Polyamines reduces lipid peroxidation induced by different pro-oxidant agents

Palmitoylspermine: A potent antioxidant in bulk oil and emulsion

This study explores the potential of polyamines and their acylated derivatives as antioxidants in plant oils and emulsions. We have shown that linseed, rapeseed, sunflower, and soybean oils naturally contain spermidine and spermine (SPM). These polyamines added to methyl linolenate effectively prevent lipid oxidation in the absence of other antioxidants. However, they showed no activity in in vitro antioxidant assays (DPPH, ABTS, Folin-Ciocalteu) and did not express Fe2+ binding. Butanoylspermine and palmitoylspermine (SPM-C16) were synthesised and their antioxidant activity was compared to underivatised polyamines and some commonly used antioxidants. SPM and SPM-C16 demonstrated the highest antioxidant activity in bulk oils, preventing hydroperoxide formation and stabilising polyunsaturated fatty acids. No prooxidative effects were observed in the 0.1 to 0.8 mmol/kg concentration range. However, in oil-in-water emulsions, only SPM-C16 retained its efficacy. These findings highlight the considerable potential of polyamines and their derivatives for stabilising various lipid systems.

Polyamines mediate cellular energetics and lipid metabolism through mitochondrial respiration to facilitate virus replication

Polyamines are critical cellular components that regulate a variety of processes, including translation, cell cycling, and nucleic acid metabolism. The polyamines, putrescine, spermidine, and spermine, are found abundantly within cells and are positively-charged at physiological pH. Polyamine metabolism is connected to distinct other metabolic pathways, including nucleotide and amino acid metabolism. However, the breadth of the effect of polyamines on cellular metabolism remains to be fully understood. We recently demonstrated a role for polyamines in cholesterol metabolism, and following these studies, we measured the impact of polyamines on global lipid metabolism. We find that lipid droplets increase in number and size with polyamine depletion. We further demonstrate that lipid anabolism is markedly decreased, and lipid accumulation is due to reduced mitochondrial fatty acid oxidation. In fact, mitochondrial structure and function are largely ablated with polyamine depletion. To compensate, cells depleted of polyamines switch from aerobic respiration to glycolysis in a polyamine depletion-mediated Warburg-like effect. Finally, we show that inhibitors of lipid metabolism are broadly antiviral, suggesting that polyamines and lipids are promising antiviral targets. Together, these data demonstrate a novel role for polyamines in mitochondrial function, lipid metabolism, and cellular energetics.

Nigella sativa-Fortified Cookies Ameliorate Oxidative Stress, Inflammatory and Immune Dysfunction in Plasmodium berghei-Infected Murine Model

Malaria impedes the ability of primary cells of the immune system to generate an efficacious inflammatory and immune response. Black seed (Nigella sativa) is a core dietary supplement and food additive in folklore. This study investigated the antioxidant, immunomodulatory, and anti-inflammatory effects of N. sativa cookies in Plasmodium berghei-infected mice. Aqueous extract of black seed was prepared, and the total phenol and flavonoid contents were determined. The mice were infected with standard inoculum of the strain NK65 P. berghei. The mice weight and behavioral changes were observed. The mice were fed with the N. sativa cookies (2.5%, 5%, and 10%) and 10 mg/kg chloroquine for 5 consecutive days after the infection was established. The reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase, catalase, and hematological parameters (red cell indices, leukocytes, and its differentials) in the infected mice were determined. The inflammatory mediators, C-reactive protein (CRP), and myeloperoxidase (MPO) were also assayed. The result revealed that black seed had a total phenol content of 18.73 mgGAE/g and total flavonoid content of 0.36 mgQUE/g. The infected mice treated with N. sativa cookies showed significantly decreased parasitaemia, MDA, and ROS levels. Furthermore, the results showed significant suppression in proinflammatory mediators (CRP and MPO) levels and enhanced antioxidant status of infected mice treated with N. sativa. The study suggests that N. sativa could function as nutraceuticals in the management of Plasmodium infection associated with inflammatory and immunomodulatory disorders.

SGLT1 and SGLT2 inhibition, circulating metabolites, and cerebral small vessel disease: a mediation Mendelian Randomization study

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) and SGLT1 inhibitors may have additional beneficial metabolic effects on circulating metabolites beyond glucose regulation, which could contribute to a reduction in the burden of cerebral small vessel disease (CSVD). Accordingly, we used Mendelian Randomization (MR) to examine the role of circulating metabolites in mediating SGLT2 and SGLT1 inhibition in CSVD.

METHODS

Genetic instruments for SGLT1/2 inhibition were identified as genetic variants, which were both associated with the expression of encoding genes of SGLT1/2 inhibitors and glycated hemoglobin A1c (HbA1c) level. A two-sample two-step MR was used to determine the causal effects of SGLT1/2 inhibition on CSVD manifestations and the mediating effects of 1400 circulating metabolites linking SGLT1/2 inhibition with CSVD manifestations.

RESULTS

A lower risk of deep cerebral microbleeds (CMBs) and small vessel stroke (SVS) was linked to genetically predicted SGLT2 inhibition. Better white matter structure integrity was also achieved, as evidenced by decreased mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), as well as lower deep (DWMH) and periventrivular white matter hyperintensity (PWMH) volume. Inhibiting SGLT2 could also lessen the incidence of severe enlarged perivascular spaces (EPVS) located at white matter, basal ganglia (BG) and hippocampus (HIP). SGLT1 inhibition could preserve white matter integrity, shown as decreased MD of white matter and DWMH volume. The effect of SGLT2 inhibition on SVS and MD of white matter through the concentration of 4-acetamidobutanoate and the cholesterol to oleoyl-linoleoyl-glycerol (18:1 to 18:2) ratio, with a mediated proportion of 30.3% and 35.5% of the total effect, respectively.

CONCLUSIONS

SGLT2 and SGLT1 inhibition play protective roles in CSVD development. The SGLT2 inhibition could lower the risk of SVS and improve the integrity of white matter microstructure via modulating the level of 4-acetamidobutanoate and cholesterol metabolism. Further mechanistic and clinical studies research are needed to validate our findings.

