BACKGROUND Diabetes is known damage the liver and kidney,leading to hepatic dysfunction and kidney failure.Honey is believed to help in lowering the blood glucose levels of diabetic patients and reducing diabetic comp...BACKGROUND Diabetes is known damage the liver and kidney,leading to hepatic dysfunction and kidney failure.Honey is believed to help in lowering the blood glucose levels of diabetic patients and reducing diabetic complications.However,the effect of stingless bee honey(SBH)administration in relieving liver and kidney damage in diabetes has not been well-studied.AIM To investigate the effect of SBH administration on the kidney and liver of streptozotocin-induced(STZ;55 mg/kg)diabetic Sprague Dawley rats.METHODS The rats were grouped as follows(n=6 per group):non-diabetic(ND),untreated diabetic(UNT),metformin-treated(MET),and SBH+metformin-treated(SBME)groups.After successful diabetic induction,ND and UNT rats were given normal saline,whereas the treatment groups received SBH(2.0 g/kg and/or metformin(250 mg/kg)for 12 d.Serum biochemical parameters and histological changes using hematoxylin and eosin(H&E)and periodic acid–Schiff(PAS)staining were evaluated.RESULTS On H&E and PAS staining,the ND group showed normal architecture and cellularity of Bowman’s capsule and tubules,whereas the UNT and MET groups had an increased glomerular cellularity and thickened basement membrane.The SBH-treated group showed a decrease in hydropic changes and mild cellularity of the glomerulus vs the ND group based on H&E staining,but the two were similar on PAS staining.Likewise,the SBME-treated group had an increase in cellularity of the glomerulus on H&E staining,but it was comparable to the SBH and ND groups on PAS staining.UNT diabetic rats had tubular hydropic tubules,which were smaller than other groups.Reduced fatty vacuole formation and dilated blood sinusoids in liver tissue were seen in the SBH group.Conversely,the UNT group had high glucose levels,which subsequently increased MDA levels,ultimately leading to liver damage.SBH treatment reduced this damage,as evidenced by having the lowest fasting glucose,serum alanine transaminase,aspartate transaminase,and alkaline phosphatase levels compared to other groups,although the levels of liver enzymes were not statistically significant.CONCLUSION The cellularity of the Bowman’s capsule,as well as histological alteration of kidney tubules,glomerular membranes,and liver tissues in diabetic rats after oral SBH resembled those of ND rats.Therefore,SBH exhibited a protective hepatorenal effect in a diabetic rat model.展开更多
Social information is widely used in the animal kingdom and can be highly adaptive.In social insects,foragers can use social information to find food,avoid danger,or choose a new nest site.Copying others allows indivi...Social information is widely used in the animal kingdom and can be highly adaptive.In social insects,foragers can use social information to find food,avoid danger,or choose a new nest site.Copying others allows individuals to obtain information without having to sample the environment.When foragers communicate information they will often only advertise high-quality food sources,thereby filtering out less adaptive information.Stingless bees,a large pantropical group of highly eusocial bees,face intense inter-and intra-specific competition for limited resources,yet display disparate foraging strategies.Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not.Our current understanding of why some species communicate foraging sites while others do not is limited.Studying freely foraging colonies of several co-existing stingless bee species in Brazil,we investigated if recruitment to specific food locations is linked to 1)the sugar content of forage,2)the duration of foraging trips,and 3)the variation in activity of a colony from 1 day to another and the variation in activity in a species over a day.We found that,contrary to our expectations,species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates.Furthermore,foragers from recruiting species did not have shorter foraging trip durations than those from weakly recruiting species.Given the intense inter-and intraspecific competition for resources in these environments,it may be that recruiting species favor food resources that can be monopolized by the colony rather than food sources that offer high-quality rewards.展开更多
