Butterbur extracts have been shown effective in the treatment of migraines and allergies.
Butterbur is an herb native to Europe, Southwestern Asia, and North Africa. It has been used to treat allergies, asthma, headache, and muscle spasms. Butterbur was shown in clinical studies to be effective for migraines, allergic rhinitis (inflammation of the mucus membranes of nose marked by runny nose, congestion, itching, and sneezing) and asthma.
Butterbur is an herb native to Europe, Southwestern Asia, and North Africa, the leaf and root extracts of which have been used to treat allergies, bronchial asthma, headache, pain, and muscle and urinary tract spasms. Petasins, the sesquiterpene compounds found in butterbur, are thought to be the active constituents (1)(2)(3).
Leaf and root extracts of butterbur are effective in controlling migraines in adults and in children (4)(5)(6)(17)(19), and asthma (7). Butterbur extract may also be effective against somatoform disorders (20).
But results from studies on allergic diseases are mixed. Some studies suggest that the efficacy of butterbur extract for allergic rhinitis is comparable to standard antihistamine drugs (8)(9)(10), but conflicting data indicate that it is no better than placebo for intermittent rhinitis (11) or for allergic skin disease (12). A systematic review of trials suggests the need for more rigorous studies before recommending use of butterbur (13).
Raw butterbur extracts may contain excessive pyrrolizidine alkaloids that can cause hepatotoxicity (14).
Sesquiterpene petasin inhibits leukotriene and histamine activities, and is thought responsible for butterbur’s anti-inflammatory and antiallergic effects (15). Petasins were also shown to have calcium channel blocking effects (18) making them effective for migraine prophylaxis (1). The vasorelaxation effects of petasin may be via direct Ca(2+) antagonism of L-type voltage-dependent Ca(2+) channel (VDCC) in vascular smooth muscle (21).
In another study, a butterbur extract showed dose-dependent inhibition effect on cyclooxygenase (COX2) and prostaglandin E2 in vitro that was not correlated to the petasin content (16).