Anna-Mari Reid

University of Pretoria | UP · Department of Plant and Soil Sciences

Background/Objectives: Loading of natural products into poly-(lactide-co-glycolic) acid (PLGA) nanoparticles as drug delivery systems for the treatment of diseases, such as tuberculosis (TB), has been widely explored. The current study investigated the use of PLGA nanoparticles with 7-methyljuglone (7-MJ), an active pure compound, isolated from the...

Background Dental caries, also known as tooth decay or cavity formation, is one of the world’s most widespread dental conditions. It is a plaque-related infection caused mainly by Streptococcus mutans. People have relied on several plant species to treat oral infections; Heteropyxis natalensis, for example, has been used to treat toothache and gum...

Background Metabolism is an important component of the kinetic characteristics of herbal constituents, and it often determines the internal dose and concentration of these effective constituents at the target site. The metabolic profile of plant extracts and pure compounds need to be determined for any possible herb-drug metabolic interactions that...

7-Methyljuglone (7-MJ) is a pure compound isolated from the roots of Euclea natalensis A. DC., a shrub indigenous to South Africa. It exhibits significant promise as a potential treatment for the highly communicable disease tuberculosis (TB), owing to its effective antimycobacterial activity against Mycobacterium tuberculosis. Despite its potential...

Cotyledon orbiculata L. var. oblonga (Haw.) DC., which is a succulent shrub distributed throughout sub-Saharan Africa, gives rise to fleshy leaves and its flowers are typically red, orange and yellow. Cotyledon orbiculata gives rise to various varieties that may be distinguished based on leaf and flower shape and geographical distribution. The leav...

Carpobrotus dimidiatus is a sturdy, trailing plant characterised by succulent, green, three-sided leaves. It can spread across extensive areas, forming a resilient ground cover that can withstand drought and salt exposure. Its large, glossy, mauve flowers emerge individually on more or less upright flowering branches. The genus, Carpobrotus, is ass...

Tylosema esculentum is an underutilised leguminous plant native to the Kalahari Desert and neighbouring sandy regions of Botswana, Namibia and South Africa. The seed forms part of the diet of the indigenous population in these countries due to being an excellent source of excellent quality protein (29–39%) and oil content (24–48%), which contains n...

Barleria obtusa is a fast-growing shrub known for its rounded, bushy appearance. It features mid-green leaves covered in fine translucent hairs with upturned edges. It produces an impressive profusion of small violet flowers in autumn, at the top of its branches. As the seed capsules mature, they become woody and release their seeds explosively. Th...

Pelargonium graveolens is a resilient, perennial shrub with sizable, velvety leaves that emit a potent rose-scented fragrance. It highlights eye-catching umbels of pinkish-white flowers. The aromatic leaves of this plant produce geranium oil. This essential oil is extensively used in cosmetics for its abilities such as removing dead skin cells, fir...

There are numerous limitations faced when investigating underexplored medicinal plants for prospective drug discovery, which the previous chapters of this book discuss. The main limitations confronted include a lack of accessibility to the plant material and a lack of accessibility to reputable published literature on the plant species and its isol...

Bulbine frutescens is an evergreen perennial that is native to Southern Africa, but can be found in Eastern, Western and Northern Cape. B. frutescens is known for its ethnobotanical use and has been used by traditional healers for years. The jelly-like juice found in the leaves has been discovered to alleviate burns, blisters, insect bites and crac...

Geranium incanum is a low, spreading, branched perennial herb growing as a ground cover with long, slender stems and a thickened tap root. Masses of eye-catching flowers are borne from September to January in shades of white to pale pink with darker veins (var. incanum) or deep magenta-pink (var. multifidum). They are commonly found in traditional...

This monograph describes Leucosidea sericea Eckl. and Zeyh and its use in Southern Africa. This chapter is a comprehensive summary of its vernacular names, botanical description, geographical distribution, ethnobotanical medicinal uses and all scientific data published on its pharmacological and biological bioactivity. In addition, the major chemic...

Barleria repens, commonly known as creeping barleria or creeping phoenix, is a perennial herb belonging to the Acanthaceae family. Originally found in tropical Africa particularly Angola, Botswana, Namibia, South Africa and Zimbabwe. It has since been introduced and spread throughout various regions within the tropics and subtropics. This plant is...

Heteropyxis natalensis is a hardy semi-deciduous tree that lacks thorns and is located along the eastern coastline and central regions of South Africa. Characteristics of the tree are that it has a mottled and flaking bark and can grow up to 15 m. The leaves of the tree are waxy and shiny with a pale green colour and a strong lavender fragrance whe...

Hypoestes aristata (Vahl) Roem. & Schult., native to sub-Saharan Africa, grows to 1.5 m tall and gives rise to flowers that are typically white or purple which occur on spike-like inflorescences. The leaves, root bark and decoctions have traditionally been used for several ailments. Therefore, the phytochemistry of H. aristata was explored and lign...

Juncus lomatophyllus Spreng. is a perennial grass-like sedge belonging to the Juncaceae family. Currently, not much has been done with regard to the biological potential of J. lomatophyllus; however, one paper has reported that J. effusus possesses anti-inflammatory properties. Furthermore, no compounds have been isolated from J. lomatophyllus; how...

Portulacaria afra, also known as elephant bush or dwarf jade plant, is a succulent plant native to South Africa which is commonly used as a houseplant due to its small leaves, plump stems and ease of care. The plant prefers bright, indirect light and well-draining soil and should be allowed to dry out slightly between watering. It is drought tolera...

