ß-caryophyllene improves sexual performance via modulation of crucial enzymes relevant to erectile dysfunction in rats.

This study sought to investigate the effect of ß-caryophyllene (BCP) on sexual performance, crucial enzymes linked to erectile function as well as lipid peroxidation in the penile tissue of paroxetine (PD)-induced rats. Animals were randomly divided into ten groups of five animals each: normal control (NC), BCP (10 mg/kg), BCP (20 mg/kg), sildenafil citrate (SD) (20 mg/kg), BCP + SD (20 mg/kg), PD (20 mg/kg), PD + BCP (10 mg/kg), PD + BCP (20 mg/kg), PD + SD (20 mg/kg) and PD + BCP (20 mg/kg) + SD (20 mg/kg). Oral administration of 20 mg/kg body weight of PD for the first 7 days was done while treatment with BCP and SD were performed between 8 and 14 days prior to euthanasia. The sexual performance study revealed that PD caused erectile dysfuction. Elevated activities of phosphodiesterase-5' (PDE-5'), arginase, adenosine deaminase (ADA), acetylcholinesterase (AChE) and angiotensin-I converting enzyme (ACE) as well as lipid peroxidation level were observed in PD-induced rats when compared to the NC group. However, treatment with sildenafil and/ or ß-Caryophyllene significantly reduced the activities of AChE, PDE-5', arginase, ADA, and ACE in penile tissues of PD-induced rats. In addition, co-administration of ß-caryophyllene and sildenafil citrate showed better modulatory effects. Thus, ß-caryophyllene could represent a potential nutraceutical in the management of erectile dysfunction.

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 berberine on cholinesterases and monoamine oxidase activities, and antioxidant status in the brain of streptozotocin (STZ)-induced diabetic rats.

OBJECTIVES: Several studies had been conducted to examine the link between diabetes and diabetes encephalopathy. This study was conducted to examine the potency of berberine (BER) on the restoration of impaired neurochemicals in the brain of streptozotocin (STZ)-induced diabetic Wistar rats. METHODS: Fifty-six (56) adult rats weighing between 200 and 230 g were randomly divided into seven groups (n=8) as follows; Group I is normal control; Groups II and III were normal rats treated with 50 and 100 mg/kg respectively; Group IV-VII were STZ-induced rats, but Groups V-VII were treated with acarbose (25 mg/kg), 50 and 100 mg/kg of BER, respectively. RESULTS: The result of the study showed that untreated STZ-induced diabetic rats have increased acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase (MAO) activities, and malonylaldehyde (MDA) level, with concomitant decrease of superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, and glutathione (GSH) level. However, daily treatment with 50 and 100 mg/kg BER and ACA significantly reversed these effects. CONCLUSIONS: The findings of this study clearly indicated that BER possesses neuro-protective and antioxidative potentials and normalize neurochemical impairment distort by diabetes.

Antioxidant properties of eugenol, butylated hydroxylanisole, and butylated hydroxyl toluene with key biomolecules relevant to Alzheimer's diseases-In vitro.

This research work examined and likened effect of eugenol a natural phenolic compound with butylated hydroxylanisole (BHA) and butylated hydroxyl toluene (BHT) synthetic phenolic compounds with key biomolecules [acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and monoamine oxidase (MAO)] relevant to Alzheimer's diseases (AD) in vitro. Ten millimolar each sample was prepared in a mixture of ethanol and water (1:1 v/v), and the interactions with AChE, BChE, and MAO were evaluated. Still, ferric reducing antioxidant property, ABTS radicals scavenging ability and lipid peroxidation were carried out. The results revealed eugenol, BHT, and BHA inhibited AChE, BChE, and MAO activities dose-dependently. Though, eugenol had greater inhibitory effect against AChE and BChE activities. Also, eugenol demonstrated higher antioxidant potential compared to BHT and BHA. The potent enzymatic inhibitory and antioxidant effects of eugenol indicate eugenol could be promising as an alternative food additive and neuromodulator in AD management. PRACTICAL APPLICATION: BHT and BHA are synthetic antioxidant employed industrially as food preservative. BHT and BHA are employed in food packaging, drugs, and cosmetics. Although BHT and BHA are widely in use but have been found were associated with alteration in sleeping, induced changes in brain serotonin and norepinephrine levels with increased cholinesterase activity. Endocrine disrupting effects, reproductive disorder is more side effects associated with the use of BHT and BHA. However, eugenol a natural compound found in plants compares favorably with BHT and BHA as antioxidant with many more health promoting benefits such as neuroprotective effects, antiapoptotic effects, and prevent aluminum toxicity. Eugenol being a natural antioxidant with no side effects showing more promising effects over the synthetic phenolic compounds and could be an alternative for the BHT and BHA.

