Aloesin

Anal Cell Pathol (Amst) . 2017;2017:8158254.

Aloesin Suppresses Cell Growth and Metastasis in Ovarian Cancer SKOV3 Cells through the Inhibition of the MAPK Signaling Pathway[Pubmed: 28702312]

Aloesin is an active constituent of the herb aloe vera and plays a crucial role in anti-inflammatory activity, ultraviolet protection, and antibacterium. We investigated the role and possible mechanisms of Aloesin in the cell growth and metastasis of ovarian cancer. It was found that Aloesin inhibited cell viability and cell clonality in a dose-dependent manner. It arrests the cell cycle at the S-phase and induced apoptosis in SKOV3 cells. In an in vivo experiment, it was observed that Aloesin inhibited tumor growth. Moreover, it inhibited migration and invasion of cancer in SKOV3 cells. Interestingly, members from the mitogen-activated protein kinase (MAPK) signaling family became less phosphorylated as the Aloesin dose increased. This suggests that Aloesin exerts its anticancer effect through the MAPK signaling pathway. Our data also highlights the possibility of using Aloesin as a novel therapeutic drug for ovarian cancer treatment.

Phytomedicine . 2017 May 15;28:19-26.

Aloesin from Aloe vera accelerates skin wound healing by modulating MAPK/Rho and Smad signaling pathways in vitro and in vivo[Pubmed: 28478809]

Background: Cutaneous wound healing is a complex process involving various regulatory factors at the molecular level. Aloe vera is widely used for cell rejuvenation, wound healing, and skin moisturizing. Hypothesis/purpose: This study aimed to investigate the effects of Aloesin from Aloe vera on cutaneous wound healing and mechanisms involved therein. Study design: This study consisted of both in vitro and in vivo experiments involving skin cell lines and mouse model to demonstrate the wound healing effects of Aloesin by taking into account several parameters ranging from cultured cell migration to wound healing in mice. Methods: The activities of Smad signaling molecules (Smad2 and Smad3), MAPKs (ERK and JNK), and migration-related proteins (Cdc42, Rac1, and α-Pak) were assessed after Aloesin treatment in cultured cells (1, 5 and 10μM) and mouse skin (0.1% and 0.5%). We also monitored macrophage recruitment, secretion of cytokines and growth factors, tissue development, and angiogenesis after Aloesin treatment using IHC analysis and ELISAs. Results: Aloesin increased cell migration via phosphorylation of Cdc42 and Rac1. Aloesin positively regulated the release of cytokines and growth factors (IL-1β, IL-6, TGF-β1 and TNF-α) from macrophages (RAW264.7) and enhanced angiogenesis in endothelial cells (HUVECs). Aloesin treatment accelerated wound closure rates in hairless mice by inducing angiogenesis, collagen deposition and granulation tissue formation. More importantly, Aloesin treatment resulted in the activation of Smad and MAPK signaling proteins that are key players in cell migration, angiogenesis and tissue development. Conclusion: Aloesin ameliorates each phase of the wound healing process including inflammation, proliferation and remodeling through MAPK/Rho and Smad signaling pathways. These findings indicate that Aloesin has the therapeutic potential for treating cutaneous wounds.

Clin Exp Dermatol . 2002 Sep;27(6):513-515.

Aloesin inhibits hyperpigmentation induced by UV radiation[Pubmed: 12372097]

Skin hyperpigmentation is caused by the overproduction of melanin pigment, which is synthesized by the action of tyrosinase. We recently reported that Aloesin inhibits tyrosinase activity. The present study was undertaken to test the inhibitory effect of Aloesin on pigmentation in human skin after UV radiation. Experimental subjects were UV-irradiated (210 mJ) on the inner forearm. UV-irradiated regions were assigned to four groups: vehicle control, Aloesin treated, arbutin treated, and Aloesin and arbutin treated. Aloesin and/or arbutin were administered four times a day for 15 days. Aloesin treatment suppressed pigmentation by 34%, arbutin by 43.5%, and the cotreatment by 63.3% compared with the control (n = 15; P < 0.05). Moreover, Aloesin treatment showed pigmentation suppression in a dose-dependent manner (n = 7; P < 0.05). These results raise the possibility that Aloesin may be used as an agent that inhibits melanin formation induced by UV radiation.

Regul Toxicol Pharmacol . 2011 Nov;61(2):215-221.

In vitro and in vivo assessment of the genotoxic activity of aloesin[Pubmed: 21821088]

Aloesin is a chromone that is a component of Aloe spp. It may have potential as a functional food ingredient as it has been shown to likely have beneficial effects in persons in a pre-diabetic state or who have metabolic syndrome. In this study the safety of Aloesin has been evaluated using a series of in vitro and in vivo genotoxicity assays including, bacterial mutation, mammalian cell cytogenetic, and mouse micronucleus tests. Aloesin did not induce reverse mutations in Salmonella typhimurium and Escherichia coli at any of the tested dose levels up to 10,000 μg/plate. Similarly, Aloesin did not increase the incidence of chromosome aberrations when incubated with Chinese hamster lung cells at any of the tested concentrations up to 10,000 μg/mL. In vivo, there was no effect of Aloesin on the incidence of micronucleated erythrocytes following oral administration on two consecutive days at doses up to 5000 mg/kg body weight. There was no evidence of toxicity to bone marrow. The results of these studies demonstrate that Aloesin is without genotoxic potential.

Biochem Mol Biol Int . 1997 Feb;41(2):285-292.

