Sustained release polymer and surfactant based solid dispersion of andrographolide exhibited improved solubility, dissolution, pharmacokinetics, and pharmacological activity.

Andrographolide (AD) is a potent natural product with a wide range of pharmacological activities. However, it has low oral bioavailability due to poor solubility and dissolution rate. Solid dispersion (SD) is a promising technique to improve the solubility and dissolution rate of such molecules. In this study, SD formulation of AD was prepared using Kollidon-SR (KSR) and Poloxamer-407 (P-407) as carriers. SD was prepared using the solvent evaporation method and evaluated for the modulation of solubility of AD. The developed SD formulation was characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Further, dissolution rate, yield, drug content, stability, flowability, and pharmacokinetic profile of SD were evaluated. The compatibility of SD with the Caco-2 cells and its impact on the P-glycoprotein (P-gp) mediated efflux was also investigated. Furthermore, carrageenan-induced paw edema, and adjuvant-induced arthritic model were used to evaluate the efficacy of SD. The results showed that SD3 (AD + KSR + P-407, 1:6:8) exhibited the highest solubility and dissolution rate, and significantly improved pharmacokinetic profile compared to native AD. SD3 was found to be stable during storage and displayed excellent yield, drug content, and flowability. This formulation was found to be compatible with the Caco-2 cells and retarded the efflux of P-gp substrate. SD3 also demonstrated substantially better efficacy than native AD in terms of paw edema inhibition (carrageenan-induced paw edema, Wistar rats), and overall improvement of disease condition (in terms of paw edema, arthritic score, AST, ALT, cytokines, radiological changes, and histopathology) in arthritic Wistar rats. In conclusion, SD3 exhibited improved solubility, dissolution rate, pharmacokinetic profile, and pharmacological activity than native AD.

Biodegradable nanocarrier of gemcitabine and tocopherol succinate synergistically ameliorates anti-proliferative response in MIA PaCa-2 cells.

Gemcitabine (GEM) is an important chemotherapeutic agent used alone or in combination with other anticancer agents for the treatment of various solid tumors. In this study, the potential of a dietary supplement, α-tocopherol succinate (TOS) was investigated in combination with GEM by utilizing human serum albumin-based nanoparticles (HSA NPs). The developed nanoparticles were characterized using DLS, SEM and FTIR and evaluated in a panel of cell lines to inspect cytotoxic efficacy. The ratio metric selected combination of the NPs was further investigated in human pancreatic cancer cell line (MIA PaCa-2 cells) to assess the cellular death mechanism via a myriad of biochemical and bio-analytical assays including nuclear morphometric analysis by DAPI staining, ROS generation, MMP loss, intracellular calcium release, in vitro clonogenic assay, cell migration assay, cell cycle analysis, immunocytochemical staining followed by western blotting, Annexin V-FITC and cellular uptake studies. The desolvation-crosslinking method was used to prepare the NPs. The average size of TOS-HSA NPs and GEM-HSA NPs was found to be 189.47 ± 5 nm and 143.42 ± 7.4 nm, respectively. In combination, the developed nanoparticles exhibited synergism by enhancing cytotoxicity in a fixed molar ratio. The selected combination also significantly triggered ROS generation and mitochondrial destabilization, alleviated cell migration potential and clonogenic cell survival in MIA PaCa-2 cells. Further, cell cycle analysis, Annexin-V FITC assay and caspase-3 activation, up regulation of Bax and down regulation of Bcl-2 protein confirmed the occurrence of apoptotic event coupled with the G0/G1 phase arrest. Nanocarriers based this combination also offered approximately 14-folds dose reduction of GEM. Overall, the combined administration of TOS-HSA NPs and GEM-HSA NPs showed synergistic cytotoxicity accompanied with dose reduction of the gemcitabine. These encouraging findings could have implication in designing micronutrient based-combination therapy with gemcitabine and demands further investigation.

Apoptotic Potential and Antitumor Efficacy of Trilliumoside A: A New Steroidal Saponin Isolated from Rhizomes of Trillium govanianum.

Natural product-derived molecules exhibit potential as anticancer agents. Trilliumoside A, a new steroidal saponin, was obtained from rhizomes of Trillium govanianum, and its anticancer activity was investigated in the presented study. Trilliumoside A was investigated in a panel of cell lines, and it exhibited promising cytotoxic activity on the A549 cells (human lung cancer cells) with an IC50 of 1.83 µM. The mechanism of cell death induced by Trilliumoside A in A549 cells and its anticancer potential in murine tumor models (EAC and EAT) were presented in the current research. Trilliumoside A was found to induce apoptosis in A549 cells by increasing the expression of various apoptotic proteins, such as Bax, Puma, cytochrome C, cleaved PARP, and cleaved caspase 3. Additionally, Trilliumoside A regulates the expression of p53, CDK2, and Cyclin A by decreasing the mitochondrial membrane potential, elevating reactive oxygen species, and stopping the growth of A549 cells in the synthesis phase (S) of the cell cycle. Trilliumoside A showed a considerable reduction in the tumor volume, the amount of ascitic fluid, and the total cell number without affecting the body weight of animals. Our results demonstrate that Trilliumoside A inhibits the proliferation of human lung cancer cells by inducing DNA damage, arresting the cell cycle, and activating the mitochondrial signaling pathway. The study demonstrated the potential of Trilliumoside A as a potential anticancer agent.