Synergistic effect of spermidine and ciprofloxacin against Alzheimer's disease in male rat via ferroptosis modulation

Alzheimer's disease (AD) is a prevalent form of neurodegenerative disease with a complex pathophysiology that remains not fully understood, and the exact mechanism of neurodegeneration is uncertain. Ferroptosis has been linked to the progression of degenerative diseases observed in AD models. The present study is designed to investigate the protective effects of spermidine, a potent antioxidant and iron chelator, and its synergistic interactions with ciprofloxacin, another iron chelator, in modulating ferroptosis and mitigating AD progression in rats. This study investigated AD-related biomarkers like neurotoxic amyloid beta (Aβ), arginase I, and serotonin. Spermidine demonstrated an anti-ferroptotic effect in the AD model, evident from the modulation of ferroptosis parameters such as hippocampus iron levels, reduced protein expression of transferrin receptor 1 (TFR1), and arachidonate 15-lipoxygenase (ALOX15). Additionally, the administration of spermidine led to a significant increase in protein expression of phosphorylated nuclear factor erythroid 2-related factor 2 (p-Nrf2) and upregulation of Cystine/glutamate transporter (SLC7A11) gene expression. Moreover, spermidine notably decreased p53 protein levels, acrolein, and gene expression of spermidine/spermine N1-acetyltransferase 1 (SAT1). Overall, our findings suggest that spermidine and/or ciprofloxacin may offer potential benefits against AD by modulating ferroptosis. Furthermore, spermidine enhanced the antioxidant efficacy of ciprofloxacin and reduced its toxic effects.

Antihelminthic and antiangiogenic effects of zinc oxide nanoparticles on intestinal and muscular phases of trichinellosis

Trichinellosis is a worldwide zoonotic disease affecting a wide range of mammals, including humans. It has intestinal and muscular phases. The current work was done to experimentally evaluate the efficacy of zinc oxide nanoparticles (ZnO NPs) and their combination with albendazole on intestinal and muscular stages of Trichinella spiralis (T. spiralis) infection. We had five main groups of mice: Group 1, non-infected control; Group 2, infected control; Group 3, infected and treated with albendazole; Group 4, infected and treated with ZnO NPs; and Group 5, infected and treated with albendazole and ZnO NPs. Each group was divided into two subgroups (A for the intestinal phase and B for the muscular phase). Drug effects were evaluated by parasitological, histopathological, and biochemical studies, including oxidant/antioxidant analysis and vascular endothelial growth factor (VEGF) gene expression in muscle tissue by quantitative real-time PCR. ZnO NPs resulted in a significant reduction of both intestinal and muscular phases of T. spiralis. Their combination with albendazole resulted in the complete eradication of adult worms and the maximum reduction of larval deposition in muscle tissue. Additionally, the treatment showed improvement in T. spiralis-induced pathological changes and oxidative stress status. Moreover, a significant decrease in VEGF gene expression was detected in the treated groups when compared with the infected control. In conclusion, ZnO NPs presented an antihelminthic effect against both adult and larval stages of T. spiralis. In addition, it enhanced antioxidant status and suppressed angiogenesis in muscle.

The Polyamine Spermine Potentiates the Propagation of Negatively Charged Molecules through the Astrocytic Syncytium

The interest in astrocytes, the silent brain cells that accumulate polyamines (PAs), is growing. PAs exert anti-inflammatory, antioxidant, antidepressant, neuroprotective, and other beneficial effects, including increasing longevity in vivo. Unlike neurons, astrocytes are extensively coupled to others via connexin (Cx) gap junctions (GJs). Although there are striking modulatory effects of PAs on neuronal receptors and channels, PA regulation of the astrocytic GJs is not well understood. We studied GJ-propagation using molecules of different (i) electrical charge, (ii) structure, and (iii) molecular weight. Loading single astrocytes with patch pipettes containing membrane-impermeable dyes, we observed that (i) even small molecules do not easily permeate astrocytic GJs, (ii) the ratio of the charge to weight of these molecules is the key determinant of GJ permeation, (iii) the PA spermine (SPM) induced the propagation of negatively charged molecules via GJs, (iv) while no effects were observed on propagation of macromolecules with net-zero charge. The GJ uncoupler carbenoxolone (CBX) blocked such propagation. Taken together, these findings indicate that SPM is essential for astrocytic GJ communication and selectively facilitates intracellular propagation via GJs for negatively charged molecules through glial syncytium.

Synthesis of new coumarin[1,3]oxazine derivatives of 7-hydroxy-6-isobornyl-4-methylcoumarin and their antioxidant activity

In this work, we synthesized a series of new 9,10-dihydro-2H,8H-chromeno[8,7e][1,3]oxazine-2-on derivatives which incorporate isobornylcoumarin and 1,3-oxazine moieties. A structure-antioxidant activity relationship was analyzed. A comparative evaluation of their radical scavenging activity, antioxidant and membrane-protective properties was carried out in test with DPPH, as well as on the models of Fe²⁺ /ascorbate-initiated lipid peroxidation and oxidative hemolysis of mammalian red blood cells. The results suggest that all the obtained coumarin[1,3]oxazine derivatives of 7-hydroxy-6-isobornyl-4-methylcoumarin are capable of exhibiting antioxidant activity in various model systems. Compound 7 with a phenyl fragment, combining high radical scavenging activity and the ability to inhibit Fe²⁺ /ascorbate-initiated peroxidation of animal lipids in a heterogeneous environment, also proved to be the most effective membrane protector and antioxidant in the model of H₂ O₂ -induced erythrocyte hemolysis.

Effect of black seeds (Nigella sativa) on inflammatory and immunomodulatory markers in Plasmodium berghei-infected mice

Nigella sativa, a core dietary supplement and food additive in folklore is one of the most broadly studied seed plants in the global nutraceutical sector. Malaria infection impairs the ability of principal cells of the immune system to trigger an efficient inflammatory and immune response. Ninety-six mice, weighing 20-25 g, were grouped into 12 consisting of 8 animals each. The mice were infected with standard inoculum of the strain NK65 Plasmodium berghei (chloroquine sensitive) and the percentage parasitemia suppression were evaluated. The individual effect of black seed supplemented diet and its combinatory effect with chloroquine (CQ) were investigated on reactive oxygen species (ROS), glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione-S-transferase (GST), serum immunoglobulins (IgG and IgM), and the hematological parameters (hemoglobin, packed cell volume, and red blood cell count) in P. berghei infected mice. The inflammatory cytokines, tumor necrosis factor (TNF-α), interleukin (IL-6 and IL-10), as well as IgG and IgM were assayed in the serum. The mice temperature and behavioral changes were observed. Infected mice treated with the dietary supplementation of black seed with a percentage inclusion (2.5%, 5%, 10%) showed significantly decreased parasitemia and ROS levels (p < 0.05) compared with the untreated mice. The result demonstrated a significant suppression in the pro-inflammatory cytokines (TNF-α, IL-6) levels and a notable elevation in the anti-inflammatory cytokine (IL-10), antioxidant markers as well as the immunoglobulin levels of the P. berghei-infected mice treated with black seed. The study revealed that black seed enhanced host antioxidant status, modulated inflammatory and immune response by regulating some inflammatory cytokines and immunomodulatory mediators. PRACTICAL APPLICATIONS: Black seed (Nigella sativa) has been a dietary supplement and natural remedy for many centuries. Inflammatory and immune diseases are the most notable cause of mortality in the world and more than 50% of deaths have been attributed to it. However, there is paucity of information on the effect of N. sativa on anti-inflammatory and immunomodulatory ability during malaria infection. The result suggests that N. sativa produced antioxidant, anti-inflammatory, and immunomodulatory effect in Plasmodium berghei-infected mice via the participation of glutathione antioxidant system, serum antibodies, and some inflammatory cytokines.

