Istradefylline induces A2A/P2X7 crosstalk expression inducing pro-inflammatory signal, and reduces AKT/mTOR signaling in melanoma-bearing mice.

ATP and adenosine (ADO) are critical players in the context of cancer. In the tumor microenvironment, the signaling dependent on these molecules, and immune cells, is regulated by an enzymatic chain and purinergic receptors called purinome. Primarily, the A2A receptor (A2AR) has a pro-tumor action since it reduces the immune response and favors the growth of malignant melanoma. Therefore, this study aimed to verify the effects of A2AR antagonism with Istradefylline (IST) on the purinergic signaling profile of the melanoma tumor and immunological compartments. We observed reduced tumor growth of melanoma in IST-treated animals. IST inhibited AKT/mTOR pathway, which is involved with tumor growth. In the tumor, spleen, and thymus, the modulation of purinergic enzymes (CD39, CD73, and E-ADA) characterized a pro-inflammatory profile since it favored increased extracellular concentrations of ATP to the detriment of ADO. A2AR inhibition generated a compensatory feedback process with increased A2AR expression at the tumor level. However, there was also an increase in the expression of the P2X7 receptor (P2X7R), which culminated in an increase in pro-inflammatory pathways with the release of IL-1ß and pro-inflammatory cytokines such as IFN-γ and TNF-α. Our data evidence the cross-involvement between expression and action of the A2AR and P2X7R. We suggest that IST is a promising drug for off-label use in cancer since it promotes an anti-tumoral response by producing pro-inflammatory cytokines and blocking of AKT/mTOR tumor growth pathway.

Induction of aggression and anxiety-like responses by perfluorooctanoic acid is accompanied by modulation of cholinergic- and purinergic signaling-related parameters in adult zebrafish.

Perfluorooctanoic acid (PFOA) is a contaminant of global concern owing to its prevalent occurrence in aquatic and terrestrial environments with potential hazardous impact on living organisms. Here, we investigated the influence of realistic environmental concentrations of PFOA (0, 0.25, 0.5, or 1.0 mg/L) on relevant behaviors of adult zebrafish (Danio rerio) (e.g., exploration to novelty, social preference, and aggression) and the possible role of PFOA in modulating cholinergic and purinergic signaling in the brain after exposure for 7 consecutive days. PFOA significantly increased geotaxis as well as reduced vertical exploration (a behavioral endpoint for anxiety), and increased the frequency and duration of aggressive episodes without affecting their social preference. Exposure to PFOA did not affect ADP hydrolysis, whereas ATP and AMP hydrolysis were significantly increased at the highest concentration tested. However, AChE activity was markedly decreased in all PFOA-exposed groups when compared with control. In conclusion, PFOA induces aggression and anxiety-like behavior in adult zebrafish and modulates both cholinergic and purinergic signaling biomarkers. These novel data can provide valuable insights into possible health threats related to human activities, demonstrating the utility of adult zebrafish to elucidate how PFOA affects neurobehavioral responses in aquatic organisms.

The addition of residue from pruning of yerba mate (Ilex paraguariensis) in laying hens modulates fatty acid profile and incorporates chlorogenic acid in the egg.

This study aimed to determine whether the addition of Ilex paraguariensis residue to the basal diet of laying hens improves bird health, production, fatty acids, egg quality, and transfer of chlorogenic acids to the egg. One hundred twenty birds of the Hy-line lineage were used, divided into five groups with six replicates and four birds per replicate, as follows: T0 (control group, without IPPR supplementation), T0.5 (basal diet plus 0.5% of IPPR), T1 (basal diet plus 1% IPPR), T1.5 (basal diet plus 1.5% IPPR), and T2 (basal diet plus 2% IPPR), for two consecutive cycles of 21 days each. The productive performance of the birds, physicochemical composition of eggs, fatty acid profile, the concentration of chlorogenic acids in eggs, leukocyte count, serum biochemistry, oxidant and antioxidant status, total bacterial count in eggs, and feces were evaluated at 21 and 42 days of the experiment. The addition of IPPR to the birds' diet no-change eggs production and feed conversion. In the egg yolks of birds that consumed IPPR, there were chlorogenic acids. There was a reduction in the total bacterial count in the feces and eggshells of the birds that received 2% of the IPPR. IPPR intake also reflected a reduction in total saturated fatty acid levels and increased monounsaturated fatty acids. These findings suggest that IPPR is a compelling alternative for laying hens; however, its ingestion also has negative effects that are discussed in below. Chlorogenic acids in the egg are desirable, as these phenolics have nutraceutical effects in humans.

