147 research outputs found

    In vivo tissue uptake of intravenously injected water soluble all-trans β-carotene used as a food colorant

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    Water soluble β-carotene (WS-BC) is a carotenoid form that has been developed as a food colorant. WS-BC is known to contain 10% of all-trans β-carotene (AT-BC). The aim of the present study was to investigate in vivo tissue uptake of AT-BC after the administration of WS-BC into rats. Seven-week-old male rats were administered 20 mg of WS-BC dissolved in saline by intravenous injection into the tail vein. At 0, 6, 24, 72, 120 and 168 hours (n = 7/time), blood was drawn and liver, lungs, adrenal glands, kidneys and testes were dissected. The levels of AT-BC in the plasma and dissected tissues were quantified with HPLC. After intravenous administration, AT-BC level in plasma first increased up to 6 h and returned to normal at 72 h. In the testes, the AT-BC level first increased up to 24 h and then did not decrease but was retained up to 168 h. In the other tissues, the level first increased up to 6 h and then decreased from 6 to 120 or 168 h but did not return to normal. The accumulation of WS-BC in testes but not in the other 5 tissues examined may suggest that AT-BC was excreted or metabolized in these tissues but not in testes. Although WS-BC is commonly used as a food colorant, its effects on body tissues are still not clarified. Results of the present study suggest that further investigations are required to elucidate effects of WS-BC on various body tissues

    The effect of an extract from Ganoderma lucidum (reishi) on the labeling of blood constituents with technetium-99m and on the survival of Escherichia coli

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    This study evaluated effects of an aqueous extract of Ganoderma lucidum (reishi) on the labeling of blood constituents with technetium-99m (99mTc) and on the survival of cultures of Escherichia coli treated with stannous chloride. Blood samples from Wistar rats were treated with reishi extract, radiolabeling procedure was performed, plasma (P), blood cells (BC) and insoluble (IF) and soluble (SF) fractions of P and BC were separated. The radioactivity was counted for the determination of the percentages of radioactivity (%ATI). Cultures of Escherichia coli AB1157 were treated with stannous chloride in the presence and absence of reishi extract. Blood samples and bacterial cultures treated with NaCl 0.9% were used as controls. Data indicated that reishi extract altered significantly (p99mTc and protecting bacterial cultures against oxidative damage induced by stannous chloride

    Antioksidativni učinci N-acetilcisteina, lipoične kiseline, taurina i kurkumina u mišićnom tkivu šarana (Cyprinus carpio L.) tretiranih kadmijem

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    We investigated the muscle tissue of a teleost Cyprinus carpio L. to find out whether N-acetylcysteine (NAC), alpha-lipoic acid (LA), taurine (TAU), and curcumin (CUR) were able to counteract oxidative stress induced by acute exposure to cadmium (Cd). The muscle tissue was dissected 96 h after a single intraperitoneal injection of Cd (5 mg kg-1) and of antioxidant substances (50 mg kg-1). Using spectrophotometry, we determined the glutathione redox status, lipid peroxidation levels and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione disulphide reductase (GR). Accumulation of Cd in the muscle was analysed using inductively coupled plasma - optical emission spectrometry (ICP-OES). All substances lowered Cd levels in the following order of effi ciency; LA=NAC>TAU=CUR. Cadmium increased SOD activity, but CAT activity declined, regardless of antioxidant treatment. Treatment with CUR induced GPx activity. Treatment with TAU lowered Cd due to higher total glutathione (tGSH). The most effective substances on lipid peroxidation were LA and NAC due to a greater Cd-lowering potential. It seems that the protective role of TAU, LA, and NAC is not necessarily associated with antioxidant enzymes, but rather with their own activity.Cilj istraživanja bio je utvrditi mogu li N-acetilcistein (NAC), α-lipoična kiselina (LA), taurin (TAU) i kurkumin (CUR) svojim antioksidativnim djelovanjem smanjiti razinu oksidativnog stresa u mišićnom tkivu šarana (Cyprinus carpio L.) akutno otrovanih kadmijem. Uzorci mišićnog tkiva skupljeni su 96 h nakon što su ribama intraperitonealno injicirani kadmij (5 mg kg-1) i ispitivani antioksidansi (50 mg kg-1). Primjenom spektrofotometrijskih metoda izmjereni su redoks status glutationa, razine lipidne peroksidacije te aktivnosti enzima superoksid dismutaze (SOD), katalaze (CAT), glutation peroksidaze (GPx) i glutation disulfi d reduktaze (GR). Maseni udio kadmija u mišićnom tkivu izmjeren je s pomoću metode induktivno spregnute plazme – optičke emisijske spektrometrije (ICP-OES). Ispitivani spojevi smanjili su nakupljanje kadmija u tkivu šarana sljedećim redoslijedom: LA=NAC>TAU=CUR. Tretman šarana kadmijem izazvao je porast aktivnosti SOD, ali se aktivnost CAT smanjila bez obzira na primjenu antioksidativnih spojeva. Dodatak CUR pojačao je aktivnost GPx. Dodatak TAU povećao je razinu ukupnoga glutationa te smanjio nakupljanje kadmija. Svi spojevi osim CUR smanjili su razinu lipidne peroksidacije te pretpostavljamo da su LA i NAC pridonijeli detoksifi kaciji kadmija. Rezultati istraživanja upućuju na to da testirani spojevi, osim CUR, imaju antioksidativni učina

