RESUMO
Background. Patients in West Africa where sickle cell anemia (SCA) is endemic have for ages been treated with natural products, especially herbs, as, is still the case in rural communities. Objective. In this paper we look closely at some of these herbs to see if there are any lessons to be learnt or clues to be found for optimizing the treatments based on them, as had been done in the case of NIPRISAN, which was developed from herbs in Nigeria based on Yoruba Medicine. Methods. Select publications on SCA, its molecular biology and pathology, and actual and experimental cases of herbal treatment were perused in search of molecular clues that can be linked to chemical constituents of the herbs involved. Results. The study revealed that during the last 2-3 decades, much progress was made in several aspects of SCA pharmacology, especially the approval of hydroxyurea. As for SCA herbalism, this paper revealed that antisickling herbs abound in West Africa and that the most promising may yet be found. Three new antisickling herbs (Entandrophragma utile, Chenopodium ambrosioides, and Petiveria alliacea) were reported in May 2011. At NIPRD, where NIPRISAN was developed, three other recipes are currently awaiting development. Conclusion. The study raised the hope that the search in the Tropics for more effective herbal recipes for managing sickle cell anaemia will be more fruitful with time and effort.
RESUMO
Leaf extracts of T. sessilifolius growing on five different host plants (Psidium guajava, Citrus lemon, Vernonia amygdalina, Persea americana and Jatropa curcas) were evaluated for antimicrobial activity of the plant. Powdered leaves of T. sessilifolius collected from each host plant was divided into two portions. One portion was used for aqueous infusion and the other portion was successively extracted with hexane, ethylacetate and methanol. Infusion of aqueous extract of powdered leaves did not show antimicrobial effect even at the concentration of 1000 and 2000 microg/ml on test microorganisms (Staph. aureus, E. coli, Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans). However in broth culture, methanolic and hexane extract had MIC range of 62.5-500 microg/ml and ethylacetate extract had 250-500 microg/ml. Phytochemical screening of leaf samples of T. sessilifolius collected from different host plants showed positive test for hydrolysable tannins, saponins, flavonoids, terpenes, cardiac glycoside, reducing sugars and proteins. LD50 concentration was found to be > 1.500 mg/kg for samples from P. guajava; 489.89 mg/kg for J. curcas and C. lemon; and 692 mg/kg for V. amydalina in mice.
