PHYTOCHEMICAL STUDIES AND IN VIVO ANTIOXIDANT ACTIVITY OF TWO LAVANDULA SPECIES (LAMIACEAE) AGAINST STREPTOZOTOCIN INDUCED OXIDATIVE STRESS IN ALBINO RATS

Abstract

Phytochemical studies of two Lavandula species namely L. dentata L. and L. angustifolia Mill. (Lamiaceae) cultivated in Egypt was carried out to subsist positive diagnostic indices for the research of their monographs as well as GC/MS analysis of their volatile oils and quantitative estimation of total phenol and flavonoid contents.

The gained results revealed both qualitative and quantitative variation in the chemical composition of the investigated species where twenty-six and thirty-one compounds were identified in the volatile oils of L. dentata L. and L. angustifolia Mill. representing 96.43 % and 98.56 % respectively, the major chemical constituents in the volatile oil of L. dentata were menthe-1,5-dien-8-ol <Para> (26.80%), caryophyllene oxide (16.40%) and guiaol<Alpha>  (15.36%), while in L. angustifolia were linalyl acetate (18.99%), citronellol<Alpha> (17.36%) and menthe-1,5-dien-8-ol<Para> (16.21%), moreover, the calculated values of total phenol and flavonoid contents were 188.50±2.07 mg GAE g^-1, 90.40±1.57 mg QE g^-1, 194.95±2.55 mg GAE g^-1, 98.83±2.68 mg QE g^-1and 167.10±2.30 mg GAE g^-1, 116.15±1.91QE g^-1,152.50±2.21mg GAE g^-1, 119.95±1.87 mg QE g^-1 for their aqueous and methanol extracts respectively.

Investigation of their antioxidants impact against Streptozotocin-induced oxidative stress in liver and kidney tissues of albino rats revealed that the methanol extract of L. angustifolia exhibited the highest antioxidant potential followed by, that of L. dentata and volatile oil L. angustifolia in dose dependent manner respectively which afford useful results for developing new natural antioxidant agents.

Key words: Lavandula, Volatile Oils, Phenols, Flavonoids, Antioxidant, Streptozotocin, Glibenclamide and Oxidative Stress.