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
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
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
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.
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.
