Effect of glutathione combined with cisplatin and oxaliplatin on the proliferation and apoptosis of lung carcinoma cell line

Thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin for the treatment of peritoneal metastasis in colorectal cancer

Advanced colorectal cancer (CRC) with peritoneal metastasis (PM) is a highly aggressive malignancy with poor prognosis. Systematic chemotherapy and local treatments are the primary therapeutic approaches. However, systemic chemotherapy is limited by low accumulation of drugs at the tumor site and systemic toxicity. Local treatments include cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). However, CRS faces challenges related to incomplete tumor resection, while HIPEC is restricted by the uneven distribution of drugs and potential complications. Herein, a thermosensitive methyl-cellulose-based injectable hydrogel carrying oxaliplatin (OXA) was synthesized to improve this situation. Specifically, methyl cellulose (MC) coagulated into a hydrogel, and OXA was loaded into the MC hydrogel to construct the OXA-MC hydrogel. We explored the OXA-MC hydrogel for the treatment of PM in CRC. The results demonstrated that the OXA-MC hydrogel had favorable biocompatibility and thermo-sensitivity and could act as a local slow-release drug carrier. Moreover, in a CT-26 tumor-bearing model, it showed a remarkable anti-tumor effect by inhibiting proliferation and promoting apoptosis. Additionally, transcriptome analysis indicated that the OXA-MC hydrogel might be involved in the regulation of the PI3K-AKT signaling pathway. In summary, we successfully prepared the OXA-MC hydrogel and provided a valid approach in the treatment of PM in CRC, which lays a foundation for other PM treatments.

Synthesis and characterization of thiocarbonato-linked platinum(IV) complexes

Herein we show the formation of new oxaliplatin-based platinum(IV) complexes by reaction with DSC-activated thiols via thiocarbonate linkage. Three model complexes based on aliphatic and aromatic thiols, as well as one complex with N-acetylcysteine as biologically active thiol were synthesized. This synthetic strategy affords the expansion of biologically active compounds other than those containing carboxylic, amine or hydroxy groups for coupling to the platinum(IV) center. The complexes were characterized by high-resolution mass spectrometry, NMR spectroscopy (¹H, ¹³C, ¹⁹⁵Pt) and elemental analysis. Their biological behavior was evaluated against two ovarian carcinoma cell lines and their cisplatin-resistant analogues. Remarkably, the platinum(IV) samples show modest in vitro cytotoxicity against A2780 cells and comparable effects against A2780cis cells. Two complexes in particular demonstrate improved activity against SKOV3cis cells. The reduction experiment of complex 8, investigated by UHPLC-HRMS, provides evidence of interesting platinum-species formed during reaction with ascorbic acid.

Multiple cellular effects of leaf extracts from Parinari curatellifolia

BACKGROUND

Parinari curatellifolia is a prominent plant in folk medicine in Sub-Saharan Africa. The plant decoctions are used to treat various ailments, including the treatment of cancer, pneumonia, fever, microbial infections and anti-inflammation. The aims of the study were to investigate the effects of P. curatellifolia leaf extracts on cell inflammatory and proliferative activity.

METHODS

Parinari curatellifolia fresh leaves were collected from Centenary in Mashonaland Central Province of Zimbabwe. Plant extracts were prepared using methanol, water, acetone and ethanol. Firstly, the effects of the extracts were determined on xanthine oxidase activity. Kinetic constants were determined for the extracts that showed inhibitory effects. Then the effects of Parinari curatellifolia water extract on LPS, menadione and hydrogen peroxide-activated nitric oxide production in RAW 264.7 cells was determined by quantifying the amount of nitrites formed. Finally, the effects of P. curatellifolia on the proliferation of Jurkat-T cells as well as its modulation of cisplatin-induced cell- cytotoxicity was investigated on a Jurkat human T-cell lymphoma cell line.

