High frequency of larval abnormalities of the toad Rhinella arenarum (Anura: Bufonidae) in an Argentinian agroecosystem

Introduction: The frequent use of pesticides is currently considered a cause of environmental pollution due to the high rate of entry of these substances into agroecosystems. This constitutes a risk for the species that inhabit these ecosystems, in particular anurans whose characteristics make them prone to exposure to and interaction with environmental pollutants. Objective: To report the occurrence of abnormalities in larvae of the common toad Rhinella arenarum inhabiting ponds surrounded by agroecosystems. Methods: In two consecutive springs (2015 and 2016), reproductive events of common toads were monitored in temporary pond systems in agricultural and non-agricultural areas, located near the city of La Plata (Buenos Aires, Argentina). The physicochemical parameters of the ponds were measured, and the stage of each reproductive event was recorded, such as the numbers of adult toads, amplexus and clutches. In the laboratory, the larvae were measured and photographed, their stage of development was recorded, and their morphology was examined under a stereomicroscope. Representative samples (normal and abnormal) from each pond studied were processed for histopathological analysis. Results: In the field studies carried out on a population of R. arenarum collected in an agroecosystem, a lower number of reproductive adults and clutches were observed in relation to the population of a non-agricultural pond. A total of 1 910 larvae were collected: 529 and 1 381 larvae from ponds located in non-agricultural and agricultural areas, respectively. Larvae from the agroecosystem showed two types of abnormalities: severe tail flexure and abdominal bloating. In addition, five degrees of severity could be determined in relation to abdominal bloating. Conclusions: This work reports the high frequency and severity of abnormalities observed in the early stages of R. arenarum larvae living within an agroecosystem, providing evidence of the negative impact that agricultural activities cause on aquatic ecosystems surrounded by farming areas.

Introducción: El uso frecuente de plaguicidas es considerado actualmente una causa de contaminación ambiental debido a las altas tasas de ingreso de estas sustancias a los agroecosistemas. Esta situación es un riesgo para las especies que habitan en estos ecosistemas, en particular los anuros cuyas características los hacen propensos a la exposición e interacción con contaminantes ambientales. Objetivo: Informar la presencia de anormalidades en larvas del sapo común Rhinella arenarum que habitan en estanques rodeados por un agroecosistema. Métodos: En dos primaveras consecutivas (2015 y 2016), se monitorearon los eventos reproductivos del sapo común proveniente de sistemas de estanques temporales ubicados en zonas agrícolas y no agrícolas, cerca de la ciudad de La Plata (Buenos Aires, Argentina). Se midieron los parámetros fisicoquímicos de los estanques y se registraron las etapas de cada evento reproductivo como el número de sapos adultos, amplexos y nidadas. En el laboratorio, las larvas fueron medidas y fotografiadas, se registró su estado de desarrollo y se examinó la morfología de cada una bajo microscopio estereoscópico. Se procesaron muestras representativas (normales y anormales) de cada estanque estudiado para análisis histopatológico. Resultados: En la población de R. arenarum que vive dentro de un agroecosistema, se observó un menor número de adultos reproductores y puestas en relación con la del estanque en la zona no agrícola. Se recolectaron un total de 1 910 larvas: 529 y 1 381 larvas de estanques ubicados en zonas no agrícolas y agrícolas, respectivamente. Las larvas del agroecosistema mostraron dos tipos de anormalidades: severa flexión de la cola y distensión abdominal. Además, se pudo determinar cinco grados de gravedad en relación con la distensión abdominal. Conclusiones: Una alta frecuencia y severidad de anormalidades en los estadios tempranos de larvas de R. arenarum que viven dentro de un agroecosistema proporciona evidencia del impacto negativo que las actividades agrícolas causan en los ecosistemas acuáticos rodeados por áreas de cultivo.

