Isolation of human salivary exosome on the morphology and gene expression of human periodontal ligament fibroblast cell line

The increasing incidence of periodontal diseases has led to the advancement in periodontal therapy including periodontal tissue regeneration. The development of human salivary-derived exosomes has become one of the promising researches to improve cell-based tissue engineering. Due to established functions showed by exosomes, human salivary exosomes were isolated and its effect on the morphology and gene expression of basic fibroblast growth factor (bFGF) and collagen type 1 (COL1) in human periodontal ligament fibroblast (HPdLF) cell line was studied. Unstimulated saliva samples collected from healthy male subjects were used. Exosomes were isolated by ultracentrifugation while the confirmation and establishment of its storage condition were carried out by Scanning Electron Microscopy (SEM), Western blot assay and Nanoparticle Tracking Analysis (NTA) in the presence and absence of protease inhibitor. Morphology and number of HPdLF cells treated with exosomes were viewed under inverted microscope and calculated by using trypan blue respectively. Determination of the gene expression level of bFGF and COL1 in the presence and absence of human salivary exosomes in HPdLF cells was performed using quantitative reverse transcriptase polymerase chain reaction (RTqPCR). This study showed that salivary exosomes were stable at several temperatures tested with and without protease inhibitor. SEM analysis demonstrated the round shape of exosomes, ranged between 10 nm to 100 nm in diameter. Western blot result confirmed that isolated exosomes expressed exosomal marker CD63. NTA estimated the concentration and individual size of exosomes. There was no significant difference in the morphology and number of HPdLF cells for both exosome treated and untreated samples, however, exosomes upregulated bFGF gene expression. This study concluded that human salivary exosomes are stable biomaterial and able to upregulate bFGF gene that was expressed by HPdLF cells. Thus, they might have potential to be used as alternative biomaterial in tissue engineering for periodontal regeneration

Commercial herbal slimming products: evaluation of heavy metals and microorganism contamination at different batch production

Herbal-based slimming products which are consumed orally may be contaminated with heavy metals as well as microorganisms. This study aimed to evaluate the safety level of these slimming products by determining heavy metals and microbial contamination in different batch production. Six different brands of herbal-based slimming products (A, B, C, G, H and I) with three different batch productions (1, 2 and 3) were investigated (n =18). Five heavy metals Arsenic, Cadmium, Chromium, Copper and Zinc were determined using an Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The presence of microorganisms was determined by total aerobic count and the bacteria were identified. The samples’ moisture content was determined by calculating the percentage of water loss after drying process. All batches of samples A and B had high content of zinc, over the permissible level of 5ppm while, 6 samples contained Chromium above the permissible level (1.5 ppm). All 3 batches of sample A presented with the highest total daily intake of heavy metals. Bacteria were present in all the samples tested with the highest numbers in samples G, H and A followed by B, I and C. The highest number of fungi was found in product A while product I was free from fungal contamination. Aspergillus spp. was the predominant fungus present in the samples. There was a weak correlation between moisture content and bacteria (r = 0.087) and fungal (r = 0.253) presence in the samples. As some herbal slimming products contain heavy metals as well as microorganisms, consumers need to be more vigilant and discerning when selecting products to be consumed