Phytochemical Screening and Biological Activities of Essential Oils from Leaves of Two Algerian Lamiaceae Plants on Callosobruchus maculatus (Fabricius, 1775)

The present work investigates the chemical composition and in vitro antioxidant activity of essential oils from leaves of Rosmarinus tounefortii De Noe and Lavandula stoechas L. grown in Algeria and to assess their bioactivity on Callosobruchus maculatus (F.). The essential oils of these plants were obtained by hydrodistillation (yield=1.6 and 0.16 ml/100 g of fresh weight for R. tounefortii and L. stoechas, respectively). GC and GC-MS revealed fenchone (24.7 %), camphor (6.9 %) and bornyl acetate (6.3 %) as major compounds of L. stoechas essential oil, while the rosemary oil was dominated by camphor (39.4 %), alpha-pinene (10.4 %) and p-cymene + limonene (11 %). Antioxidant activity was assessed in vitro using two different tests: Reducing power and scavenging activity of the free radical DPPH. For both tests, results revealed that studied essential oils exhibited lower antioxidant activity compared to the synthetic antioxidant butylated hydrxytoluene (BHT). The evaluation of the insecticidal activity showed that they had a strong toxic effect on Callosobruchus maculatus F. by fumigation tests with a significant reduction of the female's fecundity and the hatchability of laid eggs.