Antidiabetic effects of Syzygium cumini leaves: A non-hemolytic plant with potential against process of oxidation, glycation, inflammation and digestive enzymes catalysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Plant materials are commonly used in traditional medicine in order to treat various diseases such as Diabetes mellitus. Some plants, such as Syzygium cumini, have the capability to act controlling oxidative stress and protein glycation besides their potential to decrease hyperglycemia and hyperlipidemia by the inhibition of the catalysis of digestive enzymes. The aim of this study was to evaluate the antioxidant and antiglicant activity of S. cumini leaves fractions, their capacity to inhibit hydrolases and lipase enzymes, as well as the cytotoxicity effects against erythrocytes and comparate these results with isolate quercetin flavonoid. MATERIAL AND METHODS: Ethnobotanical researches, carried out by academic studies at the Federal University of Uberlandia, led us to choose S. cumini as a potential plant for treatment of Diabetes mellitus. Fractions from ethanolic extract of S. cumini (hexane/Hex, dichloromethane/DCM, ethyl acetate/EtOAc, n-butanol/ButOH and water/H2O) were used to evaluate their antioxidant (DPPH, ORAC and FRAP) and antiglycant (BSA/fructose, BSA/methylglyoxal and Arginine/Methylglyoxal) activity as well as the inhibitory potential against α-amylase, α-glucosidase and lipase. In addition, identification of the main bioactive compounds of S. cuimini leaves by HPLC-ESIMS/MS analysis was carried out. RESULTS: Our results indicate that all fractions, for exception Hex, present noteworthy antioxidant activity, mainly in EtOAc and ButOH fractions (FRAP 1154.49 ± 67.37 and 1178.27 ± 21.26 µmol trolox eq g-1, respectively; ORAC 1224.63 ± 58.16 and 1313.53 ± 85.23 µmol trolox eq g-1, respectively; DPPH IC50 15.7 ± 2.4 and 23.5 ± 2.7 µg mL-1, respectively). Regarding the antiglycant activity (BSA/fructose and Arginine/Methylglyoxal models), all fraction, for exception Hex, presented inhibition higher than 85%. All fractions were capable to inhibit 100% of α-amylase and the fractions DCM, EtOAc and ButOH inhibited α-glucosidase more than 50%. Regarding the lipase assay, DCM and Hex had the best activity (31.5 ± 14.3 and 44.3 ± 4.5 µg mL-1, respectively). Various biomolecules known as potent antioxidants were identified in these fractions, such as quercetin, kaempferol, luteolin and (Epi)catechin. CONCLUSION: S. cumini fractions and quercetin presented promising antioxidant and antiglycation properties as well as the ability to inhibit digestive enzymes. This study presents new biological activities not yet described for S. cumini which provide new possibilities for further studies in order to assess the antidiabetic potential of S. cumini fractions especially EtOAc and ButOH.

Terpenoid constituents of cinnamon and clove essential oils cause toxic effects and behavior repellency response on granary weevil, Sitophilus granarius.

This study evaluated toxic effects, repellency and respiration rate caused by terpenoid constituents of cinnamon and clove essential oils and against Sitophilus granarius L. (Coleoptera: Curculionidae). The lethal concentrations (LC50 and LC90), repellent effect, and behavior repellency response on adults of S. granarius after exposure to six concentrations of each essential oil and terpenoids were evaluated. The chemical composition of the cinnamon oil was also determined and primary compounds were eugenol (10.5%), trans-3-caren-2-ol (10.2%), benzyl benzoate (9.99%), caryophyllene (9.34%), eugenyl acetate (7.71%), α-phellandrene (7.41%), and α-pinene (7.14%). In clove essential oil, the primary compounds were eugenol (27.1%), caryophyllene (24.5%), caryophyllene oxide (18.3%), 2-propenoic acid (12.2%), α-humulene (10.8%), γ-cadinene (5.01%), and humulene oxide (4.84%). Cinnamon and clove essential oil was toxic to S. granarius. In toxic terpenoids compounds, eugenol has stronger contact toxicity in S. granarius than caryophyllene oxide, followed by α-pinene, α-humulene, and α-phellandrene. Insects reduced their respiratory rates after being exposed to essential oil terpenoids and avoided or reduced their mobility on terpenoid-treated surfaces. Cinnamon and clove essential oil, and their terpenoid constituents were toxic and repellent to adult S. granarius and, therefore, have the potential to prevent or retard the development of insecticide resistance.

Flavonoids, gallotannins and ellagitannins in Syzygium guineense and the traditional use among Malian healers.