Aloesin up-regulates cyclin E/CDK2 kinase activity via inducing the protein levels of cyclin E, CDK2, and CDC25A in SK-HEP-1 cells[Pubmed: 9063568]

In the present study, we show that Aloesin, which is a low molecular weight ingredients present in Aloe vera, stimulates the proliferation of cultured human hepatoma SK-HEP-1 cells. The incorporation of [3H] thymidine into DNA in the cell cultures was significantly increased at a dose of 10 microM Aloesin. The Aloesin-induced DNA synthesis appears to require newly synthesized proteins because cycloheximide treatment blocked the DNA synthesis evoked by this compound. We then examined whether this compound increases the intracellular levels of cell cycle regulators by immunoblotting. The data showed that Aloesin increased the levels of cyclin E, CDK2, and CDC25A in SK-HEP-1 cells. In addition, immuno-complex kinase assays showed that Aloesin up-regulated the enzyme activity of cyclin E/CDK2 kinase in a dose-dependent manner. Collectively, these results suggest that Aloesin stimulates the proliferation of SK-HEP-1 cells by inducing the intracellular levels of cyclin E/CDK2 kinase complex and CDC25A, which, together, result in the up-regulation of cyclin E-dependent kinase activity.

Fitoterapia . 2021 Apr;150:104828.

Anti-tyrosinase activity of South African Aloe species and isolated compounds plicataloside and aloesin[Pubmed: 33434632]

Tyrosinase is the key enzyme in the production of melanin. Tyrosinase inhibitors have gained interest in the cosmetics industry to prevent hyperpigmentation and skin-related disorders by inhibiting melanin production. It has been reported that several Aloe species exhibit anti-tyrosinase efficacy in vitro. In this study, the exudates of thirty-nine South African Aloe species were screened to identify species and compounds with anti-tyrosinase activity. Qualitative screening revealed that twenty-nine Aloe species exhibited tyrosinase inhibition activity with one to three active bands. Quantitative screening was performed for 29 species and expressed as IC50 values. Three species were further analysed and subsequently, Aloesin and aloeresin A was isolated from A. ferox and plicataloside from A. plicatilis and A. chabaudii. Aloeresin A was determined to be a substrate of mushroom tyrosinase. Dose-response assays showed that Aloesin (IC50 = 31.5 μM) and plicataloside (IC50 = 84.1 μM) exhibited moderate to weak activity. Molecular docking scores for plicataloside were considerably lower than for Aloesin (P < 0.01), confirming its lower IC50. Several Aloe species may have potential for the management of hyperpigmentation or as a skin lightening agent. This is the first report showing that plicataloside, present in A. plicatilis and A. chabaudii, exhibits anti-tyrosinase activity.

Phytomedicine . 2017 May 15;28:19-26.

Aloesin from Aloe vera accelerates skin wound healing by modulating MAPK/Rho and Smad signaling pathways in vitro and in vivo[Pubmed: 28478809]

Background: Cutaneous wound healing is a complex process involving various regulatory factors at the molecular level. Aloe vera is widely used for cell rejuvenation, wound healing, and skin moisturizing. Hypothesis/purpose: This study aimed to investigate the effects of Aloesin from Aloe vera on cutaneous wound healing and mechanisms involved therein. Study design: This study consisted of both in vitro and in vivo experiments involving skin cell lines and mouse model to demonstrate the wound healing effects of Aloesin by taking into account several parameters ranging from cultured cell migration to wound healing in mice. Methods: The activities of Smad signaling molecules (Smad2 and Smad3), MAPKs (ERK and JNK), and migration-related proteins (Cdc42, Rac1, and α-Pak) were assessed after Aloesin treatment in cultured cells (1, 5 and 10μM) and mouse skin (0.1% and 0.5%). We also monitored macrophage recruitment, secretion of cytokines and growth factors, tissue development, and angiogenesis after Aloesin treatment using IHC analysis and ELISAs. Results: Aloesin increased cell migration via phosphorylation of Cdc42 and Rac1. Aloesin positively regulated the release of cytokines and growth factors (IL-1β, IL-6, TGF-β1 and TNF-α) from macrophages (RAW264.7) and enhanced angiogenesis in endothelial cells (HUVECs). Aloesin treatment accelerated wound closure rates in hairless mice by inducing angiogenesis, collagen deposition and granulation tissue formation. More importantly, Aloesin treatment resulted in the activation of Smad and MAPK signaling proteins that are key players in cell migration, angiogenesis and tissue development. Conclusion: Aloesin ameliorates each phase of the wound healing process including inflammation, proliferation and remodeling through MAPK/Rho and Smad signaling pathways. These findings indicate that Aloesin has the therapeutic potential for treating cutaneous wounds.

Regul Toxicol Pharmacol . 2011 Nov;61(2):215-221.

In vitro and in vivo assessment of the genotoxic activity of aloesin[Pubmed: 21821088]

Aloesin is a chromone that is a component of Aloe spp. It may have potential as a functional food ingredient as it has been shown to likely have beneficial effects in persons in a pre-diabetic state or who have metabolic syndrome. In this study the safety of Aloesin has been evaluated using a series of in vitro and in vivo genotoxicity assays including, bacterial mutation, mammalian cell cytogenetic, and mouse micronucleus tests. Aloesin did not induce reverse mutations in Salmonella typhimurium and Escherichia coli at any of the tested dose levels up to 10,000 μg/plate. Similarly, Aloesin did not increase the incidence of chromosome aberrations when incubated with Chinese hamster lung cells at any of the tested concentrations up to 10,000 μg/mL. In vivo, there was no effect of Aloesin on the incidence of micronucleated erythrocytes following oral administration on two consecutive days at doses up to 5000 mg/kg body weight. There was no evidence of toxicity to bone marrow. The results of these studies demonstrate that Aloesin is without genotoxic potential.