ABSTRACT
In traditional Chinese medicine (TCM), the human body is divided into Yin and Yang. Diseases occur when the Yin and Yang balance is disrupted. Different herbs are used to restore this balance, achieving the goal of treatment. However, inherent difficulties in designing experimental trials have left much of TCM yet to be substantiated by science. Despite that, TCM not only remains a popular form of medical treatment among the Chinese, but is also gaining popularity in the West. This phenomenon has brought along with it increasing reports on herb-drug interactions, beckoning the attention of Western physicians, who will find it increasingly difficult to ignore the impact of TCM on Western therapies. This paper aims to facilitate the education of Western physicians on common Chinese herbs and raise awareness about potential interactions between these herbs and warfarin, a drug that is especially susceptible to herb-drug interactions due to its narrow therapeutic range.
Subject(s)
Animals , Humans , Carthamus tinctorius , Chemistry , Clinical Trials as Topic , Drugs, Chinese Herbal , Therapeutic Uses , Zingiber officinale , Chemistry , Ginkgo biloba , Chemistry , Glycyrrhiza , Chemistry , Herb-Drug Interactions , Lycium , Chemistry , Medicine, Chinese Traditional , Methods , Panax , Chemistry , Prunus persica , Chemistry , Salvia miltiorrhiza , Chemistry , Singapore , Warfarin , Therapeutic UsesABSTRACT
<p><b>OBJECTIVE</b>To explore the feasibility of selective inhibiting VEGF expression using VEGF short hairpin RNA (shRNA) interference, and observe the effects of VEGF gene silencing on NB4 cells growth.</p><p><b>METHODS</b>Three 19 bp reverse repeated motifs targeting exons 3, 4, 5 respectively of VEGF gene were synthesized and cloned into eukaryotic expression plasmid pGenesil-1 containing U6 shRNA promoter and termination signal of RNA polymerase. The recombinant plasmids pGenesil-VR1, pGenesil-VR2, pGenesil-VR3 and pGenesil-con (plasmid containing random DNA fragment) were transfected into NB4 cells respectively through lipofectamine reagent. The alteration of VEGF expression was examined by fluorescent real time RT-PCR and Western blot. The proliferation capacity of leukemia cells was measured by trypan blue exclusion, MTT assay, colony formation assay and cell cycles analysis.</p><p><b>RESULTS</b>Recombinant plasmids containing three shRNAs and random fragment were successfully constructed and transfected into NB4 cells respectively by liposome-mediated gene transfer method. shRNA in pGenesil-VR3 cells knocked down the expression of VEGF mRNA and protein dramatically in a sequence-specific manner when compared with that of pGenesil-VR1, Genesil-VR2 and pGenesil-con. The NB4 cells transfected with pGenesil-VR3 (NB4-VR3) had a more significant decrease in proliferation ability than NB4 and that transfected with pGenesil-con (NB4-con). The colony forming efficiencies of NB4-VR3, NB4-con and NB4 cell were (13.3 +/- 3.8)%, (21.3 +/- 6.4)% and (24.5 +/- 5.2)%, respectively (P < 0.05). Higher G(1) and lower S proportion were found in cell cycle distribution in comparison with the control groups by FCM.</p><p><b>CONCLUSIONS</b>The shRNA can efficiently suppress VEGF expression in NB4 cells. Selective VEGF gene silence can inhibit the malignant proliferation of leukemia cells.</p>