CHEMICAL COMPOSITION AND BIOLOGICAL (ANTIOXIDANT AND ANTIMICROBIAL) ACTIVITIES OF ESSENTIAL OILS FROM SELECTED PLANTS OF POTHOHAR PLATEAU

Abstract

Essential oils of different medicinal and aromatic plants have been potential candidates as source of food preservation, pharmaceuticals, alternative medicines and natural therapies in addition to their pharmacological properties like hepatoprotective, carminative, anticarcinogenic and antiviral effects. In present study some selected plants from Pothohar plateau were collected and subjected to essential oil extraction by hydrodistillation followed by assessment of their physical parameters like color, specific gravity, % yield etc and their biological activities including antioxidant, antimicrobial and cytotoxic attributes. The oils were then characterized by using GC and GC-MS techniques to find the chemical constituents. Overall the examined oils exhibited good antioxidant and antimicrobial behavior. To the best of our knowledge the essential oil of Parthenium hysterophorus has never been reported with regard to its composition as well as biological activities before present study. In general, Trachyspermum ammi and Cuminum cyminum essential oils showed significant activity in most of the assays performed in this study. Both showed remarkable potential for scavenging of DPPH free radical with IC50 values 2.61and 16.86 μg/mL, respectively and inhibited linoleic acid by 80.73 and 79.36% respectively. For T. ammi most sensitive bacterium was Streptococcus mutans (Inhibition zone=19.7mm; MIC=1.41 mg/mL) and fungus was Ganoderma lucidum (Inhibition zone=17.0mm; MIC=1.72 mg/mL) while for C. cyminum most sensitive bacterium was Bacillus subtilis (Inhibition zone=27.3mm; MIC=1.10 mg/mL) and fungus was Ganoderma lucidum (Inhibition zone=27.0mm; MIC=1.40 mg/mL). Both T. ammi and C. cyminum exhibited minimum hemolysis of human erythrocytes i.e. 7.98 and 4.51% respectively at 0.5 mg/mL concentration. GC-MS analysis revealed that thymol (37.75%) was the major component of T. ammi essential oil while cumaldehyde (24.10%) in C. cyminum essential oil. All the experiments were done in triplicate and mean ± S.D. was calculated.