Phytochemical and biological characterization of aqueous extract of Vassobia breviflora on proliferation and viability of melanoma cells: involvement of purinergic pathway.

Vassobia breviflora belongs to the Solanaceae family, possessing biological activity against tumor cells and is a promising alternative for therapy. The aim of this investigation was to determine the phytochemical properties V. breviflora using ESI-ToF-MS. The cytotoxic effects of this extract were examined in B16-F10 melanoma cells and the relationship if any to purinergic signaling was involved. The antioxidant activity of total phenols, (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) was analyzed, as well as production of reactive oxygen species (ROS) and nitric oxide (NO) was determined. Genotoxicity was assessed by DNA damage assay. Subsequently, the structural bioactive compounds were docked against purinoceptors P2X7 and P2Y1 receptors. The bioactive compounds found in V. breviflora were N-methyl-(2S,4 R)-trans-4-hydroxy-L-proline, calystegine B, 12-O-benzoyl- tenacigenin A and bungoside B. In vitro cytotoxicity was demonstrated at concentration ranges of 0.1-10 mg/ml, and plasmid DNA breaks only at the concentration of 10 mg/ml. V. breviflora extracts affected hydrolysis by ectoenzymes, such as ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) and ectoadenosine deaminase (E-ADA) which control levels of degradation and formation of nucleosides and nucleotides. In the presence of substrates ATP, ADP, AMP and adenosine, the activities of E-NTPDase, 5´-NT or E-ADA were significantly modulated by V. breviflora. N-methyl-(2S,4 R)-trans-4-hydroxy-L-proline presented higher binding affinity (according to receptor-ligand complex estimated binding affinity as evidenced by ∆G values) to bind to both P2X7 and P2Y1purinergic receptors.Our results suggest a putative interaction of V. breviflora bioactive compounds with growth inhibitory potential in B16-F10 melanoma and suggest that may be considered as promising compounds in melanoma and cancer treatment.

Protective effect of gallic acid and Syzygium cumini extract against oxidative stress-induced cellular injury in human lymphocytes.

CONTEXT: Syzygium cumini (Myrtaceae) presents antioxidant, anti-inflammatory, hypoglycemic and antibacterial effects; however, the cellular and molecular mechanisms of action in the immune system are not yet completely elucidated. OBJECTIVE: This study evaluates the in vitro effect of gallic acid and aqueous S. cumini leaf extract (ASc) on adenosine deaminase (ADA) and dipeptidyl peptidase IV (DPP-IV) activities, cell viability and oxidative stress parameters in lymphocytes exposed to 2, 2'-azobis-2-amidinopropane dihydrochloride (AAPH). MATERIALS AND METHODS: Lymphocytes were incubated with ASc (100 and 500 µg/ml) and gallic acid (50 and 200 µM) at 37 °C for 30 min followed by incubation with AAPH (1 mM) at 37 °C for 2 h. After the incubation time, the lymphocytes were used for determinations of ADA, DPP-IV and lactate dehydrogenase (LDH) activities, lipid peroxidation, protein thiol (P-SH) group levels and cellular viability by colorimetric methods. RESULTS: (i) HPLC fingerprinting of ASc revealed the presence of catechin, epicatechin, rutin, quercitrin, isoquercitrin, quercetin, kaempferol and chlorogenic, caffeic, gallic and ellagic acids; (ii) for the first time, ASc reduced the AAPH-induced increase in ADA activity, but no effect was observed on DPP-IV activity; (iii) ASc increased P-SH groups and cellular viability and decreased LDH activity, but was not able to reduce the AAPH-induced lipid peroxidation; (iv) gallic acid showed less protective effects than ASc. DISCUSSION AND CONCLUSION: ASc affects the purinergic system and may modulate adenosine levels, indicating that the extract of this plant exhibits immunomodulatory properties. ASc also may potentially prevent the cellular injury induced by oxidative stress, highlighting its cytoprotective effects.

