title: Phytochemistry and antileishmanial activity of the leaf latex of Aloe calidophila Reynolds.
abstract: Leishmaniasis is a major protozoal disease threatening the lives of 350 million people throughout the world. However, the therapeutic options for the disease are limited. In the present study, the antiprotozoal activity of the latex obtained from the Ethiopian plant Aloe calidophila Reynolds was evaluated by in vitro testing against Leishmania aethiopica and Leishmania major. It was found that the latex possesses moderate activity against both parasites with IC50 values of 64.05 and 82.29 µg/mL, respectively. Phytochemical investigation resulted in the isolation of three anthrones identified as aloinoside, aloin, and microdontin on the basis of IR, MS, (1) H NMR, and (13) C NMR spectral data. The isolated compounds showed strong antileishmanial activity with IC50 values ranging from 1.76 to 6.32 µg/mL against L. aethiopica and from 2.09 to 8.85 µg/mL against L. major. Although these values were higher than those of amphotericin B (IC50  = 0.109 and 0.067 µg/mL), the selectivity indices (813.35 and 694.90, respectively, against L. aethiopica and L. major) of aloinoside were much better than those of the standard drug (423.49 and 688.96). The results indicate that the isolated compounds have the potential to be used as a scaffold for the development of safe and cost-effective antileishmanial agents.
authors: Department of Pharmaceutical Chemistry and Pharmacognosy, College of Health Sciences, School of Pharmacy, Addis Ababa University, Addis Ababa, Ethiopia.
authors: Fetene
authors: F
authors: Abeje
authors: Daniel
authors: D
authors: Bisrat
authors: Asrat
authors: A
authors: Hailu
authors: Kaleab
authors: K
authors: Asres
mesh_terms: D000504:Aloe / Q000737:chemistry*; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D004912:Erythrocytes; D006461:Hemolysis; D020128:Inhibitory Concentration 50; D007840:Latex / Q000494:pharmacology*; D007891:Leishmania / Q000187:drug effects*; D018320:Leishmania major / Q000187:drug effects; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D012756:Sheep
chemical_list: D000981:Antiprotozoal Agents; D007840:Latex
keywords: Aloe calidophila; Leishmania aethiopica; Leishmania major; anthrones; antileishmanial