RESULTS

There was significant XO inhibitory activity by the ethanol and methanol extracts at 15.6 μg/ml and 3.9 μg/ml respectively. The IC50 determination for allopurinol, ethanol extract and methanol extract were 0.43 μg/ml, 1.38 μg/ml and 2.19 μg/ml respectively. The kinetic results showed that the ethanol and methanol extracts were allosteric inhibitors of XO. The water extract of P. curatellifolia inhibited NO production in RAW cells when LPS was used as an activator. P. curatellifolia and cisplatin showed dose-dependent cytotoxicity on Jurkat-T cells. Isolated DNA from the cells showed that there was DNA cleavage on cells exposed to P. curatellifolia indicating that apoptosis may be a mechanism by which P. curatellifolia exerts its cytotoxicity on Jurkat-T cells.

CONCLUSIONS

These results scientifically support the use of P. curatellifolia leaf extracts in the management of pain, inflammatory and neoplastic conditions. P. curatellifolia thus has multiple biological effects, thus, validating its use in traditional medical uses.

Evaluation of the effect of glutathione on cisplatin antitumor activity and kidney injury at different administration times

Cisplatin (cis-diamminedichloroplatinum, CDDP) is one of the most potent anticancer drugs. However, the therapeutic value of CDDP is greatly compromised by its dose-limiting nephrotoxicity. This study was performed to investigate whether reduced glutathione (GSH) was able to reduce the kidney injury induced by CDDP and whether it affected the anticancer activity of CDDP in vivo and in vitro. In in vivo experiments, mice were divided into five groups: control, CDDP only and three GSH treatment groups. Blood samples were collected 72 h after CDDP administration to determine the levels of blood urea nitrogen (BUN) and plasma creatinine (Cr). In addition, we examined antioxidative parameters, malondialdehyde (MDA) levels and histopathological changes in the kidney. In order to investigate whether GSH affected the anticancer activity of CDDP, we performed a sulforhodamine B (SRB) assay to determine the anti-proliferative effect in three tumor cell lines of treatment with CDDP alone or combined with GSH and examined the cell morphology. The results revealed that GSH decreased the BUN and Cr levels in plasma, ameliorated the pathological changes induced by CDDP and enhanced the endogenous antioxidant capacities in all three GSH groups. Furthermore, GSH significantly inhibited the growth of the three tumor cell lines when combined with CDDP and did not affect the inhibitory effect of CDDP on the carcinoma cell proliferation. In addition, we found no differences among the three GSH groups. These findings suggest that GSH is able to attenuate the nephrotoxicity induced by CDDP, not only when administered prior to CDDP, but also when administered at the same time as or subsequent to CDDP administration, without affecting the anticancer activity of CDDP. Thus, the administration of GSH is a promising approach for attenuating the nephrotoxicity caused by CDDP.

Pycnidione, a fungus-derived agent, induces cell cycle arrest and apoptosis in A549 human lung cancer cells

Pycnidione, a small tropolone first isolated from the fermented broth of Theissenia rogersii 92031201, exhibits antitumor activities through an undefined mechanism. The present study evaluated the effects and mechanisms of pycnidione on the growth and death of A549 human lung cancer cells. Pycnidione significantly inhibited the proliferation of A549 cells in a concentration-dependent manner, with a 50% growth inhibition (GI(50)) value of approximately 9.3nM at 48h. Pycnidione significantly decreased the expression of cyclins D1 and E and induced G(1)-phase cell cycle arrest and a subsequent increase in the sub-G(1) phase population. Pycnidione also markedly reduced the expression of survivin and activated caspase-8 and -3, increased reactive oxygen species (ROS) generation, caused the collapse of the mitochondrial membrane potential (MMP), and enhanced PAI-1 production, thus triggering apoptosis in the A549 cells. Taken together, pycnidione exerts anti-proliferative effects on human lung cancer cells through the induction of cell cycle arrest and apoptosis. Therefore, testing of its effects in vivo is warranted to evaluate its potential as a therapeutic agent against lung cancer.