Safety assessment and behavioral effects of Solanum guaraniticum leaf extract in rats

ABSTRACT Solanum guaraniticum is a medicinal plant traditionally used to treat gastric and liver diseases. However, there is no documented evidence corroborating its safety. The present study evaluated the potential toxicity of S. guaraniticum leaf extract after acute administration in rats. Single doses of the extract (1.250, 2.500, and 5.000 mg/kg) were administered by gavage, and the rats were then monitored for 48 h and/or 14 days. Mortality, acute signs of toxicity, and general activity in the open field test were assessed as well as hematological and biochemical parameters, enzymatic activity (δ-aminolevulinate dehydratase and acetylcholinesterase), and oxidative stress parameters (lipid peroxidation level, non-protein thiol content, tissue catalase activity, and serum ferrous reducing power). Phytochemical analysis was also performed by HPLC. The results showed that extract administration produced no deaths (LD50 > 5,000 mg/kg), and no significant adverse effects regarding food consumption, body weight gain, gross pathology, or other parameters. However, the open field tests showed a decrease in spontaneous activity (crossing and rearing) mainly at 48 h after treatment. The results suggest that S. guaraniticum extract is not acutely toxic, but causes alterations in central nervous system activity.

RESUMO Solanum guaraniticum é uma planta medicinal tradicionalmente usada para tratar doenças gástricas e hepáticas. Porém, não há evidências documentadas sobre sua segurança. O presente estudo avaliou a toxicidade do extrato das folhas de S. guaraniticum após administração aguda em ratos. Doses únicas do extrato (1.250, 2.500 and 5.000 mg/kg) foram administradas por gavagem e os animais foram monitorados por 48 h ou 14 dias. Mortalidade, sinais de toxicidade aguda e atividade geral, através do teste de campo aberto, foram analisados, assim como parâmetros hematológicos e bioquímicos, atividades enzimáticas (δ-aminolevulinato desidratase e acetilcolinesterase) e parâmetros de estresse oxidativo (nível de peroxidação lipídica, conteúdo de tióis não protéicos, atividade da catalase em tecidos e poder redutor em soro). A análise fitoquímica também foi realizada por HPLC. Os resultados mostraram que a administração do extrato não provoca mortes (LD50>5.000 mg/kg) ou efeitos adversos significativos com relação ao consumo de comida, ganho de peso corporal, análise patológica, entre outros. Entretanto, o teste de campo aberto mostrou uma diminuição na atividade espontânea geral (cruzamentos e levantadas), principalmente em 48 h após o tratamento. Portanto, nossos resultados sugerem que o extrato de S. guaraniticum não é agudamente tóxico, mas causa alterações na atividade do sistema nervoso central.

Tropane alkaloids and calystegines as chemotaxonomic markers in the Solanaceae.

This study assessed the occurrence and distribution of tropane alkaloids and calystegines in genera of the family Solanaceae to identify patterns of distribution and make evolutionary inferences. A database of tropane alkaloids and calystegines occurrences was constructed from the results of a search of scientific websites and a hand search of periodicals. The terms "Solanaceae", "tropane alkaloids", and "calystegines" were used as index terms for a full-text article search unrestricted by date of publications. The number of occurrence and chemical diversity indices were calculated and cluster analysis and principal components analysis were performed. Overall, 996 occurrences were reported, 879 of tropane alkaloids (88.3%) and 117 of calystegines (11.7%). The calystegines were significantly more relevant than tropane alkaloids for characterization of distinct groups of genera on both analyses performed here. This corroborates the trend toward a chemical dichotomy observed on database analysis and somewhat reinforces the correlation between geographic distribution and occurrence of secondary metabolites, as the presence of calystegines alone (without tropane alkaloids) was only reported in genera that have South America as their center of diversity.

Syzygium cumini seed extract ameliorates adenosine deaminase activity and biochemical parameters but does not alter insulin sensitivity and pancreas architecture in a short-term model of diabetes.

