Zeleria  Yusuf, Gebremeskel  Mebrate, Mulugeta  Desta, Sewnet  Mengistu, 
    Physicochemical Properties, Antioxidant and Antimicrobial Activities of Milk Thistle (<i>Silybum
marianum</i> L.) Seed and Leaf Oil Extracts,
    Research Journal of Medical Sciences,
    Volume 15,Issue 5,
    2021,
    Pages 78-82,
    ISSN 1815-9346,
    rjmsci.2021.78.82,
    (https://makhillpublications.co/view-article.php?doi=rjmsci.2021.78.82)
    Abstract: Milk thistle (<i>Silybum marianum</i> L.) fruit
extract (silymarin) is a flavonolignan called silybin that
has been indicated to conserve animal livers against the
harming impacts. The present study was aimed to
examine physicochemical properties antioxidant and
antimicrobial activities of oil extracted from <i>S. marianum</i>,
seeds and leaves. The oil extraction was done in Soxhelt
apparatus using petroleum ether as a solvent. Then,
physicochemical properties of the oil extracts were
conducted based on determination of oil content, specific
gravity, acid value, percent free fatty acid and peroxide
values. The antioxidant activity was investigated based on
determination of ascorbic acid content, DPPH and
hydrogen peroxide free radical scavenging activities. The
antimicrobial activity test were conducted using disc
diffusion method and broth dilution method. The result of
physicochemical properties of <i>S. marianum</i> seed and leaf
oils indicated significance differences between seed and
leaf oils were obtained for all measured parameters. It was
found that oil yield (44.5%), specific gravity (0.89), acid
value (1.54) and free fatty acids (0.78% were significantly
higher for seed oil extract. The antioxidant activities of <i>S.
marianum</i> seed and leaf oil extracts presented
significantly higher antioxidant activities with respect to
ascorbic acid content (55.05&#146;1.47) and DPPH value
(18.00&#146;2.55) for seed oil than for leaf oil. Stronger
antibacterial activity with maximum zone of inhibition
(15.50mm), bactericidal activity with MIC (0.06 &#956;L/mL)
and MBC (0.12 &#956;L/mL) were recorded for leaf oil extract
against S. aureus. The stronger antifungal activity with
maximum zone of inhibition (13.83 mm), MIC
(0.25 &#956;L/mL, the least value) and MFC (0.50 &#956;L/mL)
were recorded for seed oil against <i>A. versicolor</i>. Thus,
milk thistle has low peroxide and acid values which show
its low oxidation rancidity and high biological activities
make it suitable for nutraceutical and drug development.
    Keywords: Antioxidant activity;antimicrobial potential;DPPH;inhibition zone;minimum inhibitory concentration;test pathogens