Hirak Bhasma: A Potential Ayurvedic Antibacterial Drug Assessed by In Vitro Pre-Clinical Studies

Abstract

The growing evidences of multi drug resistance are of genuine concern to combat nosocomial diseases in current time. Herein this study Hirak Bhasma (HB), the widely used herbometallic drug in Ayurveda, was prepared as a nano-drug component and evaluated thoroughly in vitro for the pre-clinical evaluation of an effective anti-bacterial drug candidate. HB showed rich mineral constituents along with some below detection level toxic elements such as Si, Ni and Al which enhance its potential as an antibacterial drug. The nano-dust preparation of the HB came with the presence of a higher organic compositions and mineral constituents having a particle size in nanometer range as was evidenced by the physic-chemical characterization via inductively coupled plasma optical expression spectrometry (ICP-OES), Fourier transform infrared spectra (FTIR), and field emission scanning electron microscopy (FE-SEM) techniques respectively. Antimicrobial potential of 182HB was tested in clinically isolated pathogenic strains of Escherichia coli, Staphylococcus aureus and Candida intermedia through disc diffusion assay, broth turbidity measurements and cell imaging via FE-SEM. The non-cytotoxic dose of HB was found to be 50 µg/ml by the reduction of tetrazolium dye MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT assay) on the human breast cancer cell line MCF7. HB was effective in increasing the intracellular reactive oxygen species (ROS) in the bacterial cells while being helpful to keep the intracellular redox balance in human cells. This proves that HB has the potential to be the effective anti-bacterial drug for the treatment of diseases caused by bacteremia with a minimal or no side effect. Moreover, in the context of the evaluation of the ROS level, HB appeared as a promising drug candidate for the anti-inflammatory and immune-modulatory effects although it has not shown any antifungal effect. Since long the herbometallic ayurvedic compound HB claims its high potential as adaptogenic antibacterial agent, analgesic, antimicrobial, alternative antioxidant, anti-inflammatory, immunomodulator and so on; but there is lack of scientific evidences. This work reports the lagging scientific documentation for HB as antibacterial and anti-inflammatory agent.