Study on anti-inflammatory activity and mechanism of indolealkylamines in toad skin on LPS-activated neutrophils / 中国中药杂志

Indolealkylamines(IAAs) are the main hydrophilic substances in toad skin, mainly including free N-methyl-5-hydroxytryptamine, bufotenine, bufotenidine, dehydrobufotenine, and binding bufothionine. In this study, the LPS-activated neutrophils were used to investigate the structure-activity relationship and anti-inflammatory mechanism of the above-mentioned five monomers from the toad skin in vitro. The neutrophils were divided into the control group, model group(1 μg·mL~(-1) LPS), positive drug group(100 μg·mL~(-1) indometacin), as well as the low-(50 μg·mL~(-1)), medium-(100 μg·mL~(-1)) and high-dose(200 μg·mL~(-1)) free N-methyl-5-hydroxytryptamine, bufotenine, bufotenidine, dehydrobufotenine, and binding bufothionine groups. The levels of IL-6, TNF-α and IL-1β in the neutrophil supernatant of each group was measured by enzyme-linked immunosorbent assay(ELISA) after LPS stimulation, followed by the detection of apoptosis in each group after Annexin V/PI staining. The protein expression levels of caspase-3, Bax, Bcl-2, beclin1, LC3-I, and LC3-Ⅱ were assayed by Western blot. The results showed that IAAs reduced the excessive secretion of inflammatory cytokines caused by LPS compared with the model group. Besides, the activity of each free IAAs(N-methyl-5-hydroxytryptamine, bufotenine, bufotenidine and dehydrobufotenine), especially bufotenine, was stronger than that of the binding bufothionine. As revealed by Annexin V/PI staining, LPS delayed the early apoptosis of neutrophils compared with the control group, while bufotenine promoted the apoptosis of neutrophils in a dose-dependent manner, which might be related to the elevated expression of apoptosis-related protein Bax/Bcl-2. In addition, LPS activated the autophagy pathways in neutrophils. This study confirmed the efficacy of IAAs in reducing the secretion of inflammatory cytokines in neutrophils induced by LPS for the first time. For instance, bufotenine exerts the anti-inflammatory effect possibly by inducing the apoptosis of neutrophils.

Evaluation of the effect of brain and spinal cord destruction in toads by a modified way / 西安交通大学学报(医学版)

Objective: To improve the traditional teaching technique of using probe to destroy the brain tissue and spinal cord of toads. Methods:On the basis of the traditional teaching content, the distance of the probe entering the skull cavity and the specific feeling mark of destroying the brain tissue and spinal cord were added. Students were randomly divided into normal group and improved group according to the class. We observed the success rate and time spent on both the first and the second operations in the two groups. Results: The success rate of destroying the brain tissue and spinal cord in the improved group was high (93.2% vs. 72.3% for the first time). The secondary success rate was 97.7% vs. 85.1%, and it took less time (311.7±89.3) seconds vs. (511.6±171.1) seconds for the initial operation, The secondary operation time was (161.3±63.5) seconds vs. (266.0±98.2) seconds, with significant differences between the two groups (P<0.05).Conclusion: After the improvement of the content of destroying the brain tissue and spinal cord of toads in traditional teaching, it is easy to be mastered by students, with high success rate, less time spent, greater consistency with the 3R principle, and easier to be popularized and applied in teaching.

Protein identification from the parotoid macrogland secretion of Duttaphrynus melanostictus

Bufonid parotoid macrogland secretion contains several low molecular mass molecules, such as alkaloids and steroids. Nevertheless, its protein content is poorly understood. Herein, we applied a sample preparation methodology that allows the analysis of viscous matrices in order to examine its proteins. Methods: Duttaphrynus melanostictus parotoid macrogland secretion was submitted to ion-exchange batch sample preparation, yielding two fractions: salt-displaced fraction and acid-displaced fraction. Each sample was then fractionated by anionic-exchange chromatography, followed by in-solution proteomic analysis. Results: Forty-two proteins could be identified, such as acyl-CoA-binding protein, alcohol dehydrogenase, calmodulin, galectin and histone. Moreover, de novo analyses yielded 153 peptides, whereas BLAST analyses corroborated some of the proteomic-identified proteins. Furthermore, the de novo peptide analyses indicate the presence of proteins related to apoptosis, cellular structure, catalysis and transport processes. Conclusions: Proper sample preparation allowed the proteomic and de novo identification of different proteins in the D. melanostictus parotoid macrogland secretion. These results may increase the knowledge about the universe of molecules that compose amphibian skin secretion, as well as to understand their biological/physiological role in the granular gland.(AU)

Assessment of neuropharmacological potential of low molecular weight components extracted from Rhinella schneideri toad poison

