Background:Chrysophyllum pruniforme of family sapotaceae is a plant used in traditional medicine in Gabon.Materials and Methods:In this study, C. pruniforme barks were subjected to phytochemical screening and cytotoxicity investigations. Different concentrations of aqueous and total phenolic extract were tested on mice and on human erythrocytes.Results:Phytochemical screening of C. pruniforme barks revealed the presence of flavonoids, saponins, and tannins, reducing sugars, polyphenols and traces of anthraquinones. When tested in vitro, aqueous and the phenolic extracts showed hemolytic activities on human erythrocytes with phenolic compounds being more cytotoxic than aqueous extracts. In vivo study of toxicity, allowed to determine the LD50 at 90 mg/kg for the doses of 50, 150 and 250 mg/kg of body weight.Conclusion:These data indicate in one hand that C. pruniforme is rich in phenolic compounds and that the aqueous and total phenolic extracts could be considered as toxic for mice and maybe potentially toxic to humans in the other hand.

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Dans cette revue, nous mettons en avant le potentiel thérapeutique des polysaccharides isolés à partir des parois végé tales des plantes médicinales africaines. In vivo, la paroi végétale joue un rôle important dans le contrôle de la physiologie de la plante (croissance cellulaire, mécanismes de défense de la plante, morphologie de la plante). Principalement composée de polysac charides comme la cellulose, les hémicelluloses ou de pectines, la relation entre la structure chimique de ces polysaccharides et leurs fonctions biologiques a fait l'objet de très nombreuses études. Des extraits de ces parois, principalement polysaccharidi ques, isolés à partir de plantes sont également couramment utili sés comme « remède traditionnel » en Afrique. Dans cette revue, nous présentons quelques plantes médicinales africaines pour lesquelles la structure chimique de certains extraits polysaccha ridiques, présentant souvent une activité immunomodulatoire, a été déterminée. Ce type d'étude et d'approche, encore margi nale, gagnerait à être généralisé aux autres plantes médicinales africaines jusqu'alors peu étudiées. Cette propriété immunomo dulatoire de certains extraits polysaccharidiques pourrait consti tuer un complément thérapeutique de choix chez des patients immunodéprimés ou immunodéficients.Abstract: This review article aims to draw attention to thera peutic potential of plant cell wall polysaccharides isolated from African medicinal plants. Plant cell wall, or plant cell extracel lular compartment, consists on various polysaccharides having different chemical structures. Among these polysaccharides, cellulose, hemicelluloses and pectin polysaccharides are the predominant ones, and play an important role in controlling several biological processes like cell growth and morpho genesis, or defense mechanisms. The structurefunction rela tionship of plant cell wall polysaccharides have been extensively studied, regarding their in vivo biological functions. Here, we have partially described the chemical structure of several biologically active hemicelluloses or pectin polysaccharides extracts, isolated from different African medicinal plants. It appears that these polysaccharides taken individually are able to modulate the activity of the mammal immune system in different manner, providing an interesting complementary therapy to immune deficient patients for instance. Further investigations on cell wall polysaccharide structurebiological activity relationship of the numerous unexplored medicinal plants are therefore strongly suggested.