Spermidine dietary supplementation and polyamines level in reference to survival and lifespan of honey bees.

Honey bee health has been an important and ongoing topic in recent years. Honey bee is also an important model organism for aging studies. Polyamines, putrescine, spermidine and spermine, are ubiquitous polycations, involved in a wide range of cellular processes such as cell growth, gene regulation, immunity, and regulation of lifespan. Spermidine, named longevity elixir, has been most analysed in the context of aging. One of the several proposed mechanisms behind spermidine actions is antioxidative activity. In present study we showed that dietary spermidine supplementation: (a) improved survival, (b) increased the average lifespan, (c) influenced the content of endogenous polyamines by increasing the level of putrescine and spermidine and decreasing the level of spermine, (d) reduced oxidative stress (MDA level), (e) increased the antioxidant capacity of the organism (FRAP), (f) increased relative gene expression of five genes involved in polyamine metabolism, and (g) upregulated vitellogenin gene in honey bees. To our knowledge, this is the first study on honey bee polyamine levels in reference to their longevity. These results provide important information on possible strategies for improving honey bee health by introducing spermidine into their diet. Here, we offer spermidine concentrations that could be considered for that purpose.

Chromium toxicity induced oxidative damage in two rice cultivars and its mitigation through external supplementation of brassinosteroids and spermine.

The chromium (Cr) induced phytotoxicity avowed the scientific community to develop stress mitigation strategies to restrain the Cr accumulation inside the food chain. Whereas, brassinosteroids (BRs), and spermine (SPM) are well-known growth-promoting phytohormones, which enhance the plants health, and resilient the toxic effects under stress conditions. Until now, their interactive role against Cr-mitigation is poorly known. Hence, we conducted the hydroponic experiment to perceive the behavior of seed primed with BRs, or/and SPM treatment against Cr disclosure in two different rice cultivars (CY927; sensitive, YLY689; tolerant). Our findings delineated that BRs (0.01 µM), or/and SPM (0.01 mM) remarkably alleviated Cr-induced phytotoxicity by improving the seed germination ratio, chlorophyll pigments, PSII system, total soluble sugar, and minimizing the MDA contents level, ROS extra generation, and electrolyte leakage through restricting the Cr accretion in roots, and shoots of both rice cultivars under Cr stress. Additionally, the BRs, or/and SPM modulated the antioxidant enzyme, and non-enzyme activities to reduce the Cr-induced cellular oxidative damage as well as maintained the ionic hemostasis in both rice cultivars, especially in YLY689. Concisely, enhanced the plants biomass and growth. Overall, our outcomes revealed that BRs and SPM interact positively to alleviate the Cr-induced damages in rice seedlings on the above-mentioned indices, and combine treatment is much more efficient than solely. Moreover, the effect of BRs, or/and SPM was more obvious in YLY689 than CY927 to hamper the oxidative stress, and boost the antioxidant capacity.

Identification of Kukoamine A, Zeaxanthin, and Clexane as New Furin Inhibitors.

The endogenous protease furin is a key protein in many different diseases, such as cancer and infections. For this reason, a wide range of studies has focused on targeting furin from a therapeutic point of view. Our main objective consisted of identifying new compounds that could enlarge the furin inhibitor arsenal; secondarily, we assayed their adjuvant effect in combination with a known furin inhibitor, CMK, which avoids the SARS-CoV-2 S protein cleavage by means of that inhibition. Virtual screening was carried out to identify potential furin inhibitors. The inhibition of physiological and purified recombinant furin by screening selected compounds, Clexane, and these drugs in combination with CMK was assayed in fluorogenic tests by using a specific furin substrate. The effects of the selected inhibitors from virtual screening on cell viability (293T HEK cell line) were assayed by means of flow cytometry. Through virtual screening, Zeaxanthin and Kukoamine A were selected as the main potential furin inhibitors. In fluorogenic assays, these two compounds and Clexane inhibited both physiological and recombinant furin in a dose-dependent way. In addition, these compounds increased physiological furin inhibition by CMK, showing an adjuvant effect. In conclusion, we identified Kukoamine A, Zeaxanthin, and Clexane as new furin inhibitors. In addition, these drugs were able to increase furin inhibition by CMK, so they could also increase its efficiency when avoiding S protein proteolysis, which is essential for SARS-CoV-2 cell infection.

Induced genetic and chemical changes in medicinally important plant Catharanthus roseus (L.) G. Don: cold plasma and phytohormones.