Studies on toad poison are relevant since they are considered a good source of toxins that act on different biological systems. Among the molecules found in the toad poison, it can be highlighted the cardiotonic heterosides, which have a known mechanism that inhibit Na+/K+-ATPase enzyme. However, these poisons have many other molecules that may have important biological actions. Therefore, this work evaluated the action of the low molecular weight components from Rhinella schneideri toad poison on Na+/K+-ATPase and their anticonvulsive and / or neurotoxic effects, in order to detect molecules with actions of biotechnological interest. Methods: Rhinella schneideri toad (male and female) poison was collected by pressuring their parotoid glands and immediately dried and stored at -20 °C. The poison was dialysed and the water containing the low molecular mass molecules (< 8 kDa) that permeate the dialysis membrane was collected, frozen and lyophilized, resulting in the sample used in the assays, named low molecular weight fraction (LMWF). Na+/K+ ATPase was isolated from rabbit kidneys and enzyme activity assays performed by the quantification of phosphate released due to enzyme activity in the presence of LMWF (1.0; 10; 50 and 100 µg/mL) from Rhinella schneideri poison. Evaluation of the L-Glutamate (L-Glu) excitatory amino acid uptake in brain-cortical synaptosomes of Wistar rats was performed using [3H]L-glutamate and different concentration of LMWF (10-5 to 10 µg/µL). Anticonvulsant assays were performed using pentylenetetrazole (PTZ) and N-methyl-D-aspartate (NMDA) to induce seizures in Wistar rats (n= 6), which were cannulated in the lateral ventricle and treated with different concentration of LMWF (0.25; 0.5; 1.0; 2.0; 3.0 and 4.0 µg/µL) 15 min prior to the injection of the seizure agent. Results: LMWF induced a concentration-dependent inhibition of Na+/K+-ATPase (IC50% = 107.5 μg/mL). The poison induces an increased uptake of the amino acid L-glutamate in brain-cortical synaptosomes of Wistar rats. This increase in the L-glutamate uptake was observed mainly at the lowest concentrations tested (10-5 to 10-2 µg/µL). In addition, this fraction showed a very relevant central neuroprotection on seizures induced by PTZ and NMDA. Conclusions: LMWF from Rhinella schneideri poison has low molecular weight compounds, which were able to inhibit Na+/K+-ATPase activity, increase the L-glutamate uptake and reduced seizures induced by PTZ and NMDA. These results showed that LMWF is a rich source of components with biological functions of high medical and scientific interest.(AU)

Study on quality control method of toad venom based on characteristic chromatogram and QAMS / 中国中药杂志

Toad venom (Chansu) is prepared from the dried secretion of parotid gland and skin gland from Bufo bufo gargarizans or B. melanostictus. Up to now, much attention shall be paid to the poor quality of commercial toad venom because of the adulteration. So, it is urgent to establish a scientific and perfect quality control method to improve the quality of toad venom and guarantee its safety and effectiveness in clinical application. The different batches of toad venom samples were assayed by high performance liquid chromatography (HPLC) and the quantitative analysis of multi-components by single marker (QAMS) was used to detect the contents of five bufagenins. As a result, the reference characteristic chromatogram was established, displaying serotonin, gamabufotalin, arenobufagin, hellebrigenin, telocinobufagin, bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin as characteristic peaks. Taking cinobufagin as an internal reference substance, QAMS was verified for the determination of five bufagenins (gamabufotalin, bufotalin, bufalin, cinobufagin, resibufogenin) in toad venom samples. The durability and applicability of the relative correction factor (RCF) were also studied systematically. RCFs of cinobufagin to gamabufotalin, bufotalin, bufalin and resibufogenin were determined as 1.05, 0.895, 1.09 and 0.913, respectively. The characteristic chromatogram and QAMS established in this study could effectively control the quality of toad venom and provide scientific evidence for the improvement of the quality standard of the toad venom to be described in Chinese Pharmacopoeia (2020 edition).

Upgrading No.1 Military Medical Project database from Oracle 8.17 to Oracle 11g / 医疗卫生装备

Objective To upgrade No.1 Military Medical Project database from Oracle 8.17 to Oracle 11g so as to solve the problems of server overloading and client terminal failing to connect to the server due to excessive concurrent databases. Methods Exp/Imp and Toad tools of the database were used to generate and modify the upgrade statements as well as to import and export database data,so that the inter-platform and-version database upgrade could be carried out.Results The database was upgraded and the system's operation speed was enhanced greatly.Conclusion The upgrade scheme has easy operation,short time consumed,zero data loss and high reliability,and thus is worthy promoting in medium-and small-scale hospitals.