Objective: To evaluate the antioxidant and antiproliferative effect of methanolic bee pollen extract(BPE) of Malaysian stingless bee [Lepidotrigona terminata(L. terminata)]and its synergistic effect with cisplatin(a c...Objective: To evaluate the antioxidant and antiproliferative effect of methanolic bee pollen extract(BPE) of Malaysian stingless bee [Lepidotrigona terminata(L. terminata)]and its synergistic effect with cisplatin(a chemotherapeutic drug) on MCF-7 cancer cell line.Methods: The antioxidant activity of BPE from L. terminata was measured by using1,1-diphenyl-2-picrylhydrazyl radical(DPPH) assay. Antiproliferative activity at different concentrations of BPE and cisplatin was determined through using MTT assay on MCF-7 and L929 cell lines. An interaction effect(synergistic, additive and antagonistic) between BPE and cisplatin was determined by Compu Syn software based on MTT assay data.Results: The EC50(50% decrement of DPPH inhibition) of BPE was 0.5 mg/m L.L. terminata BPE exhibited antiproliferative activity on both cancer and normal cell lines.The IC50(concentration of drug that was required for 50% of cell inhibition in vitro) of BPE on MCF-7 was 15 mg/m L whereas in normal cell line L929 was 26 mg/m L. The IC50 for cisplatin on MCF-7 was 20 mmol/L. The combination effect of BPE and cisplatin on MCF-7 cells showed that BPE at 15 mg/m L was able to potentiate the inhibitory effect of cisplatin at all different concentrations(2.5–20.0 mg/m L). The average of cancer cells inhibition which was potentiated by BPE was around 50%. A combination index values of less than 1 reported in the Compu Syn software further proved the synergistic effect between BPE and cisplatin, suggesting that BPE was working synergistically with cisplatin.Conclusions: Our study therefore suggested that BPE of Malaysian stingless bee,L. terminata is a potential chemopreventive agent and can be used as a supplementary treatment for chemotherapy drugs. BPE might be able to be used to potentiate the effect of chemotherapy drugs with the possibility to reduce the required dose of the drugs. The molecular mechanisms of how the BPE exerts antiproliferative activity will be a much interesting area to look for in future studies.展开更多
Determining the levels of heavy metals in honey is a measure to control its quality. The objective of this study was to determine the contents of Cd, Cu, Pb and Zn in honey of stingless bee. The differential pulse ano...Determining the levels of heavy metals in honey is a measure to control its quality. The objective of this study was to determine the contents of Cd, Cu, Pb and Zn in honey of stingless bee. The differential pulse anodic stripping voltammetry (DPASV) was used to determine the trace elements in honey samples. Pb was detected in 100% of the samples, Cu and Zn in 98.15%, and Cd only in 33.33%. The trace elements analyzed detected in the samples remained within tolerable levels in foods for human consumption.展开更多
Objective:This study aimed to validate the synergistic effects of Cinnamomum verum(C.verum) barks and stingless bee honey(SBH)against cardiac hypertrophy(CH).Materials and Methods:Isoproterenol(ISO-group Ⅱ-30 mg/kg)-...Objective:This study aimed to validate the synergistic effects of Cinnamomum verum(C.verum) barks and stingless bee honey(SBH)against cardiac hypertrophy(CH).Materials and Methods:Isoproterenol(ISO-group Ⅱ-30 mg/kg)-induced cardiac hypertrophic Wistar rats were used in this study.Hypertrophic rats were treated using the reference drug losartan(LOS Group Ⅲ:50 mg/kg) and aqueous extracts of C.verum barks and SBH(ACH Group Ⅳ:250 mg/kg and 250 mg/kg).CH was characterized by electrocardiography,hypertrophic indices,and biochemical estimations such as total glucose,protein,albumin,lipid profiles,cardiac marker enzymes,and histopathological studies.Results:Rats received ISO had increased levels of glucose,protein,cholesterol,triglycerides,very low-density lipoprotein,and low-density lipoprotein,coupled with decreased levels of albumin and high-density lipoprotein.These levels were restored to near normal when treated with ACH extracts of the standard drugs.Contrary to the ISO-induced myocardial damaged hearts,ACH extracts had a profound effect compared to LOS,which was also reflected in histopathological studies.Conclusion:These data explicitly reveal that the ACH have a synergistic cardioprotective(antihypertrophic) effect.展开更多
Tool use-once considered rare in insects-has been documented in a crafty predator.Researchers from China Agricultural University,and two institutions under the Chinese Academy of Sciences-the Xishuangbanna Tropical Bo...Tool use-once considered rare in insects-has been documented in a crafty predator.Researchers from China Agricultural University,and two institutions under the Chinese Academy of Sciences-the Xishuangbanna Tropical Botanical Garden(XTBG)and the Institute of Zoology-revealed that the assassin bug Pahabengkakia piliceps weaponizes resin from stingless bee nests to trick its prey.展开更多
