title: Efficacy of the saponin component of Impatiens capensis Meerb.in preventing urushiol-induced contact dermatitis.
abstract: BACKGROUND
  Many different tribes of American Indians used jewelweed, Impatiens capensis Meerb, as a plant mash to reduce development of poison ivy dermatitis. Saponins are a natural soapy constituent found within plants. A 2012 study suggested that saponins may be present in jewelweed which could be responsible for its efficacy in preventing rash development following contact with Toxicodendron radicans (L.) Kuntze (poison ivy). This study validated this hypothesis and demonstrated additional biological activity of the jewelweed saponin containing extract.
  
  
  METHODS
  Fresh I. capensis leaves were extracted with methanol and further partitioned between ethyl acetate and water, with a final separation between water and n-butanol, to obtain a saponin containing extract. The presence of saponins in the extract was demonstrated by the observation of foaming and using a vanillin colorimetric assay for total saponins. Efficacy of the saponin containing extracts in rash reduction was tested by brushing poison ivy (PI) onto the forearms of volunteers (N=23) in six locations and treating these PI exposed areas with distilled water (control), saponin containing extracts, fresh plant mashes, and soaps made with and without plant extracts. Saponin containing extracts were further tested for biological activity against both gram negative and gram positive bacteria and against cancer cell lines A-375, HT-29, and MCF-7. Additionally, because saponins have been shown to have a stimulatory effect in cardiac muscle 2 µl saponin extract was applied superficially to black worms, Lumbriculus variegatus (N=5).
  Both saponin containing extracts and all soaps tested were effective in reducing poison ivy dermatitis; thus, saponin content correlates with PI rash prevention. No apparent antibiosis was observed against any bacteria tested; however, dose response cytotoxicity was documented against MCF-7 breast cancer cells and cytostatic activity was seen against the HT-29 colon cancer cell lines. Lumbriculus variegatus exhibited a 138% increase in heart rate over baseline rate five minutes post treatment implying a possible positive chronotropic effect.
authors.affiliation: Department of Biological and Allied Health Sciences, Ohio Northern University 525 S Main St, Ada OH 45801, USA. Electronic address: v-motz@onu.edu.
authors.forename: Vicki A
authors.initials: VA
authors.lastname: Motz
authors.affiliation: Department of Chemistry and Biochemistry, Ohio Northern University 525 S Main St, Ada OH 45801, USA. Electronic address: c-bowers@onu.edu.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Bowers
authors.affiliation: Department of Biological and Allied Health Sciences, Ohio Northern University 525 S Main St, Ada OH 45801, USA. Electronic address: a-kneubehl@onu.edu.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Kneubehl
authors.affiliation: Department of Biological and Allied Health Sciences, Ohio Northern University 525 S Main St, Ada OH 45801, USA. Electronic address: e-lendrum@onu.edu.
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Lendrum
authors.affiliation: Department of Biological and Allied Health Sciences, Ohio Northern University 525 S Main St, Ada OH 45801, USA. Electronic address: l-young@onu.edu.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Young
authors.affiliation: Raabe College of Pharmacy, Ohio Northern University 525 S Main St, Ada OH 45801, USA. Electronic address: d-kinder@onu.edu.
authors.forename: David H
authors.initials: DH
authors.lastname: Kinder
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002396:Catechols / Q000633:toxicity*; D045744:Cell Line, Tumor; D003877:Dermatitis, Contact / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D029069:Impatiens / Q000737:chemistry*; D008875:Middle Aged; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D002396:Catechols; D010936:Plant Extracts; D012503:Saponins; C003747:urushiol
keywords: 2.536: saponins; 2.644: Traditional medicine Northern America; Dermatitis; Pharmacognosy; Poison ivy; Urushiol