Deep sequencing analysis of toad Rhinella schneideri skin glands and partial biochemical characterization of its cutaneous secretion

Animal poisons and venoms are sources of biomolecules naturally selected. Rhinella schneideri toads are widespread in the whole Brazilian territory and they have poison glands and mucous gland. Recently, protein from toads' secretion has gaining attention. Frog skin is widely known to present great number of host defense peptides and we hypothesize toads present them as well. In this study, we used a RNA-seq analysis from R. schneideri skin and biochemical tests with the gland secretion to unravel its protein molecules. Methods: Total RNA from the toad skin was extracted using TRizol reagent, sequenced in duplicate using Illumina Hiseq2500 in paired end analysis. The raw reads were trimmed and de novo assembled using Trinity. The resulting sequences were submitted to functional annotation against non-redundant NCBI database and Database of Anuran Defense Peptide. Furthermore, we performed caseinolytic activity test to assess the presence of serine and metalloproteases in skin secretion and it was fractionated by fast liquid protein chromatography using a reverse-phase column. The fractions were partially sequenced by Edman's degradation. Results: We were able to identify several classes of antimicrobial peptides, such as buforins, peroniins and brevinins, as well as PLA2, lectins and galectins, combining protein sequencing and RNA-seq analysis for the first time. In addition, we could isolate a PLA2 from the skin secretion and infer the presence of serine proteases in cutaneous secretion. Conclusions: We identified novel toxins and proteins from R. schneideri mucous glands. Besides, this is a pioneer study that presented the in depth characterization of protein molecules richness from this toad secretion. The results obtained herein showed evidence of novel AMP and enzymes that need to be further explored.(AU)

Synergy with the active ingredients of toad venom and sorafenib suppresses hepatocellular carcinoma HepG2 cells proliferation through down-regulating Akt/NF-κB signaling pathways / 中国药理学通报

Aim To investigate the effect of the active ingredients of toad venom (bufalin and cinobufagin) combined with sorafenib on the growth of hepatocellular carcinoma HepG2 cells,and to explore the possible mechanism.Methods The rates of inhibition after treated with drugs 12,24,48 h were detected by MTT assay.The changes of cell morphology were detected by Hoechst 33342 fluorescent staining.The changes of cell cycle were detected by flow cytometry.The expressions of proteins such as Akt,p-Akt (Ser473),IκB,NF-κB,p-NF-κB p65,Bcl-2,Bax,cyclin A,PCNA were detected by Western blot.Results Bufalin,cinobufagin and sorafenib could inhibit the proliferation of HepG2 cells,presenting a dose-and time-dependent manner.Meanwhile,it could significantly increase the inhibitory rate of cells compared with those of single treatment,and they performed a synergistic activity in sorafenib combined with cinobufagin or bufalin by Jin Formula after 24 h treatment (P ＜ 0.01).The results of fluorescence staining showed the observation of the morphological features of nuclear condensation.Sorafenib induced the cell cycle G0/G1 phase arrest (P ＜0.01),and bufalin,cinobufagin and the combination treatment generated the cell cycle S phase arrest (P ＜0.01).The results of Western blot showed that the expressions of Akt,NF-κB were not obviously changed between control and all other treatment.The expression levels of p-Akt (Ser473),p-NF-κB p65,Bcl-2,PC-NA and cyclin A in combination treatment significantly decreased,and the expression levels of IκB and Bax significantly increased compared to those in single treatment (P ＜ 0.01).Conclusion The active ingredients of toad venom (bufalin and cinobufagin) combined with sorafenib performs a synergetic effect on the anti-cancer of HepG2 cells by down-regulating Akt/ NF-κB signaling pathway.