This research was carried out to evaluate the foraging behaviour of Apis mellifera and Scaptotrigona bipunctata and its relationship with environmental variables in Dombeya wallichii considering the following aspects:...This research was carried out to evaluate the foraging behaviour of Apis mellifera and Scaptotrigona bipunctata and its relationship with environmental variables in Dombeya wallichii considering the following aspects: 1) Type of resource harvested, 2) Visitation rate, 3) Length of visit, 4) sugar concentration in the stored nectar in the honey crop of A. mellifera and secreted by the flower and 5) floral constancy. Both species collected mainly nectar, with a visitation rate of 4.2 flowers for A. mellifera and 1.1 flowers for S. bipunctata and visit length of 9.2 and 34.2 seconds, respectively. The sugar concentration had a positive relationship with temperature and luminosity, with mean values of 12.3% in the nectar and 14.2% in the honey crop. Bees were classified by specialists because the pollen of D. wallichii was predominant in the pollen basket, but the pollen of Emilia sonchifolia and Raphanus sativus was also found. These results suggest that the species under study take advantage of the resources offered by D. wallichii, therefore, this species is an important source for the maintenance of the bees in the season of lack of food.展开更多
Over 50 genera of bees release pollen from flower anthers using thoracic vibrations,a phenomenon known as buzz-pollination.The efficiency of this process is directly affected by the mechanical properties of the buzzes...Over 50 genera of bees release pollen from flower anthers using thoracic vibrations,a phenomenon known as buzz-pollination.The efficiency of this process is directly affected by the mechanical properties of the buzzes,namely the duration,amplitude,and frequency.Nonetheless,although the effects of the former two properties are well described,the role of buzz frequency on pollen release remains unclear.Furthermore,nearly all of the existing studies describing vibrational properties of natural buzz-pollination are limited to bumblebees(Bombus)and carpenter bees(Xvlocopa)constraining our current understanding of this behavior and its evolution.Therefore,we attempted to minimize this shortcoming by testing whether flower anthers exhibit optimal frequency for pollen release and whether bees tune their buzzes to match these(optimal)frequencies.If true,certain frequencies will trigger more pollen release and lighter bees will reach buzz frequencies closer to this optimum to compensate their smaller buzz amplitudes.Two strategies were used to test these hypotheses:(i)the use of(artificial)vibrational playbacks in a broad range of buzz frequencies and amplitudes to assess pollen release by tomato plants(Solarium Ivcopersicum L.)and(ii)the recording of natural buzzes of Neotropical bees visiting tomato plants during pollination.The playback experiment indicates that although buzz frequency does affect pollen release,no optimal frequency exists for that.In addition,the recorded results of natural buzz-pollination reveal that buzz frequencies vary with bee genera and are not correlated with body size.Therefore,neither bees nor plants are tuned to optimal pollen release frequencies.Bee frequency of buzz-pollination is a likely consequence of the insect flight machinery adapted to reach higher accelerations,while flower plant response to buzz-pollination is the likely result of its pollen granular properties.展开更多
Vitellogenin （Vg） is an egg yolk protein that is produced primarily in the fat body of most female insects. In the advanced social structure of eusocial honeybees, the presence of the queen inhibits egg maturation i...Vitellogenin （Vg） is an egg yolk protein that is produced primarily in the fat body of most female insects. In the advanced social structure of eusocial honeybees, the presence of the queen inhibits egg maturation in the workers＇ ovaries. However in the stingless bee Melipona quadrifasciata, the workers always develop ovaries and lay a certain amount of eggs while provisioning the brood cells with larval food during what is known as the worker nurse phase. The present work is a comparative study of the presence of Vg in homogenates of the fat bodies and ovaries of the nurse workers, and the virgin and physogastric queens of M. quadrifasciata. The presence of Vg was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and irnmunoblotting using Apis mellifera anti-egg antibody. Vg was not detected in the fat bodies or ovaries of the workers, but it was found in the ovaries of virgin and physogastric queens and in the fat body ofphysogastric queens. The results are discussed, taking into account the reproductive state of the individuals and the other possible roles of Vg, such as a storage protein for metoabolism of other organs.展开更多