Uncaria tomentosa improves cognition, memory and learning in middle-aged rats.

Aging accelerates neurodegeneration, while natural and safe neuroprotective agents, such as Uncaria tomentosa, may help to overcome this problem. This study assessed the effects of U. tomentosa extract treatment on the aging process in the brain of Wistar rats. The spatial memory and learning, acetylcholinesterase (AChE) activity, and DNA damage were assessed. Animals of 14 months were tested with different doses of U. tomentosa (5 mg/kg, 15 mg/kg, and 30 mg/kg) and with different durations of treatment (one month and one year). In the Morris Water Maze (MWM), the escape latency was significantly (p < 0.0001) shorter in rats that received 5 mg/kg, 15 mg/kg, and 30 mg/kg of U. tomentosa for both one month and one year of treatment. There was a significant difference in time spent at the platform zone (p < 0.05) of the middle-aged rats treated with U. tomentosa extract for one year when compared to the control rats. The cortex and hippocampus of rats treated with U. tomentosa for one year showed significant (p > 0.05) reduction in AChE activity. DNA damage index on cortex was significantly lower (p < 0.05) in animals treated with 30 mg/kg of U. tomentosa for one month while all the tested doses demonstrated significant (p < 0.001) reductions in DNA damage index in animals treated for one year. In conclusion, U. tomentosa may represent a source of phytochemicals that could enhance memory activity, repair DNA damage, and alter AChE activity, thereby providing neuroprotection during the aging process.

Protective mechanisms of protocatechuic acid against doxorubicin-induced nephrotoxicity in rat model.

Background Doxorubicin (DOX) induces toxicity in many tissues/organs, including the heart, kidney and so on. This study was designed to evaluate the modulatory effects of protocatechuic acid (PCA) against DOX-induced nephrotoxicity in rats. Animals were randomly grouped into five groups. Methods Group 1 served as the normal control (CTR). A single dose of DOX at 20 mg/kg was administered intraperitoneally (i.p.) to animals in Group 2. Groups 3 and 4 were pretreated with PCA for 5 days (doses of 10 and 20 mg/kg body weight, respectively) after which DOX was injected (PCA-10 + DOX and PCA-20 + DOX). Group 5 received PCA only at a dose of 20 mg/kg body weight (PCA-20). Results The results revealed significant elevations (p < 0.05) in malondialdehyde content, expressions of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX2) in the kidney. Likewise, increased serum levels of creatinine and urea of DOX group were observed. A significant decrease (p < 0.05) in glutathione (GSH) level and antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione s- transferase (GST) activities in the kidney were observed compared with the control. Pretreatment with PCA (10 and 20 mg/kg, p.o.) for 5 days prior to the i.p. injection of DOX reduced MDA levels, modulated iNOS and COX2 activities and improved kidney function markers as well as oxidative stress parameters. Findings from the histopathology studies confirms the protective effects of PCA on DOX-induced damage on the kidney cells. Conclusions This study has demonstrated the anti-inflammatory and antioxidative properties of PCA, which could be part of its possible protective mechanisms against nephrotoxicity induced by DOX.

Pasting alters glycemic index, antioxidant activities, and starch-hydrolyzing enzyme inhibitory properties of whole wheat flour.

