What are the benefits of pequi oil on the skin?

Sagging skin structures, premature wrinkles, pigmentation disorders... These free radicals, particularly generated by exposure to UV rays, tobacco and pollution, are harmful to the skin. To protect against them, it is recommended to use antioxidants, which are molecules capable of trapping free radicals and preventing them from attacking cellular constituents. Rich in antioxidants, piqui oil is an interesting ingredient to combat oxidative stress.

Pequi oil notably contains beta-carotene, a pigment responsible for its orange colour. Thanks to the numerous double bonds present in its chemical structure, it can neutralise free radicals through electron donation. Beta-carotene is also believed to be capable of inhibiting the production of lipid peroxides. Its antioxidant properties are further enhanced by those of vitamins A, C and E, also found within pequi oil.

Pequi oil also possesses soothing properties, derived from its fatty acids. Several studies have highlighted that these compounds can modulate the inflammatory response by inhibiting the synthesis of certain pro-inflammatory cytokines, such as TNF-α and interleukins 1β and 6 (IL-1β and IL-6). Studies in vitro conducted on human monocyte cells TPH-1 have also shown that the linoleic acid found in pequi oil can suppress the activities of cyclooxygenases 1 and 2 (COX-1 and COX-2), enzymes catalysing the formation of inflammatory prostaglandins.

Furthermore, these results were confirmed during a study conducted with mice exhibiting ear oedema. The topical application of pure pequi oil immediately after the induction of inflammation resulted in a 38.01% reduction in oedema within 15 minutes compared to the positive control. Although clinical trials with human volunteers are still necessary to assert that pequi oil can soothe irritations and reduce redness, these initial results are promising.

Several factors suggest that pequi oil may have healing properties, potentially useful in cases of minor cuts or stretch marks. These properties are thought to stem from its richness in oleic acid, a fatty acid capable of stimulating the synthesis of collagen III. Now, collagen III is a key protein in granulation tissue synthesised by fibroblasts. This is a transitional tissue that forms following inflammation or skin injury. Moreover, studies have shown that the unsaturated fatty acids in pequi oil are also present in plasma membranes where they stimulate cell proliferation and angiogenesis, thus playing a significant role in the healing process.

A recent study involving injured rats has explored the healing potential of pequi oil. For this purpose, the rats were divided into two groups: the first benefited from regular topical application of pequi oil, while the second received no treatment. After 16 days, the average wound contraction values in the rats treated with pequi oil were 6.25 ± 0.51% compared to 4.17 ± 0.28% in the control rats. A statistically significant difference was thus observed, suggesting that pequi oil promoted the healing process in the rats. A similar action in humans can be hypothesised, although further research is necessary to confirm this.

It would appear that pequi oil has an action against certain bacteria belonging to the skin microbiota. A study in vitro conducted in 2009 indeed demonstrated that pequi oil, thanks to the oleic acid it contains, can inhibit the growth of the pathogen Staphylococcus aureus, with a minimum inhibitory concentration (MIC) of 1.25%. As a reminder, the MIC refers to the lowest concentration of a substance that can inhibit bacterial growth.

Furthermore, another study has shown that when pequi oil is combined with certain antibiotics, it is capable of enhancing their antibacterial activity. This was particularly demonstrated with erythromycin, an antibiotic commonly used to treat acne. The addition of pequi oil to the culture medium ofEscherichia coli resulted in a reduction of the antibiotic's MIC from 32 µg/mL to 2 µg/mL.

The modulating effect of pequi oil can be explained by its richness in hydrophobic compounds, specifically saturated and unsaturated fatty acids, which make the bacterial cell more permeable to the entry of antibiotics, thereby increasing their effectiveness and reducing the minimum concentration required to affect the bacteria. Furthermore, due to their detergent properties, fatty acids may have altered the amphipathic combinations of the bacterial cell membrane. More specifically, they may have solubilised membrane components such as lipids and proteins, causing a disruption of structures and affecting essential metabolic processes for obtaining energy for the bacterial cell, such as the electron transport chain and oxidative phosphorylation. These membrane damages may also result in difficulties in nutrient absorption by the bacteria.