BACKGROUND: The effects of the aqueous seed extract of Syzygium cumini (ASc) in a short-term model of diabetes in rats are little explored. The present study was designed to evaluate the effect of the ASc on adenosine deaminase (ADA) activity and on biochemical and histopathological parameters in diabetic rats. METHODS: ASc (100 mg/kg) was administered for 21 days in control and streptozotocin (STZ)-induced (60 mg/kg) diabetic rats. ADA activity, lipoperoxidation (cerebral cortex, kidney, liver and pancreas) and biochemical (serum) and histopathological (pancreas) parameters were evaluated. RESULTS: The main findings in this short-term model of Diabetes mellitus (DM) were that the ASc (i) significantly reverted the increase of ADA activity in serum and kidney; (ii) ameliorated the lipoperoxidation in the cerebral cortex and pancreas of the diabetic group; (iii) demonstrated hypolipidemic and hypoglycemic properties and recovered the liver glycogen; and iv) prevented the HOMA-IR index increase in the diabetic group. Therefore, the ASc can be a positive factor for increasing the availability of substrates with significant protective actions, such as adenosine. Moreover, by maintaining glycogen and HOMA-IR levels, the extract could modulate the hyperglycemic state through the direct peripheral glucose uptake. CONCLUSIONS: Our data revealed that the short-term treatment with ASc has an important protective role under pathophysiological conditions caused by the early stage of DM. These results enhance our understanding of the effect of the ASc on the purinergic system in DM.

Syzygium cumini is more effective in preventing the increase of erythrocytic ADA activity than phenolic compounds under hyperglycemic conditions in vitro

Syzygium cumini (S. cumini) is a plant known for its antidiabetic properties. The aim of this study was to evaluate the effect of Sc aqueous leaf extract (ASc) on adenosine deaminase (ADA) activity in erythrocytes (RBCs) exposed to high glucose concentrations (30 mM) in vitro. We also investigated the effects of the main phenolic compounds found in ASc (gallic acid, rutin, and chlorogenic acid) and the effects of insulin, caffeine, and dipyridamole, which are substances involved in the adenosine metabolism, on ADA activity in vitro. Blood samples were obtained from healthy volunteers and a suspension of RBCs was used for the determination of ADA activity. The results showed that: (1) the effect of ASc on ADA activity was more significant than the combination of phenolic compounds; (2) insulin, caffeine, or dipyridamole prevented high glucose increase of ADA activity at doses as low as 50 μU/mL, 25 μM, and 1 μM, respectively; (3) the inhibitory effect caused by ASc on erythrocyte ADA activity remained practically the same after the combination of the extract with insulin or caffeine; (4) when RBCs were exposed to ASc plus dipyridamole, this chemical attenuated the effect of ASc on ADA activity, suggesting an antagonism or a competition with ASc by the same site of action. Therefore, ASc was more effective in preventing the increase in ADA activity than phenolic compounds, suggesting that ASc may collaborate to improve endothelial dysfunction, antioxidant, anti-inflammatory, and antithrombotic properties of adenosine by affecting its metabolism. The results of this study help to provide evidence of the empirically supported benefits of the use of S. cumini in diabetes

Delta-ALA-D inhibitory potential and protective action of Syzygium jambos and Solanum guaraniticum leaf extracts on oxidatively stressed erythrocytes.

OBJECTIVE: This study aimed to investigate the effect of the leaf extracts of Syzygium jambos and Solanum guaraniticum on the δ-aminolevulinate dehydratase (δ-ALA-D) activity, their antioxidant activity and potential protective action on oxidatively stressed erythrocytes, in order to demonstrate the safety or toxicity of the plant. METHODS: In erythrocyte samples, the effect of both extracts on δ-ALA-D activity, H2O2-induced oxidative stress, and 2,2'azobis (2-amidinopropane) (AAPH)-induced hemolysis was evaluated, as well as some antioxidant mechanisms. RESULTS: Both extracts inhibited δ-ALA-D activity (S. guaraniticum > S. jambos), and an involvement of the zinc ion of the δ-ALA-D structure on the inhibition of enzyme activity was verified. S. jambos leaf extract showed marked efficiency in countering H2O2-induced lipid peroxidation and in maintaining cellular integrity against AAPH-induced hemolysis. Furthermore, S. jambos exhibited greater H2O2 scavenging activity and stronger reduction power than S. guaraniticum. DISCUSSION: Both extracts bear potent antioxidant property as an important beneficial effect. However, the inhibition of δ-ALA-D activity suggests a possible harmful effect of these vegetal preparations and indicates the need for further investigation regarding their toxicological properties. All together, these data represent a significant contribution to the knowledge of these plants, both to the scientific community and to the folk medicine.