This study was focused on the preparation of water-soluble propolis extract as the natural preservative for perishable jaboticaba juice.A successive extraction and alkaline hydrolysis were performed to produce water-s...This study was focused on the preparation of water-soluble propolis extract as the natural preservative for perishable jaboticaba juice.A successive extraction and alkaline hydrolysis were performed to produce water-soluble propolis extract.The propolis extract was found to have a high content of phenolics and flavonoids,but a low concentration of wax.The hydrolysed propolis extract was added into jaboticaba juice and the treated juice quality was monitored for 2 weeks at 4℃.The results found that the performance of propolis extract was comparable with chemical preservative,sodium benzoate in similar amount(0.035%)used in the present study.The comparison was performed based on the physiochemical properties such as pH,titratable acidity,browning index and ascorbic acid content of juice.Ascorbic acid was the most reliable parameter to monitor the kinetic degradation of jaboticaba juice.Its degradation followed a first order kinetic model with a lower kinetic constant(0.1912 mg/mL/day)than that of non-treated juice(0.2073 mg/mL/day).The second reliable parameter was titratable acidity which could be used to monitor the rate of acid formation resulting from the breakdown of fruit sugars during degradation.The acidity of juice was slightly increased with storage time following zero order kinetics.The browning index was not suitable for juice quality monitoring as the addition of propolis would reduce flavylium cations of anthocyanins to be colourless.This non-thermal extraction followed by mild alkaline hydrolysis at pH 7.5 could produce good quality propolis extract,possibly as an alternative to chemical preservatives for jaboticaba juice.展开更多
Trehalulose(1-O-α-D-glucopyranosyl-D-fructose)is a naturally occurring disaccharide composed of fructose and glucose.It is a sucrose isomer with a uniqueα-1,1 glycosidic bond that is more stable than the 1,2 glycosi...Trehalulose(1-O-α-D-glucopyranosyl-D-fructose)is a naturally occurring disaccharide composed of fructose and glucose.It is a sucrose isomer with a uniqueα-1,1 glycosidic bond that is more stable than the 1,2 glycosidic bond found in sucrose,giving it a lower glycemic index(GI).Trehalulose sugar production is often complicated,and the literature on the production is scarce.However,trehalulose is gaining popularity after a recent study revealed the abundance of this sugar in stingless bee honey(13 to 44 g per 100 g).The current short review discusses the chemical and physiological properties of trehalulose and its potential health benefits based on a bibliometric approach.Furthermore,it evaluates the antidiabetic potential of trehalulose as an emerging alternative sweetener.展开更多
基金Ministry of Higher Education,Malaysia for Fundamental Research Grant Scheme FRGS/1/2019/SKK06/USM/03/6,No.291983-329281.
文摘BACKGROUND Diabetes is known damage the liver and kidney,leading to hepatic dysfunction and kidney failure.Honey is believed to help in lowering the blood glucose levels of diabetic patients and reducing diabetic complications.However,the effect of stingless bee honey(SBH)administration in relieving liver and kidney damage in diabetes has not been well-studied.AIM To investigate the effect of SBH administration on the kidney and liver of streptozotocin-induced(STZ;55 mg/kg)diabetic Sprague Dawley rats.METHODS The rats were grouped as follows(n=6 per group):non-diabetic(ND),untreated diabetic(UNT),metformin-treated(MET),and SBH+metformin-treated(SBME)groups.After successful diabetic induction,ND and UNT rats were given normal saline,whereas the treatment groups received SBH(2.0 g/kg and/or metformin(250 mg/kg)for 12 d.Serum biochemical parameters and histological changes using hematoxylin and eosin(H&E)and periodic acid–Schiff(PAS)staining were evaluated.RESULTS On H&E and PAS staining,the ND group showed normal architecture and cellularity of Bowman’s capsule and tubules,whereas the UNT and MET groups had an increased glomerular cellularity and thickened basement membrane.The SBH-treated group showed a decrease in hydropic changes and mild cellularity of the glomerulus vs the ND group based on H&E staining,but the two were similar on PAS staining.Likewise,the SBME-treated group had an increase in cellularity of the glomerulus on H&E staining,but it was comparable to the SBH and ND groups on PAS staining.UNT diabetic rats had tubular hydropic tubules,which were smaller than other groups.Reduced fatty vacuole formation and dilated blood sinusoids in liver tissue were seen in the SBH group.Conversely,the UNT group had high glucose levels,which subsequently increased MDA levels,ultimately leading to liver damage.SBH treatment reduced this damage,as evidenced by having the lowest fasting glucose,serum alanine transaminase,aspartate transaminase,and alkaline phosphatase levels compared to other groups,although the levels of liver enzymes were not statistically significant.CONCLUSION The cellularity of the Bowman’s capsule,as well as histological alteration of kidney tubules,glomerular membranes,and liver tissues in diabetic rats after oral SBH resembled those of ND rats.Therefore,SBH exhibited a protective hepatorenal effect in a diabetic rat model.
