Effects of curcumin on the activities of the enzymes that hydrolyse adenine nucleotides in platelets from cigarette smoke-exposed rats

The protective effects of curcumin against cigarette smoke-induced toxicity: A comprehensive review

Cigarette smoking (CS) is a crucial modifiable risk of developing several human diseases and cancers. It causes lung, bladder, breast, and esophageal cancers, respiratory disorders, as well as cardiovascular and metabolic diseases. Because of these adverse health effects, continual efforts to decrease the prevalence and toxicity of CS are imperative. Until the past decades, the impacts of natural compounds have been under investigation on the harmful effects of CS. Turmeric (Curcuma longa), a rhizomatous herbaceous perennial plant that belongs to the Zingiberaceae family, is the main source of curcumin. This review is an attempt to find out the current knowledge on CS's harmful effects and protective potential of curcumin in the pulmonary, liver, brain, gastrointestinal, and testis organs. According to the present review, simultaneous consumption of curcumin and CS can attenuate CS toxicities including chronic obstructive pulmonary disease, gastrointestinal toxicity, metabolic diseases, testis injury, and neurotoxicity. Moreover, curcumin suppresses carcinogenesis in the skin, liver, lungs, breast, colon, and stomach. Curcumin mediates these protective effects through antioxidant, anti-inflammatory, anti-apoptotic, and anti-carcinogenicity properties.

Regulatory Effects of Curcumin on Platelets: An Update and Future Directions

The rhizomatous plant turmeric, which is frequently used as a spice and coloring ingredient, yields curcumin, a bioactive compound. Curcumin inhibits platelet activation and aggregation and improves platelet count. Platelets dysfunction results in several disorders, including inflammation, atherothrombosis, and thromboembolism. Several studies have proved the beneficial role of curcumin on platelets and hence proved it is an important candidate for the treatment of the aforementioned diseases. Moreover, curcumin is also frequently employed as an anti-inflammatory agent in conventional medicine. In arthritic patients, it has been shown to reduce the generation of pro-inflammatory eicosanoids and to reduce edema, morning stiffness, and other symptoms. Curcumin taken orally also reduced rats' acute inflammation brought on by carrageenan. Curcumin has also been proven to prevent atherosclerosis and platelet aggregation, as well as to reduce angiogenesis in adipose tissue. In the cerebral microcirculation, curcumin significantly lowered platelet and leukocyte adhesion. It largely modulated the endothelium to reduce platelet adhesion. Additionally, P-selectin expression and mice survival after cecal ligation and puncture were improved by curcumin, which also altered platelet and leukocyte adhesion and blood-brain barrier dysfunction. Through regulating many processes involved in platelet aggregation, curcuminoids collectively demonstrated detectable antiplatelet activity. Curcuminoids may therefore be able to prevent disorders linked to platelet activation as possible therapeutic agents. This review article proposes to highlight and discuss the regulatory effects of curcumin on platelets.

Protective Effect of α-Linolenic Acid on Non-Alcoholic Hepatic Steatosis and Interleukin-6 and -10 in Wistar Rats

Consumption of omega-3 (n-3) polyunsaturated fatty acids (PUFA) is related to improvement in the inflammatory response associated with decreases in metabolic disorders of obesity, such as low-grade inflammation and hepatic steatosis. Linseed (Linum usitatissimum) oil is a primary source of n-3 fatty acids (FAs) of plant origin, particularly α-linolenic acid, and provides an alternative for the ingestion of n-3 PUFA by persons allergic to, or wishing to avoid, animal sources. In our study, we evaluated the effect of the consumption of different lipidic sources on metabolic and inflammatory parameters in Wistar rats. We split 56 male rats into four groups that were fed for 60 days with the following diets: sesame oil, (SO, Sesamum indicum), linseed oil (LO), SO + LO (SLO), and a control group (CG) fed with animal fat. Our results reveal that the use of LO or SLO produced improvements in the hepatic tissue, such as lower values of aspartate aminotransferase, liver weight, and hepatic steatosis. LO and SLO reduced the weight of visceral fats, weight gain, and mediated the inflammation through a decrease in interleukin (IL)-6 and increase in IL-10. Though we did not detect any significant differences in the intestine histology and the purinergic system enzymes, the consumption of α-linolenic acid appears to contribute to the inflammatory and hepatic modulation of animals compared with a diet rich in saturated FAs and or unbalanced in n-6/n-3 PUFAs, inferring possible use in treatment of metabolic disorders associated with obesity and cardiovascular diseases.

