Silybum marianum seed oil

Silybum marianum seed oil comes from the milk thistle plant. Depending on the extraction method (ethanol vs. cold-pressed), this seed oil is a rich source of numerous types of antioxidants known as polyphenols. Chief among them is silymarin, which contains flavonolignans. These are what’s responsible for silymarin’s soothing, reparative benefits when applied to skin. They also give this plant ingredient the ability to neutralize highly damaging hydroxyl radicals that can form when skin is exposed to UV light.

Silymarin and other compounds in this seed oil can help inhibit destructive enzymes in skin’s uppermost layers that would otherwise damage collagen, elastin, and hyaluronic acid, leading to visibly aged skin. Silymarin and its derivative silybin have also been shown to visibly reduce dark spots. Studies have shown topical application of milk thistle can help fade discoloration from sun exposure and other sources without adverse effects.

Some research indicates that extraction via ethanol is preferred because when cold-pressed, the seed oil’s silymarin content is lower; however, cold pressing releases more of the silymarin derivative silybin, which is an even more potent antioxidant and skin soother than silymarin. Either method provides a good source of alpha tocopherol (vitamin E), phospholipids, and squalene as well as polyphenols such as vanillic acid and p-coumaric.

References for this information:

Journal of Food Biochemistry, Volume 44, October 2020, ePublication
Molecules, Volume 24, March 2019, ePublication
Journal of Cosmetic Dermatology, February 2019, pages 263–269
Indian Dermatology Online Journal, October–December 2014, pages 426–435
Pharmacognosy Magazine, January 2014, Supplement, pages S92–S99
BMC Dermatology, October 2012, ePublication

See Silybum marianum (milk thistle) fruit extract

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