Role of purinergic system and vitamin D in the anti-cancer immune response.

For several years, scientists have recognized that vitamin D plays an important role in mineral and bone homeostasis. It was mostly used to treat osteoporosis and rickets in the past decades. Vitamin D has also been discovered to be modulator of the immune system and may play a role in a variety of diseases, including autoimmune diseases, in recent years. Vitamin D interaction with the vitamin D receptor (VDR), which has transcriptional imparts and is displayed on a variety of cell types, including those of the immune system, appears to be accountable for the immune-modulating effects. The action of tumor cells and vitamin D were the first to be investigated, but the spotlight is now on immunologic and purinergic systems. We conducted a systematic search in Pub Med as well as Google scholar for studies written in English. Vitamin D, cancer, purinergic signaling, and immune response were among the search words. Vitamin D has the potential to be a useful coadjuvant in cancer therapy and the purinergic system may be a potential treatment target to cancer therapy, according to our findings.

Distinct kinetics for nucleotide hydrolysis in lymphocytes isolated from blood, spleen and cervical lymph nodes: Characterization of ectonucleotidase activity.

Ectonucleotidases are a plasma membrane-bound enzyme that hydrolyses extracellular adenosine triphosphate (eATP) and adenosine diphosphate (eADP) to adenosine monophosphate (AMP). It regulates normal function of lymphocytes, acts as an inflammatory marker and represents a molecular target for new therapeutics. Thus, this study sought to isolate lymphocytes from blood (BL), spleen (SL) and cervical lymph node (CLL), and characterize the eATP and eADP enzymatic hydrolysis in Wistar rats. The hydrolysis of the nucleotides occurred primarily at pH 8.0, 37°C in the presence of Ca2+ or Mg2+ . Chevillard-plot showed the hydrolysis of eATP and eADP at the same active site. The inhibitors of some classical ATDPases did not cause any significant change on enzymatic activity. Inhibitors of E-NTPDase (-1, -2, -3 isoforms) and E-NPP-1 decrease the enzyme activity in all resident lymphocytes. Furthermore, kinetic parameters (Vmax and Km) revealed that SL had significantly (P < .001) higher enzymatic activity when compared to BL and CLL. In conclusion, this study standardized kinetic values for eATP and eADP hydrolysis for resident lymphocytes isolated from BL, SL and CLL.

Effects of curcumin and yucca extract addition in feed of broilers on microorganism control (anticoccidial and antibacterial), health, performance and meat quality.

The aim of this study was to determine whether curcumin and yucca extract addition in broiler feed improves growth, health, and meat quality, and to measure coccidiostatic and antimicrobial activity so as to enable replacement of conventional performance enhancers. We used 240 birds in four treatments: CN, basal feed with antibiotics and coccidiostatic drugs; CU, feed with 100 mg/kg of curcumin; YE, feed with 250 mg/kg of yucca extract; and CU + YE, feed with the combination of 100 mg curcumin/kg and 250 mg yucca extract/kg. A significant reduction in oocysts was observed in birds supplemented with combined additives (CU + YE) at days 37 compared to other treatments and at 42 days in relation to the CU treatment. At 42 days, the total bacterial counts for the CN and CU treatments were lower than the others. Birds fed the additive had lower numbers of leukocytes, lymphocytes, and heterophils than did those in the CN treatment. The highest levels of antioxidants in meat were observed in the treatments with the additives, together with lower levels of lipid peroxidation compared to the CN. The lowest protein oxidation was observed in the CU + YE treatment in relation to the other treatments. Lower total levels of saturated fatty acids (SFA) were observed in the CU treatment than in the CN. There were lower levels of monounsaturated fatty acids (MUFA) in the meat of birds in the YE treatment in relation to the others. Higher levels of total polyunsaturated fatty acids (PUFA) were observed in birds that consumed curcumin, individually and in combination with yucca extract. Taken together, the data suggest that curcumin and yucca extract are additives that can potentially replace conventional growth promoters; they improved bird health. Changes in the fatty acid profile of meat (increase in the percentage of omegas) are beneficial to the health of the consumer.

