title: Clear evidence of carcinogenic activity by a whole-leaf extract of Aloe barbadensis miller (aloe vera) in F344/N rats.
abstract: Aloe barbadensis Miller (Aloe vera) is an herbal remedy promoted to treat a variety of illnesses; however, only limited data are available on the safety of this dietary supplement. Drinking water exposure of F344/N rats and B6C3F1 mice to an Aloe vera whole-leaf extract (1, 2, and 3%) for 13 weeks resulted in goblet cell hyperplasia of the large intestine in both species. Based upon this observation, 2-year drinking water studies were conducted to assess the carcinogenic potential of an Aloe vera whole-leaf extract when administered to F344/N rats (48 per sex per group) at 0.5, 1, and 1.5%, and B6C3F1 mice (48 per sex per group) at 1, 2, and 3%. Compared with controls, survival was decreased in the 1.5% dose group of female rats. Treatment-related neoplasms and nonneoplastic lesions in both species were confined primarily to the large intestine. Incidences of adenomas and/or carcinomas of the ileo-cecal and cecal-colic junction, cecum, and ascending and transverse colon were significantly higher than controls in male and female rats in the 1 and 1.5% dose groups. There were no neoplasms of the large intestine in mice or in the 0 or 0.5% dose groups of rats. Increased incidences of mucosa hyperplasia of the large intestine were observed in F344/N rats, and increased incidences of goblet cell hyperplasia of the large intestine occurred in B6C3F1 mice. These results indicate that Aloe vera whole-leaf extract is an intestinal irritant in F344/N rats and B6C3F1 mice and a carcinogen of the large intestine in F344/N rats.
authors.affiliation: Division of Biochemical Toxicology, Food and Drug Administration, Jefferson, Arkansas 72079, USA. mary.boudreau@fda.hhs.gov
authors.forename: Mary D
authors.initials: MD
authors.lastname: Boudreau
authors.forename: Paul W
authors.initials: PW
authors.lastname: Mellick
authors.forename: Greg R
authors.initials: GR
authors.lastname: Olson
authors.forename: Robert P
authors.initials: RP
authors.lastname: Felton
authors.forename: Brett T
authors.initials: BT
authors.lastname: Thorn
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Beland
mesh_terms: D000284:Administration, Oral; D000504:Aloe / Q000737:chemistry*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015197:Carcinogenicity Tests; D004305:Dose-Response Relationship, Drug; D005260:Female; D006965:Hyperplasia; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000473:pathology; D007414:Intestinal Neoplasms / Q000139:chemically induced* / Q000473:pathology; D007420:Intestine, Large / Q000187:drug effects* / Q000473:pathology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010936:Plant Extracts / Q000302:isolation & purification / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D011916:Rats, Inbred F344; D013045:Species Specificity; D016019:Survival Analysis
chemical_list: D010936:Plant Extracts