Biochemical Characterisation and In Vitro Testing of Extracts

This module explores the journey from plant material to bioactive compound evaluation, integrating techniques in natural product extraction, biochemical analysis, cell culture, and enzymatic pathway inhibition.

First, students will be introduced to plant extracts—concentrated substances derived from various plant parts such as leaves, stems, roots, flowers, and seeds. They will learn about multiple extraction techniques, each with its own advantages and limitations. The selection of an appropriate extraction method will be discussed in relation to the plant material used, the target compounds, the desired level of purity, and the intended application of the final extract.

The following section will include a demonstration of the biochemical characterisation of the extracts through three analytical assays: the Folin-Ciocalteu method for total phenolic content, the aluminium chloride assay for flavonoid content, and the FRAP assay to evaluate antioxidant activity. Data obtained from these tests will inform a thorough result analysis.

The third section will focus on basic in vitro cell culture techniques using human cell lines to investigate the cytocompatibility of the extracts. Students will perform the MTT assay, a well-established method for assessing cytotoxicity, using a range of extract concentrations and incubation periods. Data analysis will determine a safe concentration range for further application.

Finally, the Renin-Angiotensin System (RAS) will be studied as a key regulator of blood pressure via an enzymatic cascade. Emphasis will be placed on the inhibition of angiotensin I-converting enzyme (ACE) as a therapeutic target. Students will explore the physiological role of RAS and screen plant extracts for potential ACE inhibitors. A SWOT analysis of existing screening methods will guide the development of informed recommendations.

By integrating natural product research and its biomedical applications, this module offers a comprehensive, interdisciplinary learning experience.

General learning outcomes

• Formulate and apply methodological approaches in the extraction and screening of plant-derived compounds using both biochemical and cellular assays.
• Select appropriate in vitro bioassays (e.g., MTT, antioxidant assays, enzymatic inhibition tests) for identifying and evaluating bioactive fractions.
• Perform and interpret biochemical assays such as the Folin-Ciocalteu method, the aluminium chloride method, and the FRAP assay in the characterisation of plant extracts.
• Apply basic cell culture techniques to assess the cytocompatibility of plant extracts using the MTT assay and analyse data to determine safe concentration ranges.
• Explain the function of the Renin-Angiotensin System (RAS) and the role of angiotensin-converting enzyme (ACE) in blood pressure regulation.
• Design and implement a screening approach to identify potential ACE-inhibitory compounds from plant extracts.
• Critically evaluate and compare screening methodologies through SWOT analysis and formulate recommendations for methodological optimisation.