Syzygium cumini is more effective in preventing the increase of erythrocytic ADA activity than phenolic compounds under hyperglycemic conditions in vitro.

Syzygium cumini (S. cumini) is a plant known for its antidiabetic properties. The aim of this study was to evaluate the effect of Sc aqueous leaf extract (ASc) on adenosine deaminase (ADA) activity in erythrocytes (RBCs) exposed to high glucose concentrations (30 mM) in vitro. We also investigated the effects of the main phenolic compounds found in ASc (gallic acid, rutin, and chlorogenic acid) and the effects of insulin, caffeine, and dipyridamole, which are substances involved in the adenosine metabolism, on ADA activity in vitro. Blood samples were obtained from healthy volunteers and a suspension of RBCs was used for the determination of ADA activity. The results showed that: (1) the effect of ASc on ADA activity was more significant than the combination of phenolic compounds; (2) insulin, caffeine, or dipyridamole prevented high glucose increase of ADA activity at doses as low as 50 µU/mL, 25 µM, and 1 µM, respectively; (3) the inhibitory effect caused by ASc on erythrocyte ADA activity remained practically the same after the combination of the extract with insulin or caffeine; (4) when RBCs were exposed to ASc plus dipyridamole, this chemical attenuated the effect of ASc on ADA activity, suggesting an antagonism or a competition with ASc by the same site of action. Therefore, ASc was more effective in preventing the increase in ADA activity than phenolic compounds, suggesting that ASc may collaborate to improve endothelial dysfunction, antioxidant, anti-inflammatory, and antithrombotic properties of adenosine by affecting its metabolism. The results of this study help to provide evidence of the empirically supported benefits of the use of S. cumini in diabetes.

Syzygium jambos and Solanum guaraniticum show similar antioxidant properties but induce different enzymatic activities in the brain of rats.

Syzygium jambos and Solanum guaraniticum are both employed in Brazil as medicinal plants, even though their potential toxicity is not well established and they are frequently misused. The aim of this study was investigate the effect of the aqueous leaf extracts of both plants on δ-aminolevulinate dehydratase (δ-ALA-D) and acetylcholinesterase (AChE) activities and the antioxidant action against oxidative damage induced by sodium nitroprusside in rats, using in vitro assays. In addition, the presence of gallic, caffeic and chlorogenic acids, as well as rutin, quercetin and kaempferol as bioactive compounds in the extracts was identified by HPLC and their levels quantified. The antioxidant activities of both extracts were assessed by their capabilities to scavenge nitric oxide and to inhibit lipid peroxidation. Only Syzygium jambos presented thiol-peroxidase-like activity. Although neither extract affected the AChE activity, the aqueous extract of Solanum guaraniticum inhibited brain δ-ALA-D activity, suggesting a possible impairment effect on the central nervous system. Our results showed that both extracts exhibited efficient free radical scavenger activity and are an interesting source of bioactive compounds, justifying their use in folk medicine, although Solanum guaraniticum extract could have neurotoxicity properties and we therefore suggest that its use should be restricted to ensure the health of the population.

Syzygium cumini extract decrease adenosine deaminase, 5'nucleotidase activities and oxidative damage in platelets of diabetic patients.

