Effects of medwakh smoking on salivary metabolomics and its association with altered oral redox homeostasis among youth.

The use of alternative tobacco products, particularly medwakh, has expanded among youth in the Middle East and around the world. The present study is conducted to investigate the biochemical and pathophysiological changes caused by medwakh smoking, and to examine the salivary metabolomics profile of medwakh smokers. Saliva samples were collected from 30 non-smokers and 30 medwakh smokers and subjected to metabolomic analysis by UHPLC-ESI-QTOF-MS. The CRP and Glutathione Peroxidase 1 activity levels in the study samples were quantified by ELISA and the total antioxidant capacity (TAC) by TAC assay kits. Statistical measurements and thorough validation of data obtained from untargeted metabolomics identified 37 uniquely and differentially abundant metabolites in saliva of medwakh smokers. The levels of phthalate, L-sorbose, cytosine, uridine, alpha-hydroxy hippurate, and L-nicotine were noticeably high in medwakh smokers. Likewise, 20 metabolic pathways were differentially altered in medwakh smokers. This study identified a distinctive saliva metabolomics profile in medwakh smokers associated with altered redox homeostasis, metabolic pathways, antioxidant system, and CRP levels. The impact of the altered metabolites in medwakh smokers and their diagnostic utility require further research in large cohorts.

The efficacy of salivary Histatin-1 protein in wound closure of nicotine treated human periodontal ligament fibroblast cells - In vitro study.

OBJECTIVES: The aims of this study were to investigate the efficacy of Histatin-1 in wound closure as well as effects on gene expression of nicotine-treated human Periodontal Ligament Fibroblast cells (HPDL) in vitro. DESIGN: HPDL grown in 2.5% culture medium treated with 10 ng/ml Histatin - 1 in the presence/absence of 0.5 µM nicotine were subjected to wound assay and migration was studied at 0 h, 6 h, 12 h and 24 h. Cells grown in 2.5% medium served as control. Cell migration was studied by wound gap and transwell migration assays. The effect of Histatin-1 on expression of matrix metalloproteinase 8 (MMP-8), insulin-like growth factor 1 (IGF-1), transforming growth factor beta (TGF-ß), collagen type I (COL1) and plasminogen activator inhibitor 1 (PAI-1) were studied. RESULTS: Histatin-1 treatment significantly decreased percentage wound gap at 12 h (62.96 ± 3.22 vs 79.23 ± 1.73; p < 0.05) and at 24 h (38.78 ± 7.59 vs 75.21 ± 4.94; p < 0.001) compared with controls. In nicotine+Histatin-1 treated cells, wound gap decreased to 70.2 ± 2.9% (p < 0.01) at 24 h compared to nicotine alone in which 82 ± 1.64% of wound gap was retained. Transwell migration assays showed significant migration of HPDL with Histatin-1 (p < 0.05). Gene expression demonstrated significant upregulation for IGF-1, TGF ß, COL1 and PAI-1 with Histatin-1. CONCLUSION: Histatin-1 significantly mitigated the effect of nicotine in wound healing assay involving HPDL fibroblast cells at 24 h. Histatin-1 aided wound closure is attributed to the upregulation of IGF-1, TGF ß, COL1, and PAI-1 genes.