Cytotoxicity and cell cycle arrest induced by andrographolide lead to programmed cell death of MDA-MB-231 breast cancer cell line.

BACKGROUND: Breast cancer is considered as an increasing major life-threatening concern among the malignancies encountered globally in females. Traditional therapy is far from satisfactory due to drug resistance and various side effects, thus a search for complementary/alternative medicines from natural sources with lesser side effects is being emphasized. Andrographis paniculata, an oriental, traditional medicinal herb commonly available in Asian countries, has a long history of treating a variety of diseases, such as respiratory infection, fever, bacterial dysentery, diarrhea, inflammation etc. Extracts of this plant showed a wide spectrum of therapeutic effects, such as anti-bacterial, anti-malarial, anti-viral and anti-carcinogenic properties. Andrographolide, a diterpenoid lactone, is the major active component of this plant. This study reports on andrographolide induced apoptosis and its possible mechanism in highly proliferative, invasive breast cancer cells, MDA-MB-231 lacking a functional p53 and estrogen receptor (ER). Furthermore, the pharmacokinetic properties of andrographolide have also been studied in mice following intravenous and oral administration. RESULTS: Andrographolide showed a time- and concentration- dependent inhibitory effect on MDA-MB-231 breast cancer cell proliferation, but the treatment did not affect normal breast epithelial cells, MCF-10A (>80 %). The number of cells in S as well as G2/M phase was increased after 36 h of treatment. Elevated reactive oxygen species (ROS) production with concomitant decrease in Mitochondrial Membrane Potential (MMP) and externalization of phosphatidyl serine were observed. Flow cytometry with Annexin V revealed that the population of apoptotic cells increased with prolonged exposure to andrographolide. Activation of caspase-3 and caspase-9 were also noted. Bax and Apaf-1 expression were notably increased with decreased Bcl-2 and Bcl-xL expression in andrographolide-treated cells. Pharmacokinetic study with andrographolide showed the bioavailability of 9.27 ± 1.69 % with a Cmax, of 0.73 ± 0.17 µmol/L and Tmax of 0.42 ± 0.14 h following oral administration. AG showed rapid clearance and moderate terminal half lives (T1/2) of 1.86 ± 0.21 and 3.30 ± 0.35 h following IV and oral administration respectively. CONCLUSION: This investigation indicates that andrographolide might be useful as a possible chemopreventive/chemotherapeutic agent for human breast cancers.

In Vitro Metabolic Stability and Permeability of Gymnemagenin and Its In Vivo Pharmacokinetic Correlation in Rats - A Pilot Study.

Gymnema sylvestre is traditionally used for diabetes mellitus. A literature survey revealed very few reports, particularly on rat liver microsomal stability, caco-2 permeability and efflux concerns and its correlation with the bioavailability of gymnemagenin, an important component of G. sylvestre. Therefore, the objective of our study was to investigate the in vitro rat liver microsomal stability and caco-2 permeability along with the efflux of gymnemagenin and establish a probable correlation of these in vitro findings with pharmacokinetic parameters after oral and intravenous administration in rats.Rat liver microsomal stability studies to estimate the in vitro intrinsic half-life, clearance, and Caco-2 permeability after 21 days of culture to determine the apparent permeability from apical to basal and from basal to apical, and efflux ratio of gymnemagenin were performed using liquid chromatography-tandem mass spectrometry. A sensitive, robust bioanalytical method was validated and successfully applied to determine the plasma exposure of gymnemagenin. In vitro rat liver microsomal stability demonstrated that gymnemagenin metabolizes rapidly with a short apparent and intrinsic half-life (~ 7 min) and high intrinsic clearance, i.e., 190.08 µL/min/mg of microsomes. The results of the Caco-2 study indicated a poor permeability (1.31 × 10(- 6 )cm/sec) with a very high efflux ratio. The pharmacokinetic study revealed poor oral bioavailability (~ 14 %) of gymnemagenin and it was found to have a short half-life and a high clearance in rats. Our in vitro findings indicated low metabolic stability and poor Caco-2 permeability with high efflux, which might have a role in the observed poor oral bioavailability in rats.

Antimicrobial properties of Kalanchoe blossfeldiana: a focus on drug resistance with particular reference to quorum sensing-mediated bacterial biofilm formation.

OBJECTIVES: This study attempts to investigate the antimicrobial properties of Kalanchoe blossfeldiana with a particular reference to quorum sensing (QS)-mediated biofilm formation. METHODS: The methanol extract of K. blossfeldiana leaves (MEKB) was evaluated for antimicrobial properties including QS-controlled production of biofilm (including virulence factor, motility and lactone formation) in Pseudomonas aeruginosa. Methanol extract of K. blossfeldiana was also evaluated for anti-cytokine (tumour necrosis factor-alpha, interleukin-6 and interleukin-1 beta) properties in peripheral blood mononuclear cells (PBMC). KEY FINDINGS: Methanol extract of K. blossfeldiana exhibited antimicrobial effect on clinical isolates, as well as standard reference strains. Pseudomonas aeruginosa exposed to MEKB (subminimum inhibitory concentration (MIC)) displayed reduced biofilm formation, whereas supra-MIC produced destruction of preformed biofilms. Methanol extract of K. blossfeldiana reduced the secretion of virulence factors (protease and pyoverdin) along with generation of acyl homoserine lactone (AHL). Confocal laser scanning microscopy images indicate reduction of biofilm thickness. The extract also reduced cytokine formation in lipopolysaccharide-stimulated PBMC. CONCLUSIONS: Kalanchoe blossfeldiana was found to interfere with AHL production, which in turn may be responsible for downregulating QS-mediated production of biofilm and virulence. This first report on the antibiofilm and anticytokine properties of this plant may open up new vistas for future exploration of this plant for combating biofilm-related resistant infections.

Pharmacokinetic analysis and tissue distribution of andrographolide in rat by a validated LC-MS/MS method.

CONTEXT: Andrographis paniculata (Burm.f.) Nees (Acanthaceae) is widely used in tribal medicine in India and some other countries for multiple clinical applications. It contains andrographolide (AG) (diterpenoid lactone), a major phytomarker which probably accounts for its medicinal properties. OBJECTIVE: This study investigates the site-specific distribution of AG in different tissues of rats and its pharmacokinetic parameter evaluation by using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. MATERIALS AND METHODS: A simple and sensitive LC-MS/MS method has been developed and validated to quantify the presence of AG in plasma and various tissues of rat following oral administration of A. paniculata extract and AG in a dose of 133.33 and 100 mg/kg/day, respectively, for four weeks. RESULTS: The present study showed that the highest concentration of AG was in kidney (156.12 ng/g) followed by liver, spleen and brain while almost same concentration was found in heart and lung. The apparent C(max), T(max), elimination half-life and total exposure (AUC(0-α)) were 115.81 ng/ml, 0.75, 2.45 and 278.44 ngh/ml, respectively. CONCLUSION: This was an attempt to determine the presence of AG (a known biomarker) in tissues such as kidney, heart, lungs, brain and plasma of rats using a validated LC-MS/MS method. Furthermore, the observed reduced concentration in plasma and various tissues from 1 to 8 h might be attributed to relatively rapid elimination or distribution of AG from the central compartment.