Barberry is an extract produced from the root of Mahonia aquifolium, commonly known as Oregon Grape Root. The Mayo Clinic in 1999 published research proving that chronic sinusitis is caused by an underlying fungus in the sinuses with a superimposed bacterial infection. Only the acute superimposed bacterial infection is eliminated when a patient is treated with a standard pharmaceutical antibacterial; the underlying chronic fungal infection in the sinuses is not addressed. BARBERRY addresses both the bacterial and fungal infections. Many patients that have asthma and bronchospastic disease have chronic sinusitis and/or chronic bronchitis as an underlying cause. Since BARBERRY addresses the underlying infectious causes so well, it usually helps resolve the bronchospasm and asthma. Many practitioners have also found that atherosclerotic disease appears to be primarily an infectious disease caused by bacteria, fungi and sometimes viruses; those practitioners have found BARBERRY to be very helpful in resolving the infection which then causes the atherosclerosis to diminish and resolve. BARBERRY effectively treats Chlamydia pneumoniae, mycoplasma, many herpes viruses of different types and mucor; peer-reviewed literature states that all of these are known to contribute to atherosclerotic disease.