Composite biscuits from sandpaper and acha flour restore the altered activity of arginase, cholinergic, and purinergic enzymes in hypertensive-diabetic rats

Hypertension is one of the common co-morbidities in diabetes. Thus, the present study sought to study the effects of composite biscuits from the mixture of acha (Digitaria exilis) and sandpaper (Fiscus exasperata) leaf flours (ASLF) on mean arterial blood pressure (MABP), arginase, cholinergic, purinergic enzymatic cascade, and nitric oxide (NO) levels as well as oxidative status in streptozotocin (STZ)/L-N^G -nitro arginine methyl ester (L-NAME)-induced hypertensive/diabetic rats. Experimental rats were distributed randomly into 7 groups (n = 5). Group I-III rats were placed on the basal diet; IV-VII rats were placed on composite biscuits designated as A, B, C, and D respectively for 14 days. On the 13th day, the MABP of the experimental rats was monitored and recorded. Thereafter, the rats were sacrificed, tissues of interest were harvested, and homogenized. Subsequently, the activity of arginase cholinesterase and purinergic enzymes, as well as NO levels were evaluated in the experimental rats. However, hypertensive/diabetic rats placed on the formulated diet exhibited reduced MABP when compared with the untreated hypertensive/diabetic rats. Also, altered activity of arginase, cholinergic and purinergic were restored in diet-treated hypertensive/diabetic rats when compared with hypertensive/diabetic rats. Similarly, the NO level and antioxidant status of the treated hypertensive/diabetic rats were notably enhanced when compared with hypertensive/diabetic rats. It could be inferred that composite biscuits exhibited an ameliorative effect in hypertensive/diabetic states via their reductive effect on the MABP, arginase, cholinesterase, and purinergic enzymes and enhanced NO levels in hypertensive/diabetic rats. Meanwhile, the biscuit designated as D had seems better when their effects were compared holistically. PRACTICAL APPLICATIONS: Acha grains and sandpaper leaf have been used in the folklore for disease treatment. However, the production of composite biscuits from these naturally available recipes for the management of hypertensive diabetics proved therapeutic since their effect on hypertensive diabetic rats is positive. Therefore, the composite biscuit will offer nutraceutical benefits to both healthy and disease individuals.

Synthesis and Biological Activity of Unsymmetrical Monoterpenylhetaryl Disulfides

New unsymmetrical monoterpenylhetaryl disulfides based on heterocyclic disulfides and monoterpene thiols were synthesized for the first time in 48–88% yields. Hydrolysis of disulfides with fragments of methyl esters of 2-mercaptonicotinic acid was carried out in 73–95% yields. The obtained compounds were evaluated for antioxidant, antibacterial, antifungal activity, cytotoxicity and mutagenicity.

Apigenin Attenuates Functional and Structural Alterations via Targeting NF-kB/Nrf2 Signaling Pathway in LPS-Induced Parkinsonism in Experimental Rats : Apigenin Attenuates LPS-Induced Parkinsonism in Experimental Rats

Parkinson's disease (PD) is a progressive hypokinetic movement disorder caused by selective degeneration of dopaminergic neurons in striatum and dopamine deficiency in a region of the midbrain. LPS is an endotoxin, used as animal model to induce microglial activation, neuroinflammation, oxidative stress, and neurotransmitter alteration with PD-like symptoms. Therefore, to prevent neuroinflammation and neurotransmitter changes and to restore normal brain physiology, we tried apigenin (AGN) alone and in combination with piperine (bioenhancer), in LPS experimental model of rats. In this study, rats were treated with single unilateral intranigral injection of LPS at a dose of 5 μg/5 μl on day 0. The oral administration of AGN (25 and 50 mg/kg; p.o.) alone, AGN (25 mg/kg; p.o.) in combination with piperine (2.5 mg/kg; p.o.), and bromocriptine (10mg/kg; p.o.) started from day 7th once in a day. Intranigral injection of LPS significantly altered body weight and behavioral parameters assessed on weekly basis. Furthermore, the biochemical and neuroinflammatory analysis confirmed (on day 22nd) increased level of nitrite, MDA, SOD, TNF-α, IL-1β, IL-6, and caspase-1, and decreased level of CAT, GSH, and complex-I. Furthermore, altered level of neurotransmitters (DA, GABA, and glutamate) and cellular changes were observed from histopathological and immunohistochemistry (NF-kB and Nrf-2) analysis. Treatment with AGN (25 and 50 mg/kg; p.o.) alone and AGN (25 mg/kg; p.o.) in combination with piperine (2.5 mg/kg; p.o.) significantly attenuated the alteration in body weight, motor impairments, oxidative stress, neuroinflammation, and neurotransmitters in rat brain. The neuroprotective effect of AGN against LPS-induced cell death is attributed by modulating NF-kB and Nrf2 signaling pathway in the striatum.

