Also, herbal medicine may be useful alternative treatment in case of numerous side effects and drug resistance. Recently, plant as a source of medicine is gaining international popularity because of its natural origin, availability in local communities, cheaper to purchase, ease of administration, and perhaps less troublesome. In addition, it comprises determination of quantity and quality of bioactive compounds. This is followed by extraction, fractionation, and isolation of the bioactive compound where applicable. The concept of preparation of medicinal plant for experimental purposes involves the proper and timely collection of the plant, authentication by an expert, adequate drying, and grinding. Medicinal plants are extracted and processed for direct consumption as herbal or traditional medicine or prepared for experimental purposes. Subsequently, different methods described above can be grouped and discussed according to the intended biological testing to guide young researchers and make them more focused. Finally, compounds obtained are characterized using diverse identification techniques such as mass spectroscopy, infrared spectroscopy, ultraviolet spectroscopy, and nuclear magnetic resonance spectroscopy. Fractionation and purification of phytochemical substances are achieved through application of various chromatographic techniques such as paper chromatography, thin-layer chromatography, gas chromatography, and high-performance liquid chromatography.

In general, extraction procedures include maceration, digestion, decoction, infusion, percolation, Soxhlet extraction, superficial extraction, ultrasound-assisted, and microwave-assisted extractions. Solvents commonly used in extraction of medicinal plants are polar solvent (e.g., water, alcohols), intermediate polar (e.g., acetone, dichloromethane), and nonpolar (e.g., n-hexane, ether, chloroform). The nitty-gritty of these methods and the exact road map followed solely depends on the research design. The major stages included in acquiring quality bioactive molecule are the selection of an appropriate solvent, extraction methods, phytochemical screening procedures, fractionation methods, and identification techniques. Although the extracts, bioactive fractions, or compounds obtained from medicinal plants are used for different purposes, the techniques involved in producing them are generally the same irrespective of the intended biological testing. The primary objective of this study was to evaluate various methods used in the preparation and screening of medicinal plants in our daily research. It involves extraction and determination of quality and quantity of bioactive constituents before proceeding with the intended biological testing.

Preparation of medicinal plants for experimental purposes is an initial step and key in achieving quality research outcome.

Oil extractor tube