Identification of Proteins in Toad Venom by NanoLC-LTQ-Orbitrap Velos Pro / 中国药学杂志

OBJECTIVE: To proteins in toad venom. To investigate the by proteomic approach. METHODS: The total proteins from the ear-side gland of toad were digested by trypsin, and the peptides were further analyzed by the NanoLC-linear trap quadropole (LTQ)-Orbitrap Velos Pro.. The raw data acquired by mass spectrometer were imported into MaxQuant software for the identification of peptides and proteins. The proteins were categorized based on gene ontology annotation in biological process, cellular component and molecular function. RESULTS: A total of 407 protein groups and 880 peptides were identified. There were 76 pathways associated with the identified proteins in toad venom, including the 5-HT receptor mediated signaling pathway, beta adrenergic receptor signaling pathway, blood coagulation, cadherin signaling pathway, cholesterol biosynthesis, etc.. CONCLUSION: This study lays the foundation for further exploration of the proteins in toad venom and their functions.

Advance on quality control of toad venom and its key influence factors / 中国中药杂志

Toad venom (Chansu) is prepared from the dried secretion of Bufo bufo gargarizans or B. melanostictus. It is not only one of the famous and expensive traditional Chinese medicines(TCMs) from animal origin, but also one of 28 kinds of toxic TCMs to be required for special management issued by the State Council of the People's Republic of China. Chansu contains the rich bufadienolides and indole alkaloids, and displays various bioactivity including cardiotonic, anti-tumor, analgesia, and local anesthesia. Based on the published references in the recent years, the advance on the identification of adulterants and quality evaluation as well as the influence factors on the quality of toad venom was summarized to improve the quality standards and promote the level of quality control of toad venom and its preparations.

Chemical studieson hydrophilic constituents of toad skin / 中国中药杂志

Fifteen compounds were isolated from the toad skin by a combination of various chromatographic methods including macroporous resin, silica gel, ODS and semi-preparative HPLC. Their structures were identified as 4,5-dimethyl-1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinolin-6-ol(1), serotonin(2), N-methyl serotonin(3), O-methyl bufotenine(4), 1,2,3,4-tetrahydro-6-hydroxy-β-carboline(5), O-methylserotonin(6), glycinebetaine(7), caffeine(8), bufotenine(9), shepherdine(10), tryptophan(11), (5-hydroxy-1H-indol-3-yl)acetic acid(12), 5-hydroxy tryptophol(13), 2-methyl-6-hydroxy-1,2,3,4-tetrahydro-β-carboline(14), bufothionine(15). Among them, compound 1 was a new compound,compound 5 was a new natural product. Compounds 4-8 and 10-14 were separated from toad skin for the first time.

A simple and effective auxiliary device for detection of physiologic func-tion on isolated sciatic nerve and gastrocnemius in toads / 中国病理生理杂志

AIM: To design a simple and effective auxiliary device for detection of the compound action poten-tial (CAP) and the force on the isolated sciatic nerve and gastrocnemius in toads, and to investigate its practicability. METHODS: A simple “L” shape device (L tube), which was composed of a nerve chamber and an organ bath, was made for fixing the isolated sciatic nerve and gastrocnemius.After fixing, the sciatic CAP and the gastrocnemius force were detected by BL-420S data acquisition and analysis system.The specimens were radomly divided into control group, and the lidocaine nerve and muscle groups.The sciatic nerve or gastrocnemius of each lidocaine group was firstly treated with the corresponding concentration of lidocaine, and then washed out with Ringer’s solution, and its reversible anesthetic action on nerve conduction and muscle force was analyzed to verify the practicability of the L tube device.RESULTS: The CAP and the force of the sciatic-gastrocnemius specimens were detected concurrently by fixing the specimens in the L tube, and the liquid in the nerve chamber and organ bath was changed easily.Compared with the control, lidocaine at 0.05 and 0.2 g/L significantly increased the sciatic threshold stimulus voltage and maximal stimulus voltage (P ly blocked the sciatic conduction.The rest tension of the gastrocnemius was increased, and the maximal twitch force was decreased significantly by 1 g/L lidocaine (P <0.01), but the threshold and maximal stimulus voltage did not show statis-tic difference.The parameters of the sicatic nerve and gastrocnemius completely or partially recovered to the control level after washing out.CONCLUSION: As an auxiliary device, L tube makes the detection of CAP and force on the isolated sciatic nerve and gastrocnemius in toads more conveniently.