Polyamines protect boar sperm from oxidative stress in vitro

Sperm are susceptible to excessive reactive oxygen species (ROS). Spermine and spermidine are secreted in large amounts by the prostate and potent natural free radical scavengers and protect cells against redox disorder. Thus, we used boar sperm as a model to study the polyamines uptake and elucidate whether polyamines protected sperm from ROS stress. Seven mature and fertile Duroc boars (aged 15 to 30 mo) were used in this study. In experiment 1, spermine and spermidine (3.6 ± 0.3 and 3.3 ± 0.2 mmol/L, respectively) were abundant in seminal plasma, and the content of polyamine decreased (P < 0.05) after preservation at 17 °C for 7 d or incubation at 37 °C for 6 h. In experiment 2, using labeling of spermine or spermidine by conjugation with fluorescein isothiocyanate and ultra-high-performance liquid chromatography, we found that the accumulation of spermine or spermidine in sperm was inhibited by quinidine and dl-tetrahydropalmatine (THP, organic cation transporters [OCT] inhibitors, P < 0.05), but not mildronate and l-carnitine (organic cation/carnitine transporter [OCTN] inhibitors, P > 0.05). In experiment 3, the addition of spermine or spermidine (0.5 mmol/L) in the extender resulted in higher motility, plasma membrane and acrosome integrity, and lower ROS level after preservation in vitro at 17 °C for 7 d (P < 0.05). In experiment 4, in the condition of oxidative stress (treatment with H2O2 at 37 °C for 2 h), the addition of spermine (1 mmol/L) or spermidine (0.5 mmol/L) in extender increased activities of glutathione peroxidase, glutathione reductase, and glutathione S-transferase; reduced glutathione and oxidized glutathione ratio (P < 0.05); and alleviate oxidative stress-induced lipid peroxidation, DNA damage, mitochondrial membrane potential (ΔΨm) decline, adenosine triphosphate depletion, and intracellular calcium concentration ([Ca2+]i) overload (P < 0.05), thereby improving boar sperm motility, the integrity of plasma membrane and acrosome (P < 0.05) in vitro. These data suggest that spermine and spermidine alleviate oxidative stress via the antioxidant capacity, thereby improving the efficacy of boar semen preservation.

Overview of Polyamines as Nutrients for Human Healthy Long Life and Effect of Increased Polyamine Intake on DNA Methylation

Polyamines, spermidine and spermine, are synthesized in every living cell and are therefore contained in foods, especially in those that are thought to contribute to health and longevity. They have many physiological activities similar to those of antioxidant and anti-inflammatory substances such as polyphenols. These include antioxidant and anti-inflammatory properties, cell and gene protection, and autophagy activation. We have first reported that increased polyamine intake (spermidine much more so than spermine) over a long period increased blood spermine levels and inhibited aging-associated pathologies and pro-inflammatory status in humans and mice and extended life span of mice. However, it is unlikely that the life-extending effect of polyamines is exerted by the same bioactivity as polyphenols because most studies using polyphenols and antioxidants have failed to demonstrate their life-extending effects. Recent investigations revealed that aging-associated pathologies and lifespan are closely associated with DNA methylation, a regulatory mechanism of gene expression. There is a close relationship between polyamine metabolism and DNA methylation. We have shown that the changes in polyamine metabolism affect the concentrations of substances and enzyme activities involved in DNA methylation. I consider that the increased capability of regulation of DNA methylation by spermine is a key of healthy long life of humans.

Polyamines and polyamine-metabolizing enzymes in schizophrenia: Current knowledge and concepts of therapy

Polyamines play preeminent roles in a variety of cellular functions in the central nervous system and other organs. A large body of evidence suggests that the polyamine pathway is prominently involved in the etiology and pathology of schizophrenia. Alterations in the expression and activity of polyamine metabolizing enzymes, as well as changes in the levels of the individual polyamines, their precursors and derivatives, have been measured in schizophrenia and animal models of the disease. Additionally, neuroleptic treatment has been shown to influence polyamine concentrations in brain and blood of individuals with schizophrenia. Thus, the polyamine system may appear to be a promising target for neuropharmacological treatment of schizophrenia. However, for a number of practical reasons there is currently only limited hope for a polyamine-based schizophrenia therapy.

Spermidine Suppressed the Inhibitory Effects of Polyamines Inhibitors Combination in Maize (Zea mays L.) Seedlings under Chilling Stress

Chilling stress greatly inhibited the seed germination, plant growth, development and productivity in this study. The current research aimed to study the effects of different polyamine (PA) inhibitor combinations (Co), e.g., D-arginine (D-Arg), difluoromethylormithine (DFMO), aminoguanidine (Ag) and methylglyoxyl-bis-(guanyhydrazone) (MGBG) at different doses, i.e., 10 µM Co, 100 µM Co, 500 µM Co, 1000 µM Co and 1000 µM Co + 1 mM Spd (Spermidine) in two inbred lines of maize (Zea mays L.), i.e., Mo17 and Huang C, a sensitive and tolerant chilling stress, respectively. The combination treatments of PA inhibitors reduced the biosynthesis of putrescine (Put) in the tissues of both studied inbred lines. Application with 500 µM Co and 1000 µM Co did not result in a significant difference in Put concentrations, except in the coleoptile of Mo17. However, combining Spd to 1000 μM of PA inhibitors enhanced the Put, Spd, spermine (Spm) and total PAs in the roots, coleoptile and mesocotyls. Put and total PAs were increased by 39.7% and 30.54%, respectively, when Spd + 1000 µM Co were applied relative to their controls. Chilling stress and PA inhibitors treatments affected both inbred lines and resulted in differences in the PA contents. Results showed that enzymes involved in the biosynthesis of PAs (ornithine decarboxylase as ODC and S-adenosylmethionine decarboxylase as SAMDC) were significantly downregulated by 1000 µM Co in the tissues of both inbred lines. In contrast, the activity of PAO, a Pas degradation enzyme, was significantly improved by 1000 µM Co under chilling stress. However, Spd + 1000 µM Co significantly improved the activities of ODC and SAMDC and their transcript levels (ODC and SAMDC2). While it significantly downregulated the PAO activity and their relative genes (PAO1, PAO2 and PAO3) under chilling stress. Overall, this study elucidates the specific roles of Spd on the pathway of PA inhibitors and PA biosynthesis metabolism in maize seed development in response to chilling stress. Moreover, the Huang C inbred line was more tolerant than Mo17, which was reflected by higher activities of PA biosynthesis-related enzymes and lower activities of PAs' degradative-related enzymes in Huang C.

Fig (Ficus exasperata and Ficus asperifolia)-Supplemented diet improves sexual function, endothelial nitric oxide synthase and suppresses tumour necrosis factor-alpha genes in hypertensive rats

We measured the effect of varieties of Fig leaves, Ficus exasperata Vahl. (FE) and Ficus asperifolia Miq (FA), commonly found in Sub-sahara Africa for managing hypertension on sexual performance in hypertensive rats, which is unknown. Hypertensive rats experienced erectogenic damage after exposure to 40 mg kg^-1  bw^-1 , N(G)-nitro-l-arginine-methyl-ester (L-NAME). Experimental rats were grouped into eight groups (n = 6) namely: control rats, hypertensive rats, hypertensive treatment groups with atenolol (10 mg kg^-1  day^-1 ) and sildenafil (5.0 mg/kg), rats treated with FE- and FA-formulated biscuits at proportions of 2.5 g and 5.0 g respectively. Furthermore, we measured the level of sexual performance (Intromission number, latency, Mounting number, and latency), hormonal levels, phosphodiesterase-5 enzyme (PDE-5) activity and genes expressed using real-time quantitative polymerase chain reaction (RT-qPCR) in hypertensive rats. The result deduced revealed that treated hypertensive rats showed significantly reduced follicle-stimulating hormone, luteinising hormone levels, PDE-5 enzyme activity, tumour necrosis factor-alpha (TNF-α) expression while having a marked increase in testosterone level, sexual performance and endothelial nitric oxide synthase (eNOS) expression. Therefore, this study revealed the comparative dietary enhancing effect of FE- and FA-formulated biscuit on sexual behaviour activity, hormonal levels and the level of eNOS and TNF-α genes expressed in hypertensive rats.

