EVALUATION OF ANTIMICROBIAL ACTIVITY AND FATTY ACID PROFILE FROM Maesa lanceolata AND Lepidium sativium SEED OILS

ABSTRACT Although lepidium sativium and maesa lanceolata seeds are widely used in Ethiopian folk medicine and other purposes, little is known about their oil composition. Hence the present study was aimed to determine the fatty acid composition of both maesa lanceolata and four different local markets of lepidium sativium seed oil as well as the antimicrobial activity of maesa lanceolata seed oil. Lepidium sativium seed samples were collected from four different areas of Amhara region while maesa lanceolata seed was collected southern nation nationality people representative of Ethiopia. The oils from all the samples were extracted with n-hexane using soxhlet extractor. The total oil content of lepidium sativium seed samples were ranging from 18.9% to 26.9% while that of maesa lanceolata was 23.3% by mass. The fatty acid composition of each oil was determined by gas chromatography- mass spectrometer after being derivatized to the corresponding esteric acid. The lipid extract of maesa lanceolata was evaluated for its in vitro antibacterial activities against strains of two Gram-positive (Staphylococcus aureus (ATCC25923) and Streptococcus pyogenes) and two Gram-negative (Escherichia coli (ATCC255922) and K.pneumoniae (ATCC986605)) bacteria. The oil of maesa lanceolata seeds showed various degree of antimicrobial activity towards different drug resistance microbial pathogens with mean zone of inhibition ranges from 1.2 cm to 1.7 cm. The oil has shown an MIC value of 50 mg/L for all the bacteria. Thus, it was concluded that this oil demonstrated antibacterial activity against of gram positive and gram negative bacteria strains. This may partly justify the traditional use of the plant against infection. The fatty acid analysis of the lipid fractions of lepidium sativium and maesa lanceolata reaveled the presence of more than 18 and 6 fatty acids respectively. Among the fatty acids quantified, the major fatty acids of lepidium sativium seed oil were ranging from palmitic acid ( 12.9-16.2 mg/g ), stearic acid ( 4.49-6.18 mg/g), oleic acid (36.3-43.8 mg/g), linoleic acid (12.5-16.7 mg/g), linolenic acid (3.8-46.8 mg/g) and the major fatty acid of maesa lanceolata seed oils were ranging from palmitic acid (6.03 mg/g), stearic acid (1.81 mg/g), oleic acid (5.65 mg/g), linoleic acid (40.5 mg/g), linolenic acid ( 0.45 mg/g). The lepidium sativium and maesa lanceolata seed oil provide an important source of omega-3, omega-6 and omega-9 fatty acid for food supplement and medicinal purpose.