Macadamia and Sapucaia Extracts and the Skin

Macadamia (Macadamia tetraphylla) is endemic to Australia and is now commercially cultivated worldwide.¹ It is closely related genetically to the other macadamia plants, including the other main one, M. integrifolia, cultivated for macadamia nuts. Known in Brazil as sapucaia or castanha-de-sapucaia, Lecythis pisonis (also referred to as “cream nut” or “monkey pot”) is a large, deciduous tropical tree and member of the Brazil nut family, Lecythidaceae.² Various parts of both of these plants have been associated with medicinal properties, including the potential for dermatologic activity. Notably, the leaves of L. pisonis have been used in traditional medicine to treat pruritus.² This column focuses on the studies suggesting the possible benefits of macadamia and sapucaia components for skin care.

Macadamia

Extraction to Harness Antioxidant Activity

In 2015, Dailey and Vuong developed an aqueous extraction process to recover the phenolic content and antioxidant functionality from the skin waste of M. tetraphylla using response surface methodology. As an environmentally suitable solvent that is also cheap and safe, water was chosen to maximize the extraction scenario. They identified the proper conditions (90° C, a time of 20 min, and a sample-to-solvent ratio of 5 g/100 mL) to obtain sufficient phenolic compounds, proanthocyanidins, and flavonoids to render robust antioxidant function.¹

^{Baumann Cosmetic & Research Institute}

Dr. Leslie S. Baumann

Early in 2023, Somwongin et al. investigated various green extraction methods for viability in harnessing the cosmetic/cosmeceutical ingredients of M. integrifolia pericarps. Extracts were assessed for total phenolic content as well as antioxidant and anti–skin aging functions. They found that among the green extraction methods (ultrasound, micellar, microwave, and pulsed electric field extraction with water used as a clean solvent), the ultrasound-assisted extraction method netted the greatest yield and total phenolic content. It was also associated with the most robust antioxidant and anti–skin aging activities. Indeed, the researchers reported that its antioxidant activities were comparable to ascorbic acid and Trolox and its anti–skin aging potency on a par with epigallocatechin-3-gallate and oleanolic acid. The ultrasound-assisted extract was also deemed safe as it did not provoke irritation. The authors concluded that this environmentally suitable extraction method for M. integrifolia is appropriate for obtaining effective macadamia extracts for use in cosmetics and cosmeceuticals.³

Anti-Aging Activity

In 2017, Addy et al. set out to characterize skin surface lipid composition and differences in an age- and sex-controlled population as a foundation for developing a botanically derived skin surface lipid mimetic agent. They noted that fatty acids, triglycerides, cholesterol, steryl esters, wax esters, and squalene are the main constituents of skin surface lipids. The investigators obtained skin surface lipid samples from the foreheads of 59 healthy 22-year-old women, analyzed them, and used the raw components of M. integrifolia, Simmondsia chinensis, and Olea europaea to engineer a mimetic product. They reported that the esterification reactions of jojoba, macadamia, and tall oils, combined with squalene derived from O. europaea, yielded an appropriate skin surface lipid mimetic, which, when applied to delipidized skin, assisted in recovering barrier function, enhancing skin hydration, and improving elasticity as well as firmness in aged skin. The researchers concluded that this skin surface lipid mimetic could serve as an effective supplement to human skin surface lipids in aged skin and for conditions in which the stratum corneum is impaired.⁴