5 research outputs found
Antioxidant supplementation can reduce the survival costs of excess amino acid intake in honeybees
Over-consuming amino acids is associated with reduced survival in many species, including honeybees.
The mechanisms responsible for this are unclear but one possibility is that excessive intake of amino
acids increases oxidative damage. If this is the case, antioxidant supplementation may help reduce the
survival costs of high amino acid intake. We tested this hypothesis in African honeybees (Apis mellifera
scutellata) using the major antioxidant in green tea, epigallocatechin-3-gallate (EGCG). We first determined
the dose-range of EGCG that improved survival of caged honeybees fed sucrose solution. We then
provided bees with eight diets that differed in their ratio of essential amino acids (EAA) to carbohydrate
(C) (0:1, 1:250, 1:100, 1:75, 1:50, 1:25, 1:10, 1:5 EAA:C) and also in their EGCG dose (0.0 or 0.4 mM). We
found that bees fed sucrose only solution survived better than bees fed EAA diets. Despite this, bees preferred
a diet that contained intermediate ratios of EAA:C (ca. 1:25), which may represent the high
demands for nitrogen of developing nurse bees. EGCG supplementation improved honeybee survival
but only at an intermediate dose (0.3–0.5 mM) and in bees fed low EAA diets (1:250, 1:100 EAA:C). That
EGCG counteracted the lifespan reducing effects of eating low EAA diets suggests that oxidative damage
may be involved in the association between EAAs and lifespan in honeybees. However, that EGCG had no
effect on survival in bees fed high EAA diets suggests that there are other physiological costs of over-consuming
EAAs in honeybees.A grant from the BBSRC, NERC, the Wellcome Trust, Defra, and the Scottish Government under the Insect Pollinators Initiative (BB/I000968/1).http://www.elsevier.com/locate/jinsphyshj201
Antioxidant supplementation can reduce the survival costs of amino acid intake in honeybees
Over-consuming amino acids is associated with reduced survival in many species, including honeybees. The mechanisms responsible for this are unclear but one possibility is that excessive intake of amino acids increases oxidative damage. If this is the case, antioxidant supplementation may help reduce the survival costs of high amino acid intake. We tested this hypothesis in African honeybees (Apis mellifera scutellata) using the major antioxidant in green tea, epigallocatechin-3-gallate (EGCG). We first determined the dose-range of EGCG that improved survival of caged honeybees fed sucrose solution. We then provided bees with eight diets that differed in their ratio of essential amino acids (EAA) to carbohydrate (C) (0:1, 1:250, 1:100, 1:75, 1:50, 1:25, 1:10, 1:5 EAA:C) and also in their EGCG dose (0.0 or 0.4 mM). We found that bees fed sucrose only solution survived better than bees fed EAA diets. Despite this, bees preferred a diet that contained intermediate ratios of EAA:C (ca. 1:25), which may represent the high demands for nitrogen of developing nurse bees. EGCG supplementation improved honeybee survival but only at an intermediate dose (0.3–0.5 mM) and in bees fed low EAA diets (1:250, 1:100 EAA:C). That EGCG counteracted the lifespan reducing effects of eating low EAA diets suggests that oxidative damage may be involved in the association between EAAs and lifespan in honeybees. However, that EGCG had no effect on survival in bees fed high EAA diets suggests that there are other physiological costs of over-consuming EAAs in honeybees.BBSRC, NERC,
the Wellcome Trust, Defra, and the Scottish Government under the
Insect Pollinators Initiative (BB/I000968/1)This xls file contains:
• Intake Summary Sheet - intake of EGCG and amino acid diets
• Survival Amino Acid Diets
• Survival sucros
In vitro anti-HIV-1 properties of ethnobotanically selected South African plants used in the treatment of sexually transmitted diseases
Terminalia sericea extract (IC50 = 92 mg/ml) exhibited a considerable α-glucosidase inhibitory activity which was better than acarbose (IC50 = 131 mg/ml) under our assay conditions. In the reverse transcriptase assay, T. sericea also showed good inhibitory activity (IC50 = 43 mg/ml), which was higher than that of the reference drug, Adriamycin (IC50 = 100 mg/ml). The ethyl acetate extract of Elaeodendron transvaalense exhibited the most potent inhibitory activity in both the NF-κB and Tat assays with inhibitory activity of 76% and 75% respectively at a concentration of 15 mg/ml. The acetone and chloroform extracts of E. transvaalense and Zanthoxylum davyi also showed good activity in the NF-κB and Tat assays
Antioxidant supplementation can reduce the survival costs of excess amino acid intake in honeybees
Over-consuming amino acids is associated with reduced survival in many species, including honeybees.
The mechanisms responsible for this are unclear but one possibility is that excessive intake of amino
acids increases oxidative damage. If this is the case, antioxidant supplementation may help reduce the
survival costs of high amino acid intake. We tested this hypothesis in African honeybees (Apis mellifera
scutellata) using the major antioxidant in green tea, epigallocatechin-3-gallate (EGCG). We first determined
the dose-range of EGCG that improved survival of caged honeybees fed sucrose solution. We then
provided bees with eight diets that differed in their ratio of essential amino acids (EAA) to carbohydrate
(C) (0:1, 1:250, 1:100, 1:75, 1:50, 1:25, 1:10, 1:5 EAA:C) and also in their EGCG dose (0.0 or 0.4 mM). We
found that bees fed sucrose only solution survived better than bees fed EAA diets. Despite this, bees preferred
a diet that contained intermediate ratios of EAA:C (ca. 1:25), which may represent the high
demands for nitrogen of developing nurse bees. EGCG supplementation improved honeybee survival
but only at an intermediate dose (0.3–0.5 mM) and in bees fed low EAA diets (1:250, 1:100 EAA:C). That
EGCG counteracted the lifespan reducing effects of eating low EAA diets suggests that oxidative damage
may be involved in the association between EAAs and lifespan in honeybees. However, that EGCG had no
effect on survival in bees fed high EAA diets suggests that there are other physiological costs of over-consuming
EAAs in honeybees.A grant from the BBSRC, NERC, the Wellcome Trust, Defra, and the Scottish Government under the Insect Pollinators Initiative (BB/I000968/1).http://www.elsevier.com/locate/jinsphyshj201