Examples of plants used as medicine

Main article: List of plants used as medicineFew herbal remedies have conclusively demonstrated any positive effect on humans[citation needed]. Many of the studies cited refer to animal model investigations or in-vitro assays and therefore cannot provide more than weak supportive evidence.[citation needed].
-Artichoke and several other plants may reduce total serum cholesterol levels in preliminary studies. [Gebhardt, R (1998). "Inhibition of Cholesterol Biosynthesis in Primary Cultured Rat Hepatocytes by Artichoke (Cynara scolymus L.) Extracts". J Pharmacol Exp Ther 286 (3): 1122-1128. PMID 9732368.][Artichoke. Retrieved on 2007-07-24.]
-Black cohosh and other plants that contain phytoestrogens (plant molecules with estrogen activity) have some benefits for treatment of symptoms resulting from menopause.[Bai W (2007). "Efficacy and tolerability of a medicinal product containing an isopropanolic black cohosh extract in Chinese women with menopausal symptoms: A randomized, double blind, parallel-controlled study versus tibolone.". Maturitas In print. PMID 17587516.]
-Echinacea extracts can 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. [Shah SA, Sander S, White CM, Rinaldi M, & Coleman CI (Jul 2007). "Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis.". Lancet Infect Dis.. PMID 17597571.][Schoop, R, Klein, P, Suter, A, & Johnston, SL (2006). "Echinacea in the prevention of induced rhinovirus colds: a meta-analysis". Clinical Therapeutics 28 (2): 174-83. PMID 16678640.]
-Elderberry may speed the recovery from type A and B influenza.[(2004 Mar-Apr) "Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections.". J Int Med Res. 32 (2): 132-40. PMID: 15080016.] However it is possibly risky in the case of avian influenza because the immunostimulatory effects may aggravate the cytokine cascade. [(2001 Apr-Jun;) "The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines.". Eur Cytokine Netw. 12 (2): 290-6. PMID: 11399518.]
-Garlic can lower total cholesterol levels[(2001) "Garlic shows promise for improve some cardiovascular risk factors". Archives of Internal Medicine 161: 913-824.]
-Purified extracts of the seeds of Hibiscus sabdariffa may have some anti-microbial effect, but may also have some toxicity to mammalian testes.[Ali BH, Al Wabel N, & Blunden G (2005). "Phytochemical, pharmacological and toxicological aspects of Hibiscus sabdariffa L.: a review". Phytotherapy Research 19 (5): 369-75. PMID 16106391.]
-Nigella sativa (Black cumin) is a general medicinal plant can be used for diverse ailments such as cough, pulmonary infections, asthma, influenza, allergy, hypertension and stomach ache. [Hajhashemi V, Ghannadi A, & Jafarabadi H (2004). "Black cumin seed essential oil, as a potent analgesic and antiinflammatory drug.". Phytother Res. 18 (3): 195-9. PMID 15103664.][Salem (2005). "Immunomodulatory and therapeutic properties of the Nigella sativa L. seed". International Immunopharmacology 5 (13-14): 1749-1770. PMID 16275613.][Ali BH & Blunden, G (2003). "Pharmacological and toxicological properties of Nigella sativa.". Phytother Res. 17 (4): 299-305. PMID 12722128.]
-Oregano may be effective against multi-drug resistant bacteria. [Oregano Oil May Protect Against Drug-Resistant Bacteria, Georgetown Researcher Finds.]
-Pawpaw can be used for insecticidal purposes (killing lice, worms).[citation needed]
-Phytolacca or Pokeweed is used as a homeopathic remedy to treat many ailments. It can be applied topically or taken internally. Topical treatments have been used for acne and other ailments. Internal treatments include tonsilitis, swollen glands and weight loss.[citation needed]
-Peppermint oil may have benefits for individuals with irritable bowel syndrome.[Cappello G, Spezzaferro M, Grossi L, Manzoli L, & Marzio L (2007). "Peppermint oil (Mintoil((R))) in the treatment of irritable bowel syndrome: A prospective double blind placebo-controlled randomized trial". Digestive and Liver Disease 39 (6): 530-536. PMID 17420159.][Liu JH, Chen GH, Yeh HZ, Huang CK, Poon SK (Dec 1997). "Enteric-coated peppermint-oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial.". J Gastroenterol 32 (6): 765-8. PMID 9430014.]
