Plants used as medicine

Few herbal remedies have conclusively demonstrated any positive effect on humans, possibly due to inadequate testing.Many of the studies cited refer to animal model investigations or in-vitro assays and therefore cannot provide more than weak supportive evidence.

• Aloe vera has traditionally been used for the healing of burns and wounds.A systematic review (from 1999) states that the efficacy of aloe vera in promoting wound healing is unclear, while a later review (from 2007) concludes that the cumulative evidence supports the use of aloe vera for the healing of first to second degree burns.

• Artichoke (Cynara cardunculus) may reduce production cholesterol levels according to in vitro studies and a small clinical study.
• Blackberry (Rubus fruticosus) leaf has drawn the attention of the cosmetology community because it interferes with the metalloproteinases that contribute to skin wrinkling.
• Black raspberry (Rubus occidentalis) may have a role in preventing oral cancer.
• Boophone (Boophone disticha) This highly toxic plant has been used in South African traditional medicine for treatment of mental illness. Research demonstrate in vitro and in vivo effect against depression.
• Butterbur (Petasites hybridus)
• Calendula (Calendula officinalis) has been used traditionally for abdominal cramps and constipation.In animal research an aqueous-ethanol extract of Calendula officinalis flowers was shown to have both spasmolytic and spasmogenic effects, thus providing a scientific rationale for this traditional use. There is "limited evidence" that calendula cream or ointment is effective in treating radiation dermatitis.
• Cannabis, see also medical cannabis.
• Cranberry (Vaccinium oxycoccos) may be effective in treating urinary tract infections in women with recurrent symptoms
• Echinacea (Echinacea angustifolia, Echinacea pallida, Echinacea purpurea) extracts may limit the length and severity of rhinovirus colds; however, the appropriate dosage levels, which might be higher than is available over-the-counter, require further research.
• Elderberry (Sambucus nigra) may speed the recovery from type A and B influenza. However it is possibly risky in the case of avian influenza because the immune stimulatory effects may aggravate the cytokine cascade.
• Feverfew (Chrysanthemum parthenium) is sometimes used to treat migraine headaches.Although many reviews of Feverfew studies show no or unclear efficacy, a more recent RTC showed favorable results^. Feverfew is not recommended for pregnant women as it may be dangerous to the fetus.
• Gawo (Faidherbia albida), a traditional herbal medicine in West Africa, has shown promise in animal tests.
• Garlic (Allium sativum) may lower total cholesterol levels
• German Chamomile (Matricaria chamomilla) has demonstrated antispasmodic, anxiolytic, antiinflammatory and some antimutagenic and cholesterol-lowering effects in animal research. In vitro chamomile has demonstrated moderate antimicrobial and antioxidant properties and significant antiplatelet activity, as well as preliminary results against cancer. Essential oil of chamomile was shown to be a promising antiviral agent against herpes simplex virus type 2 (HSV-2) in vitro.
• Ginger (Zingiber officinale), administered in 250 mg capsules for four days, effectively decreased nausea and vomiting of pregnancy in a human clinical trial.
• Grapefruit (Naringenin) components may prevent obesity.
• Green tea (Camelia sinensis) components may inhibit growth of breast cancer cells and may heal scars faster.