Cussonia spicata Thunb., distributed throughout sub-Saharan Africa, is an evergreen tree that grows up to 17 m tall and gives rise to green flowers. The bark and roots have been traditionally used for several ailments, leading to the investigation of the phytochemistry of C. spicata. Several phytochemicals have been identified and the pharmacologic...

Elegia tectorum, commonly known as the Cape thatching reed, is located in the fynbos regions of the Western Cape and the marshes of Western and Eastern Cape. Though no medicinal properties have been reported, E. tectorum is used for thatching roofs and weaving baskets and brooms. Previous studies have suggested that Elegia tectorum may possess anti...

Hypoestes forskaolii (Vahl) R.Br. is an annual herb that gives rise to pale-pink or white flowers arranged unidirectionally in a spike formation. It is widely distributed throughout Southern Africa, Saharan highlands, Arabia and Madagascar. The fresh leaves and juice of H. forskaolii boast several ethnobotanical uses, subsequently leading to the id...

Pelargonium citronellum is an evergreen plant that can grow up to 2 m tall and produce flowers in the spring and summer. It is commonly used as a lemon-scented ingredient or flavour for multiple cuisines. The dried leaves are also used in various forms of potpourri. There is a limited amount of scientific literature on the specific plant species, a...

Salvia aurea, more commonly known as the “golden sage”, is a resilient aromatic shrub that has been used for centuries in the fight against communicable and non-communicable diseases. Decoctions produced from S. aurea have been used to promote longevity in China, whilst in ancient Rome, the medicinal properties and usage of S. aurea were classified...

Approximately 45,000 plant species have been identified in Africa, of which 5000 are used traditionally. This indicates that little is known about Africa’s flora and their link to traditional usage, leaving a gap that needs to be filled. This chapter is an introduction to the book titled “Medicinal Plants from Sub-Saharan Africa: Undiscovered Thera...

In this study, 10 essential oils (EOs), from nine plants (Cinnamomum camphora, Curcuma longa, Citrus aurantium, Morinda citrifolia, Petroselinum crispum, Plectranthus amboinicus, Pittosporum senacia, Syzygium coriaceum, and Syzygium samarangense) were assessed for their antimicrobial, antiaging and antiproliferative properties. While only S. coriac...

Without a doubt, potatoes play a vital food and nutrition security role in the world as more than a billion people consume this vegetable. Furthermore, the polyphenolic constituents of pigmented potato cultivars and their associated health benefits have been reported. However, the antioxi-dant, anticancer, and antimycobacterial activity of pigmente...

Eight prenylated xanthones including four new analogues were extracted and purified from the leaves of Garcinia xipshuanbannaensis. Multiple techniques including UV, 1D and 2D NMR, and HRESIMS were used to determine the structures of the isolated xanthones. These xanthones were evaluated for their cytotoxicity toward human cancer cells, and compoun...

In the present study, an immunological arabinan, LCP70-2A, was isolated from Ligusticum chuanxiong for the first time. The absolute molecular weight of LCP70-2A was determined to be 6.46 × 10⁴ g/mol using the HPSEC-MALLS-RID method. The absolute configuration of arabinose in LCP70-2A was determined to be L-configuration. Physicochemical characteriz...

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), known to cause the disease COVID-19, was declared a pandemic in early 2020. The objective of this review was to collate information regarding the potential of plants and natural products to inhibit coronavirus and targets associated with infection in humans and to highlight known dru...

Many plant extracts have been studied for their ability to treat tuberculosis and its associated symptoms. Both Lippia scaberrima Sond. and Aspalathus linearis (Burm.f.) R. Dahlgren, are popular forms of health teas in South Africa. This study focused on the ability of the ethanolic plant extracts of L. scaberrima and A. linearis, as well as the es...

The first vaccine was discovered for the prevention of smallpox in 1796, from where the vaccine for rabies followed in 1885. Vaccines are used to improve the immunity of an infected individual but have a very low immunogenicity and no effective responses have been found for severe infections and cancer. Adjuvants were developed to circumvent this p...

Verbascoside is found in many medicinal plant families such as Verbenaceae. Important biological activities have been ascribed to verbascoside. Investigated in this study is the potential of verbascoside as an adjuvant during tuberculosis treatment. The present study reports on the in vitro metabolism in human hepatic microsomes and cytosol incubat...

Seventy-four ethanolic extracts were prepared from traditionally used medicinal plants in the Jongilanga community in Mpumalanga South Africa. The aim was to determine the biological activity of the selected plants against cancer, mycobacteria species and acne. From the results, it was evident that Mundulea sericea was able to inhibit the prolifera...

Tuberculosis (TB) is a disease associated with high mortality rates in both developing and developed countries. Many plants have been identified which are medicinally associated with tuberculosis infection. Lippia scaberrima (LS) and the combination of LS with Aspalathus linearis (AL) were selected for the current study. LS was found to have a mini...

Tuberculosis is caused by the rod-shaped pathogenic bacterium, Mycobacterium tuberculosis. In 2014 alone this airborne disease caused 1. 5 million deaths worldwide and had an incident rate of 9.6 million individuals. Many plants are known to be medicinally associated with tuberculosis infection and therefore, many opportunities exist for product de...

Allium sativum (garlic) is well-known plant throughout the world as a food or flavour additive, but also for its medicinal properties. Validating ethnobotanical uses of a plant is vital in understanding the mechanism of the plant extract and compounds, it is also important in the development of the plant into medicinal products. Multiple in vitro a...