Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways

Abstract

The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE) in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS). The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1–10 mg/mL) and its major fatty acids such as linoleic acid and oleic acid (6.25–50 μM) effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA), phosphatidylinositol-3-kinase (PI3K/Akt), and mitogen-activated protein kinases (MAPK) signaling pathways, which may be due to linoleic acid and oleic acid.

Spent Coffee Grounds Valorization as Bioactive Phenolic Source Acquired Antifungal, Anti-Mycotoxigenic, and Anti-Cytotoxic Activities

“…The SCGs showed concerning bioactive components such as insoluble dietary fiber, polysaccharides, lipids, amino acids, proteins, alkaloids, phenolics, minerals, and volatile compounds [6]. The previous investigations have focused on the SCGs' bioactivity and their antioxidant [7], anti-inflammatory [8], dermatological, anti-melanogenesis [9], and metal scavenging properties [10]. The optimum conditions of solid/liquid SCGs-extraction using solvent systems to recover the antioxidant polyphenols were studied [11].…”

Supercritical Fluid Extraction of Pyrrolidine Alkaloid from Leaves of Piper amalago L.

“…The extractor was loaded in a random way with approximately 12 g of noncompact powdered sample. The extraction parameters of compound were performed by orthogonal array design (OAD) OA 9 (3 4 ) ( Table 1 ) [ 16 ]. In the present work, four factors were studied by a three-level OAD: modifiers, dynamics extraction time, temperature, and pressure.…”

“…Therefore, the extraction using clean technology is indispensable. In this sense, supercritical fluid extraction is safer for the human being, due to the reduction of the volume of organic solvent and extraction time [16]. Authors have been extracting alkaloids semipurified by supercritical fluid extraction [17–19], and we have extracted the pyrrolidine alkaloids with better yield than chloroform [12].…”

Inhibitory effects of Stichopus japonicus extract on melanogenesis of mouse cells via ERK phosphorylation

“…Phosphorylation of the mitogen-activated protein kinase (MAPK) signaling pathways lead to a reduction of melanin synthesis in mouse melanocytes. Several studies suggested that activation/phosphorylation of the extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways results in the inhibition of melanogenesis ( 10 , 11 ). This effect has been attributed to the phosphorylation of MITF at serine 73, which results in MITF ubiquitination and degradation ( 12 ).…”