Protective Effects of Spermidine Against Cirrhotic Cardiomyopathy in Bile Duct-Ligated Rats

Cirrhotic cardiomyopathy is a critical factor that causes morbidity and mortality in crucial conditions such as liver transplantation. In animal model, the common pathophysiologic mechanisms of cirrhotic cardiomyopathy are similar to those associated with bile duct ligation (BDL). Overproduction of inflammatory and oxidant markers plays a crucial role in cirrhotic cardiomyopathy. Spermidine, a multifunctional polyamine, is known for its antioxidant and anti-inflammatory effects. In this study, we investigated the effects of spermidine on development of cirrhotic cardiomyopathy in BDL rats. Rats were randomly housed in 6 groups. Except the normal and sham groups, BDL was performed for all the control and spermidine groups. Seven days after operation, 3 different doses of spermidine (5, 10 and 50 mg/kg) were administrated until day 28, in spermidine groups. At the end of the fourth week, the electrocardiography (ECG) and papillary muscle isolation were performed. The serum level of tumor necrosis factor-a (TNF-α), interleukin-1β (IL-1β), and IL-10 and cardiac level of superoxide dismutase, glutathione (GSH). and malondialdehyde (MDA) were assessed. Furthermore, the nuclear factor-κB (NF-κB) expression was assessed by western blot. Cardiac histopathological changes were monitored. The serum levels of magnesium (Mg) and potassium (K) were investigated. Control group, exhibited exaggerated signs of cirrhotic cardiomyopathy in comparison with the sham group. Co-administration of spermidine at the dose of 10 mg/kg in BDL rats significantly improved the cardiac condition, reduced the inflammatory mediators, and increased antioxidant enzymes. In addition, the histopathologic findings were in accordance with the other results of the study. Besides, there was no significant alteration in serum levels of Mg and K. This study demonstrates that spermidine at the dose of 10 mg/kg significantly improved the cirrhotic cardiomyopathy in BDL model in rats.

Phenolic constituents and inhibitory effects of the leaf of Rauvolfia vomitoria Afzel on free radicals, cholinergic and monoaminergic enzymes in rat's brain in vitro

OBJECTIVES

Rauvolfia vomitoria is a medicinal plant used traditionally in Africa in the management of several human diseases including psychosis. However, there is inadequate scientific information on the potency of the phenolic constituents of R. vomitoria leaf in the management of neurodegeneration. Therefore, this study characterized the phenolic constituents and investigated the effects of aqueous and methanolic extracts of R. vomitoria leaf on free radicals, Fe²⁺-induced lipid peroxidation, and critical enzymes linked to neurodegeneration in rat's brain in vitro.

METHODS

The polyphenols were evaluated by characterizing phenolic constituents using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). The antioxidant properties were assessed through the extracts ability to reduce Fe³⁺ to Fe²⁺; inhibit ABTS, DPPH, and OH radicals and Fe²⁺-induced lipid peroxidation. The effects of the extracts on AChE and MAO were also evaluated.

RESULTS

The phenolic characterization of R. vomitoria leaf revealed that there were more flavonoids present. Both aqueous and methanolic extracts of R. vomitoria leaf had inhibitory effects with the methanolic extract having higher significant (p≤0.05) free radicals scavenging ability coupled with inhibition of monoamine oxidases. However, there was no significant (p≤0.05) difference obtained in the inhibition of lipid peroxidation and cholinesterases.

CONCLUSION

This study suggests that the rich phenolic constituents of R. vomitoria leaf might contribute to the observed antioxidative and neuroprotective effects. The methanolic extract was more potent than the aqueous extract; therefore, extraction of R. vomitoria leaf with methanol could offer better health-promoting effects in neurodegenerative condition.

Spermidine, a caloric restriction mimetic, provides neuroprotection against normal and D-galactose-induced oxidative stress and apoptosis through activation of autophagy in male rats during aging

Spermidine (SPD) is a natural polyamine present in all living organisms and is involved in the maintenance of cellular homeostasis by inducing autophagy in different model organisms. Its role as a caloric restriction mimetic (CRM) is still being investigated. We have undertaken this study to investigate whether SPD, acting as a CRM, can confer neuroprotection in D-galactose induced accelerated senescence model rat and naturally aged rats through modulation of autophagy and inflammation. Young male rats (4 months), D-gal induced (500 mg/kg b.w., subcutaneously) aging and naturally aged (22 months) male rats were supplemented with SPD (10 mg/kg b.w., orally) for 6 weeks. Standard protocols were employed to measure prooxidants, antioxidants, apoptotic cell death and electron transport chain complexes in brain tissues. Gene expression analysis with reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to assess the expression of autophagy and inflammatory marker genes. Our data demonstrate that SPD significantly (p ≤ 0.05) decreased the level of pro-oxidants and increased the level of antioxidants. SPD supplementation also augmented the activities of electron transport chain complexes in aged brain mitochondria thus proving its antioxidant potential at the level of mitochondria. RT-PCR data revealed that SPD up-regulated the expression of autophagy genes (ATG-3, Beclin-1, ULK-1 and LC3B) and down-regulated the expression of the inflammatory gene (IL-6) in aging brain. Our results provide first line of evidence that SPD provides neuroprotection against aging-induced oxidative stress by regulating autophagy, antioxidants level and also reduces neuroinflammation. These results suggest that SPD may be beneficial for neuroprotection during aging and age-related disorders.

