Herbal medicine is as old as humanity itself. Evidence for the historical connection between man and his search for medicines in nature comes from various sources: preserved monuments, written documents, and even original herbal medicines. Modern science has recognized the action of some herbal medicines that ancient civilizations have known and used throughout history, and some have been incorporated into modern pharmacotherapy.

Many herbs are used as self-medication or on the recommendation of a doctor or pharmacist. They are used alone or in combination with synthetic drugs (complementary medicine). For the purpose of adequate and successfully applied therapy, it is necessary to know the precise diagnosis of the disease as well as the method of action of medicinal plants, i.e., the pharmacological action of their components. Herbal remedies and phytopreparations are used as therapeutic agents, most often with defined active components, with proven action and sometimes therapeutic efficacy. In recent decades, there has been a large increase in the number of infectious diseases that occur especially in people with weakened immunity. There has been an emerging interest in bacterial and fungal pathogens that have developed resistance to commercial antimicrobials currently in use. Systemic and opportunistic pathogens have emerged and novel approaches for their treatment are necessary.

The aim of this Special Issue is to collate original research and review articles describing advances in this field.

Potential topics include but are not limited to the following:

• Antibacterial activity of natural products
• Antifungal activity of natural products
• Mechanisms of antimicrobial action of folkloric herbal medicines
• Ethnopharmacological approaches to infectious diseases
• Treatment of infection-related diseases
• Chemistry of traditional plant formulations with antimicrobial potential
• Small and high molecular weight molecules from plants traditionally used as antimicrobials
• Structure-activity relationship studies
• Cross-reactivity and counterindications using traditional herbal medicines in conjunction with other therapies
• Potentiation of allopathic antimicrobials in combination with traditional medicines