The regulatory role of curcumin on platelet functions

Curcumin, the main ingredient of Curcuma longa L., has been used as a spice and as a herbal medicine with different therapeutic characteristics for centuries in Asian countries. This phytochemical has been shown to possess beneficial antiplatelet activity that has introduced it as a promising candidate for the treatment of thromboembolism, atherothrombosis, and inflammatory diseases. Platelet dysfunction under different circumstances may lead to cardiovascular disease, and curcumin has been shown to have beneficial effects on platelet dysfunction in several studies. Therefore, this narrative review is aimed to summarize available evidence on the antiplatelet activity of curcumin and related molecular mechanisms for this activity.

Use of Curcumin, a Natural Polyphenol for Targeting Molecular Pathways in Treating Age-Related Neurodegenerative Diseases

Progressive accumulation of misfolded amyloid proteins in intracellular and extracellular spaces is one of the principal reasons for synaptic damage and impairment of neuronal communication in several neurodegenerative diseases. Effective treatments for these diseases are still lacking but remain the focus of much active investigation. Despite testing several synthesized compounds, small molecules, and drugs over the past few decades, very few of them can inhibit aggregation of amyloid proteins and lessen their neurotoxic effects. Recently, the natural polyphenol curcumin (Cur) has been shown to be a promising anti-amyloid, anti-inflammatory and neuroprotective agent for several neurodegenerative diseases. Because of its pleotropic actions on the central nervous system, including preferential binding to amyloid proteins, Cur is being touted as a promising treatment for age-related brain diseases. Here, we focus on molecular targeting of Cur to reduce amyloid burden, rescue neuronal damage, and restore normal cognitive and sensory motor functions in different animal models of neurodegenerative diseases. We specifically highlight Cur as a potential treatment for Alzheimer's, Parkinson's, Huntington's, and prion diseases. In addition, we discuss the major issues and limitations of using Cur for treating these diseases, along with ways of circumventing those shortcomings. Finally, we provide specific recommendations for optimal dosing with Cur for treating neurological diseases.

Neuroprotective effects of curcumin against acetamiprid-induced neurotoxicity and oxidative stress in the developing male rat cerebellum: biochemical, histological, and behavioral changes

Curcumin is a molecule found in turmeric root that has anti-inflammatory, antioxidant, and anti-tumor properties and has been widely used as both an herbal drug and a food additive to treat or prevent neurodegenerative diseases. This study aimed to investigate the effect of curcumin on neurobehavioral and neuropathological alterations induced by acetamiprid on male rats. Three groups of ten male Wistar rats each were used for the study: the first was a control group (CTR) that did not consume acetamiprid (ACE); the second was an experimental group (ACE) that consumed 40 mg/kg body weight/day of acetamiprid; and the third group (CUR) received curcumin (100 mg/kg) and acetamiprid (40 mg/kg) in combination. Neurobehavioral evaluations including inclined plane performance and forepaw grip time were studied. Treatment with CUR significantly prevented ACE-treated rats from impairments in the performance of neurobehavioral tests, indicating the presence of deficits on sensorimotor and neuromuscular responses. In addition, Curcumin administration protects rats against acetamiprid-induced cerebellum toxicity such as increase in AChE and BChE activities, decrease on cells viability, oxidative stress, and an increase of intracellular calcium. Taken together, these results demonstrate for the first time that ACE treatment substantially impairs the survival of primary neuronal cells through the induction of necrosis concomitantly with the generation of an oxidative stress. Additionally, curcumin reduced histopathological changes caused by ACE.

Characterization of ectonucleoside triphosphate diphosphohydrolase (E-NTPDase; EC 3.6.1.5) activity in mouse peritoneal cavity cells

This study aimed to characterize the activity of ectonucleoside triphosphate diphosphohydrolase (E-NTPDase; EC 3.6.1.5) in peritoneal cavity cells from BALB/c mice. E-NTPDase was activated in the presence of both calcium (1.5mM) and magnesium (1.5mM) ions. However, the activity was higher in the presence of Ca²⁺ . A pH of 8.5 and temperature of 37°C were the optimum conditions for catalysis. The apparent Km values were 0.51mM and 0.66mM for the hydrolysis of adenosine triphosphate (ATP) and adenosine diphosphate (ADP), respectively. The Vmax values were 136.4 and 120.8 nmol Pi/min/mg of protein for ATPase and ADPase activity, respectively. Nucleotide hydrolysis was inhibited in the presence of sodium azide (20mM, ATP: P < .05; ADP: P < .001), sodium fluoride (20mM; ATP and ADP: P < .001), and suramin (0.3mM; ATP: P < .01; ADP: P < .05), which is a known profile for NTPDase inhibition. Although all of the diphosphate and triphosphate nucleotides that were tested were hydrolyzed, enzyme activity was increased when adenine nucleotides were used as substrates. Finally, we stress that knowledge of the E-NTPDase catalytic biochemical properties in mouse peritoneal cavity cells is indispensable for properly determining its activity, as well as to fully understand the immune response profile in both healthy and sick cells.

