RESUMO
We report here that an ethanol extract of Tetracera scandens, a Vietnamese medicinal plant, has anti-HIV activity and possesses strong inhibitory activity against HIV-1 reverse transcriptase (RTase). Using a MT-4 cell-based assay, we found that the T. scandens extract inhibited effectively HIV virus replication with an IC(50) value in the range of 2.0-2.5 µg/ml while the cellular toxicity value (CC50) was more than 40-50 µg/ml concentration, thus yielding a minimum specificity index of 20-fold. Moreover, the anti-HIV efficacy of the T. scandens extract was determined to be due, in part, to its potent inhibitory activity against HIV-1 RTase activity in vitro. The inhibitory activity against the RTase was further confirmed by probing viral cDNA production, an intermediate of viral reverse transcription, in virus-infected cells using quantitative DNA-PCR analysis. Thus, these results suggest that T. scandens can be a useful source for the isolation and development of new anti- HIV-1 inhibitor(s). [BMB reports 2012; 45(3): 165-170].
Assuntos
Fármacos Anti-HIV/farmacologia , Dilleniaceae/química , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Extratos Vegetais/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Fármacos Anti-HIV/química , Fármacos Anti-HIV/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Extratos Vegetais/química , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/isolamento & purificação , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
BACKGROUND & AIMS: Although there has been some success with protein-based anti-tumor necrosis factor alpha (TNF-alpha) therapeutics, the problems associated with protein-based drugs demand alternative approaches. We screened various herbal extracts for their ability to inhibit TNF-alpha secretions and found that BT-201, an n-butanol extract of Panax notoginseng (Burk.) F. H. Chen (P. notoginseng) has such an ability. METHODS: The purpose of this study has been to evaluate the anti-inflammatory and anti-rheumatic effects of BT-201. The anti-inflammatory effects were evaluated by measuring the effects of BT-201 on the production of TNF-alpha, interleukin (IL)-1beta, inducible nitric oxide (iNO), and matrix metalloproteinase-13 (MMP-13), in vitro. The anti-rheumatic effects were evaluated by treating mice with collagen-induced arthritis (CIA) using a daily oral administration of BT-201 at 15 mg/kg/day. In addition, the effects on NF-kappaB and mitogen-activated protein kinase (MAPK) pathways were evaluated by Western blotting using phospho-specific antibodies. RESULTS: BT-201 significantly inhibited all the inflammatory parameters evaluated in vitro and delayed the onset and progression of CIA. BT-201 inhibited the activation of NF-kappaB, ERK, p38, and JNK pathways. CONCLUSIONS: Our results demonstrated that BT-201 can modulate various aspects of inflammation in vitro and that it has disease-modifying, anti-rheumatic effects in vivo, suggesting that it can be a potential alternative to the current anti-TNF-alpha therapeutics for rheumatoid arthritis and other inflammatory disease.