Entrapment efficiency of cinobufagin and resibufogenin in toad skin extract loaded solid lipid nanoparticles:a comparison between centrifugation method and dialysis method / 国际药学研究杂志

Objective To establish an optimized method to determine the entrapment efficiencies(EE)of cinobufagin(CBG) and resibufogenin(RBG)in the toad skin extract loaded with solid lipid nanoparticles. Methods Dialysis,high-speed centrifugation and low-speed centrifugation were selected to determine the entrapment efficiencies of toad skin extract loaded solid lipid nanoparti?cles. The effects of different dialytic media on the entrapment efficiencies were investigated ,then the EE of every method were com?pared. Results Different methods had different results of EE,the EE of low-speed centrifugation,high-speed centrifugation and dialysis method in CBG and RBG were(74.00±1.69)%and(75.01±2.05)%,(83.60±0.99)%and(82.51±1.56)%,(91.01±0.75)%and(89.22± 0.88)%,respectively. The EE determined by different dialytic media of dialysis were different,but the results did not have the signifi?cant differences. Conclusion Different determination methods of EE have some significant influences on the results of EE,dialysis method is more suitable for the determination of EE for CBG and RBG in the toad skin extract loaded solid lipid nanoparticles.

Entrapment efficiency of cinobufagin and resibufogenin in toad skin extract loaded solid lipid nanoparticles: A comparison between centrifugation method and dialysis method / 国际药学研究杂志

Objective: To establish an optimized method to determine the entrapment efficiencies (EE) of cinobufagin(CBG) and resibufogenin(RBG) in the toad skin extract loaded with solid lipid nanoparticles. Methods: Dialysis, high-speed centrifugation and low-speed centrifugation were selected to determine the entrapment efficiencies of toad skin extract loaded solid lipid nanoparticles. The effects of different dialytic media on the entrapment efficiencies were investigated, then the EE of every method were compared. Results: Different methods had different results of EE, the EE of low-speed centrifugation, high-speed centrifugation and dialysis method in CBG and RBG were (74.00±1.69)% and (75.01±2.05)%,(83.60±0.99)% and (82.51±1.56)%,(91.01±0.75)% and (89.22±0.88)%, respectively. The EE determined by different dialytic media of dialysis were different, but the results did not have the significant differences. Conclusion: Different determination methods of EE have some significant influences on the results of EE, dialysis method is more suitable for the determination of EE for CBG and RBG in the toad skin extract loaded solid lipid nanoparticles.

Antiplasmodial and Cytotoxic Activities of Toad Venoms from Southern Amazon, Brazil

The drug-resistance of malaria parasites is the main problem in the disease control. The huge Brazilian biodiversity promotes the search for new compounds, where the animal kingdom is proving to be a promising source of bioactive compounds. The main objective of this study was to evaluate the antiplasmodial and cytotoxic activity of the compounds obtained from the toad venoms of Brazilian Amazon. Toad venoms were collected from the secretion of Rhinella marina and Rhaebo guttatus in Mato Grosso State, Brazil. The powder was extracted at room temperature, yielding 2 extracts (RG and RM) and a substance ('1') identified as a bufadienolide, named telocinobufagin. Growth inhibition, intraerythrocytic development, and parasite morphology were evaluated in culture by microscopic observations of Giemsa-stained thin blood films. Cytotoxicity was determined against HepG2 and BGM cells by MTT and neutral red assays. The 2 extracts and the pure substance ('1') tested were active against chloroquine-resistant Plasmodium falciparum strain, demonstrating lower IC₅₀ values. In cytotoxic tests, the 2 extracts and substance '1' showed pronounced lethal effects on chloroquine-resistant P. faciparum strain and low cytotoxic effect, highlighting toad parotoid gland secretions as a promising source of novel lead antiplasmodial compounds.

Research advances of antitumor activity of toad venom / 中国生化药物杂志

Toad venom as a Chinese traditional natural medicine with a kind of effective chemical components has been widely used for many disease.Recently more and more research was focused on its remarkable antitumor efforts, new studies have found that the mechanism was closely associated with endoplasmic reticulum stress,tumor-related inflammation, autophagy, mitochondria-induced apoptosis pathway, heat chock protein and immuneomodulatory.In this article we reviewed the antitumor research advances of toad venom and its active compounds from several aspects mentioned above.