Expression of nattokinase in Escherichia coli and renaturation of its inclusion body

Nattokinase is an important fibrinolytic enzyme with therapeutic applications for cardiovascular diseases. The full-length and mature nattokinase genes were cloned from Bacillus subtilis var. natto and expressed in pQE30 vector in Escherichia coli. The full-length gene expressed low nattokinase activity in the intracellular soluble and the medium fractions. The mature gene expressed low soluble nattokinase activity and large amount insoluble protein in inclusion bodies without enzyme activity. Large amount of refolding solutions (RSs) at different pH values were screening and RS-10 and RS-11 at pH 9 were selected to refold nattokinase inclusion bodies. The recombinant cells were lysed with 0.1mg/mL lysozyme and ultrasonic treatment. After centrifugation, the pellete was washed twice with 20mM Tris-HCl buffer (pH 7.5) containing 1% Triton X-100 to purify the inclusion bodies. The inclusion bodies were dissolved in water at pH 12.0 and refolded with RS-10. The refolded proteins showed 42.8IU/mg and 79.3IU/mg fibrinolytic activity by the traditional dilution method (20-fold dilution into RS-10) and the directly mixing the protein solution with equal volume RS-10, respectively, compared to the 52.0IU/mg of total water-soluble proteins from B. subtilis var. natto. This work demonstrated that the inclusion body of recombinant nattokinase expressed in E. coli could be simply refolded to the natural enzyme activity level by directly mixing the protein solution with equal volume refolding solution.

NTPDase1/CD39 and aberrant purinergic signalling in the pathogenesis of COPD

Purinergic receptor activation via extracellular ATP is involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Nucleoside triphosphate diphosphohydrolase-1/CD39 hydrolyses extracellular ATP and modulates P2 receptor signalling.We aimed to investigate the expression and function of CD39 in the pathogenesis of cigarette smoke-induced lung inflammation in patients and preclinical mouse models. CD39 expression and soluble ATPase activity were quantified in sputum and bronchoalveolar lavage fluid (BALF) cells in nonsmokers, smokers and COPD patients or mice with cigarette smoke-induced lung inflammation. In mice, pulmonary ATP and cytokine concentrations, inflammation and emphysema were analysed in the presence or absence of CD39.Following acute cigarette smoke exposure CD39 was upregulated in BALF cells in smokers with further increases in COPD patients. Acute cigarette smoke exposure induced CD39 upregulation in murine lungs and BALF cells, and ATP degradation was accelerated in airway fluids. CD39 inhibition and deficiency led to augmented lung inflammation; treatment with ATPase during cigarette smoke exposure prevented emphysema.Pulmonary CD39 expression and activity are increased in COPD. CD39 deficiency leads to enhanced emphysema in mice, while external administration of a functional CD39 analogue partially rescues the phenotype. The compensatory upregulation of pulmonary CD39 might serve as a protective mechanism in cigarette smoke-induced lung damage.

Metabolite Signatures in Hydrophilic Extracts of Mouse Lungs Exposed to Cigarette Smoke Revealed by 1H NMR Metabolomics Investigation

¹H-NMR metabolomics was used to investigate the changes of metabolites in the lungs of mice with and without being exposed to a controlled amount of cigarette smoke. It was found that the concentrations of adenosine derivatives (i.e. ATP, ADP and AMP), inosine and uridine were significantly changed in the lungs of mice exposed to cigarette smoke when compared with controls regardless the mice were obese or of regular weight. The decreased ATP, ADP, AMP and elevated inosine suggested that the deaminases in charge of adenosine derivatives to inosine derivatives conversion would be significantly changed in the lungs of mice exposed to cigarette smoke. Indeed, transcriptional study confirmed that the concentrations of adenosine monophosphate deaminase 2 and adenosine deaminase 2 were significantly changed in the lungs of mice exposed to cigarette smoke. We also found that the ratio of glycerophosphocholine (GPC) to phosphocholine (PC) was significantly increased in the lungs of obese mice compared with those of the regular weight mice. The GPC/PC ratio was further elevated in the lungs of obese group exposed to cigarette smoke.

