Activity of isoflavans of Dalea aurea (Fabaceae) against the opportunistic ameba naegleria fowleri.
One new and one known isoflavan, 3 S(+)-7-methoxymanuifolin K (1) and manuifolin K (2), respectively, were isolated from methanolic extracts of Dalea aurea (Fabaceae). Isoflavans 1 and 2 exhibited significant in vitro activity against the ameba Naegleria fowleri, an organism responsible for an infrequent but rapidly fatal form of primary amebic meningoencephalitis (PAM). At concentrations of 30 microM, both 1 and 2 caused growth inhibition of N. fowleri at a level comparable to amphotericin B (at 0.1 microM), the currently preferred treatment for this disease. Over a seven-day growth period, 1 and 2 (30 microM) exhibited superior growth inhibition of N. fowleri than amphotericin B after day 4. Isoflavan 2 was evaluated in a mouse model of PAM at a dose of 25 mg/kg/day for five days. While amphotericin B (2.5 mg/kg/day) offered 12.5 % protection of the mice, compound 2 did not protect the mice from PAM infection compared to controls.
Department of Chemistry and Biochemistry, The University of Tulsa, Tulsa, Oklahoma, USA. gbelofsky@efficas.com
Gil
G
Belofsky
Roberto
R
Carreno
Shannon M
SM
Goswick
David T
DT
John
D000563:Amebicides / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000656:Amoeba / Q000187:drug effects*; D000818:Animals; D020808:Central Nervous System Protozoal Infections / Q000188:drug therapy*; D004195:Disease Models, Animal; D007887:Fabaceae; D007529:Isoflavones / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008590:Meningoencephalitis / Q000188:drug therapy; D051379:Mice; D008815:Mice, Inbred Strains; D009894:Opportunistic Infections / Q000188:drug therapy; D021261:Parasitic Sensitivity Tests; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use
D000563:Amebicides; D007529:Isoflavones; D010936:Plant Extracts