Chemical composition, antibacterial and antioxidant activities of Tunisian garlic (Allium sativum) essential oil and ethanol extract

Abstract

 The aim of the study is to establish some nutritional properties of garlic cultivated in Tunisia and to evaluate the antioxidant and the antimicrobial activites of its essential oil and ethanol extract. Tunisian garlic (Allium sativum) was characterized for moisture, ash and protein contents which were determined as 66%, 1.4% and 5.2% respectively. In addition, Fe (5.90 mg/kg), Cu (1.61 mg/kg), Mg (15 mg/kg) and P (140 mg/kg) were reported such as the major minerals in garlic. The fat profile of tunisian garlic was conducted, the main fatty acids identified were lauric acid (49.3%) and linoleic acid (20.4%). Essential oil obtained from A. sativum was analysed by capillary GCMS. Diallyl disulfide (49.1%) and diallyl trisulfide (30.38%) were the main components of the five identified components. The phenolic content of the ethanol extract are analysed for its phenolic profiles, colorimetric analysis revealed that the total phenols, flavonoids and proanthocyanidins contents were respectively 43.63 mg GA/g, 13.18 mg quercetin/g and 24.24 mg of catechin/g. Antioxidant activity was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, essential oil presented the highest antioxidant activity compared to its ethanol extract. IC50 values observed for the essential oil and ethanol extract were 300 μg/ml and 600 μg/ml respectively. The essential oil and ethanol extract from raw garlic were tested for antimicrobial activity against seven microorganisms. The results showed that ethanol extract was active against all tested strains: Escherichia coli, Salmonella typhi, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Yersinia enterocolitica and Bacillus cereus.

Content of bioactive compounds and antioxidant activity in garlic (Allium sativum L.)

“…In other studied varieties of garlic higher total polyphenols content was found in the area of Nitra. Chekki et al (2014) indicated, that the total polyphenols content in garlic is in the wide range from 436 mg kg -1 to 645 mg kg -1 , which good correlate with the results of this work. Some authors reported even a higher value of TPC in garlic: 812 mg kg -1 (Charles, 2013), 1290 mg kg -1 (Wangcharoen & Morasuk, 2009).…”

“…The coefficient of correlation (r = 0.9315 -0.9978) confirmed strong dependency between the content of polyphenols, total sulfur content and the antioxidant activity and the results are in good agreement with the findings of Mahmutović et al (2014), who confirmed correlations between total polyphenols content, total sulfur content and antioxidant activity in garlic. Ramkissoon et al (2012), Chekki et al (2014) indicated correlations between total polyphenols content and antioxidant activity in garlic, onion and other vegetable..…”

Evaluation and comparison of the content of total polyphenols and antioxidant activity of selected species of the genus Allium

“…In comparison with this study Batcioglu et al (2012) indicated lower total polyphenol content in garlic is 780 mg*kg -1 , similarly Charles (2013) recorded that TPC in garlic is 812 mg*kg -1 . Some authors reported even a lower value of TPC in garlic: 436 mg*kg -1 (Chekki et al, 2014), 410 mg*kg -1 (Wangcharoen and Morasuk, 2007), 493 mg*kg -1 (Jastrzebski et al, 2007). By way of contrast Wangcharoen and Morasuk (2009) The values of antioxidant activity in the studied samples are presented in Table 3.…”

Investigation into SARS-CoV-2 Resistance of Compounds in Garlic Essential Oil

“…Besides, allicin is a typical reactive sulfur species found in the essential oil. 5 Recently, many people have been infected with a novel coronavirus (SARS-CoV-2), and the death toll has reached thousands and been increasing day by day, which is a major problem in the world. 6 Therefore, the demand to seek for natural and safe medicines to prevent coronavirus is of great concern for all scientists around the world.…”