Intraspecific Chemical Variability of Essential Oil of Hoslundia opposita
Chemical investigation on leaves oil of Hoslundia opposita, aromatic plant used 
in traditional medicine, harvested from 20 localities of C?te d’Ivoire 
was realized by GC and GC/MS. In total, 101 compounds were identified 
accounting to 92% - 99%, aromatic compounds such benzyl benzoate and sesquiterpenes 
namely germacrene D, β-caryophyllene and α-humulene hydroxyl were found as the major constituents. As regard, 
the chemical profiles of our samples, it was found a great chemical variability 
suggesting a high polymorphism degree. In order to study this chemical 
variability, the results were submitted to the principal components and cluster 
analysis which allowed distinguishing two main groups of essential oils with 
respect to sampling site. The cluster I was dominated by benzyl benzoate (15%) 
and thymol (7.4%) comprising 6 localities, cluster II was characterized by 
phytol (8.5%) and α-humulene (7%) and constituted by 14 localities.
Antimicrobial and cytotoxicity activity of selected Pare folk medicinal plants
Aim: The study aimed to evaluate antimicrobial and cytotoxicity of Grewia villosa , Cassia abbreviata and Hoslundia opposita . Methods: Microdilution method and brine shrimp lethality test were employed to evaluate antimicrobial and cytotoxicity of plant extracts. Results: The extracts of G. villosa , C. abbreviata and H. opposita showed different levels of antimicrobial activities on Gram negative bacterial and fungal species tested. The minimum inhibition concentration (MIC) ranges of G. villosa , C. abbreviata and H. opposita extracts were 0.391-25, 0.195-25 and 0.391-25 mg/mL respectively. Cassia abbreviata stem methanolic extracts and roots ethyl acetate extracts exhibited the highest activity with minimum inhibition concentration (MIC) of 0.195 mg/mL against S. typhi and K. oxytoca respectively. At least one of the extract from each plant exhibited a cytotoxicity nature when tested on brine shrimps where the G. villosa stem chloroform extract was the most cytotoxic with fifty percent lethal concentration (LC50) of 48.432 µg/mL. Conclusion: The findings in this study validate the traditional use of G. villosa , C. abbreviata and H. opposita in management of bacterial and fungal infections. Further phytochemical investigations on G. villosa , C. abbreviata and H. opposita growing in Pare Mountains are recommended to contribute to drug development.
Inhibition of Root Growth and Polyamine Metabolism in Sunflower (Helianthus annuus) Seedlings Under Cadmium and Copper Stress
Although sunflower is usually regarded as a highly tolerant crop, impairment of root growth at initial stages of plant development may result in poor crop establishment and higher susceptibility to pathogen attack. In order to evaluate if Cd2+ and Cu2+ may impact on sunflower germination and initial root development, a pot experiment under controlled conditions was carried out. Possible involvement of polyamine metabolism in sunflower response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of these heavy metals showed significant inhibition of root growth, being this inhibition greater for Cd2+. Both metals caused significant increases in proline contents at the highest concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+ treatments, especially between days 3 and 10. Metals also increased putrescine (Put) contents at all concentrations assayed from the seventh day onward, causing no variations on this polyamine time-course pattern. Spermine and spermidine contents, however, were increased only by 1 mM Cd2+. Arginine decarboxylase seems to have been the enzyme responsible for Put increases under both metal treatments. This work demonstrates that initial root growth of sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also shows that polyamines are key biological compounds, which are probably involved in signaling pathways triggered under stress environmental conditions.