This study was designed to compare the antioxidant and antidiabetic activities of raw and paste wheat flour. The raw flour was cooked, dried, and milled to obtain the paste flour. The glycemic index, starch, amylose, and amylopectin contents were determined. The inhibitory effects of the raw and paste flour on α-glucosidase and α-amylase activities as well as metal-induced pancreatic damage were also determined. Pasting reduced the glycemic index (63.15%), starch (22.83 g/100 g), amylose (2.88 g/100 g), and amylopectin (17.74 g/100 g) contents. The raw (IC 50 = 0.50 and 1.20 mg/ml) and paste (IC 50 = 0.29 and 1.66 mg/ml) flours reduced the activities of α-amylase and α-glucosidase, respectively. The paste flour exhibited stronger inhibitory effects against Fe2+-induced pancreatic damage compared to raw flour. The paste flour exhibited better antioxidant and antidiabetic properties and could be a good processing method to improve the medicinal properties of wheat flour.

Modulatory effect of quercetin and its glycosylated form on key enzymes and antioxidant status in rats penile tissue of paroxetine-induced erectile dysfunction.

This study sought to compare the effects of quercetin and rutin on some enzymes linked to erectile function as well as antioxidant status in penile tissue of paroxetine - induced erectile dysfunction in rats. Animals were randomly divided into twelve groups: normal control (NC), sildenafil (SD), quercetin (QA) (25 and 50 mg/kg), rutin (RU) (25 and 50 mg/kg), PAR (10 mg/kg); PAR + SD; PAR + QA, PAR + RU (25 and 50 mg/kg). After 14 days' treatment, phosphodiesterase-5' (PDE-5'), arginase, adenosine deaminase (ADA), acetylcholinesterase (AChE) and angiotensin-I converting enzyme (ACE) activities as well as malondialdehyde (MDA) and non-protein thiol levels were determined in rat penile tissues. Elevated levels of PDE-5', arginase, AChE, ADA and ACE activities and MDA were observed in PAR-induced rats with concomitant decrease in non-protein thiol levels when compared to the NC group. However, treatment with SD, QA and RU significantly reduced the activities of AChE, PDE-5', arginase, ADA and ACE and MDA levels and elevated non-protein thiol levels in penile tissues of PAR-induced rats. Furthermore, administration of QA and RU in PAR-induced rats modulated the key enzymes relevant to erection, improved antioxidant status and could be potential functional food ingredients and nutraceuticals in the prevention and/or management of erectile dysfunction.

African crocus (Curculigo pilosa) and wonderful kola (Buchholzia coriacea) seeds modulate critical enzymes relevant to erectile dysfunction and oxidative stress.

Background The seeds of African crocus (AC) (Curculigo pilosa) and wonderful kola (WK) (Buchholzia coriacea) are commonly used in folklore medicine in managing erectile dysfunction (ED) without the full understanding of the possible mechanism of actions. This study investigated and compared the effects of aqueous extracts from the seeds of AC and WK on arginase and acetylcholinesterase (AChE) activities and some pro-oxidant [FeSO4 and sodium nitroprusside (SNP)]-induced lipid peroxidation in rat penile homogenate in vitro. Method Aqueous extracts of AC and WK were prepared, and their effects on arginase and AChE activities as well as FeSO4- and SNP-induced lipid peroxidation in rat penile homogenate were assessed. Furthermore, phenolic constituents of the extract were determined using high-performance liquid chromatography coupled with diode-array detector (HPLC-DAD). Results Both extracts exhibited concentration-dependent inhibition on arginase (AC, IC50=0.05 mg/mL; WK, IC50=0.22 mg/mL) and AChE (AC, IC50=0.68 mg/mL; WK, IC50=0.28 mg/mL) activities. The extracts also inhibited FeSO4- and SNP-induced lipid peroxidation in rat penile homogenate. HPLC-DAD analysis revealed the presence of phenolic acids (gallic, caffeic, ellagic and coumaric acids) and flavonoids (catechin, quercetin and apigenin) in AC and WK. AC had higher arginase inhibitory and antioxidative activities but lower AChE inhibitory properties when compared with WK. Conclusions These effects could explain the possible mechanistic actions of the seeds in the management/treatment of ED and could be as a result of individual and/or synergistic effect of the constituent phenolic compounds of the seeds.

