Wound Healing (in Vivo), Antioxidant, Cytotoxicity and Anti-Microbial Effects of 3,4,5-Trihydroxy-N0-[(2-Methyl-1h-Indol-3-Yl)- Methylidene] Benzohydrazide (Tibh)
In new drugs development, hybrid molecules might possess synergistic result and thus a greater activity than each of its constituents. Subsequently 3,4,5-trihydroxy-N'-[(5-methyl-1H-indol-3-yl)-methylidene]benzohydrazide (TIBH) was previously synthesized upon the reaction of the appropriate indole carboxaldehydes with gallic hydrazide. In this study TIBH was tested for wound healing, antioxidant (DPPH and FRAP), cytotoxicity (MTT against human normal fibroblast) and anti-microbial activities. Minimal inhibitory concentration (MIC) method was performed to test TIBH antimicrobial effect against two strains of Staphylococcus aureus (ATCC25923) and Escherichia coli (ATCC 25922). Rats in Negative control, Positive control, TIBH low dose and high dose groups (n=6) were respectively topically treated with 0.2 mL of the vehicle (2% CMC /20% glycerol v/v), Intrasite gel, 10 and 20 mg/ml of TIBH once daily post wound induction surgery. After 15 days, wound closure percentage, histopathological changes of the wound sites (Hematoxylin and eosin and Masson’s trichrome staining), Bax protein expression, SOD (superoxide dismutase) activity and malondialdehyde levels (representing lipid peroxidation) were evaluated and compared between control and TIBH treated rats. TIBH showed a remarkable DPPH radical scavenging activity, with IC50 values of 33.8 µg/ml, when compared to reference controls (ascorbic acid and quercetin). Cytotoxicity result showed that TIBH in concentration more than 154 µM (50 µg/ml) was toxic against human normal fibroblast with the IC50 equal to 77.4 µM (25.18 µg/ml). Antimicrobial assay reported that TIBH MIC against two tested strains was greater than the highest tested concentration of the TIBH (200 µg/ml). Evaluation of the effect of TIBH in wound healing showed that TIBH 10 mg/ml increased wound closure, promoted faster re-epithelization and collagen synthesis. It decreased number of inflammatory cells, decreased Bax protein expression and finally increased SOD activity and decreased lipid peroxidation. In conclusion TIBH showed to be a strong antioxidant and a wound healing promoter.
Index Terms - Wound Healing, Immunohistochemistry, DPPH, FRAP, Cytotoxicity, Antimicrobial.