CD4/CD8 ratio, comorbidities, and aging in treated HIV infected individuals on viral suppression.

The progression of the human immunodeficiency virus (HIV) infection to acquired immunodeficiency syndrome (AIDS) can be efficiently interrupted by antiretroviral therapy (ART). However, even successfully treated HIV-infected individuals are prone to develop non-AIDS-related diseases that affect the metabolism and several organs and systems. Biomarkers that predict the occurrence of comorbidities may help develop preventive measures. Current research shows that CD4+ T cell counts and viral load do not predict the development of non-AIDS-related diseases. The CD4/CD8 ratio has been indicated as a suitable marker of persistent immune dysfunction and the occurrence of non-AIDS-related events in treated HIV-positive patients. In this study, we explored the relationship between CD4/CD8 ratios, comorbidities, and aging in ART-treated HIV patients on viral suppression. We collected and evaluated data from 352 HIV-positive adults who were virologically suppressed (<40 copies/mL) on ART and with CD4 counts above 350 cells/mm3 . The median age for participants was 46 years, 218 individuals had at least one comorbidity, and 239 had inverted CD4/CD8 ratios (<1). Current CD4/CD8 ratios were predicted by baseline CD4/CD8 ratios and nadir CD4 counts. Despite the high rates of inverted CD4/CD8 ratios and prevalence of comorbidities, no association between them was observed. The prevalence of comorbidities was significantly higher in older individuals, though aging alone did not explain the rate of all individual comorbidities. Low CD4/CD8 ratios were linked to neurocognitive disorders, suggesting that persistent T cell dysfunction contributes to neurocognitive decline.

Increased cytokines production and oxidative stress are related with purinergic signaling and cell survival in post-thyroidectomy hypothyroidism.

Thyroid hormones have essential roles in regulation of cellular functions, including the immune system. The purinergic signaling, activated through extracellular nucleotides and nucleosides has also strong implications in immune response regulation. Hypothyroidism may involve effects on the immune and purinergic systems. In view of that, we evaluated cytokines levels, their relation with the expression of purinergic enzymes and the effects of this condition on immune system cells from patients with post-thyroidectomy hypothyroidism. Increased IL6, IL10, IL17 and TNF-α levels as well as an increase in CD73 expression in lymphocytes were observed in patients' blood. Moreover, augmented myeloperoxidase activity, lipid peroxidation and thiolgroup production were observed in post-thyroidectomy hypothyroidism. In addition, proliferation and cell death of lymphocytes were enhanced when exposed to patients' serum. This study demonstrates that hypothyroidism is related to changes in the purinergic system, increased cytokines production and oxidative stress, which interfere in the cell life and signaling.

Experimental listeriosis: A study of purinergic and cholinergic inflammatory pathway.

The cholinergic, purinergic and oxidative stress systems were related to nervous system damage in some pathologies, as well as being involved in pro-inflammatory and anti-inflammatory pathways. The objective was to investigate changes in purinergic, cholinergic systems and oxidative stress related to the neuropathology of listeriosis. Gerbils were used as experimental models. The animals were divided in two groups: control and infected. The animals were orally infected with 5 × 108 CFU/animal of the pathogenic strain of Listeria monocytogenes. Collected of material was 6 and 12th days post-infection (PI). Infected animals showed moderate mixed inflammatory infiltrates in the liver. The spleen and brain was used for PCR analyses, confirming infection by L. monocytogenes. Increase in number of total leukocytes because of an increase in lymphocytes in infected (P < 0.001). ATP and ADP hydrolysis by NTPDase was lower at 6 and 12th days PI in infected animals than in the control group. ADA (adenosine deaminase) activity was higher on the 6th day PI (P < 0.05) and decreased on the 12th day PI (P < 0.05) in infected animals. AChE (acetylcholinesterase) activity did not differ between groups on the 6th day PI; however, activity decreased in infected group on the 12th day PI (P < 0.05). On the 12th day PI, an increase of oxygen-reactive species levels and lower catalase and superoxide dismutase activities in the infected group was observed, characterizing a situation of cerebral oxidative stress. The inflammatory and oxidative mechanisms are present in listeriosis in asymptomatic animals, and that ectonucleotidases and cholinesterase's are involved in immunomodulation.