Aqueous extracts of two tropical ethnobotanicals (Tetrapleura tetraptera and Quassia undulata) improved spatial and non-spatial working memories in scopolamine-induced amnesic rats: Influence of neuronal cholinergic and antioxidant systems.

BACKGROUND: Tetrapleura tetraptera (TT) and Quassia undulata (QU) are two predominant tropical ethnobotanicals with various medicinal values but are commonly used in folklore for the treatment of mental illness without justifiable mechanisms of action. AIM OF THE STUDY: To investigate the effects of aqueous extracts from TT fruits and QU leaves on the spatial and non-spatial working memory, antioxidant status and activities of neuronal marker enzymes of scopolamine-induced amnesic rats and thus, understand the possible mechanism of action of these plants. MATERIALS AND METHODS: Fifty-five albino rats were divided into eleven groups. Group I (normal rats) received normal saline (p.o), Group II-V (normal rats) administered with 50 and 300 mg/kg of each extract group VI (induced rats) received 2 mg/kg of scopolamine (i.p.), groups VII-X (induced rats) pretreated with 50 and 300 mg/kg of TT and QU extracts (p.o) before scopolamine administration, group XI (induced rats) treated with 2.5 mg/kg of donepezil. The treatment lasted for 14 days and amnesia was induced by a single dose of 2 mg/kg of scopolamine on the last day. Spatial (Y-maze) and non-spatial (novel objectect recoginiton test) working memories of the rats were tested. Thereafter, the animals were sacrificed and homogenates of isolated brain samples were assayed for cholinesterase activity and malondialdehyde (MDA) content. The phenolic characterisation of the samples was also carried out using HPLC-DAD chromatography. RESULTS: Administration of 2 mg/kg of scopolamine brought about a decrease in spatial and non-spatial memory indeces, increase in acetylcholinesterase and butyrylcholinesterase activities, as well as increased MDA content compared to the control. However, pretreatment with both extracts improved both spatial and non-spatial working memories and ameliorated the increased enzyme activities and MDA contents. Furthermore, the HPLC-DAD characterization of the extracts revealed the presence of p-coumaric acid, rutin, catechin, ellagic acid, quercetin, caffeic acid, chlorogenic acid and galic acid. CONCLUSION: The ability of the extracts to improved cognitive function and ameliorate impairment in cholinergic enzyme activities and antioxidant status in scopolamine-induced amnesic rats could help justify the possible neuroprotective properties of TT and QU and also explain possible mechanism of action of these ethnobotanicals as obtained in folklore medical practices.

Sildenafil, a phosphodiesterase-5 inhibitor, offers protection against carbon tetrachloride-induced hepatotoxicity in rat.

BACKGROUND: Elevation of phosphodiesterase-5 (PDE5) activity converts cyclic guanosine monophosphate (cGMP) to 5'-GMP, a mechanism that could be associated with drug-mediated hepatotoxicity. This study investigated whether selective inhibition of PDE5 by sildenafil could offer protection against hepatotoxicity induced by carbon tetrachloride (CCl4). METHODS: CCl4 (0.5 mL/kg) was administered intraperitoneally to induce hepatotoxicity. The control group received normal saline. Sildenafil (5 mg, 10 mg, and 20 mg/kg, p.o.) was administered to CCl4-treated rats. RESULTS: CCl4 significantly increased the serum levels of gamma glutamyl transferase (γ-GT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) and reduced total protein (TP) (p<0.05). Pretreatment with sildenafil moderately reduced ALP, AST, and ALT activities with modest increase in TP level. CCl4-induced changes in the antioxidant status of the liver were significantly improved by sildenafil, especially at the lowest dose of 5 mg/kg by elevating the levels of reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) and preventing lipid peroxidation (p<0.05). Sildenafil did not significantly alter the total cholesterol and triglyceride levels. However, high-density lipoprotein (HDL) level was significantly increased by sildenafil (p<0.05). CONCLUSIONS: The results from this study suggest that sildenafil, when used at low doses, may be a useful pharmacological protective agent against CCl4-induced hepatotoxicity.