BACKGROUND: Catharanthus roseus (L.) G. Donis a medicinal plant species belonging to the Apocynaceae family, which produces vinblastine and vincristine along with 100 other monoterpenoid indole alkaloids. The process of biosynthesis of C. roseus alkaloids is complex, in which many genes, enzymes, and regulators are involved. Induced mutations may be considered as a potential source for producing a higher amount of vinblastine and vincristine in this plant species. Therefore, the objective of the present study was to examine the effects of different treatments utilized on the induced genetic changes in C. roseus plants and enzyme activities. METHODS AND RESULTS: Spermine, jasmonic acid, methyjasmonate, putrescine, and cold plasma treatments were used for seed treatments. Different molecular markers, namely inter simple sequence repeat, inter retrotransposon amplified polymorphism, and retrotransposon microsatellite amplified polymorphism were employed to reveal the induced genetic changes. Antioxidant enzyme activities were also studied. The treated plants showed genetic variability and a significant increase in antioxidant enzyme activity compared to the control plants. The putrescine treatment resulted in the highest level of activity in superoxidase. A significant positive correlation occurred between the molecular markers data and antioxidant enzyme activities in treated plants. CONCLUSION: Our data revealed that the different phytohormones and cold plasma treatments could induce both genetic and chemical content changes in C. roseus plants.

Pre-harvest spray of GABA and spermine delays postharvest senescence and alleviates chilling injury of gerbera cut flowers during cold storage.

Short vase life, capitulum wilting, neck bending, and postharvest chilling injury (CI) are major disorders have negative impact on quality and marketing of gerbera cut flowers. Low storage temperatures prolonging the vase life, but on the other hand leads serious CI which decreases the quality and consumer preferences. Spermine (SPER) and γ-aminobutyric acid (GABA) were identified as anti-aging factors delay the senescence and elevate the chilling tolerance in many species. Greenhouse-grown gerbera cv. 'Stanza' sprayed with 2 mM SPER and 1 mM GABA twice (2 T) or thrice (3 T). Cut flowers were stored at 1.5 °C and 8 °C postharvest to study the effects of GABA and SPER on senescence and CI. Vase life, CI and quality of cut flowers were improved by GABA and SPER treatments. No CI was observed in GABA-treated flowers at 1.5 °C; while, flowers sprayed with water showed severe CI. GABA treatments efficiently prolonged the vase life for 6-7 days more than the control (15 days). GABA and SPER increased the fresh weight, solution uptake, protein and proline contents, catalase, peroxidase, and superoxide dismutase activities, while decreased the electrolyte leakage, H2O2, and malondialdehyde contents, polyphenol oxidase, lipoxygenase, and phospholipase D activities. GABA and SPER significantly prolonged the vase life and prevented degradation of proteins and chilling damage and increased capacity of detoxifying and scavenging of H2O2 and reactive oxygen species (ROS), led to alleviate the negative consequences of the senescence and CI.

Spermine Protects Cardiomyocytes from High Glucose-Induced Energy Disturbance by Targeting the CaSR-gp78-Ubiquitin Proteasome System.

PURPOSE: To determine the mediation of spermine on energy metabolism disorder and diabetic cardiomyopathy (DCM) development as well as the underlying mechanisms. METHODS: An in vitro model of DCM was established by incubating primary cultured neonatal rat cardiomyocytes with high glucose (HG). Spermine content was assessed by RP-HPLC. The protein levels were detected by western blot. Mitochondrial functions were analyzed using the respiratory chain complex assay kit and immunofluorescence staining. RESULTS: The endogenous content of spermine was decreased in the HG group, and the protein levels of ornithine decarboxylase, respiratory chain complex (I-V), mitochondrial fusion-related protein (Mfn1, Mfn2), Cx43, N-cadherin, CaSR, and ß-catenin (in cytomembrane) were also down-regulated by HG. In contrast, the protein levels of spermine-N1-acetyltransferase, gp78, Fis1, Drp1, and ß-catenin were up-regulated by HG. Meanwhile, we observed that HG increased ubiquitination levels of Mfn1, Mfn2, and Cx43, decreased membrane potential (ΔΨm), and the opening of mitochondrial permeability transport pore (mPTP) followed by intracellular ATP leakage. The supplement of spermine or siRNA-mediated knockdown of gp78 significantly alleviated the detrimental effects of HG, while downregulation of CaSR aggravated the development of DCM. We further confirmed that the lower level of spermine by HG activates the gp78-ubiquitin-proteasome pathway via downregulation of CaSR protein level, which in turn damages mitochondrial gap junction intercellular communication and leads to reduced ATP level. CONCLUSION: The protective role of spermine on energy metabolism disorder is based on higher CaSR protein level and lower gp78 activation, pointing to the possibility that spermine can be a target for the prevention and treatment of DCM.

