Blocking IgE with L-glutamic acid analogs as an alternative approach to
Background: IgE–mediated allergic diseases have increased in the last
decades. The most prevalent allergens from castor seeds are Ric c1 and
Ric c3, isoforms of 2S albumin. These allergenic proteins cross-react
with allergens from peanut, shrimp, fish, corn, gramineous, house dust,
and tobacco. The usual allergy treatment employs antihistaminic and,
immunotherapies. We propose an alternative immunotherapeutic approach,
denoted “IgE-blockage” by L-Glutamic acid or modified-glutamic acid.
Methods: Six compounds, D-glutamic acid, L-glutamic acid,
N-methyl-L-glutamic acid, N-acetyl-L-glutamic acid, N- (4-nitrobenzoyl)
-L-glutamic acid, and N-carbamyl-L-glutamic, were tested as a blocker.
To evaluate motor coordination and the sedative/hypnotic activity of
L-glutamic acid, a rota-rod test and a thiopental sodium-induced
sleeping test were used. Results: the compounds, L- Glutamic acid and
L-Nitrobenzoyl glutamic acid, were the most active compounds to block
the interaction of castor allergens with IgE. These compounds also
prevent cross-responses with allergens from food sources and inhalants
that cross-react with them. In the sleeping test, the groups that
received L-glutamic acid at doses of 10 and 30 mg/kg had a sleeping time
similar to the vehicle control group. No changes in the animals’
behavior were observed and there was no difference between the
L-glutamic acid groups and the vehicle control groups in the rota-rod
test. Conclusion: L-glutamic acid and L-Nitrobenzoyl glutamic acid could
be used as IgE blockers to prevent allergic diseases.