Piperlongumine inhibits antioxidant enzymes, increases ROS levels, induces DNA damage and G2/M cell cycle arrest in breast cell lines

Therapeutic potential of bark extracts from Macaranga denticulata on renal fibrosis in streptozotocin-induced diabetic rats

Macaranga denticulata (MD) bark is commonly utilized in traditional medicine for diabetes prevention and treatment. The bark extract of MD is rich in prenyl or farnesyl flavonoids and stilbenes, which possess antioxidant properties. Although data suggest the potential therapeutic benefits of the use of MD in treating diabetic nephropathy (DN), the precise mechanisms underlying MD-initiated protective effects against DN are not well understood. This study aimed to assess the renoprotective properties of MD extract by examining renofibrosis inhibition, oxidative stress, and inflammation utilizing streptozotocin-induced DN male Sprague - Dawley rats. Diabetic rats were intraperitoneally injected with streptozotocin (STZ) to induce diabetes. After 6 days, these rats were orally administered MD extract (200 mg/kg/day) or metformin (200 mg/kg/day) for 14 days. The administration of MD extract significantly lowered blood glucose levels, restored body weight, and reduced urine levels of various biomarkers associated with kidney functions. Histopathological analysis revealed protective effects in both kidneys and pancreas. Further, MD extract significantly restored abnormalities in advanced glycation end products, oxidative stress biomarkers, and proinflammatory cytokine levels in STZ-treated rats. MD extract markedly reduced renal fibrosis biomarker levels, indicating recovery from renal injury, and reversed dysregulation of sirtuins and claudin-1 in the kidneys of rats with STZ-induced diabetes. In conclusion, data demonstrated the renoprotective role of MD extract, indicating plant extract's ability to suppress oxidative stress and regulate proinflammatory pathways during pathological changes in diabetic nephropathy.

Natural products for enhancing the sensitivity or decreasing the adverse effects of anticancer drugs through regulating the redox balance

Redox imbalance is reported to play a pivotal role in tumorigenesis, cancer development, and drug resistance. Severe oxidative damage is a general consequence of cancer cell responses to treatment and may cause cancer cell death or severe adverse effects. To maintain their longevity, cancer cells can rescue redox balance and enter a state of resistance to anticancer drugs. Therefore, targeting redox signalling pathways has emerged as an attractive and prospective strategy for enhancing the efficacy of anticancer drugs and decreasing their adverse effects. Over the past few decades, natural products (NPs) have become an invaluable source for developing new anticancer drugs due to their high efficacy and low toxicity. Increasing evidence has demonstrated that many NPs exhibit remarkable antitumour effects, whether used alone or as adjuvants, and are emerging as effective approaches to enhance sensitivity and decrease the adverse effects of conventional cancer therapies by regulating redox balance. Among them are several novel anticancer drugs based on NPs that have entered clinical trials. In this review, we summarize the synergistic anticancer effects and related redox mechanisms of the combination of NPs with conventional anticancer drugs. We believe that NPs targeting redox regulation will represent promising novel candidates and provide prospects for cancer treatment in the future.

Delivery of piperlongumine via hyaluronic acid/phenylboronic acid-mediated dual targetable polymersome for enhanced anticancer functionality against pancreatic tumor

Pancreatic cancer cells highly resistance to conventional chemo drugs, resulting low survival rates. The aim of the study was to design and develop dual targeting polymersomes (DTPS) loaded with phyto alkaloid agent i.e., piperlongumine (PL) for effective pancreatic cancer treatment. Here, hyaluronic acid (HA) was functionalized with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPEPEG-NH2), poly(ethylene glycol) bis (amine) (PEG), and phenylboronic acid (PBA) moieties. The designed DTPS could selectively recognize CD44/sialic acid (SA) and deliver PL to MIA PaCa-2 pancreatic cancer cells, facilitated via HA-CD44 and PBA-SA interactions. Drug release and stability results implied sustained PL release profile and pH sensitivity. DTPS could be more efficiently bound with SA than other sugars based on fluorescence spectroscopy. The anticancer efficacy of designed polymersomes was tested with H6C7 normal pancreas cells and SA/CD44-overexpressed MIA PaCa-2 pancreatic cancer cells. DTPS showed both SA and CD44-mediated higher cellular uptake while single-targeted polymersomes showed CD44-mediated cellular uptake. The PL-loaded DTPS efficiently uptake by MIA PaCa-2 cancer cells, causing up to 80 % cell growth inhibition, reduced cell spheroids volume and increased dead cells by 58.3 %. These results indicate that the newly developed DTPS can effectively serve as a pH-responsive drug delivery system for efficient treatment of cancer.