Ginkgolide B Regulates CDDP Chemoresistance in Oral Cancer via the Platelet-Activating Factor Receptor Pathway

The platelet-activating factor receptor (PAFR) is a key molecule that participates in intracellular signaling pathways, including regulating the activation of kinases. It is involved in cancer progression, but the detailed mechanism of its chemosensitivity is unknown. The purpose of the current study was to elucidate the mechanism regulating cisplatin (CDDP) sensitivity through PAFR functions in oral squamous cell carcinoma (OSCC). We first analyzed the correlation between PAFR expression and CDDP sensitivity in seven OSCC-derived cell lines based upon cell viability assays. Among them, we isolated 2 CDDP-resistant cell lines (Ca9-22 and Ho-1-N-1). In addition to conducting PAFR-knockdown (siPAFR) experiments, we found that ginkgolide B (GB), a specific inhibitor of PAFR, enhanced both CDDP chemosusceptibility and apoptosis. We next evaluated the downstream signaling pathway of PAFR in siPAFR-treated cells and GB-treated cells after CDDP treatment. In both cases, we observed decreased phosphorylation of ERK and Akt and increased expression of cleaved caspase-3. These results suggest that PAFR is a therapeutic target for modulating CDDP sensitivity in OSCC cells. Thus, GB may be a novel drug that could enhance combination chemotherapy with CDDP for OSCC patients.

Pharmacognosy, phytochemistry, pharmacology and clinical application of Ginkgo biloba

In the present review, we are highlighted various pharmacognostic and pharmacological aspects of the different parts of plant Ginkgo biloba. Leaves are mainly potential source of phytochemical constituents. The plant encompasses variety of pharmacological activities namely antioxidant, hypolipidemic, antibacterial, etc. The pharmacological profile of plant is mainly attributed to the presence of chemicals such as Ginkgolide A, Ginkgolide B, Ginkgolide C, Bilobalide, Ginkgotoxin, ginkgolides and bilobalide are the major constituents. The pills with the highest concentration of plant extract (100 mg) allow the intake of the highest antioxidants concentration. It is also used along with 5-flurouracil in cancer treatment. There is need to explore more activities of the plant.

Ginkgolide B Protects Cardiomyocytes from Angiotensin II-Induced Hypertrophy via Regulation of Autophagy through SIRT1-FoxO1

Ginkgolide B (GB) is an active ingredient extracted from Ginkgo biloba leaves. However, the effects of GB on cardiac hypertrophy remain unclear. The study is aimed at determining whether GB could alleviate cardiac hypertrophy and exploring its underlying molecular mechanism. Rat cardiomyocyte cell line H9c2 cells were pretreated with GB and incubated with angiotensin II (Ang II) to simulate an in vitro cardiac hypertrophy model. Cell viability, cell size, hypertrophy markers, and autophagy were determined in H9c2 cells after Ang II treatment. Proteins involved in autophagy and the SIRT1 pathway were determined by western blot. Our data demonstrated that GB attenuated Ang II-induced cardiac hypertrophy and reduced the mRNA expressions of hypertrophy marker, atrial natriuretic peptide (ANP), and β-myosin heavy chain (β-MHC). GB further increased Ang II-induced autophagy in H9c2 cells and modulated expressions of autophagy-related proteins Beclin1 and P62. Modulation of autophagy using autophagy inhibitor 3-methyladenine (3-MA) could abrogate GB-downregulated transcription of NPPA. We then showed that GB attenuated Ang II-induced oxidative stress and reduction in SIRT1 and FoxO1 protein expression. Finally, the effect of GB on autophagy and cardiac hypertrophy could be reversed by SIRT1 inhibitor EX-527. GB inhibits Ang II-induced cardiac hypertrophy by enhancing autophagy via the SIRT1-FoxO1 signaling pathway and might be a potential agent in treating pathological cardiac hypertrophy.