Kukoamine A Protects against NMDA-Induced Neurotoxicity Accompanied with Down-Regulation of GluN2B-Containing NMDA Receptors and Phosphorylation of PI3K/Akt/GSK-3ß Signaling Pathway in Cultured Primary Cortical Neurons.

Kukoamine (KuA) is a spermine alkaloid present in traditional Chinese medicine Cortex Lycii radices, which possesses various pharmacological properties. Our previous studies have demonstrated that KuA exerts neuroprotective effects against H2O2-induced oxidative stress, radiation-induced neuroinflammation, oxidative stress and neuronal apoptosis, as well as neurotoxin-induced Parkinson's disease through apoptosis inhibition and autophagy enhancement. The present study aimed to investigate the neuroprotective effects of KuA against NMDA-induced neuronal injury in cultured primary cortical neurons and explore the underlying mechanism. Incubation with 200 µM NMDA for 30 min induced excitotoxicity in primary cultured cortical neurons. The results demonstrated that pretreatment with KuA attenuated NMDA induced cell injury, LDH leakage and neuronal apoptosis. KuA also regulated apoptosis-related proteins. Thus, incubation with the alkaloid decreased the ratio of Bax/Bcl-2, and inhibited the release of cytochrome C, the expression of p53 and the cleavage of caspase-3. Moreover, KuA prevented the upregulation of GluN2B-containing NMDA receptors (NMDAR). Additionally, pretreatment with KuA reversed NMDA-induced dephosphorylation of Akt and GSK-3ß and the protective effect of KuA on NMDA-induced cytotoxicity was abolished by wortmannin, a PI3K inhibitor. Taken together, these results indicated that KuA exerted neuroprotective effects against NMDA-induced neurotoxicity in cultural primary cortical neurons and caused the down-regulation of GluN2B-containing NMDARs as well as the phosphorylation of proteins belonging to the PI3K/Akt/GSK-3ß signaling pathway.

Separation and Characterization of Phenolamines and Flavonoids from Rape Bee Pollen, and Comparison of Their Antioxidant Activities and Protective Effects Against Oxidative Stress.

Phenolamines and flavonoids are two important components in bee pollen. There are many reports on the bioactivity of flavonoids in bee pollen, but few on phenolamines. This study aims to separate and characterize the flavonoids and phenolamines from rape bee pollen, and compare their antioxidant activities and protective effects against oxidative stress. The rape bee pollen was separated to obtain 35% and 50% fractions, which were characterized by HPLC-ESI-QTOF-MS/MS. The results showed that the compounds in 35% fraction were quercetin and kaempferol glycosides, while the compounds in 50% fraction were phenolamines, including di-p-coumaroyl spermidine, p-coumaroyl caffeoyl hydroxyferuloyl spermine, di-p-coumaroyl hydroxyferuloyl spermine, and tri-p-coumaroyl spermidine. The antioxidant activities of phenolamines and flavonoids were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assays. It was found that the antioxidant activity of phenolamines was significantly higher than that of flavonoids. Moreover, phenolamines showed better protective effects than flavonoids on HepG2 cells injured by AAPH. Furthermore, phenolamines could significantly reduce the reactive oxygen species (ROS), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and increase the superoxide dismutase (SOD) and glutathione (GSH) levels. This study lays a foundation for the further understanding of phenolamines in rape bee pollen.

Anti-Osteoporotic Effects of Kukoamine B Isolated from Lycii Radicis Cortex Extract on Osteoblast and Osteoclast Cells and Ovariectomized Osteoporosis Model Mice.