Resveratrol-mediated reversal of changes in purinergic signaling and immune response induced by Toxoplasma gondii infection of neural progenitor cells.

The effects of Toxoplasma gondii during embryonic development have not been explored despite the predilection of this parasite for neurons and glial cells. Here, we investigated the activation of the purinergic system and proinflammatory responses during congenital infection by T. gondii. Moreover, neuroprotective and neuromodulatory properties of resveratrol (RSV), a polyphenolic natural compound, were studied in infected neuronal progenitor cells (NPCs). For this study, NPCs were isolated from the telencephalon of infected mouse embryos and subjected to neurosphere culture in the presence of EGF and FGF2. ATP hydrolysis and adenosine deamination by adenosine deaminase activity were altered in conditions of T. gondii infection. P2X7 and adenosine A2A receptor expression rates were augmented in infected NPCs together with an increase of proinflammatory (INF-γ and TNF-α) and anti-inflammatory (IL-10) cytokine gene expression. Our results confirm that RSV counteracted T. gondii-promoted effects on enzymes hydrolyzing extracellular nucleotides and nucleosides and also upregulated P2X7 and A2A receptor expression and activity, modulating INF-γ, TNF-α, and IL-10 cytokine production, which plays an integral role in the immune response against T. gondii.

Spray-dried porcine plasma added to diets contaminated with aflatoxins and fumonisins shows beneficial effects to piglet health.

This study was aimed to analyze the effects of spray-dried porcine plasma (SDPP) on the health of post weaning piglets challenged with diets contaminated with aflatoxins and fumonisins. Fifty-six male piglets (7.15 ± 0.61 kg) were allocated in four groups: CTL group received a regular diet; SDPP group received a regular diet and 6% SDPP; MYC group received a diet containing 300 µg/kg aflatoxins and 8,000 µg/kg fumonisins; group MYC+SDPP received 300 µg/kg aflatoxins, 8,000 µg/kg fumonisins and 6% SDPP. The animals that received the experimental diet containing mycotoxins (MYC group) had lower weight gain at the end of the experiment compared to the other treatments. Animals receiving SDPP showed decreased urea levels throughout the experiment (P<0.05). Animals from MYC group presented an increased on reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) levels and decreased catalase activity (P<0.05). In contrast, SDPP prevented the increase of ROS and TBARS and stimulated superoxide dismutase activity (P<0.05). In conclusion, diet contaminated with mycotoxins (group MYC) caused subclinical intoxication in the piglets, as observed by the increase on free radical's production and lipid peroxidation. Conversely, SDPP presented a protective effect, minimizing the effects of oxidative stress caused by aflatoxins and fumonisins ingestion.

Metaphylactic effect of minerals on immunological and antioxidant responses, weight gain and minimization of coccidiosis of newborn lambs.

The aim of this study was to evaluate the metaphylactic effect of minerals on immunological and antioxidant responses, as well as performance and prevention of coccidiosis in newborn lambs. We divided 110 newborn lambs into two groups (55/group): control (untreated) and treated with two doses of 0.33 mL/kg of a mineral complex (zinc, copper, selenium, and manganese) on day of life (DOL) 1 and 30. Total blood was collected at DOL 1, 15, 30 and 45 to measure antioxidant enzymes, biochemical and immunology analyses, and haemogram. Treated animals were heavier (P < .05) than untreated lambs on DOL 15 and 45, but not on DOL 30 due to a coccidiosis outbreak. Catalase activity did not differ between groups, while superoxide dismutase and xanthine oxidase activities were higher (P < .05) in treated lambs compared with control animals. Serum levels of total protein and globulins were higher (P < .05) in treated animals (DOL 15, 30 and 45). A significant increased on the number of lymphocytes (DOL 45), as well as on seric levels of immunoglobulins (IgM and IgG) was observed in treated animals (DOL 15 and 30). Serum Ig levels remained constant throughout the experiment in the treated group, but fluctuated in the control group. Serum glucose levels were greater in treated animals (DOL 15 and 30). It is possible to conclude that subcutaneous administration of minerals has beneficial effects on lambs by increasing antioxidant and immunological defenses, reflected by greater weight gain, which could mitigate the impact of coccidiosis.