Changes in inflammatory/cardiac markers of HIV positive patients.

HIV replication promotes atherogenesis and participates in the immune response to the virus, thereby influencing the inflammatory profile. These changes may, in turn, contribute to the risk of cardiovascular diseases with involvement of platelets. However, adenine nucleotides and nucleosides involved in thromboregulation and modulation of immune response may therefore be affected by these alterations. OBJECTIVES: This study sought to evaluate the profile of pro and anti-inflammatory cytokines (IL-10, IL-6, IL-17, TNF, IL-4, IL-2 and IFN-gamma), cardiac markers (troponin, CK, CK MB, LDH, CRP) in HIV-positive patients and assess the in vitro effect of antiretroviral therapy on the activities of ectonucleotidases (E-NTPDase and E-5'-nucleotidase) in human platelets. DESIGN AND METHODS: Blood samples were obtained from ten HIV positive patients at the Infectious Disease Clinic of the University Hospital of Santa Maria, Brazil and ten HIV negative individuals (control group) for this study. RESULTS: The results revealed that there were significant (P < 0.05) increases in serum levels of IL-6 and IFN-gamma with no significant (P > 0.05) changes in the serum levels of the cardiac markers investigated (CK, CK-MB, troponin, LDH and CRP). In addition, the ectonucleotidases (E-NTPDase and E-5'-nucleotidase) activities were not altered (P > 0.05) in human platelets when incubated with different antiretroviral drugs in vitro. CONCLUSIONS: The results of this study suggest that, despite successful treatment, a proinflammatory state is not altered in HIV patients, and that antiretroviral therapy per se does not change the purinergic profile.

Phenolic constituents and modulatory effects of Raffia palm leaf (Raphia hookeri) extract on carbohydrate hydrolyzing enzymes linked to type-2 diabetes.

This study sought to investigate the effects of Raffia palm (Raphia hookeri) leaf extract on enzymes linked to type-2 diabetes mellitus (T2DM) and pro-oxidant induced oxidative stress in rat pancreas. The extract was prepared and its α-amylase and α-glucosidase inhibitory effects were determined. Radical [2,2-diphenyl-1-picrylhydrazyl (DPPH)] scavenging and Fe2+-chelating abilities, and inhibition of Fe2+-induced lipid peroxidation in rat pancreas homogenate were assessed. Furthermore, total phenol and flavonoid contents, reducing property, and high performance liquid chromatography diode array detector (HPLC-DAD) fingerprint of the extract were also determined. Our results revealed that the extract inhibited α-amylase (IC50 = 110.4 µg/mL) and α-glucosidase (IC50 = 99.96 µg/mL) activities in concentration dependent manners which were lower to the effect of acarbose (amylase: IC50 = 18.30 µg/mL; glucosidase: IC50 = 20.31 µg/mL). The extract also scavenged DPPH radical, chelated Fe2+ and inhibited Fe2+-induced lipid peroxidation in rat pancreas all in concentration dependent manners with IC50 values of 402.9 µg/mL, 108.9 µg/mL and 367.0 µg/mL respectively. The total phenol and flavonoid contents were 39.73 mg GAE/g and 21.88 mg QAE/g respectively, while the reducing property was 25.62 mg AAE/g. The HPLC analysis revealed the presence of chlorogenic acid (4.17 mg/g) and rutin (5.11 mg/g) as the major phenolic compounds in the extract. Therefore, the ability of the extract to inhibit carbohydrate hydrolyzing enzymes and protect against pancreatic oxidative damage may be an important mechanisms supporting its antidiabetic properties and could make Raffia palm leaf useful in complementary/alternative therapy for management of T2DM. However, further studies such as in vivo should be carried out.

Sepsis induced by cecal ligation and perforation (CLP) alters nucleotidase activities in platelets of rats.