Osteoporosis is an abnormal bone remodeling condition characterized by decreased bone density, which leads to high risks of fracture. Previous study has demonstrated that Lycii Radicis Cortex (LRC) extract inhibits bone loss in ovariectomized (OVX) mice by enhancing osteoblast differentiation. A bioactive compound, kukoamine B (KB), was identified from fractionation of an LRC extract as a candidate component responsible for an anti-osteoporotic effect. This study investigated the anti-osteoporotic effects of KB using in vitro and in vivo osteoporosis models. KB treatment significantly increased the osteoblastic differentiation and mineralized nodule formation of osteoblastic MC3T3-E1 cells, while it significantly decreased the osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. The effects of KB on osteoblastic and osteoclastic differentiations under more physiological conditions were also examined. In the co-culture of MC3T3-E1 cells and monocytes, KB promoted osteoblast differentiation but did not affect osteoclast differentiation. In vivo experiments revealed that KB significantly inhibited OVX-induced bone mineral density loss and restored the impaired bone structural properties in osteoporosis model mice. These results suggest that KB may be a potential therapeutic candidate for the treatment of osteoporosis.

Comparative Study of the Chemical Constituents and Bioactivities of the Extracts from Fruits, Leaves and Root Barks of Lycium barbarum.

The fruits, leaves and root barks of L. barbarum plant are widely used as functional foods and as ingredients in traditional Chinese prescriptions and patent medicines. They are considered to have different pharmacological activities and health benefits because of their diverse constituents. Here, the chemical constituents of the extracts from fruits, leaves and root barks of L. barbarum were compared by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-HR-MS). A total of 131 compounds were identified and seven of them were quantified. Among them, 98, 28 and 35 constituents were detected in fruits, leaves and root barks respectively. Dicaffeoylspermidine/spermine derivatives were the most detected compounds (74/131); among them, dicaffeoylspermine isomers and propionyl-dicaffeoylspermidine were found in root barks in very large amounts (e.g., kukoamine B = 10.90 mg/g dry powder); dicaffeoyl-spermidine isomers were detected in fruits/leaves in a high amount, and many of their glycosylated derivatives were mainly detected in fruits. In addition, six saponins from L. barbarum fruits were reported for the first time, and 5,6-dihydrosolasonine was reported for the first time in plants. The activity assays showed that the root bark extract possessed the strongest antioxidative activity and cytotoxicity, which was presumed due to the large amount of dicaffeoylspermine/spermidines in root barks. Fourteen potential bioactive components from fruits were identified by a target cell-based screening method. These results will help to understand the different biological activities of these three parts of L. barbarum plant and will benefit the discovery of new functional components.

Trodusquemine enhances Aß42 aggregation but suppresses its toxicity by displacing oligomers from cell membranes.

Transient oligomeric species formed during the aggregation process of the 42-residue form of the amyloid-ß peptide (Aß42) are key pathogenic agents in Alzheimer's disease (AD). To investigate the relationship between Aß42 aggregation and its cytotoxicity and the influence of a potential drug on both phenomena, we have studied the effects of trodusquemine. This aminosterol enhances the rate of aggregation by promoting monomer-dependent secondary nucleation, but significantly reduces the toxicity of the resulting oligomers to neuroblastoma cells by inhibiting their binding to the cellular membranes. When administered to a C. elegans model of AD, we again observe an increase in aggregate formation alongside the suppression of Aß42-induced toxicity. In addition to oligomer displacement, the reduced toxicity could also point towards an increased rate of conversion of oligomers to less toxic fibrils. The ability of a small molecule to reduce the toxicity of oligomeric species represents a potential therapeutic strategy against AD.

Spermine protects alpha-synuclein expressing dopaminergic neurons from manganese-induced degeneration.

Manganese exposure is among the many environmental risk factors linked to the progression of neurodegenerative diseases, such as manganese-induced parkinsonism. In animal models, chronic exposure to manganese causes loss of cell viability, neurodegeneration, and functional deficits. Polyamines, such as spermine, have been shown to rescue animals from age-induced neurodegeneration in an autophagy-dependent manner; nonetheless, it is not understood whether polyamines can prevent manganese-induced toxicity. In this study, we used two model systems, the Caenorhabditis elegans UA44 strain and SK-MEL-28 cells, both expressing the protein alpha-synuclein (α-syn) to determine whether spermine could ameliorate manganese-induced toxicity. Manganese caused a substantial reduction in the viability of SK-MEL-28 cells and hastened neurodegeneration in the UA44 strain. Spermine protected both the SK-MEL-28 cells and the UA44 strain from manganese-induced toxicity. Spermine also reduced the age-associated neurodegeneration observed in the UA44 strain compared with a control strain without α-syn expression and led to improved avoidance behavior in a functional assay. Treatment with berenil, an inhibitor of polyamine catabolism, which leads to increased intracellular polyamine levels, also showed similar cellular protection against manganese toxicity. While both translation blocker cycloheximide and autophagy blocker chloroquine caused a reduction in the cytoprotective effect of spermine, transcription blocker actinomycin D had no effect. This study provides new insights on the effect of spermine in preventing manganese-induced toxicity, which is most likely via translational regulation of several candidate genes, including those of autophagy. Thus, our results indicate that polyamines positively influence neuronal health, even when exposed to high levels of manganese and α-syn, and supplementing polyamines through diet might delay the onset of diseases involving degeneration of dopaminergic neurons.