-Rauvolfia Serpentina, high risk of toxicity if improperly used[citation needed], used extensively in India for sleeplessness, anxiety, and high blood pressure[citation needed]. The first proven allopathic medicine for high blood pressure was extracted from this herb.[citation needed] -Salvia lavandulaefolia may improve memory [Sage Improves Memory, Study Shows.]
-St. John's wort, has yielded positive results, proving more effective than a placebo for the treatment of mild to moderate depression in some clinical trials: however, safety and efficacy profiles (that is, amount of drug needed for a clinical effect) have not been shown.[Gaster, B & Holroyd, J (2000). "St John's wort for depression: a systematic review.". Archives of Internal Medicine 160 (2): 152-6. PMID 10647752.]
-Valerian root can be used to treat insomnia. Clinical studies show mixed results[Bent S, Padula A, Moore D, Patterson M, & Mehling W. (2006). "Valerian for sleep: a systematic review and meta-analysis.". Am J Med. 119 (12): 1005-1012. PMID 17145239.][Taibi DM, Landis CA, Petry H, & Vitiello MV (2007). "A systematic review of valerian as a sleep aid: safe but not effective". Sleep Med Rev 11 (3): 209-230. PMID 17517355.] A valerian/hops combination has shown efficacy [Koetter U, Schrader E, K?ufeler R, & Brattstr?m A. (2007). "A randomized, double blind, placebo-controlled, prospective clinical study to demonstrate clinical efficacy of a fixed valerian hops extract combination (Ze 91019) in patients suffering from non-organic sleep disorder.". Phytother Res In print. PMID 17486686.]
-Feverfew can be used to treat migraine headaches.[Shrivastava R, Pechadre JC, & John GW (2007). "Tanacetum parthenium and Salix alba (Mig-RL) combination in migraine prophylaxis: a prospective, open-label study". Clinical Drug Investigation 26 (5): 287-296. PMID17163262.]However, many reviews of these studies show no efficacy [Silberstein, SD (2005). "Preventive treatment of headaches". Current Opinion in Neurology 18 (3): 289-292. PMID 15891414.] and dangerous side effects.[Yao M, Ritchie HE, & Brown-Woodman PD (2006). "A reproductive screening test of feverfew: is a full reproductive study warranted?". Reproductive Toxicology 22 (4): 688-693. PMID 16781113.][Modi S & Lowder DM (2006). "Medications for migraine prophylaxis". American Family Physician 73 (1): 72-78. PMID 16417067.]
-Saw Palmetto can be used for BPH. Supported in some studies [Marks LS, Partin AW, Epstein JI, Tyler VE, Simon I, Macairan ML, Chan TL, Dorey FJ, Garris JB, Veltri RW, Santos PB, Stonebrook KA, & deKernion JB (2000). "Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia.". J. Urol 163 (5): 1451-1456. PMID 10751856.], failed to confirm in otherrs. [Bent S, Kane C, Shinohara K, Neuhaus J, Hudes ES, Goldberg H, & Avins AL. (2006). "Saw palmetto for benign prostatic hyperplasia". New England Journal of Medicine 354 (6): 557-566. PMID 16467543.]
-Lemon juice or apple cider vinegar can be used to treat acne.[citation needed]
-Green tea components may inhibit growth of breast cancer cells[(2007) "Activation of FOXO3a by the Green Tea Polyphenol Epigallocatechin-3-Gallate Induces Estrogen Receptor Expression Reversing Invasive Phenotype of Breast Cancer Cells". Cancer Research 67: 5763-5770. DOI:10.1158/0008-5472.CAN-06-4327.] and may heal scars faster. [Zhang Q, Kelly AP, Wang L, French SW, Tang X, Duong HS, Messadi DV, & Le AD (2006). "Green tea extract and (-)-epigallocatechin-3-gallate inhibit mast cell-stimulated type I collagen expression in keloid fibroblasts via blocking PI-3K/AkT signaling pathways". J Invest Dermatol 126 (12): 2607-2613. PMID 16841034.]
-Lemon grass can lower cholesterol. [citation needed]
-Honey may reduce cholesterol.[(2004 Spring;) "Natural honey lowers plasma glucose, C-reactive protein, homocysteine, and blood lipids in healthy, diabetic, and hyperlipidemic subjects: comparison with dextrose and sucrose". J Med Food: 100-7. PMID: 15117561.] May be useful in wound healing. [Healing Honey: The Sweet Evidence Revealed. ] http://en.wikipedia.org/wiki/Main_page