The Friendly Naturopath

The Natal Lily (Clivia miniata) is a popularly traded plant in South Africa which has decreased by over 40% over the last 90 years (Groner et al., 2022, p.1). It is a herbaceous evergreen flowering plant from the Amaryllidaceae family endemic to South Africa and Eswatini (Groner et al., 2022, p.3). The antiviral and antifungal properties of its roots and leaves have been traditionally used to treat fevers, snake bites, infertility, urinary tract disorders and induce uterotonic activity (Groner et al., 2022, p.3; Musara et al., 2021, p.012). Rasethe et al., (2019, p.4) also suggest its use in treating human immunodeficiency virus (HIV), arthritis, skins disorders and tuberculosis. It’s on the Red List of South African plants as being in danger of extinction due to overharvesting for medicinal plant trade, habitat loss due commercial forest plantations, crop cultivation, urban and coastal development, as well as climate change (Williams et al., 2008).

Nowadays, there are fewer traditional healers harvesting plant materials themselves, as commercial harvesters have made it easier to procure medicines whilst practicing in major cities (van Wyk & Prinsloo, 2018, p.337). Consequently, the focus has shifted from customary conservation practices and seasonal restrictions to profit-oriented harvesting which is often more destructive to plant populations (van Wyk & Prinsloo, 2018, p.337). As the human population increases, urbanisation, ongoing infrastructure development, over-exploitation and clearing of natural areas for mining, agriculture and forestry are resulting in land use change which is showing to be the most detrimental factor to the sustained population of C.miniata (Groner et al., 2022, p.2; van Wyk & Prinsloo, 2018, p.337). On the other hand, growing populations also increase the need for medicinal medicine, placing further demand on already reduced resources (van Wyk & Prinsloo, 2018, p.337).

Utilising Species Distribution Models with a metapopulation model (RAMAS-GIS), Groner et al. (2022, p.1) demonstrated how climate change, land cover change and harvesting each substantially reduced the native population of C.miniata, with land cover change and excessive harvesting causing the most significant decline. Results suggested conservation efforts should prioritise protecting suitable habitat and enforcing sustainable harvesting to support viable metapopulation even with the impacts of climate change (Groner et al., 2022, p.1). Inadequate management of wild C.miniata could result in its extinction by 2050 (Groner et al., 2022, pp. 6-8). Therefore, securing a high-quality source in a good quality habitat should be a priority to conserve the species (Groner et al., 2022, p.9).

To address over-exploitation, agencies such as World Health Organisation (WHO), International Union for the Conservation of Nature (IUCN) and World Wide Fund (WWF) recommend wild species be brough into cultivation systems (Schippmann et al., 2002, p.142). However, it is acknowledged that this too, could result in a loss of incentive to conserve wild populations, thus enhancing environmental degradation and loss of genetic diversity (Schippmann et al., 2002, p.142). Furthermore, in South Africa, environmental legislation is fragmented due to shared responsibility between national and provincial governments (van Wyk & Prinsloo, 2018, p.339). According to van Wyk & Prinsloo (2018, p.339), other challenges include:

1. A lack of institutional support for the production and dissemination of key species for cultivation
2. Low prices paid to plant material harvesters by herbal traders, and
3. Many important medicinal species take a long time to mature.

Therefore, harvesters and healers must take responsibility to ensure sustainable practices are implemented to protect plants from extinction (Groner et al., 2022, p.9).

Comparable consequences relating to other medicinal plants are seen in different parts of the world (Groner et al., 2022, p.1). The demand for Panax quinquefolius in Chinese markets is so great that illegal harvesting is a serious problem that has seen a significant decline in both abundance and average stature (Applequist et al., 2020, p.11). In the Eastern Himalayas, the snow lotus is considered endangered due to overharvesting and climate change (Cavaliere, 2009, p.50). Whilst repeated attempts have been made to cultivate snow lotus, little success has been made as it requires very unique conditions in order to grow and take years to mature (Cavaliere, 2009, p.50). In Canada, the Rhodiola Rosea Commercialisation Project was implemented to cultivate and protect the herb from extinction, due to increased competition with invasive species and global warming elevating sea levels where the plant grows (Cavaliere, 2009, p.49).

Shifts in phenology are suggested to result in disruptive ecological effects, including increased competition from other plant species, compromised growing seasons, and reduced pollination opportunities which can disrupt the entire ecosystem (Cavaliere, 2009, p.54). In the early 2000s, this phenological shifts were shown to reduce Matricaria recutita and Foeniculum vulgare yields in specific climates by 80% and 100%, respectively (Cavaliere, 2009, pp.55 & 57). Furthermore, changing temperatures and environments are suspected to affect the production of secondary metabolites, and thus may change therapeutic activity, quality and safety of medicinal plants (Applequist et al., 2020, p.10).