Sepsis is a potentially lethal condition, and it is associated with platelet alterations. The present study sought to investigate the activity of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), E-5'-nucleotidase, and ecto-adenosine deaminase (E-ADA) in the platelets of rats that were induced with sepsis. Male Wistar rats were divided into three groups of ten animals each: a negative control group (normal; NC); a group that underwent surgical procedures (sham); and a group that underwent cecal ligation and perforation (CLP). The induction of sepsis was confirmed by bacteremia, and the causative pathogen identified was Escherichia coli. Hematological parameters showed leukocytosis and thrombocytopenia in animals in the septic group. The results also revealed that there were significant (p < 0.05) increases in adenosine triphosphate (ATP) and adenosine monophosphate (AMP) hydrolyses, and in the deamination of adenosine in the CLP group compared to the sham and control groups. Conversely, ADP hydrolysis was significantly decreased (p < 0.05) in the CLP group compared to the sham and control groups. Purine levels were analyzed by high-performance liquid chromatography (HPLC) in serum samples from control, sham, and CLP groups. Increased concentrations of ATP, adenosine, and inosine were found in the CLP group compared to the sham and control groups. Conversely, the concentrations of ADP and AMP in the CPL group were not significantly altered. We suggest that alterations in hematological parameters, nucleotide hydrolysis in platelets, and nucleotide concentrations in serum samples of rats with induced sepsis may be related to thromboembolic events.

Safety evaluation of supratherapeutic dose of Maytenus ilicifolia Mart. ex Reissek extracts on fertility and neurobehavioral status of male and pregnant rats.

Maytenus ilicifolia Mart. ex Reissek is a plant commonly used in folklore medicine in the management of gastric diseases in South America. This study explores the effects of a supratherapeutic dose of aqueous and ethanol extracts of M. ilicifolia (1360 mg/kg) on fertility and neurobehavioral status in male and pregnant rats. A battery of sensory-motor developmental endpoints was carried out to assess impairments on pups of dams orally treated with the aqueous extract of M. ilicifolia during the organogenesis period of pregnancy (GD 9 through GD 14). The neuromotor maturation reflexes and physical developments of the offspring were not significantly different between the groups (p < 0.05). Also, the hippocampal morphology revealed no indices of cell loss in the CA1, CA2, CA3 and CA4 areas. As second protocol, some fertility aspects were investigated in young post pubertal male Wistar rats treated with the ethanol extract for 30 days. The semen quality and testicular tissue morphology of male rats treated with the ethanol extract of M. ilicifolia remained unaffected upon treatment. Thus, the results indicate that the high-dose of M. ilicifolia extracts have no neurotoxic potential on offspring and seem not to affect the sperm quality of male rats.

Characterization of E-NTPDase (EC 3.6.1.5) activity in hepatic lymphocytes: A different activity profile from peripheral lymphocytes.

The activity of ectonucleoside triphosphate diphosphohydrolase (E-NTPDase; EC 3.6.1.5) was characterized in hepatic lymphocytes (HL) of rats. For this purpose, a specific method for the isolation of lymphocytes from hepatic tissue was developed. Subsequently, E-NTPDase activity of rat HL was compared with that of rat peripheral lymphocytes. The HL showed high cell count and viability. Also, the characterization test revealed that the optimal E-NTPDase activities were attained at 37°C and pH 8.0 in the presence of Ca2+ . In addition, in the presence of specific E-NTPDase inhibitors (20mM sodium azide and 0.3mM suramin), there were significant inhibitions in nucleotide hydrolysis. However, there was no significant change in adenosine triphosphate (ATP) or adenosine diphosphate (ADP) hydrolysis in the presence of inhibitors of other E-ATPase (0.1mM Ouabain, 0.5mM orthovanadate, and 1mM, 5mM, and 10mM sodium azide). Furthermore, the kinetic behavior of the enzyme in HL showed apparent Km of 134.90 ± 0.03µM and 214.40 ± 0.06µM as well as Vmax of 345.0 ± 28.32 and 242.0 ± 27.55 Æžmol Pi/min/mg of protein for ATP and ADP, respectively. The Chevillard plot revealed that ATP and ADP were hydrolyzed at the same active site of the enzyme. Our results suggest that the degradation of extracellular nucleotides in HL may have been primarily accomplished by E-NTPDase. The higher E-NTPDase activity observed in HL may be attributed to the important physiological functions of ATP and ADP in HL. SIGNIFICANCE OF THE STUDY: Extracellular purine nucleotides are able to interact with specific receptors and trigger a number of important physiological functions in cells. This interaction is controlled by ectonucleoside triphosphate diphosphohydrolase (E-NTPDase), enzyme that present their catalytic site at the extracellular space and degrades nucleotides. This purinergic signaling has important functions in peripheral lymphocytes and may represent an important new therapeutic target for the treatment of immunological diseases. However, there is dearth of information on the involvement of E-NTPDase in liver lymphocytes. The liver is an important organ, which performs both metabolic and toxicological roles in living organism, and hepatic lymphocytes may play crucial action in the regulation of immune responses in the liver tissue. Furthermore, various chronic diseases such as cirrhosis may be treated with novel pharmacotherapy by targeting the modulation of hepatic lymphocytes. Thus, the significance of this study is to evaluate the activity of E-NTPDase in liver lymphocyte and compare its activity with the peripheral lymphocytes.

