rats. Unib-Wh rats received pretreatment of R. mangle after the induction of gastric injury with absolute ethanol and ischemia-reperfusion. Gastric tissues from both methods were prepared to the enzymatic assays, the levels of sulfhydril compounds (GSH), lipid peroxides (LPO), and the activities of glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and myeloperoxidase (MPO) were measured. The RM protected the gastric mucosa in both methods used, ethanol-induced gastric ulcer and ischemia-reperfusion, probably, by modulating the activities of the enzymes SOD, GPx, and GR and increasing or maintaining the levels of GSH; in addition, LPO levels were reduced. The results suggest that the RM antioxidant activity leads to tissue protection; thus one of the antiulcer mechanisms present on the pharmacological effects of R. mangle is the antioxidant property.

Isolation and evaluation of the antioxidant activity of phenolic constituents of the Garcinia brasiliensis epicarp.

A new glycosylated biflavonone, morelloflavone-4'″-O-ß-d-glycosyl, and the known compounds 1,3,6,7-tetrahydroxyxanthone, morelloflavone (fukugetin) and morelloflavone-7″-O-ß-d-glycosyl (fukugeside) were isolated from the epicarp of Garcinia brasiliensis collected in Brazil. The structures of these compounds were established using 1H and 13C NMR, COSY, gHMQC and gHMBC spectroscopy. The compounds exhibited antioxidant activity. The greatest potency was displayed by morelloflavone (2), with IC50=49.5mM against DPPH and absorbance of 0.583 at 400µg/mL for the reduction of Fe3+. The weakest potency was displayed by 1,3,6,7-tetrahydroxyxanthone (1), with IC50=148mM against DPPH and absorbance of 0.194 at 400µg/mL for the reduction of Fe3+.

Mechanisms of action underlying the gastric antiulcer activity of the Rhizophora mangle L.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhizophora mangle, the red mangrove, has long been known as a traditional antiulcer medicine. The present work evaluated the mechanisms of action involved in the anti-ulcer properties of the Rhizophora mangle bark extracts. MATERIALS AND METHODS: Gastroprotection of Rhizophora mangle was evaluated in rodent experimental models (ethanol). To elucidate the mechanisms of action the antisecretory action and involvement of NO, SH, mucus and PGE(2) were evaluated. The acetic acid-induced gastric ulcer model, Western blotting assay (COX-1, COX-2 and EGF) and immunohistochemical localization of HSP-70, PCNA and COX-2 were also used to evaluate the Rhizophora mangle healing properties. RESULTS: Results showed that Rhizophora mangle bark crude extract (CE), as well as ethyl acetate (EtOAc) and butanolic fractions (BuOH) provided significant gastroprotection at all the tested doses. Thereby, the following protocols were performed using the lowest dose capable of producing the most effective gastroprotection, which was the BuOH 0.5mg/kg (P<0.001). Several mechanisms are involved in the antiulcer activity of Rhizophora mangle, such as, participation of NO, SH and mucus. The enhancement of PGE(2) levels and the upregulation of COX-2 and EGF seem to be directly linked to the antisecretory, cytoprotective and healing effects of BuOH. HSP-70 and PCNA are also involved in this cicatrisation process. No sign of toxicity was observed in this study, considering the analyzed parameters. CONCLUSION: Our study reinforces its traditional medicinal use. Considering that the current therapies are based on the use of antisecretory or cytoprotective drugs, the Rhizophora mangle arises as a promising alternative antiulcer therapy.

Secondary metabolites of Miconia rubiginosa.

The Miconia genus is the most representative of the Melastomataceae family, and some species are commonly used in Brazilian folk medicine as anti-inflammatory agents. In this work we investigated the leaves from Miconia rubiginosa (Bonpl.) DC, using high-speed countercurrent chromatography, which yielded 11 substances (eight flavonoids, gallic acid, casuarictin, and schizandriside). Identification was achieved using nuclear magnetic resonance spectroscopy and high-performance liquid chromatography-circular dichroism-diode array detection analyses.

Abarema cochliacarpos: gastroprotective and ulcer-healing activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Abarema cochliacarpos (Gomes) Barneby & Grimes (Mimosaceae) is a species--in folk medicine of Lagarto city, Sergipe state, northeastern Brazil--reputed to heal gastric ulcer and gastritis. AIM OF THE STUDY: Chloroform (CE) and methanolic (ME) extracts as well as ethyl acetate fraction (AF), butanolic fraction (AC) and aqueous fraction (AQF) of the methanolic extract of Abarema cochliacarpos bark were evaluated against acute gastric ulcer. The AC fraction was selected to assess its activity in ulcer healing and its gastroprotective effects via mucus and gastric secretion. MATERIAL AND METHODS: The gastroprotective action of CE and ME extracts and the fractions of the latter were evaluated in a rodent experimental model. The action mechanisms, involvements of the antisecretory action and mucus production, toxicological and healing activity of the AC (150 mg/kg, p.o.) were evaluated. We also used histological analysis (HE and PAS) and immunohistochemical (PCNA, COX-2, VEGF and HSP-70) assays to evaluate the effects of Abarema cochliacarpos. RESULTS: CE (200 and 400 mg/kg, p.o.) and ME (100, 200 and 400 mg/kg, p.o.) extracts were able to protect gastric mucosa against absolute ethanol. Respective inhibitions produced were: 65.31% and 83.80% by the first; 91.69%, 96.75% and 99.80% by the second; and 74.24% by the AC fraction. Antisecretory and mucus production effects were exhibited by the AC fraction, which also accelerated the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA) and induced healing factors including COX-2, VEGF and HSP-70. CONCLUSION: All these results suggest that Abarema cochliacarpos (Gomes) Barneby & Grimes presents gastroprotective effects and wound-healing properties.

