Some Biological Activities and Safety of Mineral Pitch

Mineral pitch, a form of mineral dripping from the cracks of the rocks, has been historically used through topical and oral administrations for health benefits. Its biological activities and safety have not been well characterized. The purpose of this study was to investigate the antioxidative activity, antimicrobial activity, cytotoxicity and heavy metal determination of mineral pitch in comparison to coal tar. The total phenolic content and antioxidative activity of mineral pitch were higher than those of coal tar. Antimicrobial activities against Staphylococcus aureus, Escherichia coli and Candida albicans of mineral pitch were less than coal tar. A dichloromethane extract of mineral pitch could inhibit the growth of those three microbes, while the butanol extract showed the growth inhibition on S. aureus and C. albicans. From the MTT assay, mineral pitch was notably toxic to normal human lung fibroblast (MRC-5), human breast carcinoma cells (MDA-MB-231), human lung carcinoma cells (A549), human cervical carcinoma cells (Hela), human colorectal adenocarcinoma cells (SW-620), human ovarian carcinoma cells (SKOV-3) and human hepatocarcinama cells (HepG2). Inductively coupled plasma-mass spectrometry (ICP-MS) analysis indicated the high content of heavy metals, especially, As, Hg, and Pb in mineral pitch which might relate to the cytotoxicity.