26 Jan 2022

Conservation of Endangered Medicinal Plant Species

Anjali Singh, MS

As a content and community manager, I leverage my expertise in plant biotechnology, passion for tissue culture, and writing skills to create compelling articles, simplifying intricate scientific concepts, and address your inquiries. As a dedicated science communicator, I strive to spark curiosity and foster a love for science in my audience.

Table of Contents

Introduction

Plants produce an extensive array of secondary metabolites that can be used as ingredients for pharmaceuticals, flavors, agrochemicals, fragrances, colors, biopesticides, and food additives. Some of the useful substances/chemicals found in plants include alkaloids, carbon compounds, essential oils, resins, nitrogen, glycosides, hydrogen, tannins, and gums. And, most of these substances isolated from plants possess medicinal properties. They are used as a precursor for the synthesis of useful medicines/drugs.

In developing countries, approximately 80% of people rely on traditional medicine to meet their basic health care needs, and about 85% of this medicine uses plant extracts.

There is a rapid increase in the use of medicinal plants around the world due to the increasing demand for herbal drugs, natural health products, and secondary metabolites of medicinal plants. And, now it has become difficult to obtain plant-based compounds because of the rapid population growth and intense competition for cultivable lands.

This article presents an overview of the situation of medicinal plants availability worldwide and approaches to save these plants and use them with a sustainable approach.

The Situation on the Rarity of Medicinal Plants

According to an IUCN report around 50-80 thousand flowering plant species are used for medicinal purposes, and among these around 15 thousand are on the verge of extinction. The reason is the increasing population, increasing market demands, overexploitation, overharvesting, and habitat destruction. Also, 20% of the population is already exhausted from human consumption and population growth.

The distribution of medicinal plants is not uniform worldwide. China and India have the maximum diversity of medicinal plants followed by Colombia, South Africa, and the United States. And, the risk of extinction of these medicinal plants is mostly supposed to be in countries like China, India, Kenya, Uganda, Tanzania, and Nepal.

However, the harvesting pressure on these plants doesn’t affect each medicinal plant in the same way. Despite being all important factors affecting species rarity, overexploitation, indiscriminate collection, uncontrolled deforestation, and habitat destruction do not suffice to explain individual species' susceptibility.

Moreover, some biological characteristics also correlate with the extinction risk of these plants. It includes habitat specificity, population size, reproductive system, distribution range, growth rate, and species diversity.

Conservation Strategies for Medicinal Plants

In recent decades, demand for medicinal plants has increased multifold. In North America, Europe, and Asia demand for wild resources has increased by 8–15 % per year. And, it must be noted that after a certain threshold the reproductive capacity of the plants becomes irreversibly reduced.

Some strategies to conserve medicinal plants include: Ex-situ conservation and in-situ conservation.

• Ex-situ conservation: In this process, endangered species are protected outside their natural habitat. Examples include botanical gardens and seeds banks.
• In-situ conservation: It’s protecting the endangered species in their natural habitat by the conservation of their ecosystem and natural habitats. Its examples are natural reserves and wild nurseries.

Apart from ex-situ and in-situ conservation, good agricultural practices (GAP) is another approach to conserve plant species. For improved yields and quality of target products, these practices provide the appropriate levels of water, nutrients, optional additives, and environmental factors including temperature, light, and humidity.

The GAP approach includes:

• The ecological environment of production sites
• Germplasm, cultivation
• Collection
• Quality aspects of pesticide detection
• Macroscopic or microscopic authentication
• Chemical identification of bioactive compounds
• Inspection of metal elements

One other advanced technique to conserve endangered medicinal plants is the tissue culture technique.

How can Tissue Culture Protect The Endangered Medicinal Plants?

Tissue culture is an advanced technique, where a whole plant can be regenerated by using a few tissues from the plant. It has several advantages over conventional techniques, which include:

• Producing disease-free plants
• Conserve genetics of plant species
• Higher plant multiplication rate
• Produce plants in a shorter time and irrespective of their season.

And, many more.

It involves several techniques including suspension culture, somatic embryogenesis, hairy root culture, protoplast culture, organogenesis, and others. However, not all these techniques can be used to conserve plant genetics. Given below are some tissue culture techniques that have been used in previous studies to serve the purpose.

Somatic Embryogenesis

Somatic embryogenesis is the process of generating a non-zygotic embryo from a plant cell or tissue, which can emerge as new plants. The technique has been successfully implemented for several medicinal plants.

For example, the successful germination of somatic embryos has been observed in nine varieties of Medicago sativa. A protocol for induction of direct somatic embryogenesis and subsequent plant regeneration for Malaxis densiflora was observed in seed-derived protocorms cultured on half-strength MS medium supplemented with 2,4-D at 3.39 µM and TDZ at 6.80 µM producing maximum embryoids per explants.

Cryopreservation

Cryopreservation is a method of long-term preservation in liquid nitrogen (-196 °C) that arrests cell division and metabolic and biochemical processes of stored cells/tissues.

Here, the whole plant can be regenerated again using frozen cells. So, this technique provides a better approach to preserve endangered medicinal plant species, such as Rauvolfia serpentine, D. lanalta, and A. Belladonna.

Apart from these conservation approaches and good practices, sustainable use of medicinal plants should be promoted and other good harvesting practices should be curated, especially to preserve the medicinal plants having limited abundance and slow growth.

How Plant Cell Technology Is Helping Culturists Worldwide In Their Tissue Culture Applications?

Plant Cell Technology is helping tissue culturists around the world by providing unique and world-class products and services that smoothen their process. It has MS media, agar, gellan gum, Plant Preservative Mixture (PPM), culture vessels, Biocoupler (TM), and masks in its store to facilitate your processes.

And, that’s not it! Plant Cell Technology also offers consultation services to culturists of all sizes that help to get instant solutions to your tissue culture problems.

So, visit plantcelltechnology.com today and find out more about our product and services and how they help you to excel in your tissue culture processes.

Happy Culturing!!

References

1. Nagaveni, Kumari & Bc, Chandana & Hc, Kumari & Kolakar, Shashikala. (2018). Role of plant tissue culture in micropropagation, secondary metabolites production, and conservation of some endangered medicinal crops. 7.
2. Chen, S. L., Yu, H., Luo, H. M., Wu, Q., Li, C. F., & Steinmetz, A. (2016). Conservation and sustainable use of medicinal plants: problems, progress, and prospects. Chinese medicine, 11, 37. https://doi.org/10.1186/s13020-016-0108-7.