Spermine and oxacillin stress response on the cell wall synthesis and the global gene expression analysis in Methicillin-resistance Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a rapidly emerging bacteria causing infection, which has developed resistance to most of the beta-lactam antibiotics because of newly acquired low-affinity penicillin-binding protein (PBP2a), which can continue to build the cell wall when beta-lactams block other PBPs. Exogenous spermine exerts a dose-dependent inhibition effect on the growth of Escherichia coli, Salmonella enterica serovar, and S. aureus. Selection of an MRSA Mu50 derivative which harbors mutation on PBP2 gene (named as MuM) showing spermine resistance and which confers a complete abolishment of spermine-beta-lactam synergy was identified. To further investigate the gene expression changes, a transcriptome profiling of MuM against Mu50 (wild-type) without any treatment, MuM and Mu50 in response to high dose spermine and Mu50 in response to spermine-beta-lactam synergy at 15, 30 and 60 min time points was performed. Functional annotation was further performed to delineate the metabolic pathways associated with the significant genes. A significant down-regulation in the iron regulatory system, potassium channel uptake and polyamine transport system with an up-regulation in general stress response sigB dependent operon in MuM strain at 15, 30 and 60 min time points with spermine treatment compared to Mu50 strain was observed. Analysis of spermine-dependent synergy with beta-lactams on cell wall synthesis revealed that it significantly reduces the degree of cross-linkage on cell wall with no change in trypsin digestion pattern of purified PBPs and without affecting PBPs expression or PBPs acylation by Bocillin. A strong relation between PBP2 protein and general stress sigB response, iron, potassium and polyamine transport systems was observed. SigB regulon should be activated on stress, which was not seen in some of our previous studies where it was down-regulated in wild-type Mu50 strain with spermine stress. Here, an intriguing finding is made where there seems to be a correction of this abnormal response of no SigB induction to a significant induction by PBP2 mutation. In MuM strain, a significant down-regulation of KdpABC operon genes at 15, 30 and 60 min time points on spermine stress is seen, which seems to be absent without spermine treatment. Since KCL has been found to protect the cell against spermine stress in wild-type strain by induction of KdpABC operon, it fails to do so in MuM strain underlying the importance of PBP2 protein in spermine stress. Analysis of spermine-dependent synergy with beta-lactams on cell wall synthesis revealed that it significantly reduces the degree of cross-linkage on cell wall with no change in trypsin digestion patterns of purified PBPs and without affecting PBPs expression or PBPs acylation by Bocillin. Furthermore, spermine does not help in enhancing the binding of beta-lactams to PBPs and binding of spermine to PBPs does not cause conformational changes to PBPs, as tested with trypsin digestion patterns. Future studies on the molecular mechanism of spermine interactions with these systems hold great potential for the development of new therapeutics for MRSA infections.

Curcumin mediates polyamine metabolism and sensitizes gastrointestinal cancer cells to antitumor polyamine-targeted therapies.

