Alpha Mangostin promotes myogenic differentiation of C2C12 mouse myoblast cells

Effects of Protein Hydrolysate from Silkworm (Bombyx mori) pupae on the C2C12 Myogenic Differentiation

This study investigated the effects and active compounds of silkworm pupae, an edible insect, on C2C12 muscle differentiation. The protein of silkworm pupae was extracted using sonication after defatting with hexane. Subsequently, the extract was rehydrated using Alcalase to obtain a protein hydrolysate. The silkworm pupae protein hydrolysate effectively promoted C2C12 myogenic differentiation without cytotoxicity. Subsequently, the hydrolysate was fractionated into four subfractions using preparative high-performance liquid chromatography (Prep-HPLC). Subfraction 1 was the most effective in promoting C2C12 myogenic differentiation and significantly upregulated the expression of myoblast transcription factors, 1.5-fold of myoblast determination protein 1 (MyoD), 2-fold of myogenin, and 3-fold of myosin heavy chain (MyHC). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and multivariate statistical analysis were used to identify the active peptides in silkworm pupae responsible for the observed effects; then, dipeptides and essential amino acids, such as isoleucine (Ile), valine (Val), and methionine (Met), were identified. In addition, Val, Ile, and two dipeptides underwent quantification to determine the potential bioactive peptides that enhanced C2C12 myogenic differentiation. This study suggests that the peptides from silkworm pupae could be used as a nutraceutical to enhance muscle growth.

Discovery of phenylcarbamoyl xanthone derivatives as potent neuroprotective agents for treating ischemic stroke

Compounds of natural sources are widespread discovered in the treatment of ischemic stroke. Alpha-mangostin, a natural prenylated xanthone, has been found to display a therapeutic potential to treat ischemic stroke. However, the direct application of α-mangostin is limited due to its cytotoxicity and relatively low efficacy. Herein, structural modification of α-mangostin was necessary to improve its drug-ability. Currently, 34 α-mangostin phenylcarbamoyl derivatives were synthesized and evaluated for their neuroprotective activities by glutamate-induced excitotoxicity and H₂O₂-induced oxidative damage models in vitro. The results showed that compound 2 had the most therapeutic potential in both models. Whereafter, 2 has been proved to have powerful therapeutic effects by the MCAO ischemic stroke model in rats, which might be due to inhibition of inflammatory reaction and free radical accumulation. Besides, acute toxicity assay in rats showed that compound 2 had excellent safety. Overall, 2 could be a promising neuroprotective agent for the treatment of ischemic stroke deserving further investigations.

α-Mangostin suppressed melanogenesis in B16F10 murine melanoma cells through GSK3β and ERK signaling pathway

Mangosteen (Garcinia mangostana L) fruit contains many xanthones in its pericarp, such as α-mangostin. Here, we aimed to elucidate the physiological effect of α-mangostin and the mechanism on melanogenesis in mouse B16F10 cells. The melanin production in B16F10 cells was decreased by α-mangostin treatment. α-Mangostin also suppressed the enzymatic activity of tyrosinase, the critical enzyme for melanin synthesis. Furthermore, Western blot analysis revealed that α-mangostin down-regulated the protein quantity of tyrosinase, tyrosinase relative protein (TRP)-2, and microphthalmia-associated transcription factor (MITF). We also used inhibitors of the extracellular signal-regulated kinase (ERK), and glycogen synthase kinase 3 (GSK-3β) to identify the upstream signaling cascade of MITF. Results showed us GSK3β plays a more important role in α-mangostin regulated melanogenesis. Further, the de-pigmentation effect on normal human epidermal melanocytes (NHEMs) of α-mangostin was also confirmed. These results suggested that α-mangostin is a reagent for depigmentation and it has the potential to be applied as a component of cosmetics or pharmaceuticals for the therapy of spots, chloasma, or melanosis.

α-Mangostin suppressed the melanin production in B16F10 cells.

α-Mangostin suppressed the activity of tyrosinase.

α-Mangostin suppressed the protein expression of tyrosinase, TRP-2 and MITF.

GSK3β is involved in α-mangostin-regulated melanogenesis.

α-Mangostin suppressed the melanin production in normal human melanocytes.

Ionic Silicon Protects Oxidative Damage and Promotes Skeletal Muscle Cell Regeneration

Volumetric muscle loss injuries overwhelm the endogenous regenerative capacity of skeletal muscle, and the associated oxidative damage can delay regeneration and prolong recovery. This study aimed to investigate the effect of silicon-ions on C2C12 skeletal muscle cells under normal and excessive oxidative stress conditions to gain insights into its role on myogenesis during the early stages of muscle regeneration. In vitro studies indicated that 0.1 mM Si-ions into cell culture media significantly increased cell viability, proliferation, migration, and myotube formation compared to control. Additionally, MyoG, MyoD, Neurturin, and GABA expression were significantly increased with addition of 0.1, 0.5, and 1.0 mM of Si-ion for 1 and 5 days of C2C12 myoblast differentiation. Furthermore, 0.1-2.0 mM Si-ions attenuated the toxic effects of H2O2 within 24 h resulting in increased cell viability and differentiation. Addition of 1.0 mM of Si-ions significantly aid cell recovery and protected from the toxic effect of 0.4 mM H2O2 on cell migration. These results suggest that ionic silicon may have a potential effect in unfavorable situations where reactive oxygen species is predominant affecting cell viability, proliferation, migration, and differentiation. Furthermore, this study provides a guide for designing Si-containing biomaterials with desirable Si-ion release for skeletal muscle regeneration.