Adenosine signaling and adenosine deaminase regulation of immune responses: impact on the immunopathogenesis of HIV infection.

Infection by human immunodeficiency virus (HIV) causes the acquired immune deficiency syndrome (AIDS), which has devastating effects on the host immune system. HIV entry into host cells and subsequent viral replication induce a proinflammatory response, hyperactivating immune cells and leading them to death, disfunction, and exhaustion. Adenosine is an immunomodulatory molecule that suppresses immune cell function to protect tissue integrity. The anti-inflammatory properties of adenosine modulate the chronic inflammation and immune activation caused by HIV. Lack of adenosine contributes to pathogenic events in HIV infection. However, immunosuppression by adenosine has its shortcomings, such as impairing the immune response, hindering the elimination of the virus and control of viral replication. By attempting to control inflammation, adenosine feeds a pathogenic cycle affecting immune cells. Deamination of adenosine by ADA (adenosine deaminase) counteracts the negative effects of adenosine in immune cells, boosting the immune response. This review comprises the connection between adenosinergic system and HIV immunopathogenesis, exploring defects in immune cell function and the role of ADA in protecting these cells against damage.

Hypothyroidism and hyperthyroidism change ectoenzyme activity in rat platelets.

The purinergic system has an important role in the regulation of vascular functions. The interference of thyroid hormones in this system and in cardiovascular events has been studied in recent years. However, the mechanisms involved in vascular, purinergic, and oxidative changes in thyroid disorders are not completely understood. Therefore, the present study aimed to assess purinergic enzyme activity in platelets from rats with hypothyroidism and hyperthyroidism induced, respectively, by continuous exposure to methimazole (MMI) at 20 mg/100 mL or L-thyroxine at 1.2 mg/100 mL in drinking water for 1 month. Results showed that rats exposed to L-thyroxine had a significant decrease in NTPDase activity, wherein ATP hydrolysis was 53% lower and ADP hydrolysis was 40% lower. Moreover, ecto-5'-nucleotidase activity was decreased in both groups, by 39% in the hypothyroidism group and by 52% in the hyperthyroidism group. On the other hand, adenosine deaminase (ADA) activity was increased in hyperthyroidism (75%), and nucleotide pyrophosphatase/phosphodiesterase (NPP) activity was increased in animals with hypothyroidism (127%) and those with hyperthyroidism (128%). Our findings suggest that changes in purinergic enzyme and purine levels could contribute to the undesirable effects of thyroid disturbances. Moreover, oxidative stress and, in particular, a high level of ROS production, showed a causal relation with changes in ectonucleotidase activity and nucleotide and nucleoside levels.

Post-thyroidectomy hypothyroidism increases the expression and activity of ectonucleotidases in platelets: Possible involvement of reactive oxygen species.

Signaling mediated by purines is a widespread mechanism of cell-cell communication related to vasomotor responses and the control of platelet function in the vascular system. However, little is known about the involvement of this signaling as well as the role of reactive oxygen species (ROS) in the development of hypothyroidism. Therefore, the present study investigates changes in the purinergic system, including enzyme activities and expression in platelets, and oxidative profiles in patients with post-thyroidectomy hypothyroidism. The nucleoside triphosphate diphosphohydrolase 1 (NTPDase/CD39) expression in patients increased by 40%, and the adenosine triphosphate (ATP) or adenosine diphosphate (ADP) hydrolyzing activity increased by 82% and 70%, respectively. The activities of ecto-5´-nucleotidase and adenosine deaminase (ADA) also significantly enhanced (39% and 52%, respectively), which correlates with a 45% decrease in adenosine concentration. Furthermore, these patients demonstrated an increased production of ROS (42%), thiobarbituric acid reactive substances (TBARS) (115%), carbonyl protein (30%) and a decreased glutathione S-transferase (GST) activity (20%). This study demonstrates that hypothyroidism interferes with adenine nucleoside and nucleotide hydrolysis and this is correlated with oxidative stress, which might be responsible for the increase in ADA activity. This increase causes rapid adenosine deamination, which can generate a decrease in their concentration in the systemic circulation, which can be associated with the development of vascular complications.