ETHNOPHARMACOLOGICAL RELEVANCE: Syzygium guineense has been traditionally used in Mali in West Africa for the treatment of different diseases such as stomach problems, wounds, inflammations and various female disorders. AIMS OF THE STUDY: (1) To perform an ethnopharmacological survey on the traditional use of S. guineense among Malian healers. (2) To isolate and identify chemical constituents from S. guineense leaves and to study their radical scavenging and enzyme inhibitory effects. MATERIALS AND METHODS: In four different districts in Mali, 44 healers were interviewed about their medicinal use of S. guineense. A methanol extract of the leaves of this tree was prepared and further fractionated using different chromatographic methods. Isolated compounds were identified by 1D and 2D NMR spectroscopy. Extracts and isolated compounds were investigated as DPPH radical scavengers and as inhibitors of xanthine oxidase and 15-lipoxygenase, and the methanol extract was tested for toxicity towards Artemia salina nauplii. RESULTS: Major uses by Malian healers were against dermatosis, pain, malaria/fever and for wound healing. There was little consensus about the use in the different districts. Leaves were most commonly used. From the methanol leaf extract, the flavonoids gallocatechin (1), myricetin (2), myricetin-3-O-glucoside (3), myricetin-3-O-rhamnoside (4), myricetin-3-O-glucuronide (5) and myricetin-3-O-ß-D-(6″-galloyl)galactoside (6), the gallotannins 1,2,3,6-tetra-O-galloyl-ß-D-glucose (7) and 1,2,3,4,6-penta-O-galloyl-ß-D-glucose (8), and the ellagitannins casuarictin (9) and casuarinin (10) were isolated. These ten polyphenols are all new for the species. The crude methanol extract was active as a radical scavenger and as an inhibitor of xanthine oxidase and 15-lipoxygenase. Among the isolated compounds, pentagalloylglucose was the best enzyme inhibitor (IC50 25±4µM for 15-lipoxygenase, 8±1µM for xanthine oxidase), while casuarictin (IC50 3.9±0.1µM), casuarinin (IC50 4.5±0.3µM) and pentagalloylglucose (IC50 5±1µM) showed the highest radical scavenging activity. The methanol extract was non-toxic to Artemia salina nauplii. CONCLUSION: S. guineense leaves are commonly used among Malian healers, however the traditional practice varies a lot between different regions. The leaves of S. guineense are rich in polyphenols; several are galloylated, either as galloylated flavonoids, gallotannins or ellagitannins. The high content of biologically active polyphenols might be important for medicinal effects of this plant and might give a rationale for the widespread usage of S. guineense in Mali.

Histological effects of Eugenia jambolana seed extract on liver of adult albino rats.

BACKGROUND: The therapeutic value of Eugenia jambolana, commonly known as 'Jamun' in Hindi, has been recognized in different system of traditional medicine for the treatment of various conditions. Its seeds are used for the treatment of diabetes mellitus and hyperlipedemia by reducing the lipid levels in the body; this action is presumed to be due to blocking the action of enzyme 3-hydroxyl methyl glutaryl (HMG-CoA reductase in the liver. Herbal drugs are getting into use with the notion that these are relatively harmless; the practice has shown that many of them also have toxic effects. Since hardly any work is available on the toxic aspect of Eugenia Jamblana, the present study was planed to see the effect-of ethanolic extract of Eugenia Jamblana on liver using albino rats as an experimental model. METHODS: The animals were divided into three groups A, B and C. Group A served as a control and received only distilled water comparable to the experimental animals calculated according to their body weight, where as B and C served as experimental groups. 100 and 200 mg of ethanolic extract of Eugenia Jamblana was dissolved in one ml of distilled water each and was given orally for 30 days/kg body weight. RESULTS: liver enzyme ALT and gamma GT were significantly raised when compared to the control group, p-value being < 0.05. Histological studies showed ballooning degeneration of hepatocytes, focal areas of hepatocytes necrosis with lymphocytic infiltration, providing supportive evidence for biochemical findings indicative of functional derangement. The effect of the extract was not dose dependent. Statistical analysis using ANOVA and chi-square showed statistically significant difference when the values from experimental animals were compared with those from the control, indicating that the ethanolic extract of Eugenia Jamblana seed possesses hepatotoxic effect. CONCLUSION: The ethanolic extract of Eugenia jambolana seed extract is toxic to liver as evident by derangement in liver enzyme levels and disturbed liver histology.

Comparison of acute toxicity of 2-phenoxyethanol and clove oil to juvenile and embryonic stages of Danio rerio.

