PYCNOGENOL FOR HAY FEVER A report recently published in the Journal of Phytotherapy Research shows that Pycnogenol, the extract of French Maritime Pine Bark can relieve the symptoms of hay fever by inhibiting the release of histamine. Histamines are part of the body's immune system, they are released from mast cells in the body in response to perceived threats. However the body is often guilty of unnecessary histamine release, which causes the irritation in allergies such as hay fever and sinusitis.