Urginea sanguinea: medicinal wonder or death in disguise?

Untargeted Phenolic Profiling and Functional Insights of the Aerial Parts and Bulbs of Drimia maritima (L.) Stearn

Drimia maritima (L.) Stearn (squill), belonging to the Asparagaceae family, is acknowledged as a medicinally valuable species from the Drimia genera. In this study, water, methanol, and ethyl acetate extracts of D. maritima aerial parts and bulbs were investigated for their polyphenols profile and evaluated for their antioxidant and enzyme inhibition properties. Phenolics were profiled through an untargeted metabolomics approach using an ultra-high pressure liquid chromatograph coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS). This analysis revealed an enrichment of low molecular weight phenolics and flavonoids in the aerial parts of D. maritima, while lignans mainly characterized bulb extracts. Antioxidant capacity was investigated by different assays, including phosphomolybdenum assays, radical scavenging (DPPH: 2,2-diphenyl-1-picrylhydrazyl; ABTS: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), as well as reducing ability (CUPRAC: cupric reducing antioxidant capacity; FRAP: ferric reducing antioxidant power), and metal chelating. In radical scavenging and reducing power assays, the water extract of aerial parts exhibited the strongest ability (DPPH: 36.99 mg trolox equivalent (TE)/g; ABTS: 85.96 mg TE/g; CUPRAC: 87.37 mg TE/g; FRAP: 55.43 mg TE/g). In general, the ethyl acetate extracts from aerial parts and bulbs provided the weakest antioxidant capacity. Concerning enzyme inhibitory activities, the water extracts of the bulb were poorly active, while the ethyl acetate extracts from both plant portions displayed the best α-amylase inhibitory abilities. The best acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) abilities were recorded by ethyl acetate extract of aerial parts (2.36 mg galantamine equivalent (GALAE)/g) and bulbs (5.10 mg GALAE/g), respectively. Overall, these results support the medicinal aptitude of D. maritima and its possible use as a natural source of antioxidants and enzyme inhibitors with functional potential.

The Utilization of Selected Threatened or Protected Plant Species; A Case of Limpopo Province, South Africa

In Limpopo Province, harvesting plants for herbal use by traditional health practitioners and ordinary people is an everyday practice. The study investigated the utilization of the following Threatened or Protected Plant-listed species (TOPS): Alepidea amatymbica Eckl. & Zeyh., Brackenridgea zanguebarica Oliv., Dioscorea sylvatica Eckl., Drimia sanguinea (Schinz) Jessop, Siphonochilus aethiopicus (Schweinf.) B.L.Burtt and Warburgia salutaris (G.Bertol.) Chiov. in Limpopo Province, South Africa. A total of 333 participants were interviewed in this study, across the five districts of the Limpopo Province. Results indicate that traditional health practitioners (THPs) and community members (CMs) use these species exclusively for medicinal purposes. Remedies were often prepared using the underground parts of the plants, which were purchased chiefly from muthi shops–shops trading in both indigenous and exotic plant and animal material used for witchcraft and/or healing. Just over 58.4% of respondents indicated that they purchase material from muthi shops due to their scarcity in local communal lands. In contrast, nearly 40% of participants disclosed that they harvest material from open access land. Only 1.6% of participants sourced these plants from their home gardens. The preference for underground parts and species rarely cultivated in home gardens will lead to extinction of wild populations unless users switch to alternative parts for sustainability.

Bulbous Plants Drimia: "A Thin Line between Poisonous and Healing Compounds" with Biological Activities

