Antimicrobial Activity of Spray Dryer Licorice (Glycyrrhiz glabra L.) Extract Against Multi-Drugs Resistant Bacteria

The licorice has been used in pharmaceutical and confectionery industries because of the presence of glycyrrhizin. Stability study was done for spray dryer licorice extract (SDLE) according to the WHO guidelines on stability testing of active substances and pharmaceutical products. For long term stability study, SDLE was stored at 25 C, 65 % R. H for 12 months and for accelerated stability, SDLE was stored at 40 C, 75 % R. H for 6 months study physical examination and determination of glycyrrhizin content were done every 3 months. The extensive use of Antibiotics has led to growing resistance and spread of many bacterial pathogen, which now constituents a serious medical problem. Plant may be considered a new antibacterial activity. A study was conducted to determine the antibacterial activities of licorice root spray dried extract in methanol, water and ethanol against bacteria using the well diffusion method. The extracts showed significant antibacterial activities against five gram-positive (Bacillus subtilis and Staphylococcus aureus, Micrococcus lutes and Staphylococcus epidermes) and three gram-negative (Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa) bacteria. The protein/peptides were isolated and separated on SDS-PAGE. The glycyrrhizin destroyed proteins of K. pneumoniae but in S. epidermes it resulted in appearance of even more protein bands when compared to the protein profile of the untreated bacteria. The extra protein bands were of both low and larger molecular weight than the native proteins present in untreated bacteria.