Regioselective synthesis, biological evaluation, and molecular docking of dihydropyrimidin-4-ols as acetylcholinesterase inhibitors.

A new series of 3,6-disubstituted 2-(methylthio)-4-(trifluoromethyl)-3,4-dihydropyrimidin-4-ols displaying methyl, phenyl, aryl, and heteroaryl groups at the 6-position; and methyl, ethyl, allyl, and phenyl groups at the 3-position of the dihydropyrimidine ring, were synthesized and evaluated in vitro for acetylcholinesterase inhibitory activity. Seven compounds showed activity with IC50 values in the lower micromolar range. The compound 4-trifluoromethyl-6-(4-fluorophenyl)-3-methyl-2-methylthio-3,4-dihydropyrimidin-4-ol (6e) had the best inhibitory activity (IC50 2.2 ± 0.9 µm) and this inhibition was characterized as competitive. The molecular docking study showed that the acetylcholinesterase enzyme accommodates compound 6e in its catalytic site. The enantiomers of compound 6e, present similar interactions: π-π stacking interactions between the aromatic ring of the ligand's 4-fluorophenyl moiety and the aromatic rings of the electron-rich Trp84; and H-bonds between the hydroxyl group of Tyr121 and the hydroxyl moiety from 6e. The antioxidant effect of the dihydropyrimidin-4-ols was also investigated.

Oxidative stress in rats experimentally infected by Sporothrix schenckii.

The aim of this study was to evaluate whether oxidative stress occurs in rats experimentally infected by Sporothrix schenckii, and its possible effect on disease pathogenesis. Thirty rats were divided into two groups: the group A (uninfected, n = 18) and the group B (infected by S. schenckii, n=21). Blood samples were collected on days 15, 30 and 40 post-infection (PI). At each sampling time, six rats of the group A, and seven of the group B were bled. TBARS (thiobarbituric acid reactive substances) levels in serum samples were measured to evaluate lipid peroxidation. In addition, catalase (CAT) and superoxide dismutase (SOD) activities, known as biomarkers of antioxidants levels, were verified in whole blood. Seric pro-inflammatory cytokine levels were measured (IFN-γ, TNF-α, and IL-6), which showed that these inflammatory mediators were at higher levels in the infected rats (P < 0.001). In comparison to uninfected animals, rats with sporotrichosis showed significantly higher (p < 0.01) levels of TBARS on day 40 PI; CAT activity was significantly increased (p < 0.01) on days 30 and 40 PI; and SOD activity was increased (p < 0.01) on day 40 PI. Infected rats showed larger testicles and granulomas in the testicular capsule, as well as hepatic granulomas and splenic follicular hyperplasia. All tissues (testicle, spleen, and liver) showed inflammation associated with numerous fungal structures. These results demonstrated that the intense inflammatory response (seric and tissue) in sporotrichosis is a likely mechanism for redox imbalance, and consequently cause the oxidative stress in experimentally infected rats.

Quercetin changes purinergic enzyme activities and oxidative profile in platelets of rats with hypothyroidism.

Diseases related to thyroid hormones have been extensively studied because affect a large number of individuals, and these hormones participate in the regulation of the whole organism homeostasis. However, little is known about the involvement of purinergic signaling related to oxidative stress in hypothyroidism and possible therapeutic adjuncts for treatment of this disorder. Thus, the present study investigates the effects of quercetin on NTPDase, 5'-nucleotidase and adenosine deaminase activities, platelet aggregation and oxidative profile in platelets of rats with methimazole (MMI)-induced hypothyroidism. Methimazole at a concentration of 20mg/100mL was administered for 90days. From the second month the animals received quercetin 10 or 25mg/kg for 60days. Results showed that: Ecto-5'-nucleotidase activity decreased in methimazole/water group and the treatment with quercetin 25mg/kg decreased NTPDase, 5'-nucleotidase and adenosine deaminase activities. Moreover, platelet aggregation increased in methimazole/water group. Lipid peroxidation increased while superoxide dismutase and catalase activities decreased, but, interestingly, the treatment with quercetin reversed these changes. These results demonstrated that quercetin modulates adenine nucleotide hydrolysis decreasing the ADP formation and adenosine deamination. At the same time quercetin improves the oxidative profile, as well as reduces platelet aggregation, which together with the modulation in the nucleotides levels can contribute to the prevention of platelet disorders.

