A review on the Using medicinal plants as an alternative to antibiotics
A review on the Using medicinal plants as an alternative to antibiotics
Yasaman Bahmani,1,*
1. Islamic Azad University, Science and Research Branch
Introduction: the use of antibiotics has reduced child mortality and is critical for invasive surgeries and treatments such as chemotherapy. However, the number of infections caused by multidrug-resistant bacteria is increasing worldwide. Antibiotic resistance has been introduced as one of the biggest threats to human health.
The advent of antibiotics changed the treatment of infections, but the development of antibiotic resistance threatened this achievement. One of the reasons for the development of drug resistance is excessive use of antibiotics and their indiscriminate and inappropriate prescription.
The use of medicinal plants in treatment has a long history. Human societies learned the properties of different plants through trial and error. Years of use and trial and error taught humans to find the medicinal properties in which part of the plant, such as the skin, seeds, flowers, etc. The use of medicinal plants in different forms is the oldest medicinal method. Centuries ago in Iran, China, Egypt and India, the use of herbal medicines in traditional medicine for treatment has been common. The first instructions for making herbal medicine are from 5000 years ago. This instruction was discovered on a Sumerian clay slab. Examining historical Iranian manuscripts provides a lot of information on the use of medicinal plants. The Egyptian Medical Papyrus of Iberus, written around 1550 BC, is about plants and mentions 700 species of plants for treatment. Traditional Indian medicine or Ayurveda is one of the oldest health care and treatment systems.
Plants were always used for different purposes because of their aroma, taste, color and properties. The concern about the dangers of chemicals has made them look for natural alternatives to chemical additives or poisons. Medicinal plants, unlike synthetic chemical drugs, cause less side effects. Plant extracts have biologically active compounds. As a result, they can be used in the treatment of diseases. Due to the presence of numerous secondary compounds, plant extracts show many therapeutic properties such as antimicrobial, anti-biofilm and antioxidant properties. For example, phenolic compounds have multiple biological effects, among which antioxidant properties can be mentioned.
Methods: Preparation of plant samples, such as grinding and drying, as well as different extraction methods, affect the preservation of secondary and effective compounds in the final extracts. For extracting and preparing plant samples, plant organs such as leaves, bark, roots, fruits and flowers can be used.
Maceration, percolation, Soxhlet, microwave, sonication extraction and other methods can be used to prepare plant extracts. Maceration is a technique that has been widely used in medicinal plant research. Maceration involved soaking the plant material in a sealed container with a solvent and letting it rest at room temperature for at least 3 days. After soaking for at least 3 days, the solution is clarified by filtration. The choice of solvents determines the type of compound extracted from the samples. Brewing and boiling follow the same principle as soaking. Each is soaked in cold or boiling water.
Maceration technique is the most practical and simple method. In this method, the solvents used in the soaking process play an important role. Also, different solvents such as water, ethanol, methanol, hexane can be used. Each of these solvents as well as different extraction methods can further extract certain secondary metabolites. Then the effects of plant extracts on different microbes are investigated. Antimicrobial property testing methods include disc diffusion , agar dilution, broth macrodilution, broth microdilution, and a concentration gradient test.
Results: Research has shown that some medicinal plants such as Adiantum capillus-veneris, Quercus infectoria and artemisia have antimicrobial properties.
Conclusion: Extracts are hydrophobic and volatile compounds, studying them in order to increase the stability and consequently the efficiency of the extract can be improved.