Cognitive impairment by non-insulin-dependent diabetes mellitus was attenuated by dietary supplements of marble vine (Dioclea reflexa) and plantain (Musa paradisiaca) dough meals in albino rats

This study investigates the protective effect of formulated marble vine/plantain dough meals on cognitive impairment in diabetic rats. Wistar rats were divided into eight groups (n = 6) and fed with HFD for 14 days and a single dose of streptozotocin intraperitoneally on the 14th day (except control rats). Diabetic rats were treated with formulated diets and metformin. The ameliorative effect of the formulated doughs on cerebral damage in diabetic rats with respect to weight gain/loss, glucose and insulin levels, oxidative damage, neurological dysfunction, and histological alterations were assessed. The formulated diet had high protein and fiber content values ranged from 13.00 to 25.04 g/100 g and from 5.23 to 6.20 g/100 g, respectively compared to the control. Blood glucose level was observed, thereby mitigating the cerebral oxidative damage. The diet significantly ameliorated the neurological dysfunction as adjudged by increased dopamine concentration and lowered acetylcholinesterase activity; results were also supported by the outcomes from brain histopathological study. PRACTICAL APPLICATIONS: Underutilized leguminous seeds such as marble vine seeds are known for their nutraceutical potentials due to their numerous biochemical components. The study provides preliminary information on the potential of marble vine/plantain functional dough meals in the management of neurological complications resulting from type 2 diabetes mellitus in albino rats. Generally, the formulated doughs possess neuroprotective potentials in preventing neurological complications arising from diabetes. However, the effect of marble vine-plantain dough meal in managing the brain damage should be further investigated through the clinical trials before development for pharmaceutical applications.

Orange-fleshed sweet potatoes composite bread: A good carrier of beta (β)-carotene and antioxidant properties

Orange-fleshed sweet potato (OFSP) is one of the unique varieties of sweet potatoes tuber that has attracted food professionals due to its great health benefits. This study investigates into β-carotene and antioxidant properties of OFSP composite bread. Random Surface Methodology was used for the experimental design. Analysis carried out on the bread includes antioxidant activity, alpha-amylase, and alpha-glycosidase inhibitory activity, protein & β-carotene retention/losses, glycemic index, and sensory evaluation. Total phenol ranged from 7.32 to 21.93 mg GAE/g, total flavonoid ranged between 6.12 and 13.20 mg QE/g and FRAP ranged from 12.31 to 40.36 mg AEE/g. The estimated glycemic index ranged from 51.42% to 72.80%. The value of β-carotene before and after processing ranged from 15.4 to 39.1 mg/100 g and 8.9 to 18.4 mg/100 g, respectively. OFSP composite bread has high antioxidant potential and may be used as functional foods. PRACTICAL APPLICATIONS: Orange-fleshed sweet potatoes (OFSP) is a novel variety of sweet potatoes that have been sight-saw to owe numerous health benefits in terms of vitamins, minerals, β-carotene, antioxidants but it is low in protein. Incorporation of plant protein will help to increase its protein content and enhance its utilization in confectionery industries as a good carrier for antioxidants and other health benefits components.

Influence of gallic and tannic acid on therapeutic properties of acarbose in vitro and in vivo in Drosophila melanogaster

Background

In this study, gallic acid (GA) and its polymeric form-tannic acid (TA) which are two phenolic acids found abundantly distributed in plant food sources were investigated for their influence on therapeutic properties of acarbose (AC) in vitro and in vivo in Drosophila melanogaster.

Methods

Combinations of AC and GA or TA were assessed for their alpha-glucosidase and alpha-amylase inhibitory effects as markers of anti-hyperglycemic properties, as well as their free radicals scavenging, Fe²⁺ chelating and malondialdehyde (MDA) inhibitory effects (in vitro). Furthermore, wild type D. melanogaster cultures were raised on diets containing AC, GA, TA and their various combinations for seven days. Thereafter, flies were homogenized and glucose concentrations, alpha-glucosidase and alpha-amylase activities, as well as reactive oxygen species (ROS) and total thiol levels were determined.

Results

The results showed that GA and TA up to 5 mg/ml significantly (p < 0.05) increased the enzymes' inhibitory effects and antioxidant properties of AC in vitro. Also, there was significant reduction in glucose concentration, enzyme activities and ROS level in D. melanogaster fed diets supplemented with phenolic acids and acarbose.

Conclusions

These bioactive compounds–drug interactions provide useful information on improving the therapeutic properties of acarbose especially in its use as an antidiabetic drug.

The Benefit of Passion Fruit as an Anti-ulcerogenic Diet: Scientific Evidence by In vitro and In silico H+/K+ATPase Inhibitory Activity Assessment

BACKGROUND

H+/K+ ATPase a protein present in the gastric parietal cells is a better target for the prevention and treatment of gastric ulcer. Plant flavonoids have been reported to elicit anti-ulcer activity by inhibiting the proton pump as well as by antioxidant defense mechanism.

METHODS

Chloroform fraction of hydro-alcoholic extract of passion fruit was screened for proton pump inhibitory assay using goat parietal cell. In-silico computational docking studies were carried out using Glide program in order to validate the inhibitory action of selected constituents.

RESULTS

The flavonoid rich fruit possess a promising radical scavenging activity against DPPH. 10.41μg/mL is sufficient to inhibit 50% of ATPase enzyme activity. A synergistic activity was also achieved by the fruit with sub-effective doses of lansoprazole. Fenton's oxidation induced by H2O2 was also blunted by the fruit extract.

CONCLUSION

The in-vitro and in-silico findings indicated that, passion fruit can be a good dietary supplement for the prevention and management of ulcer.

Bcl-2 expression in a diabetic embryopathy model in presence of polyamines

The frequency of congenital malformations is 3-5 times higher in mothers with pregestational diabetes mellitus than in general population. Apparently, this problem is due to change in the expression of apoptotic and antiapoptotic genes induced by the oxidative stress derived from the diabetes/hyperglycemia. One of these genes is Bcl-2, which is associated with the control and inhibition of apoptosis. The purpose of the present work was to study the effect of polyamine addition over expression of Bcl-2 gene in a model of diabetic embryopathy. For this, gestational day 10.5 (GD10.5) rat embryos were incubated at 37°C for 24 h in control medium, medium with high glucose, or medium with high glucose and supplemented with spermidine or spermine. Post-cultured embryos were harvested and observed to obtain morphological scores; some of them were subjected to molecular biology studies: DNA isolation plus conventional PCR or RNA isolation plus RT-PCR; other embryos were fixed with paraformaldehyde and used for immunohistochemical detection of Bcl-2 protein. Although Bcl-2 mRNA was similarly expressed in all rat embryo treatments, Bcl-2 protein was found only in control-incubated embryos. In conclusion, it seems that the inhibition of Bcl-2 gene expression induced by glucose was not reversed by polyamines.