Effect of dietary supplementation of Padauk (Pterocarpus soyauxii) leaf on high fat diet/streptozotocin induced diabetes in rats' brain and platelets.

BACKGROUND: This study investigated the effects of Padauk leaf on brain malondialdehyde (MDA) content, acetylcholinesterase (AChE) activities, ectonucleotidases and adenosine deaminase (ADA) activities in the platelet of high fat diet and streptozotocin (STZ)-induced diabetic rats. METHODS: The animals were divided into six groups (n=7): normal control rats; diabetic rats+high fat diet (HFD); diabetic rats+HFD+Metformin; diabetic rats+HFD+acarbose; diabetic rats+HFD+10% Padauk leaf; normal rats+basal diet+10% Padauk leaf. After 30days of experiment comprising of acclimatization, dietary manipulation, pre-treatment with STZ and supplementation with Padauk leaf, the animals were sacrificed and the rats' brain and blood were collected for subsequent analysis. RESULTS: The results demonstrated that the elevated MDA content and AChE activity in the diabetic rats were significantly reduced when compared with the control rats. Furthermore, the increased NTPDases, 5'-nucleotidase and ADA activities in the diabetic rats were significantly reduced when compared with the control rats. CONCLUSION: This study demonstrated that Padauk leaf exhibited modulatory effects on purinergic and cholinergic enzymes involved in the prevention of platelet abnormality and consequent vascular complications in diabetic state.

Effects of chlorogenic acid on adenine nucleotides hydrolyzing enzyme activities and expression in platelets of rats experimentally demyelinated with ethidium bromide.

BACKGROUND: The effects of chlorogenic acid (one of the major phenolic acid found in human diets) were investigated on the adenine nucleotides hydrolyzing enzymes; ecto-nucleotide pyrophosphatase/phophodiesterase (E-NPP), ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), E-5'- nucleotidase and ecto-adenosine deaminase (E-ADA) activities and expression in platelets of rats experimentally demyelinated with ethidium bromide. METHODS: Rats were divided into four groups of eight animals each. Group I rats were control rats; injected with saline (CT), group II rats were injected with saline and treated with chlorogenic acid (AC), group III rats were injected with 0.1% ethidium bromide (EB) and group IV rats were injected with 0.1% EB and treated with chlorogenic acid (EB+AC). The activities of the enzymes were analyzed using colorimetric methods, and the gene expression of NTPDase 1, 2 and 3 were analyzed using the polymerase chain reaction (PCR). RESULTS: The results revealed that there was a significant (P<0.01) reduction in E-NPP activity in EB group (1.63±0.10nmol p-nitrophenol released/min/mg protein) when compared to CT group (2.33±0.14nmol p-nitrophenol released/min/mg protein). However, treatment with chlorogenic acid significantly (P<0.05) increased E-NPP activity in EB group. Furthermore, no significant (P>0.05) change was observed in the E-NPP activity of EB+AC group (2.19±0.08nmol p-nitrophenol released/min/mg protein) when compared to CT group (2.33±0.14nmol p-nitrophenol released/min/mg protein). In addition, there was a significant (P<0.05) increase in AMP hydrolysis in EB rat group when compared to CT group. No significant (P>0.05) difference was observed in AMP hydrolysis between AC, AC+EB and CT groups. Conversely, there were no significant (P>0.05) differences in ATP and ADP hydrolyses between all the groups (AC, EB, AC+EB and CT groups). Likewise, there were no significant (P>0.05) changes in E-ADA activity and percentage platelet aggregation among all groups studied. Similarly, no significant (P>0.05) change was observed in the expression of E-NTPDase 1, 2 and 3 in all the groups tested. CONCLUSIONS: Our study revealed that chlorogenic acid may modulate the hydrolysis of adenine nucleotides in platelets of rats demyelinated and treated with chlorogenic acid via alteration of E-NPP and ecto-5'-nucleotidase activities.