Free and nanoencapsulated curcumin prevents cigarette smoke-induced cognitive impairment and redox imbalance

Cigarette smoke-exposure promotes neurobiological changes associated with neurocognitive abnormalities. Curcumin, a natural polyphenol, have shown to be able to prevent cigarette smoke-induced cognitive impairment. Here, we investigated possible mechanisms involved in curcumin protection against cigarette smoke-induced cognitive impairment and, due to its poor bioavailability, we investigated the potential of using curcumin-loaded lipid-core nanocapsules (C-LNC) suspension. Rats were treated with curcumin and cigarette smoke, once a day, 5 days each week, for 30 days. Animals were divided into ten groups: I, control (vehicle/corn oil); II, curcumin 12.5mg/kg; III, curcumin 25mg/kg; IV, curcumin 50mg/kg; V, C-LNC 4 mg/kg; VI, tobacco exposed; VII, curcumin 12.5mg/kg along with tobacco exposure; VIII, curcumin 25mg/kg along with tobacco exposure; IX, curcumin 50mg/kg along with tobacco exposure; X, C-LNC 4 mg/kg along with tobacco exposure. Cigarette smoke-exposure impaired object recognition memory (P<0.001), indicated by the low recognition index, increased biomarkers of oxidative/nitrosative stress such as TBARS (P<0.05) and NOx (P<0.01), decreased antioxidant defenses such as NPSH content (P<0.01) and SOD activity (P<0.01) and inhibited the activities of enzymes involved in ion homeostasis such as Na(+),K(+)-ATPase and Ca(2+)-ATPase. Both curcumin formulations (free and nanoencapsulated) prevented the memory impairment, the redox imbalance and the alterations observed in the ATPases activities. Maintenance of ion homeostasis and redox balance is involved in the protective mechanism of curcumin against tobacco-induced cognitive impairment. Our results suggest that curcumin is a potential therapeutic agent for neurocognition and that C-LNC may be an alternative to its poor bioavailability.

Activities of enzymes that hydrolyze adenine nucleotides in lymphocytes from patients with rheumatoid arthritis

The purpose of this study was to investigate the activities of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase; EC 3.6.1.5; CD39) and adenosine deaminase (E-ADA; EC 3.5.4.4) in lymphocytes from patients with rheumatoid arthritis (RA). Thirty patients diagnosed with RA through American College of Rheumatology criteria as well as 30 healthy patients were selected. Peripheral blood lymphocytes were isolated, and E-NTPDase and E-ADA activities were assayed. The results demonstrated an increased E-NTPDase activity (both ATP and ADP as substrates) and a decreased E-ADA activity in RA patients. These data suggest an organic effort to preserve the adenosine level, which is known to have anti-inflammatory and analgesic properties, working as a potent suppressor of immune response.

Curcumin protects against cigarette smoke-induced cognitive impairment and increased acetylcholinesterase activity in rats

Cigarette smoke, a widely spread habit, is associated with a decline in cognitive function and studies have demonstrated that curcumin (Cur), an Indian spice, possesses a strong neuroprotective potential. Considering the relevance of investigating dietary compounds this study aimed to investigate the effect of Cur on memory and acetylcholinesterase (AChE) activity in brain structures and blood of cigarette smoke-exposed rats. Male Wistar rats were treated with curcumin and cigarette smoke, once a day, 5 days each week, for 30 days. The experimental procedures were divided in two sets of experiments. In the first, the animals were divided into 4 groups: Vehicle (corn oil), Cur 12.5 mg/kg, Cur 25 mg/kg and Cur 50 mg/kg. In the second, the animals were divided into 5 groups: Vehicle (corn oil), Smoke, Smoke plus Cur 12.5 mg/kg, Smoke plus Cur 25 mg/kg and Smoke plus Cur 50 mg/kg. Treatment with Cur significantly prevented the decreased latency and cholinergic alterations in cigarette smoke-exposed rats. These AChE alterations could suggest a role in the memory impairment promoted by cigarette smoke-exposure and point toward the potential of Cur to modulate cholinergic neurotransmission and, consequently, improve cognition deficits induced by smoke. This study suggests that the dietary compound Cur may be involved in cholinergic system modulation and as a consequence exert an effect on learning and memory.