No abstract

Melatonin had indirect effects on lung cancer cells by enhancement of immunomodulatory effects, but further studies of mechanism(s) involved are needed.

Chito-oligosaccharides (CHOS) are oligomers of D-glucosamine and N-acetyl-glucosamine. Anti-inflammatory activities of a wide variety of CHOS mixtures have previously been reported, mainly based on studies with mouse models and murine macrophages. Since the mouse and human immune systems are quite different, gaining insight into the activity of CHOS on human cell lines, using well-characterized CHOS mixtures, is of considerable interest. Bacillus subtilis chitosanase (BsCsn46A) can efficiently convert chitosan to mixtures of water soluble low molecular weight CHOS. Here, the anti-inflammatory activity of a properly characterized CHOS mixture was studied, using human THP-1 cells that were differentiated to mature monocytes using vitamin D3. Addition of CHOS reduced the production of multiple pro-inflammatory cytokines associated with bacterial lipopolyssacharide (LPS)-stimulated inflammation, in a dose-dependent manner and without affecting cell viability. Interestingly, only minimal effects of CHOS were observed in similar experiments with phorbol 12-myristate 13-acetate- (PMA-) differentiated, macrophage-like, THP-1 cells. Altogether, in addition to showing promising biological effects of well-characterized low molecular weight soluble CHOS in a human system, the present study also points at Vitamin D3-stimulated THP-1 cells as a favorable system for assessing the anti-inflammatory activity of bioactive compounds.

To assess the presence and absence of mycoplasma contamination in cell culture, Fourier transform infrared (FTIR) microspectroscopy, coupled with multivariate analysis, was deployed to determine the biomolecular changes in hepatocellular carcinoma cells, HepG2, before and after mycoplasma contamination. The contaminated HepG2 cells were treated with antibiotic BM-Cyclin to decontaminate the mycoplasma, and polymerase chain reaction (PCR) was then performed to confirm the presence or the absence of mycoplasma contamination. The contaminated and decontaminated HepG2 cells were analyzed by FTIR microspectroscopy with principal component analysis (PCA) and peak integral area analysis. The results showed that the FTIR spectra of contaminated HepG2 cells demonstrated the alteration in the IR spectra corresponding to the lipid, protein, and nucleic acid regions. PCA analysis distinguished the spectral differences between the groups of mycoplasma-contaminated and -decontaminated cells. The PCA loading plots suggest that lipid and protein are the main contributed molecules for the difference between these two cell groups. Peak integral area analysis illustrated the increase of lipid and nucleic acid and the decrease of protein contents in the contaminated HepG2 cells. FTIR microspectroscopy is, therefore, proven to be a potential tool for assessing mycoplasma removal by monitoring biomolecular alterations in cell culture.

Lindernia crustacea (L.) F. Muell. var. crustacean or “Ya Kap Hoi: YKH” was misunderstood as “Ya Yad Nam Kang” and cancer curative. This study aimed to investigate anticancer activity by the analysis of chemical constituent in extracts and in vitro screening of biological activities of the extract in several aspects such as cancer cell lines cytotoxic activity, immune cell proliferating activity, reducing power activity, alkylation activity. The HPLC analysis showed the absence of plumbagin peak observed in the HPLC chromatograms of both YKH aqueous and YKH ethanolic extracts. The YKH ethanolic extract yielded more chemical constituents than that of the YKH aqueous extract. The YKH aqueous extract was inactive against all cancer cells tested. Interestingly, YKH ethanolic extract caused cancer cell death in HCT116 colon cancer, HepG2 liver cancer, and Jurkat leukemic cancer cell lines in the concentration dependent manner. The following IC50 concentrations of the YKH ethanolic extract that possessed 50 % cell death after 24 h exposure in HCT116, HepG2, and Jurkat cell line were 195.4 ± 12, 171.7 ± 8.7, and 48.8 ± 5.7 µg/mL, respectively. Both aqueous and ethanolic extracts of YKH showed high antioxidant activity based on reducing power activity but did not have alkylation activity. At high concentration (250 µg/mL), YKH ethanolic extract can inhibit immune cells proliferation activity more than the YKH aqueous extract. An unexpected but critical outcome of our studies was the finding that anticancer activity is promised by selecting the plant extraction solvent with less polarity. Potential anticancer constituents were extracted from YKH using ethanol and these constituents cannot be found in aqueous solution of YKH.