Neuroprotective effects of pretreatment with quercetin as assessed by acetylcholinesterase assay and behavioral testing in poloxamer-407 induced hyperlipidemic rats.

Hyperlipidemia is a group of disorders characterized by excessive lipids in the bloodstream. It is associated with the incidence of cardiovascular diseases and recognized as the most important factor underlying the occurrence of atherosclerosis. This study was conducted to investigate whether pretreatment with quercetin can protect against possible memory impairment and deterioration of the cholinergic system in hyperlipidemic rats. Animals were divided into ten groups (n=7): saline/control, saline/quercetin 5mg/kg, saline/quercetin 25mg/kg, saline/quercetin 50mg/kg, saline/simvastatin (0.04mg/kg), hyperlipidemia, hyperlipidemia/quercetin 5mg/kg, hyperlipidemia/quercetin 25mg/kg, hyperlipidemia/quercetin 50mg/kg and hyperlipidemia/simvastatin. The animals were pretreated with quercetin by oral gavage for a period of 30days and hyperlipidemia was subsequently induced by intraperitoneal administration of a single dose of 500mg/kg of poloxamer-407. Simvastatin was administered after the induction of hyperlipidemia. The results demonstrated that hyperlipidemic rats had memory impairment compared with the saline control group (P<0.001). However, pretreatment with quercetin and simvastatin treatment attenuated the damage caused by hyperlipidemia compared with the hyperlipidemic group (P<0.05). Acetylcholinesterase (AChE) activity in the cerebral hippocampus was significantly (P<0.001) reduced in the hyperlipidemic group compared with the control saline group. Pretreatment with quercetin and simvastatin treatment in the hyperlipidemic groups significantly (P<0.05) increased AChE activity compared with the hyperlipidemic group. Our results thus suggest that quercetin may prevent memory impairment, alter lipid metabolism, and modulate AChE activity in an experimental model of hyperlipidemia.

Comparative Effects of Alkaloid Extracts from Aframomum melegueta (Alligator Pepper) and Aframomum danielli (Bastered Melegueta) on Enzymes Relevant to Erectile Dysfunction.