Diabetes mellitus, a chronic metabolic disorder, has assumed epidemic proportions and its long-term complications can have devastating consequences. The oxidative stress in diabetes was greatly increased due to prolonged exposure to hyperglycemia and impairment of oxidant/antioxidant equilibrium. Syzygium cumini is being widely used to treat diabetes by the traditional practitioners over many centuries. Adenosine deaminase (ADA) and 5'-Nucleotidase (5'NT) are enzymes of purine nucleoside metabolism that play an important role in the regulation of adenosine (Ado) levels. In this study, we investigated the effect of Syzygium cumini aqueous leaves extract (ASc) on ADA and 5'NT activities and on parameters of oxidative stress under in vitro conditions, using platelets of patients with Type 2 diabetes mellitus. Platelet-Rich Plasma (PRP) was assayed by ADA, 5'NT, Catalase (CAT), Superoxide Dismutase (SOD) activities and Thiobarbituric acid reactive substances (TBARS) levels. We observed that ADA, 5'NT activities and TBARS levels were significantly higher when compared to the control group, and ASc (100 and 200 µg/mL) prevented these effects. Our study demonstrates that ASc was able to remove oxidant species generated in diabetic conditions and modulates in the Ado levels. Then, ASc may promote a compensatory response in platelet function, improving the susceptibility-induced by the diabetes mellitus.

Comparative evaluation of adenosine deaminase activity in cerebral cortex and hippocampus of young and adult rats: effect of garlic extract (Allium sativum L.) on their susceptibility to heavy metal exposure.

Adenosine plays an important neuromodulatory role in the central nervous system, and adenosine deaminase is an important enzyme in the degradation of adenine nucleotides. Methylmercury is the most prevalent form of mercury found in the environment. Methylmercury neurotoxicity has been correlated to the production of reactive oxygen species. In this study, its potential pathogenic effects were investigated in vitro in cerebral cortex and hippocampus of rats. We first observed that adenosine deaminase activity was higher in young rat brains when compared to the 60-day-old rats and was higher in hippocampus when compared to the cortex. Methylmercury (0.1, 1.0, 20 microM) inhibited adenosine deaminase activity in 7- and 60-day-old rats in a concentration-dependent manner. We have demonstrated that methylmercury-induced inhibition was antagonized by garlic alcoholic extract, but sodium selenate did not alter enzyme activity. In addition, glutathione and dithiothreitol restored the methylmercury-induced decrease of adenosine deaminase activity. These results demonstrated that there are age-related changes in adenosine deaminase activity and that thiol agents may contribute to the maintenance of adenosine deaminase activity and may be important in the neuromodulation of adenosine. Garlic alcoholic extract may be effective in reducing the effect of methylmercury-induced adenosine deaminase, which may be due to its sulphur-containing compounds.

Morfogênese de Lolium multiflorum Lam. e Paspalum urvillei steud sob níveis de adubação de fósforo e potássio / Lolium multiflorum Lam. and Paspalum urvillei steud morphogenesis under levels of phosphorus and potash

O estudo foi conduzido em área de várzea, com o objetivo de avaliar a resposta morfogênica de Lolium multiflorum e Paspalum urvillei, submetidos a níveis de adubação (50, 100 e 150 por cento da recomendação) de fósforo (P) e potássio (K). Foram utilizados afilhos marcados para avaliar as taxas de alongamento e aparecimento de lâminas foliares e o filocrono. Os níveis de adubação afetaram (P<0,044) a taxa de alongamento de lâminas foliares de , no período de 03/08 a 17/08, com variação de 0,374 a 0,436mm GD-1 afilho-1, do menor ao maior nível de adubação. O intervalo para surgimento de folhas foi de 11,7 dias e o filocrono de 156 GD, na média dos tratamentos e períodos. Em P. urvillei, os níveis de adubação não afetaram a taxa de alongamento de lâminas foliares, sendo na média dos períodos e tratamentos de 0,375mm GD-1 afilho-1. Houve efeito dos níveis de adubação no aparecimento de folhas no período de 19/10 a 09/11, quando o nível de 100 por cento da adubação, apresentou a maior taxa de alongamento de lâminas foliares, diferindo (P<0,003) dos demais. O filocrono foi maior (250 GD) no período de 04/01 a 24/01, nos demais (19/10 a 09/11 e 02/02 a 23/02) foi semelhante (166 e 175 GD, respectivamente). Os maiores níveis de adubação de P e K influenciam as taxas de alongamento em e de aparecimento de folhas em P. urvillei. Os valores de filocrono das espécies são semelhantes, demonstrando a potencialidade de crescimento e produção de forragem da espécie nativa principalmente.