Alka Madaan

1,8-Naphthyridine-3-carboxamide derivatives with anticancer and anti-inflammatory activity.

A number of 1-propargyl-1,8-naphthyridine-3-carboxamide derivatives (15-35) have been synthesized and screened for their in vitro cytotoxicity and anti-inflammatory activity. Compounds 22, 31 and 34 have shown high cytotoxicity against a number of cancer cell lines, while compound 24 showed significant anti-inflammatory activity.

1,8-Naphthyridine Derivatives: A Review of Multiple Biological Activities.

The 1,8‐naphthyridine group of compounds have gained special attention of researchers on account of their demonstrating a variety of interesting biological activities. A wide range of biological properties establishes them as potent scaffolds in therapeutic and medicinal research. The broad spectrum of activities primarily includes antimicrobial, antiviral, anticancer, anti‐inflammatory, and analgesic activities. 1,8‐Naphthyridine derivatives have also exhibited potential applications in neurological disorders such as Alzheimers disease, multiple sclerosis, and depression. In addition, these synthetic derivatives have been found to possess activities such as anti‐osteoporotic (α(v)β(3) antagonists), anti‐allergic, antimalarial, gastric antisecretory, bronchodilator, anticonvulsant, anti‐hypertensive, platelet aggregation inhibition, anti‐oxidant, EGFR inhibition, protein kinase inhibition, ionotropic agent, β‐3 antagonist, MDR modulator, adenosine receptor agonist, adrenoceptor antagonist, and pesticide activities. In spite of the widespread application of the 1,8‐naphythyridine scaffolds, only a limited number of review articles are available till date. In this review, we attempt to compile and discuss the key data available in the literature for the multiple biological activities of 1,8‐naphthyridine derivatives, in a chronological manner. This review compilation (with 199 references) may be helpful in understanding the diverse biological properties of 1,8‐naphthyridines and provide insights into their mechanism of action. This may direct future research in the synthesis of new derivatives and exploring this scaffold for other possible biological activities.

Efficiency and mechanism of intracellular paclitaxel delivery by novel nanopolymer-based tumor-targeted delivery system, NanoxelTM

IntroductionAn increasing research interest has been directed toward nanoparticle-based drug delivery systems for their advantages. The appropriate amalgamation of pH sensitivity and tumor targeting is a promising strategy to fabricate drug delivery systems with high efficiency, high selectivity and low toxicity.Materials and Methods A novel pH sensitive Cremophor-free paclitaxel formulation, NanoxelTM, was developed in which the drug is delivered as nanomicelles using a polymeric carrier that specifically targets tumors. The efficiency and mechanism of intracellular paclitaxel delivery by NanoxelTM was compared with two other commercially available paclitaxel formulations: AbraxaneTM and IntaxelTM, using different cell lines representing target cancers [breast, ovary and non-small cell lung carcinoma (NSCLC)] by transmission electron microscopy and quantitative intracellular paclitaxel measurements by high performance liquid chromatography.ResultsThe data obtained from the present study revealed that the uptake of nanoparticle-based formulations NanoxelTM and AbraxaneTM is mediated by the process of endocytosis and the uptake of paclitaxel was remarkably superior to IntaxelTM in all cell lines tested. Moreover, the intracellular uptake of paclitaxel in NanoxelTM- and AbraxaneTM-treated groups was comparable. Hence, the nanoparticle-based formulations of paclitaxel (NanoxelTM and AbraxaneTM) are endowed with higher efficiency to deliver the drug to target cells as compared to the conventional Cremophor-based formulation.ConclusionNanoxelTM appears to be of great promise in tumor targeting and may provide an advantage for paclitaxel delivery into cancer cells.

Anti-inflammatory activity of a naphthyridine derivative (7-chloro-6-fluoro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide) possessing in vitro anticancer potential

We have previously synthesized a series of 1,8-naphthyridine-3-carboxamide derivatives to identify potential anti-cancer/anti-inflammatory compounds. Three derivatives, 7-chloro-N-(3-(cyclopentylamino)-3-oxo-1-phenylpropyl)-6-fluoro-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-22), 7-chloro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-31) and 7-chloro-6-fluoro-N-(2-hydroxy-3-oxo-1-phenyl-3-(phenylamino)propyl)-4-oxo-1-(prop-2-yn-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxamide (C-34) demonstrated high cytotoxicity against a number of cancer cell lines and inhibited secretion of IL-1-β and IL-6. In the present study, C-22, C-31 and C-34 were assessed for modulation of pro-inflammatory cytokines, TNF-α and IL-8, chemokine RANTES and NO produced by lipopolysaccharide (LPS)-treated mouse Dendritic cells (DCs). Among the 3 compounds, C-34 showed the most potent inhibition of inflammatory markers in DC model at 0.2 and 2 μM. C-34 also significantly downregulated the secretion of TNF-α, IL-1-β and IL-6 by murine splenocytes and THP-1 cells against LPS induced levels. In vitro effects of C-34 on bone marrow toxicity were assessed in CFU-GM assay. Human CFU-GM population was comparatively more sensitive to C-34 (0.1-10 μM) than murine CFU-GM. IC50 values for murine and human CFU-GM were not attained. C-34 was further examined for in vivo suppression of LPS induced cytokines in a mice model. At doses ranging from 1.25 to 5 mg/kg, C-34 led to significant inhibition of TNF-α, IL-1-β, IL-6 and MIP-1-α. At the highest dose of 5 mg/kg, C-34 also protected LPS-treated mice against endotoxin-induced lethality. In conclusion, C-34 demonstrates anti-inflammatory activity in vitro and in vivo in addition to cytotoxic properties. This finding suggests its potential for further development as a synthetic naphthyridine derivative with dual anti-cancer and anti-inflammatory (cytokine inhibition) properties.

