Tetrahydroquinoline/4,5-dihydroisoxazole hybrids with a remarkable effect over mitochondrial bioenergetic metabolism on melanoma cell line B16F10

Background: Melanin plays a crucial role in camouflage, social communication and protection against harmful ultraviolet radiations. Melanin is synthesized by melanocytes through melanogenesis and several intrinsic and extrinsic factors are involved during the process. Any change occuring in the normal melanogenesis process can cause severe pigmentation problems of hypopigmentation or hyperpigmentation. Objective: The present study is based on the evaluation of the effect of thymoquinone on melanogenesis and their possible mechanism of action using the B16F10 melanoma cell line for the production via blocking signaling pathways. Methods: Phase contrast microscopy, cell viability, tyrosinase activity, melanin content and western blot analysis were used in the present study. Results: In the present investigation, cultured melanocytes exhibit that the stimulation of melanin synthesis when treated with thymoquinone. Tyrosinase activity and melanin production in B16F10 melanoma cell line was increased in doze-dependent manner. In western blot, we investigated the involvement of the cAMP/PKA pathway in thymoquinone induced melanogenesis. It was observed protein kinase inhibitors PKA, PKC, PKB and MEK1 decreased the stimulatory effects of thymoquinone from 11.45- fold value to 8.312, 6.631, 4.51, and 7.211-fold value, respectively. However, the results also prove that thymoquinone may partially induce tyrosinase expression via PKA, PKB, PKC and MEK1 signaling pathways. Conclusion: The present finding proposed that thymoquinone is a protective challenger for melanogenesis and it might be useful for the treatment of hypopigmentary disorders.

Download Full-text

In Vitro Anticancer Potential of Jasione montana and Its Main Components Against Human Amelanotic Melanoma Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22073345 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3345

Author(s):

Aleksandra Maria Juszczak ◽

Robert Czarnomysy ◽

Jakub Władysław Strawa ◽

Marijana Zovko Končić ◽

Krzysztof Bielawski ◽

...

Keyword(s):

Cell Line ◽

Melanoma Cell ◽

Melanoma Cell Line ◽

Binding Assay ◽

Annexin V ◽

Melanoma Cells ◽

Amelanotic Melanoma ◽

Cytotoxic Activities ◽

Ionization Mass ◽

Caspase 9

Jasione montana L. (Campanulaceae) is used in traditional Belarusian herbal medicine for sleep disorders in children, but the chemical composition and biological activity have not been investigated. In this study, the activities of J. montana extracts, their fractions and main compounds were evaluated in amelanotic melanoma C32 (CRL-1585) cells and normal fibroblasts (PCS-201-012). The extracts and fractions were analyzed using liquid chromatography–photodiode array detection–electrospray ionization–mass spectrometry (LC–PDA–ESI–MS/TOF) to characterize 25 compounds. Further, three major and known constituents, luteolin (22) and its derivatives such as 7-O-glucoside (12) and 7-O-sambubioside (9) were isolated and identified. The cytotoxic activities against fibroblasts and the amelanotic melanoma cell line were determined using the fixable viability stain (FVS) assay. The influence of diethyl ether (Et2O) fraction (JM4) and 22 on apoptosis induction was investigated using an annexin V binding assay. The obtained results showed significant cytotoxicity of JM4 and 22 with IC50 values of 119.7 ± 3.2 and 95.1 ± 7.2 μg/mL, respectively. The proapoptotic potential after 22 treatment in the C32 human amelanotic melanoma cell line was comparable to that of vinblastine sulfate (VLB), detecting 29.2 ± 3.0% apoptotic cells. Moreover, 22 displayed less necrotic potential against melanoma cells than VLB. In addition, the influences of JM4 and 22 on the dysfunction of the mitochondrial membrane potential (MMP), cell cycle and activity of caspases 3, 8, 9, and 10 were established. The effects of JM4 on MMP change (74.5 ± 3.0% of the cells showed a reduced MMP) corresponded to the results obtained from the annexin V binding assay and activation of caspase-9. JM4 and 22 displayed a significant impact on caspase-9 (40.9 ± 2.4% of the cells contained active caspase-9 after JM4 treatment and 16.6 ± 0.8% after incubation with 22) and the intrinsic (mitochondrial) apoptotic pathway. Moreover, studies have shown that JM4 and 22 affect the activation of external apoptosis pathways by inducing the caspase-8 and caspase-10 cascades. Thus, activation of caspase-3 and DNA damage via external and internal apoptotic pathways were observed after treatment with JM4 and 22. The obtained results suggest that J. montana extracts could be developed as new topical preparations with potential anticancer properties due to their promising cytotoxic and proapoptotic potential.

Download Full-text