基金This study was funded by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[FAPESP,Process No.:2015/24617-2]the Swiss National Science Foundation Ambizione fellowship awarded to C.G.[grant no.PZOOP3_142628/1].
文摘Social information is widely used in the animal kingdom and can be highly adaptive.In social insects,foragers can use social information to find food,avoid danger,or choose a new nest site.Copying others allows individuals to obtain information without having to sample the environment.When foragers communicate information they will often only advertise high-quality food sources,thereby filtering out less adaptive information.Stingless bees,a large pantropical group of highly eusocial bees,face intense inter-and intra-specific competition for limited resources,yet display disparate foraging strategies.Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not.Our current understanding of why some species communicate foraging sites while others do not is limited.Studying freely foraging colonies of several co-existing stingless bee species in Brazil,we investigated if recruitment to specific food locations is linked to 1)the sugar content of forage,2)the duration of foraging trips,and 3)the variation in activity of a colony from 1 day to another and the variation in activity in a species over a day.We found that,contrary to our expectations,species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates.Furthermore,foragers from recruiting species did not have shorter foraging trip durations than those from weakly recruiting species.Given the intense inter-and intraspecific competition for resources in these environments,it may be that recruiting species favor food resources that can be monopolized by the colony rather than food sources that offer high-quality rewards.
基金Supported by Fundamental Research Grant Scheme,Ministry of Education Malaysia(Grant No:FRGS/2/2013/SKK01/USM/03/3)
文摘Objective: To evaluate the antioxidant and antiproliferative effect of methanolic bee pollen extract(BPE) of Malaysian stingless bee [Lepidotrigona terminata(L. terminata)]and its synergistic effect with cisplatin(a chemotherapeutic drug) on MCF-7 cancer cell line.Methods: The antioxidant activity of BPE from L. terminata was measured by using1,1-diphenyl-2-picrylhydrazyl radical(DPPH) assay. Antiproliferative activity at different concentrations of BPE and cisplatin was determined through using MTT assay on MCF-7 and L929 cell lines. An interaction effect(synergistic, additive and antagonistic) between BPE and cisplatin was determined by Compu Syn software based on MTT assay data.Results: The EC50(50% decrement of DPPH inhibition) of BPE was 0.5 mg/m L.L. terminata BPE exhibited antiproliferative activity on both cancer and normal cell lines.The IC50(concentration of drug that was required for 50% of cell inhibition in vitro) of BPE on MCF-7 was 15 mg/m L whereas in normal cell line L929 was 26 mg/m L. The IC50 for cisplatin on MCF-7 was 20 mmol/L. The combination effect of BPE and cisplatin on MCF-7 cells showed that BPE at 15 mg/m L was able to potentiate the inhibitory effect of cisplatin at all different concentrations(2.5–20.0 mg/m L). The average of cancer cells inhibition which was potentiated by BPE was around 50%. A combination index values of less than 1 reported in the Compu Syn software further proved the synergistic effect between BPE and cisplatin, suggesting that BPE was working synergistically with cisplatin.Conclusions: Our study therefore suggested that BPE of Malaysian stingless bee,L. terminata is a potential chemopreventive agent and can be used as a supplementary treatment for chemotherapy drugs. BPE might be able to be used to potentiate the effect of chemotherapy drugs with the possibility to reduce the required dose of the drugs. The molecular mechanisms of how the BPE exerts antiproliferative activity will be a much interesting area to look for in future studies.
