Mullein plant is a medicinal herb that contains over 300 species. The plant is native to Asia, Europe and North-Africa. It was historically used as a therapeutic astringent and emollient. The flowers and leaves of the plant traditionally conferred analgesic, anti-inflammatory, antiseptic, spasmolytic, astringent, diuretic, emollient, expectorant and wound healing functions. Historically, the smoke from burning leaf was inhaled to relieve chest congestion. Mullein tea was taken as a sedative and pain-killer. Research later led to the discovery that mullein leaf comprises various chemical constituents such as saponins, iridoid, flavonoids, vitamin C, phenylethanoid glycosides and minerals that have continued to contribute to the therapeutic function of the mullein leaf.
One of the functions exhibited by mullein leaf extract is the fight of body invaders, specifically bacteria and some viruses. Researchers at Clemson University confirmed the antibacterial properties of mullein. In the year 2002, they reported that mullein leaf extracts are potent against some species of bacteria especially against klebsiella pneumonia, Escherichia coli, staphylococcus aureus and epidermidis that are commonly found on lungs and skin. In vitro studies have shown activity against viruses such as influenza and herpes simplex as well. Additionally, a study by “BMC Complementary and Alternative Medicine” done in 2012 also exhibited that mullein leaf extract is potent against parasites as it killed tape worms and round worms in vitro. Mullein also has ability to maintain appropriate cellular growth. In the same study, growth of tumors induced in potatoes was suppressed by mullein leaf extract. Unfortunately, activity against bacteria and parasites has not been tested on human beings.
A 2011 study by “Evidence Based Complementary and Alternative Medicine” showed that mullein leaf functions as an expectorant as it helps expel mucus from the lungs and throat. Additionally, it lubricates the lungs and throat membranes while reducing the swelling which helps alleviate the irritation. Mullein contains approximately 3 % mucilage that helps in the soothing action of mullein on the body’s mucus membranes. On the other hand, mulleins saponins give mullein leaf the expectorant functions. According to the Maryland Medical Center the use of 3g of mullein herb daily is adequate for expectorate function. Mullein leaves improves lung congestion by stimulating the coughing up of phlegm. It can also be used to relieve lymphatic stagnancy. To achieve the effect it can either be used internally or applied eternally over the affected area.
Typically, free radicals containing oxygen and nitrogen species are the cause of various immune complications. Mullein leaves contain an extract with a powerful antioxidant and anti-inflammatory that helps the body get rid of these harmful radicals (Mariassyova, 2006). Additionally, pain relieving and anti-inflammatory properties makes mullein leaf an essential compound in relieving joint pain. Homeopathic formulations containing fresh leaves are used to achieve a good effect.
Mullein leaves also confer a cosmetic function as they have been used in cosmetic preparations to soften and debride the skin. In addition, topical application of the poultice of the leaves enhances the wound healing process. It helps in regeneration of the epidermis and deposition of connective tissue. For instance, ointments prepared from the leaves are used for burn wounds .When used topically; it causes an irritating effect to the skin that dilates the capillaries thus increasing circulation to the area. This aids in its therapeutic wound healing abilities, thinning mucus that can readily be expelled. Good for ulcers, burns, tumors and piles as well.
However, it is worth noting that mullein is toxic in large doses. Nonetheless, its protective biochemical functions as an expectorant, demulcent, anti-viral and mild-diuretic, analgesic, antioxidant, antiviral, estrogenic and hypotonic functions make it a significant substance in herbal therapy.