Formation of gallic acid layer on γ-AlOOH nanoparticles surface and their antioxidant and membrane-protective activity

In the reported study we prepared gallic acid modified γ-AlOOH nanoparticles. We proposed mechanism of phenolic compounds binding on the alumina, suggesting covalent and electrostatic interactions. Most of the properties of alumina nanoparticles (NPs) are unchanged, but there is partial reduction of surface charge. Prepared samples are colloidally stable hydrosols. It allowed us to perform biological studies on cellular and non-cellular models, which showed nontoxicity of both pure and hybrid γ-AlOOH nanoparticles. Furthermore, pure alumina NPs exhibit antioxidant properties, which are enhanced after gallic acid immobilization on their surface. Also, hybrid alumina-gallic acid NPs showed membrane-protective activity.

Polyamines in Food

The polyamines spermine, spermidine, and putrescine are involved in various biological processes, notably in cell proliferation and differentiation, and also have antioxidant properties. Dietary polyamines have important implications in human health, mainly in the intestinal maturation and in the differentiation and development of immune system. The antioxidant and anti-inflammatory effect of polyamine can also play an important role in the prevention of chronic diseases such as cardiovascular diseases. In addition to endogenous synthesis, food is an important source of polyamines. Although there are no recommendations for polyamine daily intake, it is known that in stages of rapid cell growth (i.e., in the neonatal period), polyamine requirements are high. Additionally, de novo synthesis of polyamines tends to decrease with age, which is why their dietary sources acquire a greater importance in an aging population. Polyamine daily intake differs among to the available estimations, probably due to different dietary patterns and methodologies of data collection. Polyamines can be found in all types of foods in a wide range of concentrations. Spermidine and spermine are naturally present in food whereas putrescine could also have a microbial origin. The main polyamine in plant-based products is spermidine, whereas spermine content is generally higher in animal-derived foods. This article reviews the main implications of polyamines for human health, as well as their content in food and breast milk and infant formula. In addition, the estimated levels of polyamines intake in different populations are provided.

Antioxidant Activity of Natural Allylpolyalkoxybenzene Plant Essential Oil Constituents

Free-radical-scavenging capacity antioxidant and membrane-protective properties of natural and related synthetic allylpolyalkoxybenzenes with different numbers of alkoxy/methoxy groups in the aromatic ring were evaluated using several in vitro models. These included the DPPH assay, inhibition of lipid peroxidation products accumulation, inhibition of H₂O₂-induced hemolysis, and oxidation of oxyhemoglobin. A synthetic protocol for the synthesis of natural nothoapiol (9) from a parsley seed metabolite, apiol (7), was developed. A structure-activity relationship study revealed that both the methylenedioxy fragment and methoxy groups in the aromatic ring are favorable for antioxidant activity. Hydroxyapiol (14), containing a hydroxy group in the aromatic core, was identified as the most potent compound. The pentaalkoxy-substituted nothoapiol (9) showed antioxidant activity in mouse brain homogenates, whereas in mouse erythrocytes it exhibited a marked pro-oxidant effect. Despite their low free-radical-scavenging capacity, allylpolyalkoxybenzenes can contribute to the total antioxidant potencies of plant essential oils.

Eggplant (Solanum spp) supplemented fruits diet modulated the activities of ectonucleoside triphosphate diphosphohydrolase (ENTPdase), monoamine oxidase (MAO), and cholinesterases (AChE/BChE) in the brain of diabetic Wistar male rats

Type 2 diabetes mellitus is associated with complications such as Alzheimer disease (AD). Tropical eggplant (Solanum gilo, Solanum kumba, and Solanum aethiopicum) fruits have been extensively used for the treatment of different ailments. This study assesses the effect of an eggplant supplemented-diet on purinergic, monoaminergic, and cholinergic enzyme systems in diabetic male rats, besides determining the presence of alkaloids using GC-MS chromatography. Results from this study show that eggplant fruit diet modulates the activities of the enzymes in purinergic, monoaminergic, and cholinergic enzyme systems associated with AD-like symptoms. Solanum kumba-supplemented diet significantly (p < 0.05) reduced enzyme activities better than S. gilo and S. aethiopicum, which could be due to its rich phytochemical constituents. In conclusion, eggplant fruits could serve as a holistic measure in the prevention of diabetes-related complications such as neurodegenerative disease. PRACTICAL APPLICATIONS: The therapeutic management of diabetes fails to holistically address inflammatory response which likely contributes to type 2 diabetes mellitus (T2DM) occurrence by causing insulin resistance; this, in turn, is intensified in the presence of hyperglycemia to promote long-term complications such as neurodegenerative disorders. The health benefit of a tropical eggplant fruit diet inform a nutritional and therapeutic approach for the prevention and treatment of T2DM and its associated complications such as neurodegenerative disorders has been proved. The eggplant fruit-supplemented diet, which is cost-effective with little or no side effect, could substantially increase the antioxidant status and also modulate the activities of neuronal enzymes in a diabetic model with dementia, as well as Alzheimer's-like symptoms. This study, therefore, revealed more of the benefits of tropical eggplant fruits vis-à-vis their management in hyperglycemia-mediated neurodegeneration.

Phenolic analysis and erectogenic function of African Walnut (Tetracarpidium conophorum) seeds: The impact of the seed shell on biological activity

This study investigated the erectogenic potential of African walnut seed (AWS). The extract from AWS cooked with/without shell interacted with phosphodiesterase-5 (PDE-5), arginase, angiotensin-I converting enzymes (ACE), and acetylcholinesterase (AChE); enzymes associated with erectile dysfunction (ED) and Fe²⁺ -induced malonaldehyde (MDA) production in the isolated penile tissue. The results showed that the extracts inhibited the enzymes and MDA production, but Walnut cooked with shell had the highest effect. This agreed with increased phenolic acids and flavonoids, found in the AWS cooked with the shell, compared with that cooked without shell. The inhibition of enzymes and antioxidative potentials could be among the possible mechanisms of actions of AWS in the management/treatment of ED. However, cooking walnut seed with the shell seem to be a contributing factor, as this could prevent possible leaching out of the phytochemicals that could be responsible for these biological effects. PRACTICAL APPLICATIONS: Walnut seed possesses a high content of phenolic compounds and inhibit enzymes relevant to the management of erectile dysfunction. Traditionally, Walnut seed is being cooked with/without the shell and consumed for the purpose of alternative medicine in folklore. Our investigation revealed the possible mechanism underlying the therapeutic effect Walnut seed in the management of ED, but the impact of the shell during cooking contributes to this effect. This result will inform the consumers and food scientist on the importance of cooking Walnut seed with the shell in order to maximize its nutraceutical values.