Curcumin, a natural polyphenol that contributes to the flavor and yellow pigment of the spice turmeric, is known for its antioxidant, anti-inflammatory, and anticarcinogenic properties. Capable of affecting the initiation, promotion, and progression of carcinogenesis through multiple mechanisms, curcumin has potential utility for both chemoprevention and chemotherapy. Previous studies demonstrated that curcumin can inhibit ornithine decarboxylase (ODC) activity in human leukemia and breast cancer cells, and pretreatment with dietary curcumin blocks carcinogen-induced ODC activity in rodent models of skin, colon, and renal cancer. The current study investigated the regulation of polyamine metabolism in human gastric and colon carcinoma cell lines in response to curcumin. Curcumin treatment significantly induced spermine oxidase (SMOX) mRNA and activity, which results in the generation of hydrogen peroxide, a source of ROS. Simultaneously, curcumin down regulated spermidine/spermine N1-acetyltransferase (SSAT) activity and the biosynthetic enzymes ODC and S-adenosylmethionine decarboxylase (SAMDC), thereby diminishing intracellular polyamine pools. Combination treatments using curcumin with the ODC inhibitor 2-difluoromethylornithine (DFMO), an agent currently in clinical chemoprevention trials, significantly enhanced inhibition of ODC activity and decreased growth of GI cancer cell lines beyond that observed with either agent alone. Similarly, combining curcumin with the polyamine analogue bis(ethyl)norspermine enhanced growth inhibition that was accompanied by enhanced accumulation of the analogue and decreased intracellular polyamine levels beyond those observed with either agent alone. Importantly, cotreatment with curcumin permitted the lowering of the effective dose of ODC inhibitor or polyamine analogue. These studies provide insight into the polyamine-related mechanisms involved in the cancer cell response to curcumin and its potential as a chemopreventive or chemotherapeutic agent in the GI tract.

Effects of spermine on the antioxidant status and gene expression of antioxidant-related signaling molecules in the liver and longissimus dorsi of piglets.

Previous studies showed that spermine could protect the organism from oxidative damage in vivo. However, in vivo information on the antioxidant-related underlying molecular mechanism of spermine is limited. In this experiment, we further evaluated the effects of spermine supplementation and extended spermine administration on the antioxidant status and antioxidant-related signaling molecules gene expression in the liver and longissimus dorsi of piglets. A total of 80 piglets were randomly distributed to two groups, that is, those with adequate nutrient intake administrated with spermine (0.4 mmol/kg BW) or those with restricted nutrient intake supplemented by saline. The piglets were fed in pairs for 7 h or 3, 6, or 9 days. The results are as follows: (1) spermine can promote the antioxidant capacity by increasing enzymatic antioxidant capacity, glutathione content and clearance of oxygen radicals; (2) spermine significantly increased the mRNA levels of enzymatic antioxidant substances, NF-E2-related nuclear factor 2, Kelch-like ECH-associated protein 1, and the mammalian target of rapamycin but decreased the mRNA levels of ribosomal p70 S6 kinase in the liver and longissimus dorsi of the piglets.

Roles of spermine in modulating the antioxidant status and Nrf2 signalling molecules expression in the thymus and spleen of suckling piglets-new insight.

This study aimed to investigate the effects of spermine and extended spermine administration on the antioxidant status and expression of NF-E2-related factor 2 (Nrf2) signalling molecules in the thymus and spleen in suckling piglets. One half of eighty 12-day-old suckling piglets obtained sufficient nutrient intake supplemented with spermine (0.4 mmol/kg body weight), and another half received restricted nutrient intake supplemented with physiological saline in equal doses once a day for 7 hr or 3, 6 or 9 days in pairs. Spermine supplementation and its extended duration significantly decreased malondialdehyde (MDA) and protein carbonyl (PC) contents (p < .05), but markedly improved antisuperoxide anion (ASA), antihydroxyl radical (AHR), catalase (CAT), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities (p < .05) and glutathione (GSH) content (p < .05) in the thymus and spleen. Additionally, real-time PCR analysis showed that spermine administration and extended spermine intake reduced Kelch-like ECH-associated protein 1 (Keap1) gene transcription and enhanced SOD1, GPx1, CAT, glutathione reductase (GR) and Nrf2 mRNA levels of the thymus and spleen (p < .05), and also improved GST gene expression in the thymus (p < .05). Notably, the spermine-supplemented time for the optimal effects of suckling piglet was determined to be 6 days. Collectively, the current study suggested that spermine supplementation and extended spermine administration could protect the health of the thymus and spleen from early weaning by enhancing the antioxidant status and regulating the expression of antioxidant-related signalling molecules.

Exogenous spermine preserves mitochondrial bioenergetics via regulating Src kinase signaling in the spinal cord.

