Decelerated skin aging effect of rubber (Hevea brasiliensis) seed oil in cell culture assays

Rubber seeds, the abundant by-products of rubber tree (Hevea brasiliensis), have been studied for sustainable utilization. Nevertheless, there is no information available regarding activity against skin aging. The study aimed to prepare rubber seed oil (RSO) and evaluate fatty acid compositions by gas chromatography - mass spectrometry (GC/MS), linamarin contamination by ultra-high performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS). Additionally, cytotoxicity assay and anti-skin aging activities, including cell proliferating stimulation, cellular antioxidant, collagen stimulation, and matrix metalloproteinase-2 (MMP-2) inhibition, were analyzed in immortalized human skin keratinocytes (HaCaT cells) and human dermal fibroblasts. RSO was pale-yellow oily liquid with an extraction yield of 35.79 ± 0.52%. Principal fatty acids were comprised of oleic (43.37 ± 0.76%), linoleic (38.49 ± 0.81%), palmitic (11.47 ± 0.12%), and stearic (6.66 ± 0.05%) acids. Linamarin contamination was not detected in 100 µg/mL RSO, demonstrating the absence of a cyanogenic glucoside. Non-cytotoxic concentrations of RSO in both cells were in the range of 0.0001-0.1 mg/mL. Activities of RSO against skin aging included the cell proliferating stimulation, the antioxidant activity, the collagen stimulation, and the MMP-2 suppression at mRNA expression level and enzymatic activity. Study results have suggested that rubber seeds can probably be employed as a promising ingredient in the preparations designed for deceleration of skin aging.