Recent reports reveal that there is increasing incidence of infections of multidrug-resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Flavonoids and related compounds have been shown to possess potent antimicrobial activities. Most of the flavonoids are considered as constitutive antimicrobial substances recently termed as “Phytoanticipins,” especially those belonging to prenylated flavonoids and isoflavones. The current review highlights the structure prerequisites for isoflavones as antibacterial agents. Structure–activity relationship (SAR) conclusions have been drawn by comparing the reported minimum inhibitory concentration values for the various isoflavones against S. aureus and MRSA. There exists a significant co-relationship between the presence of certain functional groups (prenyl group, phenolic hydroxyl) at particular positions and antibacterial activity of the compounds. These trends have been postulated with a view of assisting better drug designing of future next-generation antiinfectives, particularly against the bothersome multidrug-resistant microbes. The SAR of these isoflavones has also proved to be a basis to explore the mechanism of antibacterial action. Thus, the study would prove extremely useful to synthesize antibacterial isoflavones in future, which would eventually be beneficial for optimizing the lead molecule for the antibacterial action

Background:Garlic (Allium sativum) has been known to exhibit a wide range of pharmacological activities which are attributed mainly to the organosulfur compounds present in it. Allicin and garlic oil, components obtained from garlic, have been explored and found to be biologically active on various fronts. Allicin is known to have major stability issues due to rapid degradation even at low temperatures, whereas garlic oil, being lipophilic, shows poor bioavailability after oral administration.Objective:To develop novel strategies for optimum delivery of allicin and garlic oil so as to achieve effective availability in the physiological system.Materials and Methods:Garlic cloves were lyophilized to obtain allicin-releasing garlic powder (ARGP). This powder was analyzed spectrophotometrically and was used to formulate buccal tablets. Garlic oil was obtained by hydrodistillation of garlic cloves and analyzed by gas chromatography. Self-nanoemulsifying systems (SNS) containing garlic oil were prepared using suitable surfactants and cosurfactants. The SNS were adsorbed on Aerosil 200 and filled in hard gelatin capsules. Both the formulations were suitably evaluated.Results:Buccal tablets containing ARGP showed satisfactory physical parameters as well as in vitro drug release, mucoadhesive strength, moisture uptake capacity and drug content. Evaluation of capsules containing SNS of garlic oil also gave satisfactory results. The adsorbed SNS when dispersed in water formed nanoemulsions.Conclusion:Buccal tablets as well as capsules containing garlic oil SNS provide promising strategies to overcome the difficulties associated with formulation of allicin and garlic oil.