Regulation of mitochondrial metabolism is becoming an important target in inhibiting necrosis and apoptosis following secondary spinal cord injury, and physiological compounds that reduce mitochondrial dysfunction are regarded as efficient protective reagents following injury. It has been demonstrated that spermine, a polyamine composed of four primary amines, may be taken up by a mitochondria­specific uniporter and may preserve mitochondrial bioenergetics, suggesting that it may be important in the pathophysiology of mitochondria. However, the protective mechanism has not yet been definitively clarified. In the present study, isolated spinal cord mitochondria were incubated with spermine to evaluate its physiological functions and Src kinase activities. The results revealed that spermine increased oxidative phosphorylation, attenuated mitochondrial swelling and maintained the membrane potential. An inhibitor of Src kinases, amino­5-(4­chlorophenyl)­7­(t­butyl)pyrazolo[3,4­d]pyrimidine (PP2), markedly reduced the effects of spermine. However, inhibition of tyrosine phosphatases by vanadate led to marginal increases in the effects of spermine. Therefore, the present study hypothesized that tyrosine phosphorylation sites are present in the subunits of respiratory chains and mitochondrial permeability transition pore proteins, which may be modified via phosphorylation and dephosphorylation. Furthermore, spermine may upregulate the phosphorylation of Src kinases, and PP2 and vanadate conversely regulate Src phosphorylation. The results of the present study suggest that spermine is a strategic regulator within mitochondria that may activate Src kinases in the spinal cord, and tyrosine phosphorylation signaling is a primary regulatory pathway of mitochondrial metabolism.

Design, synthesis and in vitro antikinetoplastid evaluation of N-acylated putrescine, spermidine and spermine derivatives.

A structure-activity relationship study on polyamine derivatives led to the synthesis and the determination of antikinetoplastid activity of 17 compounds. Among them, a spermidine derivative (compound 13) was specifically active in vitro against Leishmania donovani axenic amastigotes (IC50 at 5.4µM; Selectivity Index >18.5) and a spermine derivative (compound 28) specifically active against Trypanosoma brucei gambiense (IC50 at 1.9µM; Selectivity Index >52).

Nitric oxide rescues thalidomide mediated teratogenicity.

Thalidomide, a sedative drug given to pregnant women, unfortunately caused limb deformities in thousands of babies. Recently the drug was revived because of its therapeutic potential; however the search is still ongoing for an antidote against thalidomide induced limb deformities. In the current study we found that nitric oxide (NO) rescues thalidomide affected chick (Gallus gallus) and zebrafish (Danio rerio) embryos. This study confirms that NO reduced the number of thalidomide mediated limb deformities by 94% and 80% in chick and zebrafish embryos respectively. NO prevents limb deformities by promoting angiogenesis, reducing oxidative stress and inactivating caspase-3 dependent apoptosis. We conclude that NO secures angiogenesis in the thalidomide treated embryos to protect them from deformities.

Modulation of opening of rat liver mitochondrial membrane permeability transition pore by different fractions of the leaves of Cnestis ferruginea. D.C.

BACKGROUND: Increased attention is now directed towards the search for novel naturally occurring anticancer agents that can induce mitochondrial membrane permeability transition (MMPT) pore opening and cell death as a chemotherapeutic mechanism to combat cancer incidence. AIM: The inductive effects of partially purified fractions of leaves of Cnestis ferruginea- on rat liver MMPT pore opening was investigated. METHOD: De-fatted methanol extract of leaves of Cnestis ferruginea was partitioned between water, chloroform, ethylacetate, or butanol separately in succession. The extract solutions were concentrated at 40 degrees C to obtain water (WF), chloroform (CF), ethylacetate (EF) and butanol (BF) fractions. The effects of these fractions (0.2- 1.4 mg/ml) on MMPT pore opening or mitochondrial swelling in the presence and absence of calcium were evaluated The effects of these fractions on the rat liver mitochondrial F0F1-ATPase activity were also assessed. RESULTS: Ca(2+)-induced MMPT pore opening was inhibited by 1 mg/ml each of MECF, CF, BF, WF and EF by 75.0%, 83.0%, 88.0%, 68.0%, and 71.0%, respectively and compared with the effect of spermine, a standard inhibitor. However, in the absence of Ca2+, the fractions significantly induced MMPT pore opening in intact mitochondria by 7.0, 5.7, 0.7, 4.8, 10.9 folds, respectively. In normal rat liver mitochondria, F1F0-ATPase activity was stimulated maximally by MECF, CF, EF, BF and WF by 4.7, 12.7, 1.6, 3.6 and 1.5 folds, respectively, thus indicating that the chloroform fraction is the most potent and therefore contains the active principle in the plant. CONCLUSION: The present study revealed that the leaves of Cnestis ferruginea contain bioactive substances that induced mitochondrial membrane permeability transition and activated the specific activity of F0F1 ATPase. Thus, suggesting strongly that these bioactive agents may serve as a useful chemotherapeutic strategy in cancer therapy.