While many natural extracts and essential oils are known for a single benefit, Indian sandalwood is a multi-functional ingredient.

The active ingredient of Indian sandalwood can achieve multiple benefits and, in addition to its therapeutic benefits, the oil is renowned for its olfactory characteristics, having a soft, warm and woody odour. As a result of this scent, the oil has found its way into many applications, including cosmetics, skincare, perfumery and aromatherapy.

Quintis, a leading supplier of sustainable Indian sandalwood, commissioned studies looking into the antioxidant and anti-aging potential of Indian sandalwood oil against environmental stressors. Two of the key studies – the in vitro Cellular Study and the in vivo Clinical Trial – have shown conclusively that Indian sandalwood oil is a great natural multi-purpose ingredient for cosmetic care as it is an effective protective and anti-aging active ingredient, and it has scientifically-proven bioactivities with multiple benefits on skin.

Cellular study

The 2021 in vitro Cellular Study found that Indian sandalwood oil is a more potent antioxidant than the known lipophilic antioxidant vitamin E (alpha-tocopherol).

The study found that with subsequent exposure to environmental stressors, Indian sandalwood oil recorded a reactive oxygen species reduction 30-40% higher than the recorded reduction from Vitamin E.

In more detail, when isolated skin tissue was exposed to simulated environmental pollution, including cigarette smoke and ozone pollution, the enzyme Matrix metalloproteinase-1 (MMP1), which digests the collagen tissue was increased. However, when the skin isolates were treated with Indian sandalwood oil, the enzyme MMP1 was decreased, suggesting the collagen protective effect of Indian sandalwood reduces the appearance of wrinkles (1).

Skin cells were also exposed to a source of blue light and those cells produced reactive oxygen species, which begins a cascade of reactions detrimental to a healthy skin. However, when the cell cultures were treated with sandalwood oil, production of reactive oxygen species was reduced by up to 76%.

Clinical evaluation

The 2022 in vivo Clinical Study reinforced Indian sandalwood as a powerful antioxidant, which offers protection against environmental blue light damage.

The study is the first Clinical Trial of its kind proving that Indian sandalwood at concentrations of 0.1%, 1% and 10% protects the skin against the oxidative stress induced by ambient dust and environmental blue light exposure, and the overall efficacy is comparable to the topical skin protective effect of Vitamin E2.

To evaluate the effects of Indian sandalwood oil on skin, the level of oxidised squalene was monitored as a measurement of skin oxidation. The study assessed the protective effect of a cosmetic product containing Indian sandalwood oil against cutaneous oxidative stress induced by environmental pollution such as ambient dust and blue light at a wavelength of 412 nm (2).

The results indicated that there was a dose-dependent decrease in the levels of free radical damage, with a concentration of Quintis Indian sandalwood (1%) representing a 24% decrease in squalene monohydroperoxide (SQOOH) compared to non-treated study areas.

Safe essential oil

Indian sandalwood oil is considered a safe essential oil for skin application based on several skin irritation and sensitisation studies conducted since the 1970s by reputed organisations such as the Institute of Fragrance Research.  Study panels with sensitive skin have shown an average of 2% sensitivity in large cohort studies. However, the normal skin panels showed no reaction to sandalwood used even at 100% (3). The International Fragrance Association (IFRA) approves Indian sandalwood oil at 100% for most of the topical uses, with the exceptions of mucosa, axilla and paediatric skin. This is a remarkable contrast to the majority of other essential oils where the usage levels stand at usually less than 10% on skin application.

Multi-functional ingredient

Quintis’ studies have conclusively shown Indian sandalwood oil is a natural anti-inflammatory and a strong shield against free radicals and premature aging. Through the in vitro Cellular Study and in vivo Clinical Trial, it has identified a need to support cosmetic and personal care formulators by continuing to provide education and communicate the results of studies looking at the benefits of Indian sandalwood oil.

Including the protective and anti-aging active ingredient as a multi-functionality ingredient in cosmetics and dermatology will open up the potential to offer those benefits to consumers through a range of topical products.

References

1. Francois-Newton, V., et al. (2021). ‘Antioxidant and Anti-Aging Potential of Indian Sandalwood Oil against Environmental Stressors In Vitro and Ex Vivo.’ Cosmetics 8(2): 53.
2. Lutchmanen Kolanthan, V., et al. (2022). ‘Clinical Evaluation of Indian Sandalwood Oil and Its Protective Effect on the Skin against the Detrimental Effect of Exposome.’ Cosmetics 9(2): 35.
3. Tisserand, R. and R. Young (2013). Essential oil safety-e-book: A guide for health care professionals, pp418-419 Elsevier Health Sciences.

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*Technical Product Specialist, Quintis Ltd, Australia (www.quintis.com.au).