文摘Determining the levels of heavy metals in honey is a measure to control its quality. The objective of this study was to determine the contents of Cd, Cu, Pb and Zn in honey of stingless bee. The differential pulse anodic stripping voltammetry (DPASV) was used to determine the trace elements in honey samples. Pb was detected in 100% of the samples, Cu and Zn in 98.15%, and Cd only in 33.33%. The trace elements analyzed detected in the samples remained within tolerable levels in foods for human consumption.
文摘Objective:This study aimed to validate the synergistic effects of Cinnamomum verum(C.verum) barks and stingless bee honey(SBH)against cardiac hypertrophy(CH).Materials and Methods:Isoproterenol(ISO-group Ⅱ-30 mg/kg)-induced cardiac hypertrophic Wistar rats were used in this study.Hypertrophic rats were treated using the reference drug losartan(LOS Group Ⅲ:50 mg/kg) and aqueous extracts of C.verum barks and SBH(ACH Group Ⅳ:250 mg/kg and 250 mg/kg).CH was characterized by electrocardiography,hypertrophic indices,and biochemical estimations such as total glucose,protein,albumin,lipid profiles,cardiac marker enzymes,and histopathological studies.Results:Rats received ISO had increased levels of glucose,protein,cholesterol,triglycerides,very low-density lipoprotein,and low-density lipoprotein,coupled with decreased levels of albumin and high-density lipoprotein.These levels were restored to near normal when treated with ACH extracts of the standard drugs.Contrary to the ISO-induced myocardial damaged hearts,ACH extracts had a profound effect compared to LOS,which was also reflected in histopathological studies.Conclusion:These data explicitly reveal that the ACH have a synergistic cardioprotective(antihypertrophic) effect.
文摘Tool use-once considered rare in insects-has been documented in a crafty predator.Researchers from China Agricultural University,and two institutions under the Chinese Academy of Sciences-the Xishuangbanna Tropical Botanical Garden(XTBG)and the Institute of Zoology-revealed that the assassin bug Pahabengkakia piliceps weaponizes resin from stingless bee nests to trick its prey.
文摘This research was carried out to evaluate the foraging behaviour of Apis mellifera and Scaptotrigona bipunctata and its relationship with environmental variables in Dombeya wallichii considering the following aspects: 1) Type of resource harvested, 2) Visitation rate, 3) Length of visit, 4) sugar concentration in the stored nectar in the honey crop of A. mellifera and secreted by the flower and 5) floral constancy. Both species collected mainly nectar, with a visitation rate of 4.2 flowers for A. mellifera and 1.1 flowers for S. bipunctata and visit length of 9.2 and 34.2 seconds, respectively. The sugar concentration had a positive relationship with temperature and luminosity, with mean values of 12.3% in the nectar and 14.2% in the honey crop. Bees were classified by specialists because the pollen of D. wallichii was predominant in the pollen basket, but the pollen of Emilia sonchifolia and Raphanus sativus was also found. These results suggest that the species under study take advantage of the resources offered by D. wallichii, therefore, this species is an important source for the maintenance of the bees in the season of lack of food.
基金support provided by the CAPES Foundation(Brazilian Ministry of Education)the National Council of Scientific and Technological Development(CNPq+1 种基金Brazilian Ministry of Science and Technology)the Minas Gerais State Foundation for Research Aid(FAPEMIG)were also greatly appreciated.