Anticancer and immunomodulatory activities of novel 1,8-naphthyridine derivatives

A number of 1,8-naphthyridine derivatives (22–62) have been synthesized and screened for their in vitro cytotoxicity against eight tumors and two non-tumor cell lines. Halogen substituted 1,8-naphthyridine-3-caboxamide derivatives showed potent activity with compound 47 having IC50 of 0.41 and 0.77 μM on MIAPaCa and K-562 cancer cell lines, respectively while, compound 36 had IC50 of 1.19 μM on PA-1 cancer cell line. However, one of the unsubstituted 1,8-naphthyridine-C-3’-heteroaryl derivative 29 showed potent cytotoxicity with IC50 of 0.41 and 1.4 μM on PA-1 and SW620 cancer cell lines, respectively. These compounds were also evaluated for anti-inflammatory activity as suggested by downregulation of proinflammaotory cytokines.

Review of Hair Follicle Dermal Papilla cells as in vitro screening model for hair growth

Hair disorders such as hair loss (alopecia) and androgen dependent, excessive hair growth (hirsutism, hypertrichosis) may impact the social and psychological well‐being of an individual. Recent advances in understanding the biology of hair have accelerated the research and development of novel therapeutic and cosmetic hair growth agents. Preclinical models aid in dermocosmetic efficacy testing and claim substantiation of hair growth modulators. The in vitro models to investigate hair growth utilize the hair follicle Dermal Papilla cells (DPCs), specialized mesenchymal cells located at the base of hair follicle that play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. In this review, we have compiled and discussed the extensively reported literature citing DPCs as in vitro model to study hair growth promoting and inhibitory effects. A variety of agents such as herbal and natural extracts, growth factors and cytokines, platelet‐rich plasma, placental extract, stem cells and conditioned medium, peptides, hormones, lipid‐nanocarrier, light, electrical and electromagnetic field stimulation, androgens and their analogs, stress‐serum and chemotherapeutic agents etc. have been examined for their hair growth modulating effects in DPCs. Effects on DPCs’ activity were determined from untreated (basal) or stress induced levels. Cell proliferation, apoptosis and secretion of growth factors were included as primary end‐point markers. Effects on a wide range of biomolecules and mechanistic pathways that play key role in the biology of hair growth were also investigated. This consolidated and comprehensive review summarizes the up‐to‐date information and understanding regarding DPCs based screening models for hair growth and may be helpful for researchers to select the appropriate assay system and biomarkers. This review highlights the pivotal role of DPCs in the forefront of hair research as screening platforms by providing insights into mechanistic action at cellular level, which may further direct the development of novel hair growth modulators.

Evaluation of in vitro Anti-psoriatic Activity of a Novel Polyherbal Formulation by Multiparametric Analysis

BACKGROUND We have developed a novel aqueous polyherbal formulation (SIRB-001) consisting of 3 herbs; Rheum palmatum L., Lonicera Japonica and Rehmannia glutinosa Libosch in the ratio 1:1:3. SIRB-001 has demonstrated efficacious effects in psoriasis patients. OBJECTIVE This study was aimed at scientifically evaluating the in vitro antipsoriatic activity of SIRB-001. METHOD The in vitro anti-psoriatic properties of SIRB-001 were assessed in human keratinocyte cell line; HaCaT. Anti-proliferative effect was studied using MTT assay. Apoptosis was examined by flow cytometry and colorimetric methods. Inflammatory markers and VEGF were determined by ELISA. IL-17/IL-23 secretion was assessed in immune cells. Signaling markers (kinases) by enzymatic assay and Topoisomerase-II activity by Kinetoplast DNA Cleavage assay was tested. RESULTS SIRB-001 significantly inhibited (p<0.01) proliferation of HaCaT cells and induced apoptosis. Significant (p<0.01) downregulation of pro-inflammatory markers (TNF- α, IFN-γ, IL-6, NO, sPLA2) and VEGF was observed. IL-17/IL-23 secretion was significantly (p<0.01) alleviated in immune cells (RAW264.7 and THP-1). Inhibition of signaling markers (AKT1, FLT3, MAPK1, PRKCA, MAP2K) was observed. SIRB-001 demonstrated inhibition of Topoisomerase-II activity. High Performance Liquid Chromatography (HPLC) analysis of SIRB-001 was carried out using standard marker compounds chlorogenic acid (tR=13.98min), Acteoside (tR=24.22 min) and Rhein (tR=53.76 min). CONCLUSION The in vitro results substantiate the anti-psoriatic effect of SIRB-001 in patients. SIRB-001 exerted anti-psoriatic effects at cellular level via multiple arms (antiproliferative, pro-apoptotic, anti-inflammatory, anti-angiogenic). This study provides insight into mechanism of action of SIRB-001 and highlights its promising potential for development as a herbal therapeutic agent for psoriasis, emphasizing the need of further pharmacological evaluation and toxicological studies.