title: In vitro antitrypanosomal and antiplasmodial activities of crude extracts and essential oils of Ocimum gratissimum Linn from Benin and influence of vegetative stage.
abstract: BACKGROUND
  Different parts of Ocimum gratissimum Linn are largely used in folk medicine for the treatment of many diseases, some of which related to parasitical infections as fevers and headaches. In order to validate their use and to clarify the plant part which possesses the best antiparasitic properties, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils and crude extracts from leaves, stems and seeds of Ocimum gratissimum as well as their cytotoxicity.
  
  
  METHODS
  The essential oils and ethanol crude extracts of leaves and stems of Ocimum gratissimum from Benin, were obtained in pre and full flowering stages. Seeds obtained only in full flowering stage, were also extracted. The oils were isolated by hydrodistillation and analyzed by GC/MS and GC/FID. Extracts and essential oils were tested in vitro against Trypanosoma brucei brucei and Plasmodium falciparum. Cytotoxicity was evaluated in vitro against Chinese Hamster Ovary (CHO) cells and the human non cancer fibroblast cell line (WI38) through MTT assay to evaluate the selectivity and toxicity was assessed against Artemia salina Leach.
  
  
  RESULTS
  The essential oils and non-volatile crude extracts of Ocimum gratissimum were more active on Trypanosoma brucei brucei than on Plasmodium falciparum (3D7). This activity varies according to the vegetative stage (pre and full flowering) and the plant part (seeds, stems and leaves) extracted. The best growth inhibition of Trypanosoma brucei brucei was observed with ethanol crude extracts of leaves (IC50=1.66 ± 0.48 μg/mL) and seeds (IC50=1.29 ± 0.42 μg/mL) in full flowering stage with good selectivity (SI>10). The chemical composition of the essential oil from aerial parts (47 compounds), characterized by the presence as main constituents of p-cymene, thymol, γ-terpinene, β-myrcene and α-thujene, depends on the vegetative stage. The oil contained some minor compounds such as myrcene (IC50=2.24 ± 0.27μg/mL), citronellal (IC50=2.76 ± 1.55μg/mL), limonene (IC50=4.24 ± 2.27μg/mL), with good antitrypanosomal activities. These oils and crude extracts were not toxic against Artemia salina Leach and had a low cytotoxicity except leaves and seeds ethanol extracts obtained in full flowering which showed toxicity against CHO and WI38 cells.
  
  
  CONCLUSIONS
  Our study shows that ethanol crude extracts of leaves and seeds of Ocimum gratissimum in full flowering stage can be a good source of antitrypanosomal agents. This is the first report about the relation between the plant part extracted, the vegetative stage of the plant, the antitrypanosomal and antiplasmodial activities and the cytotoxicity of essential oils and non-volatile extracts of Ocimum gratissimum from Benin.
authors: Laboratory of Physic and Synthesis Organic Chemistry (LaCOPS), University of Abomey-Calavi, Faculty of Sciences and Technics (FAST), BP: 4521, Cotonou, Benin; National Laboratory of Pharmacognosy, Benin center of Scientific and Technical Research (CBRST), BP 06 Oganla, Porto-Novo, Benin.
authors: Bénédicta G H
authors: BG
authors: Kpadonou Kpoviessi
authors: Laboratory of Physic and Synthesis Organic Chemistry (LaCOPS), University of Abomey-Calavi, Faculty of Sciences and Technics (FAST), BP: 4521, Cotonou, Benin; Pharmacognosy Research Group, Louvain Drug Research Institute, Université catholique de Louvain, B1.72.03 Av. E. Mounier 72, B-1200 Bruxelles, Belgium.
authors: Salomé D S
authors: SD
authors: Kpoviessi
authors: National Laboratory of Pharmacognosy, Benin center of Scientific and Technical Research (CBRST), BP 06 Oganla, Porto-Novo, Benin.
authors: Eléonore
authors: E
authors: Yayi Ladekan
authors: National Laboratory of Pharmacognosy, Benin center of Scientific and Technical Research (CBRST), BP 06 Oganla, Porto-Novo, Benin.
authors: Fernand
authors: F
authors: Gbaguidi
authors: Université de Liège, Drug Research Center, Laboratoire de Pharmacognosie, Av. de l׳Hôpital 1, B36, B-4000 Liège, Belgium.
authors: Michel
authors: M
authors: Frédérich
authors: National Laboratory of Pharmacognosy, Benin center of Scientific and Technical Research (CBRST), BP 06 Oganla, Porto-Novo, Benin.
authors: Mansourou
authors: M
authors: Moudachirou
authors: Pharmacognosy Research Group, Louvain Drug Research Institute, Université catholique de Louvain, B1.72.03 Av. E. Mounier 72, B-1200 Bruxelles, Belgium.
authors: Joëlle
authors: J
authors: Quetin-Leclercq
authors: Laboratory of Physic and Synthesis Organic Chemistry (LaCOPS), University of Abomey-Calavi, Faculty of Sciences and Technics (FAST), BP: 4521, Cotonou, Benin.
authors: Georges C
authors: GC
authors: Accrombessi
authors: Pharmacognosy Research Group, Louvain Drug Research Institute, Université catholique de Louvain, B1.72.03 Av. E. Mounier 72, B-1200 Bruxelles, Belgium. Electronic address: joanne.bero@uclouvain.be.
authors: Joanne
authors: J
authors: Bero
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D001156:Artemia / Q000187:drug effects; D016466:CHO Cells; D002460:Cell Line; D002470:Cell Survival; D006224:Cricetinae; D003412:Cricetulus; D006801:Humans; D031339:Ocimum; D009822:Oils, Volatile / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D018547:Plant Stems; D010963:Plasmodium falciparum / Q000187:drug effects; D012639:Seeds; D014344:Trypanocidal Agents / Q000494:pharmacology*; D014346:Trypanosoma brucei brucei / Q000187:drug effects
chemical_list: D000962:Antimalarials; D009822:Oils, Volatile; D010936:Plant Extracts; D014344:Trypanocidal Agents
keywords: Antiplasmodial activity; Antitrypanosomal activity; Crude extracts; Cytotoxicity; Essential oils; Ocimum gratissimum