Objective: To investigate the mechanism of anticancer activity of a pigment OR3 from Streptomyces coelicolor in in vitro and in vivo metastatic breast cancer models and to characterize the pigment.
Methods: The anticancer mechanism was analyzed in MDA-MB-231 cells using MTT, lactate dehydrogenase, caspase, DNA fragmentation, clonogenic, flow cytometry, Western blot, and scratch assays. The effects of OR3 on xenograft mouse models were evaluated by tumor volume measurement, hematological analysis, and histopathological observation. The characterization of OR3 was also performed using gas chromatograohy-mass spectrometry and nuclear magnetic resonance spectroscopy.
Results: OR3 exhibited potent cytotoxicity against MDA-MB-231 cells, with no observed effects on HEK-293 cells. Caspase-9 activation was detected in OR3-treated MDA-MB-231 cells. Flow cytometry showed a dose-dependent induction of apoptosis and cell cycle arrest at the sub-G1 and S phases. Furthermore, OR3 completely inhibited MDA-MB-231 cell migration and demonstrated anti-proliferative effects by downregulating the protein expression of KPNA2, XPO1, RAB5B, and p38 MAPK. In in vivo studies, OR3 was non-toxic to mice, inhibited tumor xenograft growth, and maintained normal hematological parameters and tissue architecture. Nuclear magnetic resonance spectroscopy demonstrated the presence of a prodigiosin-like compound, while gas chromatography-mass spectrometry analysis identified additional compounds in OR3.
Conclusions: Our findings validate OR3 pigment as a promising compound for the treatment of metastatic breast cancer, warranting further studies.
Objective: To investigate the protective effects of Lepidium draba L. (L. draba) on cyclophosphamide (CP)-induced hepatotoxicity and nephrotoxicity in rats.
Methods: A total of 36 rats were divided into six groups as follows: the sham control group, the CP group (CP 100 mg/kg i.p. on days 1, 7, 14, 21, 28, and 35), the CP groups treated with L. draba extract (100, 200 and 400 mg/kg of L. draba extract for 28 d), and the L. draba extract alone group (400 mg/kg of L. draba extract for 28 d). Serum parameters of renal and hepatic function, as well as pro-inflammatory and anti-inflammatory cytokines associated with liver and kidney damage were measured. Moreover, Bax, Bcl-2, and caspase-3 gene expression and histopathological changes were assessed.
Results: L. draba extract alleviated CP-induced hepatotoxicity and nephrotoxicity by decreasing nitric oxide, TBARS, IL-6, TNF-α, and IL-Ιβ levels, as well as increasing superoxide dismutase, catalase and glutathione peroxidase activities, and FRAP, MIF, and TGF-β levels. In addition, the extract downregulated the expression of pro-apoptotic genes (Bax and caspase-3) and mitigated the destruction of glomeruli and renal tubules as well as the degeneration of hepatocytes.
Conclusions: L. draba extract can protect hepatic and renal structure and function against CP-induced toxicities, and may be used as a therapeutic agent for CP-induced hepatotoxicity and nephrotoxicity.
Objective: To investigate the anti-melanogenic potential of ligustroside isolated from Ligustrum japonicum.
Methods: The cytotoxicity of ligustroside was tested via MTT assay. Furthermore, the effects of ligustroside on the expression of critical melanogenic markers such as tyrosinase, tyrosinase related proteins (TRPs), and microphthalmia-associated transcription factor (MITF) were analyzed at both mRNA and protein levels via RT-qPCR and Western blot, respectively, in α-melanocyte stimulating hormone-induced B16F10 cells. In addition, phosphorylation of p38, ERK and JNK proteins was investigated. Immunofluorescence analysis of MITF was also conducted.
Results: Ligustroside significantly reduced intracellular tyrosinase activity and melanin content by 37.11% and 29.12%, respectively, compared to untreated cells. Moreover, it downregulated the expression of MITF, tyrosinase, TRP-1, and TRP-2 at the mRNA and protein levels by regulating both the mitogen-activated protein kinase (MAPK) and protein kinase A (PKA)/cAMP response element-binding protein (CREB) signaling pathways. Ligustroside also suppressed the nuclear protein expression of MITF, β-catenin, and p-CREB, and decreased immunofluorescence intensity of nuclear MITF.
Conclusions: Ligustroside derived from Ligustrum japonicum shows a significant anti-melanogenesis effect via suppression of the MAPK and PKA/CREB signaling pathways.
Objective: To investigate the chemical components of Semen podocarpi extract (SPE) and its effect on nasopharyngeal carcinoma cells and CNE-2R cells.
Methods: Chemical components in SPE were identified by UPLC-MS/MS. CCK-8 and cell cloning experiments were applied to evaluate the effects of SPE on the proliferation of CNE-2R cells, and a single-hit multitarget model was used to calculate the radiobiological parameters. Cell apoptosis and cell cycle were analyzed by flow cytometry, and the levels of genes and proteins of the Raf/MEK/ERK pathway were determined by RT-PCR and Western blotting.
Results: A total of 37 compounds from SPE were identified, and SPE with or without irradiation inhibited the proliferation of CNE-2R cells. SPE also promoted apoptosis, arrested cells in the G2/M phase, and presented radiosensitizing effects. Compared with irradiation alone, the effects of SPE+irradiation on apoptosis and cell cycle distribution were not significantly different. In addition, SPE had no significant effect on MEK gene expression. SPE significantly increased the gene expression of C-Raf and significantly reduced the protein expression of C-Raf, as well as the gene and protein expression of ERK1 and ERK2. The protein levels of C-Raf, ERK1, and ERK2 were also significantly lower in cells treated with SPE+irradiation than in cells treated with irradiation alone.
Conclusions: The effects of SPE on inhibiting cell proliferation and promoting apoptosis are likely associated with cell cycle arrest and Raf/MEK/ERK pathway regulation, and the mechanism underlying radiosensitization by SPE may involve downregulating the protein expression of C-Raf, ERK1, and ERK2.