We hypothesized that the administration of explosion-puffed coffee, containing
γ-aminobutyric acid
(GABA) and 5-hydroxytryptophan (5-HTP), would be associated with a
reduction of the caffeine effect on sleep behavior and behavioral
patterns, which was investigated in a
Drosophila model. The effects of feeding roasted
coffee beans (RB), explosion-puffed coffee beans puffed at 0.75 MPa and 0.9 MPa (PB 7.5 and PB 9.0, respectively), or decaffeinated coffee beans (DeRB) on locomotor activity and behavioral patterns of
Drosophila was analyzed. In the decreasing order, the total chlorogenic acid (caffeoylquinic acids, CQA) content was PB 7.5 > PB 9.0 > RB. PB content analysis showed high levels of
GABA and 5-HTP, compared with that of RB, which corresponded with the sleep-wake behavior of
Drosophila.
The RB and PB (PB 7.5 and PB 9.0) groups were not significantly
different with respect to an activity count during the subjective night
and day period compared with the normal controls. Sleep bout numbers of
the normal, PB, and DeRB groups showed significant differences as
compared with the caffeine and RB groups (
p < 0.05). The PB and DePB groups showed a significantly increased transcript levels for the
GABA receptors
compared to the caffeine group. The caffeine and RB groups displayed
better climbing ability than the other groups, covering an average
distance 6 cm in the related test; the average distance covered by the normal, PB 7.5, and DeRB groups was < 4 cm.
The normal and DeRB groups showed similar behavior patterns with
respect to total distance, velocity, moving, not moving, and meander.
However, the PB 7.5 group significantly regulated not moving and meander
of flies compared to flies receiving only caffeine and RB. Suppression
of the stimulating effect of caffeine by explosion-puffed coffee
administration was indicated in the above results, which can be
attributed to the increased content of GABA and 5-HTP with explosive
puffing process carried out at 0.75 MPa. Results of the underlying mechanism of the behavioral change patterns of explosive puffed with or without caffeine in
Drosophila
models, transcript level for the Dop1-R1 receptor in caffeine group was
significantly higher than normal, PB, and DePB groups. Flies exposed to
the caffeine had significantly decreased transcript levels for the GABA
receptors. PB 7.5 and DePB showed higher level of GABA content than RB.
