Abstract
A plethora of pathogenic microorganisms is responsible for several
infectious diseases. For many decades, the treatment of microbial infections includes
the use of various antimicrobial agents. However, the extensive use of antibiotics has
been found to develop multiple drug resistance (MDR) in many pathogens.
Furthermore, the rate of MDR is higher in developing countries because of
indiscriminate use and self-medication. The emergence of MDR limits the
effectiveness and therapeutic options for common infections. As a result, much
attention is given to naturally derived products that can be used as potential, with better
efficacy, less expensive alternative, and safe antimicrobials for the treatment of
common infections.
Herbal medicines have always been used as an alternative to treat diseases due to
toxicity and associated side effects of allopathic medicines. In recent years, the use of
herbs and spices in therapy has been gradually increasing in many developing countries
because of their safety, efficacy, and other beneficial effects. Spices and herbs have
been used for thousands of years for flavouring and preserving foods. Many of these
herbs and spices, such as thyme, cinnamon, clove, oregano, cardamom, nutmeg, mint,
and cumin, are known to exert a range of therapeutic activities, including antioxidant,
anti-inflammatory, and anticancerogenic. These are also useful for preventing lipid
oxidation and free radical scavenging agents in living organisms.
Spices and herbs demonstrate antimicrobial activity due to the presence of some of the
important phytochemicals or essential oils, which are naturally toxic to microbes. The
phytochemical screening disclosed the presence of a number of secondary metabolites
such as resins, phenols, alkaloids, flavonoids, sterols, reducing sugars, tannins,
glycosides, etc. and various essential oils which act on a wide range of microorganisms
such as fungi, viruses, bacteria, protozoa, etc. The antimicrobial activity of the spices
depends on the composition, the type of the spices, and various other environmental
factors. The mechanism of its action by which these phytoconstituents act is generally
complex and mostly depends on the presence of chemical constituents. It is also
affected by the different cell wall components, such as its composition and the presenceof different proteins on the cell envelope, as these are the major components that
interact with the molecules. Some essential oils in plants cause partial disintegration
due to the disruption of the lipopolysaccharide in the outer layer. It also inhibits the
synthesis of nucleic acids, polysaccharides, and proteins in bacterial and fungal cells.
Thus, the use of spices and herbs presents a great potential to be used as an alternative
or in addition with the allopathic medicine to decrease the side effects and
progressively increase the resistance of pathogens induced by the use of allopathic
drugs.
Keywords: Alkaloids, Spices, Herbs, Bacterial resistance, Essential oils, Cell wall synthesis inhibition, Protein synthesis.