Platycodon grandiflorus enhances the effect of DDP against lung cancer by down regulating PI3K/Akt signaling pathway.

Cisplatin (DDP) is a first-line drug for non-small cell lung cancer (NSCLC), but its efficacy and applications are constrained by intolerance and serious side effects. Platycodon grandiflorus (PG) is usually used as lung medicinal drug to enhance other drug's effect on lung diseases. Therefore, present study aim to investigate anti-NSCLC effect of PG with DDP and mechanism involved in the combination for the first time. The results showed that compared with DDP group, the combined groups (DDP combined with 1, 2 and 4 g/kg of PG) reduced the tumor luminescence density by 26.0%, 78.2% and 32.8% respectively, and decreased the death rates, lung index, pathological damage and inflammation in lung tissue. Protein analysis of lung tissue showed that its anticancer effect may be associated with tumor cell apoptosis. Therefore, vitro studies showed that PG combined with DDP down-regulated the expression of p-Akt and PI3K and improved the protein expression of cleaved-caspase 9 in A549 cell and PG promotes the apoptosis of DDP and these mechanisms were related by inhibition of the PI3K/Akt signaling pathway. Our study confirms that the combination of PG and DDP will help enhance efficacy of DDP and is important for improving platinum-based chemotherapy.