Cardio-protective and antioxidant properties of caffeic acid and chlorogenic acid: Mechanistic role of angiotensin converting enzyme, cholinesterase and arginase activities in cyclosporine induced hypertensive rats

Caffeic acid (CAA) and chlorogenic acid (CHA) are important members of hydroxycinnamic acid with natural antioxidant and cardio-protective properties. The present study aimed to determine the effect of CAA and CHA on systolic blood pressure, heart rates (HR) as well as on the activity of the angiotensin-1-converting enzyme (ACE), acetylcholinesterase (AChE), butrylcholinesterase (BChE) and arginase in cyclosporine-induced hypertensive rats. Experimental rats were distributed into 7 groups (n = 6): normotensive control rats; hypertensive rats (induced rats) as well as hypertensive- treated groups with captopril (10 mg/kg/day), CAA (10 and 15 mg/kg/day) and CHA (10 and 15 mg/kg/day), respectively. The experiment lasted for 7 days and the systolic blood pressure (SBP) and heart rates were recorded using tail-cuff method. Oral administration of captopril, caffeic acid and chlorogenic acid normalized hypertensive effect caused by cyclosporine administration. CAA and CHA significantly (P < 0.05) reduced SBP and HR, activity of ACE, AChE, BChE and arginase in the treated hypertensive rats compared with cyclosporine induced-hypertensive rats. Likewise, CAA and CHA improved nitric oxide (NO) bioavailability, increased catalase activity and reduced glutathione content while malondialdehyde (MDA) level was reduced compared with cyclosporine hypertensive rats. Findings from this study shows that CAA and CHA exhibited blood pressure lowering properties and reduced activities of key enzymes linked to the pathogenesis of hypertension in cyclosporine-induced rats. These might be some of the possible mechanisms of action by which their cardio-protective properties are exhibited.

Polyamine Metabolism and Gene Methylation in Conjunction with One-Carbon Metabolism

Recent investigations have revealed that changes in DNA methylation status play an important role in aging-associated pathologies and lifespan. The methylation of DNA is regulated by DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) in the presence of S-adenosylmethionine (SAM), which serves as a methyl group donor. Increased availability of SAM enhances DNMT activity, while its metabolites, S-adenosyl-l-homocysteine (SAH) and decarboxylated S-adenosylmethionine (dcSAM), act to inhibit DNMT activity. SAH, which is converted from SAM by adding a methyl group to cytosine residues in DNA, is an intermediate precursor of homocysteine. dcSAM, converted from SAM by the enzymatic activity of adenosylmethionine decarboxylase, provides an aminopropyl group to synthesize the polyamines spermine and spermidine. Increased homocysteine levels are a significant risk factor for the development of a wide range of conditions, including cardiovascular diseases. However, successful homocysteine-lowering treatment by vitamins (B6, B12, and folate) failed to improve these conditions. Long-term increased polyamine intake elevated blood spermine levels and inhibited aging-associated pathologies in mice and humans. Spermine reversed changes (increased dcSAM, decreased DNMT activity, aberrant DNA methylation, and proinflammatory status) induced by the inhibition of ornithine decarboxylase. The relation between polyamine metabolism, one-carbon metabolism, DNA methylation, and the biological mechanism of spermine-induced lifespan extension is discussed.

Biological Activities Evaluation of Enantiopure Isoxazolidine Derivatives: In Vitro, In Vivo and In Silico Studies

A series of enantiopure isoxazolidines (3a-c) were synthesized by 1,3-dipolar cycloaddition between a (-)-menthone-derived nitrone and various terminal alkenes. The screened compounds were evaluated for their antioxidant activity by two in vitro antioxidant assays, including β-carotene/linoleic acid bleaching, and inhibition of lipid peroxidation (thiobarbituric acid reactive species, TBARS). The results revealed that compound 3b (EC₅₀ = 0.55 ± 0.09 mM) was the most potent antioxidant as compared to the standard drug (EC₅₀ = 2.73 ± 0.07 mM) using the TBARS assay. Furthermore, the antimicrobial activity was assessed using disc diffusion and microdilution methods. Among the synthesized compounds, 3c was found to be the most potent antimicrobial agent as compared to the standard drug. Subsequently, the acute toxicity study has also been carried out for the newly synthesized compounds and the experimental studies revealed that all compounds were safe up to 500 mg/kg and no death of animals were recorded. The cytotoxicity of these compounds was assessed by the MTT cell proliferation assay against the continuous human cell lines HeLa and compound 3c (GI₅₀ = 46.2 ± 1.2 μM) appeared to be more active than compound 3a (GI₅₀ = 200 ± 2.8 μM) and 3b (GI₅₀ = 1400 ± 7.8 μM). Interestingly, all tested compounds displayed a good α-amylase inhibitory activity in competitive manner with IC₅₀ values ranging between 23.7 and 64.35 μM when compared to the standard drug acarbose (IC₅₀ = 282.12 μM). In addition, molecular docking studies were performed to understand the possible binding and the interaction of the most active compounds to the α-amylase pocket.

In vitro anticholinesterase, antimonoamine oxidase and antioxidant properties of alkaloid extracts from kola nuts (Cola acuminata and Cola nitida)

Background

The development of cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for management of neurodegenerative diseases such as Alzheimer’s disease (AD) has come with their undesirable side effects. Hence, research for potent but natural ChE and MAO inhibitors with little or no side effects is essential. This study investigated the potentials of alkaloid extracts from two Cola species as nutraceuticals for prevention and management of AD.

Methods

Alkaloid extracts were obtained from two Cola species (Cola nitida [KN] and Cola acuminata [KA]) by solvent extraction method. The extracts were characterized for their alkaloid contents using gas chromatography (GC). The effects of the extracts on ChE and MAO activities were investigated in vitro. Also, the extracts’ ability to inhibit Fe2+-induced lipid peroxidation in rat brain homogenate, scavenge DPPH and OH radicals, as well as chelate Fe2+ were determined.

Results

GC characterization revealed the presence of augustamine and undulatine as the predominant alkaloids in the extracts. There was no significant (P > 0.05) difference in the inhibitory effects of the extracts on ChE activities. However, KA extract exhibited significantly higher (P < 0.05) MAO inhibitory effect than KN. Also, KA extract inhibited Fe2+- induced malondialdehyde (MDA) production in rat brain homogenate more significantly than KN, while there was no significant difference in DPPH and OH radicals scavenging, as well as Fe2+-chelating abilities of the extracts.

Conclusions

Our findings revealed that KN and KA alkaloid extracts exhibited significant effect in vitro on biological pathways that may contribute to neuroprotection for the management of neurodegenerative diseases.