文摘Over 50 genera of bees release pollen from flower anthers using thoracic vibrations,a phenomenon known as buzz-pollination.The efficiency of this process is directly affected by the mechanical properties of the buzzes,namely the duration,amplitude,and frequency.Nonetheless,although the effects of the former two properties are well described,the role of buzz frequency on pollen release remains unclear.Furthermore,nearly all of the existing studies describing vibrational properties of natural buzz-pollination are limited to bumblebees(Bombus)and carpenter bees(Xvlocopa)constraining our current understanding of this behavior and its evolution.Therefore,we attempted to minimize this shortcoming by testing whether flower anthers exhibit optimal frequency for pollen release and whether bees tune their buzzes to match these(optimal)frequencies.If true,certain frequencies will trigger more pollen release and lighter bees will reach buzz frequencies closer to this optimum to compensate their smaller buzz amplitudes.Two strategies were used to test these hypotheses:(i)the use of(artificial)vibrational playbacks in a broad range of buzz frequencies and amplitudes to assess pollen release by tomato plants(Solarium Ivcopersicum L.)and(ii)the recording of natural buzzes of Neotropical bees visiting tomato plants during pollination.The playback experiment indicates that although buzz frequency does affect pollen release,no optimal frequency exists for that.In addition,the recorded results of natural buzz-pollination reveal that buzz frequencies vary with bee genera and are not correlated with body size.Therefore,neither bees nor plants are tuned to optimal pollen release frequencies.Bee frequency of buzz-pollination is a likely consequence of the insect flight machinery adapted to reach higher accelerations,while flower plant response to buzz-pollination is the likely result of its pollen granular properties.
文摘Vitellogenin （Vg） is an egg yolk protein that is produced primarily in the fat body of most female insects. In the advanced social structure of eusocial honeybees, the presence of the queen inhibits egg maturation in the workers＇ ovaries. However in the stingless bee Melipona quadrifasciata, the workers always develop ovaries and lay a certain amount of eggs while provisioning the brood cells with larval food during what is known as the worker nurse phase. The present work is a comparative study of the presence of Vg in homogenates of the fat bodies and ovaries of the nurse workers, and the virgin and physogastric queens of M. quadrifasciata. The presence of Vg was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and irnmunoblotting using Apis mellifera anti-egg antibody. Vg was not detected in the fat bodies or ovaries of the workers, but it was found in the ovaries of virgin and physogastric queens and in the fat body ofphysogastric queens. The results are discussed, taking into account the reproductive state of the individuals and the other possible roles of Vg, such as a storage protein for metoabolism of other organs.
基金Jabo Plantation Sdn Bhd(4C541 and 4C542)for the financial support.
文摘This study was focused on the preparation of water-soluble propolis extract as the natural preservative for perishable jaboticaba juice.A successive extraction and alkaline hydrolysis were performed to produce water-soluble propolis extract.The propolis extract was found to have a high content of phenolics and flavonoids,but a low concentration of wax.The hydrolysed propolis extract was added into jaboticaba juice and the treated juice quality was monitored for 2 weeks at 4℃.The results found that the performance of propolis extract was comparable with chemical preservative,sodium benzoate in similar amount(0.035%)used in the present study.The comparison was performed based on the physiochemical properties such as pH,titratable acidity,browning index and ascorbic acid content of juice.Ascorbic acid was the most reliable parameter to monitor the kinetic degradation of jaboticaba juice.Its degradation followed a first order kinetic model with a lower kinetic constant(0.1912 mg/mL/day)than that of non-treated juice(0.2073 mg/mL/day).The second reliable parameter was titratable acidity which could be used to monitor the rate of acid formation resulting from the breakdown of fruit sugars during degradation.The acidity of juice was slightly increased with storage time following zero order kinetics.The browning index was not suitable for juice quality monitoring as the addition of propolis would reduce flavylium cations of anthocyanins to be colourless.This non-thermal extraction followed by mild alkaline hydrolysis at pH 7.5 could produce good quality propolis extract,possibly as an alternative to chemical preservatives for jaboticaba juice.
文摘Trehalulose(1-O-α-D-glucopyranosyl-D-fructose)is a naturally occurring disaccharide composed of fructose and glucose.It is a sucrose isomer with a uniqueα-1,1 glycosidic bond that is more stable than the 1,2 glycosidic bond found in sucrose,giving it a lower glycemic index(GI).Trehalulose sugar production is often complicated,and the literature on the production is scarce.However,trehalulose is gaining popularity after a recent study revealed the abundance of this sugar in stingless bee honey(13 to 44 g per 100 g).The current short review discusses the chemical and physiological properties of trehalulose and its potential health benefits based on a bibliometric approach.Furthermore,it evaluates the antidiabetic potential of trehalulose as an emerging alternative sweetener.