OBJECTIVES: Anaesthetics are used in aquaculture to prevent stress and mechanical damage to fish during handling or the treatment of fish in breeding, blood sampling and other veterinary interventions. Clove oil and 2-phenoxyethanol are used in the Czech Republic in a water bath for the short-term immobilization of the fish. DESIGN: Acute toxicity tests were performed on aquarium fish Danio rerio, which is considered to be one of the model organisms most commonly used in toxicity testing. The semi-static method according to OECD No. 203 (Fish acute toxicity test) was used for testing juvenile fish. Embryo toxicity tests were performed in zebrafish embryos (D. rerio) in compliance with the OECD No. 212 methodology (Fish, short-term toxicity test on embryo and sac-fry stages). The results obtained (the number of dead individuals at particular test concentrations) were subjected to a probit analysis using the EKO-TOX 5.2 programme in order to determine LC50 clove oil and 2-phenoxyethanol values. The statistical significance of the difference between LC50 values in juvenile and embryonic stages of D. rerio was tested using the Mann-Whitney non-parametric test implemented in the Unistat 5.1 programme. RESULTS: The LC50 clove oil mean value was 18.8 +/- 5.52 mg.L-1 in juvenile D. rerio, and 15.64 +/- 3.30 mg.L-1 in embryonic stages of D. rerio. The LC50 2-phenoxyethanol mean value was 338.22 +/- 15.22 mg.L-1 in juvenile D. rerio, whereas in embryonic stages of D. rerio it was 486.35 +/- 25.53 mg.L-1. CONCLUSIONS: The study proved statistically significantly higher (p<0.01) sensitivity in juvenile fish to 2-phenoxyethanol compared to the embryonic stages. Acute toxicity values of clove oil for juvenile and embryonic stages were comparable.

Atividades antiúlcera e antioxidante de Syzygium jambos(L. ) Alston / Antiulcer and antioxidant activities of Syzygium jambos(L. ) Alston

O jambeiro (Syzygium jambos (L.) Alston) constitui uma das diversas espécies frutíferas e medicinais pertencentes à família Myrtaceae. O extrato hidroetanólico a 70 ´POR CENTO´ liofilizado de folhas de S. jambos apresentou atividade dose-dependente em modelo de úlcera gástrica induzida por etanol acidificado, sendo que a dose de 400 mg/kg reduziu significativamente a Área Total de Lesão (81,64%) e a Área Relativa de Lesão (65,11%), em comparação ao grupo controle. Nesta dose, o extrato apresentou-se mais eficaz que o fármaco empregado como referência (Iansoprazol 30 mg/kg). No modelo de indução de úlcera gástrica por ácido acético, o extrato (400 mg/kg) não apresentou resultados significativos na cura das lesões. A atividade antioxidante do mesmo extrato e de quatro frações foi avaliada através da medida da capacidade seqüestrante de radicais 1, 1-difenil-2-picrilidrazila. O extrato hidroetanólico a 70% liofilizado apresentou CE `IND.50´ de 5,36 ± 0,06 µg/mL, valor comparável ao do Trolox (CE `IND.50´ = 4,98 ± 0,04 µg/mL), substância antioxidante de referência...

Genotoxicity induced by Eugenia caryophyllata infusion.

Several therapeutic properties have been described for Eugenia caryophyllata (clove). In the present study the infusion of E. caryophyllata was evaluated in a series of bacterial and cell-free assays in order to determine genotoxic potential. Negative results were obtained in the SOS chromotest and in the Salmonella reversion assay using strains TA97a, TA98, TA100, and TA102. However, in a forward mutagenesis assay an increase in mutagenesis and high cytotoxicity was observed with the CC104 mutMmutY strain, suggesting that oxidative DNA damage occurred. The treatment of plasmid with clove infusion showed that DNA strand breaks and sites recognized by formamidopyrimidine-DNA-glycosylase (FPG/MutM) were generated. Data suggest that the occurrence of oxidative DNA damage, with low mutagenic potential, may also be involved in the cytotoxicity attributed to clove infusion.

Investigation of the antimutagenic effects of selected South African medicinal plant extracts.

Dichloromethane extracts from different parts of Rhamnus prinoides, Ornithogalum longibracteatum, Gardenia volkensii, Spirostachys africana, Diospyros whyteana, Syzigium cordatum and Prunus africana were investigated for mutagenic and antimutagenic effects in Salmonella/microsome and micronucleus tests. None of the extracts tested in the Ames test were found to induce mutations or to modify the effect of the mutagen 4-nitroquinoline-oxide (4NQO). In the micronucleus test, extracts from twigs/bark of R. prinoides, twigs of D. whyteana, P. africana and S. cordatum significantly lowered the effect of the mutagen mitomycin C (MMC). Extracts from twigs/bark of G. volkensii and S. africana were genotoxic in the micronucleus test, while extracts of O. longibracteatum leaves potentiated the genotoxicity of MMC. This preliminary investigation shows that plant extracts used in traditional medicine may have particular effects with regard to mutagenicity and antimutagenicity indicating careful use in some instances and the need to isolate their active principles for further research.