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.

No abstract

No abstract

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.

No abstract

No abstract

Abstract. Mengome, Mewono L, Mboma R, Engohang-Ndong J, Angone SA. 2021. Ethnobotanical survey and phytochemical screening of anti-snakebite plants used in Bissok District of Gabon. Biodiversitas 22: 3264-3275. Snakebites remain a major health issue in tropical and subtropical regions in the world. The limited access of antivenom sera in remote areas of many countries forces populations to rely on plant-based remedies to manage snakebite-induced injury. In this study, we conducted an ethnobotanical survey of medicinal plants used for the management of snakebites in the district of Bissok (Northern Gabon). After collecting and verifying the authenticity of the plants, we further performed their phytochemical analysis. The procedure used in this study involved a structured questionnaire and direct interviews of local populations. Overall, data collected on-site included local names, the part of the plant used, the preparation, and the route of administration. The presence of some phytochemical compounds was determined according to standard methods. Overall, a total of 29 species of plants belonging to 20 different families were reported to be used to treat snakebites. The plants used were herbs (44.80%), trees (24.10%), shrubs (20.70%), liana (10.30%), and rhizomes (6.90%). They were mainly used as poultice or crush, and to a lesser extent as decoction and maceration. Regarding the route of administration, interviewees reported mainly external use on the site of the bite. Concerning the chemical composition, we found that the antivenom plants were rich in chemical compounds known to have antivenom, antipyretic and antimicrobial properties, e.g. alkaloids, terpenoids, flavonoids, steroids, coumarins, phenols, tannins gallic Our results open avenues to develop venom enzyme inhibitory assays.

Aim: In plants, are found large amount of vitamin (A, B, C, E), mineral (Zn, Cu, Se) and biochemical (glutathione, taurine, phenol acids) substances which also have a well-known antioxidant power. These substances have phytotheraptic applications in the fight against aging caused by oxidative stress and are oxidative component of acute pathologies: (infectious, traumatic, inflammatory and allergic). Strychnos icaja Baillon (Loganiaceae) is a tropical shrub common in the tropical forest of Central Africa. Strychnos species is mainly used by the local population as an arrow or ordeal poison, for treatment of haemorrhoids and malaria by the Pygmies tribes from Cameroon due to its magic-medical property. This study determined the medicinal uses of Strychnos and assessed its antioxidant potential. Methodology: Extracts of alkaloids, aqueous, ethyl acetate, dichloromethane and butanol from Strychnos were evaluated for their antioxidant properties. An ethnobotanical survey of 20 traditional therapists was carried to obtain the medicinal uses of the root of Strychnos icaja. Results: 1,1-diphenyl-2-picryl-hydrazyl (DPPH) test shows good antiradical activity. Antioxidant activity by the ferric reducing antioxidant power (FRAP) test, show that Strychnos total alkaloids of the roots have a value of 5.94 ± 0.14mmol EAA/g that is significantly close from Ascorbic acid (5.86 ± 0.51 mmol EAA/g). The results of survey of traditional therapists identified six indications of this plant, namely in the treatment of haemorrhoids, against ear infections, male urethritis, rheumatic and dental pain and sterility in women. Conclusion: The Strychnos icaja possesses antioxidant activity, this can find use in the treatment of inflammatory diseases.