Komane Baatile, Vermaak Ilze, Summers Beverley, Viljoen Alvaro
Department of Pharmaceutical Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
Department of Pharmaceutical Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa; SAMRC Herbal Drugs Research Unit, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
J Ethnopharmacol. 2015 Dec 24;176:327-35. doi: 10.1016/j.jep.2015.10.037. Epub 2015 Oct 31.
Sclerocarya birrea (A.Rich.) Hochst (Marula) nut oil is a popular ingredient in cosmetics such as skin lotions, lipsticks and foundations. The demand for this African oil increased tremendously such that in 2008 almost US$ 20 million was spent on Marula oil for cosmetic product manufacturing. The ethnobotanical literature states that the Zulu people in South Africa amongst others applied the oil to maintain a healthy skin. Scientific studies to support the traditional use as well as the inclusion of Marula oil in cosmetic products is lacking. This study evaluated the irritancy potential (safety), the moisturising and hydrating effects as well occlusivity properties (efficacy) of Marula oil after topical application. In addition, the Marula oil used in this study was comprehensively characterised using two-dimensional gas chromatography coupled to mass spectrometry.
Quantification of the fatty acid methyl esters (FAMEs) was done using a LECO Pegasus 4D GC × GC-MS. To determine the safety and efficacy of Marula oil healthy caucasian adult female volunteers (n = 20) who complied with the inclusion and exclusion criteria for the irritancy patch, moisture efficacy, hydrating and occlusivity tests were recruited for each study. A 2 × magnifying lamp (visual observation), Chromameter®, Aquaflux® and Corneometer® instruments were used to evaluate and monitor the irritancy level, skin barrier function, transepidermal water loss, hydrating and occlusive effects of topically applied Marula oil.
The GC × GC-MS analysis identified several saturated as well as unsaturated fatty acids. Oleic acid was the major fatty acid constituting 69.0% of the oil followed by palmitic acid (15.3%), linoleic acid (9.2%), palmitoleic acid (4.1%) and stearic acid (1.5%). The clinical study revealed that Marula oil is non-irritant (p < 0.001), with moisturising and hydrating properties (p < 0.001) when applied to a lipid-dry (xerosis) skin. Additionally the oil exhibited occlusive effects (p < 0.001) when applied to normal skin. These findings may be linked to the absorption of the oil into the skin due to the high percentage of oleic acid and the presence of palmitic acid which are known to disturb the stratum corneum intercellular lipids. These fatty acids present in Marula oil are very similar to those present in the epidermis, and can be considered biomimetic.
Marula oil rich in fatty acids exhibits moisturising, hydrating and occlusive properties. As the oil is non-irritating and provides a moisturising effect with moderate prevention of transepidermal water loss, average moisture retention properties and noteworthy occlusive effects, its inclusion in cosmetic products based on its traditional use may be justified depending on the application.
比勒陀利亚硬核油桃木（马鲁拉果）籽油是护肤品、口红和粉底等化妆品中常用的成分。对这种非洲油的需求急剧增加，以至于2008年用于化妆品制造的马鲁拉果油花费近2000万美元。民族植物学文献表明，南非的祖鲁人等群体使用这种油来保持皮肤健康。目前缺乏支持其传统用途以及将马鲁拉果油用于化妆品的科学研究。本研究评估了局部应用马鲁拉果油后的刺激潜力（安全性）、保湿和补水效果以及封闭性（功效）。此外，本研究中使用的马鲁拉果油通过二维气相色谱-质谱联用进行了全面表征。
使用LECO Pegasus 4D GC×GC-MS对脂肪酸甲酯（FAMEs）进行定量分析。为了确定马鲁拉果油的安全性和功效，每项研究招募了符合刺激性贴片、保湿功效、补水和封闭性测试纳入和排除标准的健康白种成年女性志愿者（n = 20）。使用2倍放大镜（目视观察）、色度仪、水分通量仪和角质层水合度测定仪评估和监测局部应用马鲁拉果油后的刺激水平、皮肤屏障功能、经表皮水分流失、补水和封闭效果。
GC×GC-MS分析鉴定出几种饱和脂肪酸和不饱和脂肪酸。油酸是主要脂肪酸，占油的69.0%，其次是棕榈酸（15.3%）、亚油酸（9.2%）、棕榈油酸（4.1%）和硬脂酸（1.5%）。临床研究表明，马鲁拉果油无刺激性（p < 0.001），应用于干性皮肤（皮肤干燥症）时具有保湿和补水特性（p < 0.001）。此外，该油应用于正常皮肤时具有封闭效果（p < 0.001）。这些发现可能与油中高比例的油酸和已知会干扰角质层细胞间脂质的棕榈酸被皮肤吸收有关。马鲁拉果油中存在的这些脂肪酸与表皮中存在的脂肪酸非常相似，可以被认为是仿生的。
富含脂肪酸的马鲁拉果油具有保湿、补水和封闭特性。由于该油无刺激性，能提供保湿效果，适度防止经表皮水分流失，具有平均保湿性能和显著的封闭效果，根据其传统用途将其纳入化妆品中可能是合理的，具体取决于应用情况。