To address the effects of climate change and globalisation, habitat conservation and cultivation projects are recommended to preserve medicinal plants, as well as sustainability training for harvesters that certify them for commercial procurement (Applequist et al., 2020, p.10). Additionally, regulatory programs that monitor raw material quality and safety are also highly recommended to mitigate the effects of climate change (Applequist et al., 2020, p.10; Ekor, 2014, p.1).

For example, due to industrialisation within developing countries, herbal medicine has been shown to be at increased risk of heavy metal contamination and adulteration with synthetic drugs (Bogusz et al., 2002, p. 219). In Saudi Arabia between 2000-2001, 247 herbal remedies were screened using inductive coupled plasma-mass spectrometry and microbiological examination for arsenic, mercury and lead (Bogusz et al., 2002, p. 219). Of these samples, over 30% (n=77) exhibited contaminants (Bogusz et al., 2002, p. 219). Thirty-nine samples contained high concentrations of heavy metals, particularly remedies to treat leukaemia (arsenic content ≈ 522-161,600 ppm) and whitening skin creams (mercury content ≈ 5,700-126,000 ppm) (Bogusz et al., 2002, p. 219). Eight preparations contained synthetic drugs, including benzodiazepines and tricyclic antidepressants in sedative preparations, cyproheptadine in a remedy to gain bodyweight, as well as ibuprofen and dipyrone in herbal capsules to treat rheumatism (Bogusz et al., 2002, p. 219). Eighteen samples were contaminated with micro-organisms and 14 with toxic substances of natural origin overall questioning how “natural” natural medicines are (Bogusz et al., 2002, p. 219).

Similar concerns are seen in China, which has undergone unprecedented rapid economic growth consequently associated with severe pollution of heavy metals, exhaust gases, biochemical and hazardous substances (Chen et al., 2021, p.3). As heavy metals and metalloids are readily absorbed into the roots of herbs and accumulate in the edible parts of medicinal plants, a rise in contamination has significantly increased the need for quality assessment (Chen et al., 2021, pp.3-4). However, in developing nations who lack the resources to perform testing, contamination is particularly risky for consumers (Applequist et al., 2020, p.13).

The reality is, “safety” and “natural” are not synonymous (Ekor, 2014, p.7). Therefore, regulatory policies need to be standardised on a global scale to ensure herbal medicines maintain quality safety and efficacy to protect consumers (Ekor, 2014, p.7; Govindaraghavan & Sucher, 2015, p.363). Such regulations include (Govindaraghavan & Sucher, 2015, p.363):

• Good agricultural and collection practice (GACP)
• Good plan authentication and identification practice (GPAIP), and
• Good manufacturing practices (GMP)

In Australia, botanicals are mostly listed “complementary medicines” as they are considered to carry only a “low risk” of adverse effects (Govindaraghavan & Sucher, 2015, p.364). The Australian regulatory guidelines for complementary medicines (ARGCM) comprise specific guidelines for herbal medicine manufacturing and testing criteria for quality assurance (Govindaraghavan & Sucher, 2015, p.364). These guidelines apply GMP process controls and validation to comply with best global practice (Govindaraghavan & Sucher, 2015, p.364). In addition, the Therapeutic Goods Administration (TGA) also provide specific guidelines for “listed medicines” to ensure quality and safety (Govindaraghavan & Sucher, 2015, p.364; Therapeutic Goods Administration [TGA], 2019). Similar guidelines and regulatory bodies are also present in Canada, Europe and the USA, however not all international firms adopt auditing programs to qualify herbal sources in accordance with stringent GMP protocols (Govindaraghavan & Sucher, 2015, p.364).

Govindaraghavan & Sucher (2015, p.370) recommend an international regulatory body to enable a unified global approach that allows for full transparency of herbal and nutraceutical quality along the entire supply chain. Quality assurance needs to be amended to verify evidence-based, phytochemistry-related efficacy as well as safety (Govindaraghavan & Sucher, 2015, p.370). This is similar to registered medicines in Australia, which are evaluated for efficacy, quality and safety (TGA, 2019). To adopt this recommendation globally will require authenticity and homogeneity assurance, validated extract manufacturing protocols, and harmonised validated test methodologies (Govindaraghavan & Sucher, 2015, p.370). In support of global standards, the American Botanical Council formed the Sustainable Herbs Program, designed to support high quality herbal products, sustainable and ethical sourcing and greater overall transparency by educating consumers and professionals about the risks of climate change and unethical manufacturing (American Botanical Council, n.d.).

Overall, a vast majority of earth’s population relies on medicinal plants for primary healthcare. The impacts of climate change on plant phenology and chemistry, coupled with unethical and unsustainable overharvesting has put the future of herbal medicine at risk. As seen with herbal medicine species like C.miniata, population declines are a combined result of climate change and overharvesting. However, globalisation has also resulted in reduced quality and adulteration of herbal medicine, as seen in China and Saudi Arabia where heavy metals, microorganisms and pharmaceuticals and other biohazardous substances are contaminating herbal supply. To address these issues, cultivation and conservation strategies need to be implemented locally, whilst globalised standards must be enforced to ensure transparent manufacturing and quality protocols are followed.