Aframomum melegueta (alligator pepper (AP)) and Aframomum danielli (bastered melegueta (BM)) seeds have been known to improve sexual function in folkloric medicine. This study investigates the effects of AP and BM seeds' alkaloid extracts on the activities of enzymes (acetylcholinesterase (AChE), angiotensin-1-converting enzyme (ACE), phosphodiesterase-5 (PDE-5), and arginase) relevant to erectile dysfunction (ED). Alkaloids from the seeds were prepared by the solvent extraction method and their interactions with AChE, ACE, PDE-5, and arginase were assessed. Gas chromatographic (GC) analyses of the extracts were also performed. The results revealed that the extracts inhibited the enzymes in a concentration-dependent manner. However, alkaloid extract from AP seed had higher AChE (IC50 = 5.42 µg/mL) and ACE (IC50 = 12.57 µg/mL) but lower PDE-5 (IC50 = 33.80 µg/mL) and arginase (IC50 = 31.36 µg/mL) inhibitory effects when compared to that of BM extract (AChE, IC50 = 42.00; ACE, IC50 = 60.67, PDE-5, IC50 = 7.24; and arginase, IC50 = 2.53 µg/mL). The GC analyses revealed the presence of senkirkine, angustifoline, undulatine, myristicin, safrole, lupanine, powelle, and indicine-N-oxide, among others. The inhibition of these enzymes could be the possible mechanisms by which the studied seeds were being used in managing ED in folklores. Nevertheless, the seed of AP exhibited higher potentials.

Guarana (Paullinia cupana) ameliorates memory impairment and modulates acetylcholinesterase activity in Poloxamer-407-induced hyperlipidemia in rat brain.

Hyperlipidemia is a risk factor for the development of cognitive dysfunction and atherosclerosis. Natural compounds have recently received special attention in relation to the treatment of disease due to their low cost and wide margin of safety. Thus, the aim of this study was to determine the possible preventive effect of guarana powder (Paullinia cupana) on memory impairment and acetylcholinesterase (AChE) activity in the brain structures of rats with Poloxamer-407-induced hyperlipidemia. Adult male Wistar rats were pretreated with guarana (12.5, 25 and 50mg/kg/day) and caffeine (0.2mg/kg/day) by gavage for a period of 30days. Simvastatin (0.04mg/kg) was administered as a comparative standard. Acute hyperlipidemia was induced with intraperitoneal injections of 500mg/kg of Poloxamer-407. Memory tests and evaluations of anxiety were performed. The cortex, cerebellum, hippocampus, hypothalamus and striatum were separated to assess acetylcholinesterase activity. Our results revealed that guarana powder was able to reduce the levels of TC and LDL-C in a manner similar to simvastatin. Guarana powder also partially reduced the liver damage caused by hyperlipidemia. Guarana was able to prevent changes in the activity of AChE and improve memory impairment due to hyperlipidemia. Guarana powder may therefore be a source of promising phytochemicals that can be used as adjuvant therapy in the management of hyperlipidemia and cognitive disorders.

Alterations of Na+/K+-ATPase, cholinergic and antioxidant enzymes activity by protocatechuic acid in cadmium-induced neurotoxicity and oxidative stress in Wistar rats.

BACKGROUND: This study assessed the possible protective mechanisms of protocatechuic acid (PCA) against cadmium (Cd)-induced oxidative stress and neurotoxicity in rats. METHODS: Male wistar strain rats weighing between 150-160g were purchased and acclimatized for two weeks. The rats were divided into seven groups of seven each; NC group received normal saline, CAD group received 6mg/kg of Cd-solution, CAD+PSG group received Cd-solution and prostigmine (5mg/kg), CAD+PCA-10 and CAD+PCA-20 groups received Cd-solution and PCA (10mg/kg and 20mg/kg) respectively, PCA-10 and PCA-20 groups received 10mg/kg and 20mg/kg PCA each. Animals were administered normal saline, Cd and PCA daily by oral gavage for 21days. After which the animals were sacrificed, the brain excised, homogenized and centrifuged. The activities of enzymes (Na+/K+-ATPase, cholinesterases, catalase, glutathione peroxidase, superoxide dismutase) and levels of oxidative stress markers (lipid peroxidation and reduced glutathione) linked to neurodegeneration were subsequently assessed. RESULTS: Significant (p<0.05) alterations in the enzyme activities and levels of oxidative stress markers were observed in CAD group when compared to the NC group. However, the activities of the enzymes were reversed in CAD+PSG and CAD+PCA groups. CONCLUSIONS: PCA may protect against cadmium-induced neurotoxicity by altering the activities of Na+/K+-ATPase, acetylcholinesterase, butyrylcholinesterase and endogenous antioxidant enzymes.