    Structure-Based Predictive Models for Allosteric Hot Spots

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    In allostery, a binding event at one site in a protein modulates the behavior of a distant site. Identifying residues that relay the signal between sites remains a challenge. We have developed predictive models using support-vector machines, a widely used machine-learning method. The training data set consisted of residues classified as either hotspots or non-hotspots based on experimental characterization of point mutations from a diverse set of allosteric proteins. Each residue had an associated set of calculated features. Two sets of features were used, one consisting of dynamical, structural, network, and informatic measures, and another of structural measures defined by Daily and Gray [1]. The resulting models performed well on an independent data set consisting of hotspots and non-hotspots from five allosteric proteins. For the independent data set, our top 10 models using Feature Set 1 recalled 68–81% of known hotspots, and among total hotspot predictions, 58–67% were actual hotspots. Hence, these models have precision P = 58–67% and recall R = 68–81%. The corresponding models for Feature Set 2 had P = 55–59% and R = 81–92%. We combined the features from each set that produced models with optimal predictive performance. The top 10 models using this hybrid feature set had R = 73–81% and P = 64–71%, the best overall performance of any of the sets of models. Our methods identified hotspots in structural regions of known allosteric significance. Moreover, our predicted hotspots form a network of contiguous residues in the interior of the structures, in agreement with previous work. In conclusion, we have developed models that discriminate between known allosteric hotspots and non-hotspots with high accuracy and sensitivity. Moreover, the pattern of predicted hotspots corresponds to known functional motifs implicated in allostery, and is consistent with previous work describing sparse networks of allosterically important residues

    The International Natural Product Sciences Taskforce (INPST) and the power of Twitter networking exemplified through #INPST hashtag analysis

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    Background: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to bring together in collaborative environment individuals and organizations interested in natural product scientific research, and to empower their interactions by using digital communication tools. Methods: In this work, we present a general overview of INPST activities and showcase the specific use of Twitter as a powerful networking tool that was used to host a one-week "2021 INPST Twitter Networking Event" (spanning from 31st May 2021 to 6th June 2021) based on the application of the Twitter hashtag #INPST. Results and Conclusion: The use of this hashtag during the networking event period was analyzed with Symplur Signals (https://www.symplur.com/), revealing a total of 6,036 tweets, shared by 686 users, which generated a total of 65,004,773 impressions (views of the respective tweets). This networking event's achieved high visibility and participation rate showcases a convincing example of how this social media platform can be used as a highly effective tool to host virtual Twitter-based international biomedical research events

    Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

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    Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

    Bromelain Modulates Liver Injury, Hematological, Molecular, and Biochemical Perturbations Induced by Aluminum via Oxidative Stress Inhibition

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    Aluminum (Al) is an important factor in the environment as it is used in agriculture and several industries leading to hazardous effects via oxidative stress. Bromelain is a cheap extract from the byproduct waste of Ananas comosus stem. It has been used in several biological and therapeutic applications. So, this study was undertaken to assess the hepatoprotective potential of bromelain versus oxidative stress induced by aluminum chloride in rats. Results revealed that administration of AlCl3 reduced the body and liver weights and increased Al concentration in the blood and liver tissue. Also, AlCl3 caused valuable changes in hematological parameters and increased TBARS and H2O2 concentrations in rat liver. Enzymatic (SOD, CAT, GPx, GR, and GST) and nonenzymatic (GSH) antioxidants and protein content were significantly decreased. Furthermore, alterations in liver biomarkers such as bilirubin level and enzyme activities in both serum and liver homogenate (LDH, ALP, AST, and ALT) were detected. AlCl3 also caused inflammation as indicated by upregulation of the inflammation-related genes [interleukin 1 beta (IL-1β)], tumor necrosis factor-alpha (TNF-α), as well as matrix metalloproteinase (MMP9), and downregulation of nuclear factor erythroid 2 (Nrf2) expression. In addition, histopathological examination showed significant variations in the liver that confirms the biochemical results. Otherwise, bromelain intake alone slumped lipid peroxidation and gotten better antioxidant status significantly. Moreover, supplementation with bromelain before AlCl3 intoxication restores enzymatic and nonenzymatic antioxidants as well as biochemical indices and tissue architecture with respect to the AlCl3 group. In conclusion, bromelain proved its remarkable protective power to abolish AlCl3 toxicity. So, it might represent a new strategy in the therapy of metal toxicity by its antioxidant capacity
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