Anti-inflammatory intestinal activity of Abarema cochliacarpos (Gomes) Barneby & Grimes in TNBS colitis model.

AIM OF THE STUDY: To assess the anti-inflammatory effect of butanolic fraction of methanolic extract from bark of Abarema cochliacarpos in acute ulcerative colitis model induced by intracolonic administration of trinitrobenzene sulfonic acid (TNBS) in Wistar rats. MATERIALS AND METHODS: Abarema cochliacarpos (100 and 150mg/kg/day) was administered by gavage 48, 24 and 1h prior to the induction of colitis with 10mg/kg of TNBS and, 24h later. RESULTS: Phytochemical studies by mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) revealed that catechins were a major component into condensate class of tannins. Treatment with Abarema cochliacarpos decreased significantly macroscopic damage as compared with TNBS (p<0.05). Histological analysis showed that both doses of the extract improved the microscopic structure and preserved some areas of the colonic mucosa structure. In addition, myeloperoxidase activity (MPO), as a marker of neutrophil infiltration, was decreased in a dose-dependent way (p<0.01 and p<0.001 respectively), TNF-alpha level was also diminished with the highest dose of the extract (p<0.001) and, IL-10 level obtained no significant results. In order to elucidate some of the mechanisms, expression of inducible inflammatory enzymes, such as cyclooxygenase (COX)-2 and nitric oxide synthase (iNOS), were studied showing a significant reduction. Finally, the involvement of c-Jun N-terminal kinase (JNK) signalling demonstrated a reduction in the JNK activation with the highest dose (p<0.05 vs TNBS). CONCLUSIONS: We have shown for the first time that the extracts obtained from Abarema cochliacarpos bark possess active substances, which exert marked protective effects in acute experimental colitis, confirming and justifying, at least in part, the popular use of this plant to treat gastrointestinal diseases.

High-performance liquid chromatographic quantification of flavonoids in Eriocaulaceae species and their antimicrobial activity.

Quantification of prepared samples by analysis using high performance liquid chromatography with DAD detection was developed to analyze rutin, 6-methoxyapigenin, and 6-methoxyapigenin-7-O-beta-D-glucopyranoside isolated from methanolic extracts of different genus: Syngonanthus, Leiothix and Eriocaulon (Eriocaulaceae). The linearity, accuracy, and the inter-day precision of the procedure were evaluated. The calibration curves were linear. The recoveries of the flavonoids in the samples analyzed were 96.3% to 98.5%. The percentage coefficient of variation for the quantitative analysis of the flavonoids in the analyses of the samples was under 5%. The antimicrobial activity of the five methanol extracts of these Eriocaulaceae species was assayed against the microorganisms Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Salmonella setubal, Saccharomyces cerevisiae and Candida albicans. Measured MIC values ranged from 1.25 to 10.00 mg/mL. The flavonoid contents suggest that Eriocaulaceae species may be a promising source of compounds to produce natural phytomedicines.

Characterization of flavonoid and naphthopyranone derivatives from Eriocaulon ligulatum using liquid chromatography tandem mass spectrometry.

Liquid chromatography-electrospray ionization multistage ion trap mass spectrometry (LC-ESI-IT-MS(n)) was used to analyze the secondary metabolites in the methanol extract of the capitulae of Eriocaulon ligulatum. The major components were mono- and diglycosides of flavonoids and naphthopyranones. Eleven compounds, including four new flavonol glycosides, were identified based on their fragmentation patterns in MS experiments and on NMR analysis of the isolated compounds. The described data may contribute to a better understanding of the taxonomic classification of the Eriocaulaceae family.

Flavonoids and a naphthopyranone from Eriocaulon ligulatum and their mutagenic activity.

A new acylated flavonoid, 6,4'-dimethoxyquercetin-3-O-beta-D-6''[3,4,5-trihydroxy (E)-cinnamoyl]glucopyranoside, and a naphthopyranone dimer, named eriocauline, together with 2 other known flavonoids, 6-methoxyapigenin-7-O-beta-D-glucopyranoside and 6-methoxyapigenin-7-O-beta-D-allopyranoside, have been isolated from the capitulae of Eriocaulon ligulatum. The compounds were identified using spectroscopic methods (HR-ESI-MS, and 1-D and 2-D NMR). The methanol extract exhibited mutagenic activity in the Salmonella/microsome assay, in strains TA100, TA97a and TA102 and for dichloromethane extract tested in strain TA98.

Evaluation of Strychnos pseudoquina ST. HIL. leaves extract on gastrointestinal activity in mice.

Strychnos pseudoquina ST. HIL. (Loganiaceae) was investigated for its ability to protect the gastric mucosa against injuries caused by non-steroidal anti-inflammatory drugs (piroxicam) and a necrotizing agent (HCl/EtOH) in mice. The MeOH extract and enriched alkaloidic fraction (EAF) provided significant protection in experimental models wheer used at doses of 250 and 1000 mg/kg. In vivo tests were carried out to evaluate for possible toxic effects and no mortality was observed up to the 5 g/kg dose level. Phytochemical investigation led to the isolation of a new indole alkaloid, which elucidated the observed pharmacological effects.