Implication of methylselenocysteine in combination chemotherapy with gemcitabine for improved anticancer efficacy.

The limitations associated with cancer monotherapy including dose dependent toxicity and drug resistance can be addressed by combination chemotherapy. The combination of antineoplastic agents improves the cytotoxic activity in comparison to the single-agent based therapy in a synergistic or an additive mode by reducing tumor growth as well as metastatic ability. In the present investigation, we explored the potential of methylselenocysteine (MSC) in combination chemotherapy with gemcitabine (GEM). The cytotoxic activity of GEM and MSC was determined in various cell lines and based on the activity, A549 cells were explored for the mechanistic studies including DAPI staining, measurement of oxidative stress, mitochondrial membrane potential loss, nitric oxide level, western blotting, cell migration and colony formation assays. A549 cells in combination treatment with MSC and GEM demonstrated enhanced cytotoxicity with more irregular cellular morphology as well as chromatin condensation and nuclear blebbing. The selected combination also significantly triggered ROS generation and mitochondrial destabilization, and alleviated cell migration potential and clonogenic propensity of A549 cells. Also, caspase-3 and PARP mediated apoptosis was observed in the combination treated cells. MSC based drug combination could offer the attributes of improved drug delivery and there was a 6-folds dose reduction of GEM in combination. Further, antitumor study in Ehrlich solid tumor model showed the efficacy of MSC combination with GEM for the enhanced antitumor activity. The proposed combination demonstrated the potential for further translational studies.

Mechanistic investigation of synergistic interaction of tocopherol succinate with a quinoline-based inhibitor of mammalian target of rapamycin.

OBJECTIVES: Cancer monotherapy is associated with various limitations; therefore, combination chemotherapy is widely explored for optimum drug efficacy. In this study, 4-(N-Phenyl-N'-substituted benzenesulfonyl)-6-(4-hydroxyphenyl) quinoline-based mammalian target of rapamycin (mTOR) inhibitor (IIIM-4Q) was investigated in combination with tocopherol succinate (TOS), and the mechanism of cytotoxicity was elucidated. METHODS: The cytotoxic potential of IIIM-4Q and TOS was evaluated in five cell lines. Further, to understand the mechanism of cytotoxicity of IIIM-4Q, TOS and their combination, various studies including morphological analysis using scanning electron microscopy and 6-diamidino-2-phenylindole (DAPI) staining, estimation of reactive oxygen species (ROS) level, measurement of mitochondrial membrane potential (MMP), in-vitro cell migration assay, Western blotting and staining with acridine orange (AO) for autophagy detection were performed. KEY FINDINGS: Investigated combination was synergistic in nature and exhibited greater oxidative stress and mitochondrial dysfunction in pancreatic cancer cells. The migration potential of MIA PaCa-2 cells was significantly mitigated under the influence of this combination, and morphological changes such as chromatin condensation and nuclear blebbing were observed. Also, poly (adenosine diphosphate-ribose) polymerase cleavage and caspase-3 activation were observed in IIIM-4Q and TOS combination-treated cells. CONCLUSIONS: The investigated combination synergistically inhibited proliferation of MIA PaCa-2 cells through simultaneous induction of autophagy followed by apoptosis, and this combination demonstrated potential for further translational studies.

Drug resistance in cancer: mechanisms and tackling strategies.

Drug resistance developed towards conventional therapy is one of the important reasons for chemotherapy failure in cancer. The various underlying mechanism for drug resistance development in tumor includes tumor heterogeneity, some cellular levels changes, genetic factors, and others novel mechanisms which have been highlighted in the past few years. In the present scenario, researchers have to focus on these novel mechanisms and their tackling strategies. The small molecules, peptides, and nanotherapeutics have emerged to overcome the drug resistance in cancer. The drug delivery systems with targeting moiety enhance the site-specificity, receptor-mediated endocytosis, and increase the drug concentration inside the cells, thus minimizing drug resistance and improve their therapeutic efficacy. These therapeutic approaches work by modulating the different pathways responsible for drug resistance. This review focuses on the different mechanisms of drug resistance and the recent advancements in therapeutic approaches to improve the sensitivity and effectiveness of chemotherapeutics.