Effect of Bensulfuron Pollution on Levels of Bufadienolides from Venom Secreted by Toad / 分析化学

Ulta performance liqiuid chromatography-triple quadrupole tandem mass spectrometry ( UPLC-MS/MS) was used to monitor the relative levels of bufadienolides in toad venom in normal and bensulfuron-polluted groups. Methanol extract of toad venom was separated by UPLC ( ODS-C18 ) using a gradient elution of water contains 0. 1% formic acid and acetonitrile. Mass spectrometry was used in an ESI source operated in positive ion and MRM mode. The parameters in the source were set as follows: capillary voltage 3. 0 kV; sampling cone voltage 30 V; and desolvation temperature 500℃. In this method, external calibrations of 6 standards were typically constructed (R2=0. 9953-0. 9992). The LOD was 0. 42-4. 86 ng/mL. Intra- and inter-day precision was 3. 8%-6. 8% and 4. 0%-8. 8%, respectively. The recovery of standard was evaluated by spiking the standard compound into toad venom. Their average recoveries were 96. 9%-109. 6%, and RSDs were 2. 0%-8. 1%. This method was further employed into monitoring the levels of 36 bufadienolides. The levels of more than 20 bufadienolides were greatly different after bensulfuron pollution, suggesting that the bensulfuron pollution could change the chemical expression pattern of bufadienolides in toad venom.

Stimulating effects of toad venom (CHANSU) in the rat hind paw / 中国药学杂志

OBJECTIVE: The stimulating effects of toad venom (Chansu) on rats were investigated in this study. METHODS: After treatment with toad venom (sc, 10 and 50 mg · mL-1), foot swelling and foot-ground reaction force were observed to reflect the inflammation and pain, respectively. The levels of inflammatory mediators (PGE2, PGF2α, PGE1, and 8, 9-DiHETrE) were further determined using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). RESULTS: No raising foot was observed in the normal rats group, but this foot-ground reaction force was significant in the toad venom 10 and 50 mg · mL-1 groups. The number of raising foot after toad venom treatments were (14 ± 5) and (99 ± 8) times in 10 min (P 2 and PGF2α, and reduced the relative content of anti-inflammatory PGE1 and 8, 9-DiHETrE in the rat hind-paw. CONCLUSION: Toad venom can dose-dependently produce stimulating effects in the rat paw.

Biological characterization of compounds from Rhinella schneideri poison that act on the complement system

Background The skin secretions of toads of the family Bufonidae contain biogenic amines, alkaloids, steroids (bufotoxins), bufodienolides (bufogenin), peptides and proteins. The poison of Rhinella schneideri, formerly classified as Bufo paracnemis, presents components that act on different biological systems, including the complement system. The aim of this study was to isolate and examine the activity ofRhinella schneideri poison (RsP) components on the complement system.Methods The components active on the complement system were purified in three chromatographic steps, using a combination of cation-exchange, anion-exchange and gel filtration chromatography. The resulting fractions were analyzed by SDS-PAGE and screened for their activity in the hemolytic assay of the classical/lectin complement pathways. Fractions active on the complement system were also assessed for their ability to generate C3 fragments evaluated by two dimensional immunoelectrophoresis assay, C3a and C5a by neutrophil chemotaxis assay and SC5b-9 complex by ELISA assay.Results The fractionation protocol was able to isolate the component S5 from theRsP, as demonstrated by SDS-PAGE and the RP-FPLC profile. S5 is a protein of about 6000 Da, while S2 presents components of higher molecular mass (40,000 to 50,000 Da). Fractions S2 and S5 attenuated the hemolytic activity of the classical/lectin pathways after preincubation with normal human serum. Both components stimulated complement-dependent neutrophil chemotaxis and the production of C3 fragments, as shown by two-dimensional immunoelectrophoresis. S2 showed a higher capacity to generate the SC5b- 9 complex than the other fractions. This action was observed after the exposure of normal human serum to the fractions.Conclusions This is the first study to examine the activity of RsP components on the complement system. Fractions S2 and S5 reduced the complement hemolytic activity, stimulated complement-dependent neutrophil chemotaxis and stimulated the production of C3 fragments, indicating that they were able to activate the complement cascade. Furthermore, fraction S2 was also able to generate the SC5b-9 complex. These components may be useful tools for studying dysfunction of the complement cascade.