Drimia (synonym Urginea) plants are bulbous plants belonging to the family Asparagaceae (formerly the family Hyacinthaceae) and are distinctive, powerful medicinal plants. Just some species are indigenous to South Africa and have been traditionally utilized for centuries to cure various diseases and/or ailments. They have been recognized among the most famous and used medicinal plants in South Africa. Traditionally, the plants are used for various illnesses such as dropsy, respiratory disease, bone and joint complications, skin disorders, epilepsy and cancer. A number of studies have reported biological properties such as antiviral, antibacterial, antioxidant and anti-inflammatory, immunomodulatory, and anticancer activities. Their bulbs are a popular treatment for colds, measles, pneumonia, coughs, fever and headaches. However, some plant species are regarded as one of the six most common poisonous plants in Southern Africa that are toxic to livestock and humans. Due to the therapeutic effects of the Drimia plant bulb, research has focused on the phytochemicals of Drimia species. The principal constituents isolated from this genus are cardiac glycosides. In addition, phenolic compounds, phytosterols and other phytochemical constituents were identified. This study constitutes a critical review of Drimia species' bioactive compounds, toxicology, biological properties and phytochemistry, advocating it as an important source for effective therapeutic medicine. For this purpose, various scientific electronic databases such as ScienceDirect, Scopus, Google Scholar, PubMed and Web of Science were researched and reviewed to conduct this study. Despite well-studied biological investigations, there is limited research on the toxic properties and the toxic compounds of certain Drimia species. Searching from 2017 to 2021, Google Scholar search tools retrieved 462 publications; however, only 3 investigated the toxicity and safety aspects of Drimia. The aim was to identify the current scientific research gap on Drimia species, hence highlighting a thin line between poisonous and healing compounds, dotted across numerous publications, in this review paper.

Tswana traditional health practitioners' perspectives on the management of diabetes and hypertension: a qualitative study using focus group discussions

INTRODUCTION

The literature suggests the involvement of Traditional Health Practitioners (THPs) perspectives in treating diabetes and hypertension in Africa. This study sought the perspectives of Tswana THPs in the management of both diabetes and hypertension.

METHODS

Using a semi-structured interview guide, four Focus Group Discussions (FGDs) sessions were held with 40 THPs; FGD1 (12) FGD2 (6); FGD3 (13) and FGD4 (9) who were purposely selected from Bojanala and Dr. Ruth Sekgopomati Districts in the North-West Province of South Africa.

RESULTS

Tswana THPs perceived diabetes as a "sugar" disease and described hypertension as a disease associated with the abnormal flow of blood in a patient's body. In addition, some of the signs and symptoms of both diabetes and hypertension mentioned by Tswana THPs agreed with scientific literature. Tswana THPs employed the use of the following plants: borago officinalis, ziziphus mucronata, hypoxis hemerocallidea, sutherlandia frutescens, senna italica, urginea sanguinea and eucalyptus globulus in the management of diabetes and hypertension.

CONCLUSION

Some of the medicinal plants employed by THPs in the management of both diabetes and hypertension has been proven scientifically to be effective against these chronic conditions.

Traditional medical uses of Drimia species in terms of phytochemistry, pharmacology and toxicology

Drimia genus includes plants that used from ancient time for various ailments such as dropsy, respiratory ailment, bone and joint complications, skin disorders, epilepsy and cancer. Toxic properties of some Drimia species also were noted by ancient scientists and these plants have been traditionally used for rat control. Bufadienolides have been identified as the main constituents in the genus of Drimia. Phenolics, sterols, protein and some of other phytochemicals have been also isolated from these plants. Pharmacological and clinical studies have strongly approved their effect on cardiovascular system. Extracts and compounds isolated from Drimia species showed biological activities such as antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory and insecticidal effects through several in vivo and in vitro studies. Moreover, cytotoxic and antitumor activities which may be related to bufadienolide content of these plants have been considered by many researchers. Traditional therapeutic values of these plants for treating respiratory and rheumatic ailments as well as skin disorders are needed to be validated through more researches. Toxic effects of these plants and isolated compounds have been investigated through several in vivo studies. Drimia plants and their isolated compounds have narrow therapeutic index, so patients should be prohibited from applying these plants without medical supervision and should be informed about the main intoxication symptoms before starting treatment. Moreover, interaction of Drimia plants with other constituents of traditional herbal mixtures as well as chemical and biological modalities for reducing toxicity of bufadienolide compounds can be subjected for future studies.

The chemistry and biological activity of the Hyacinthaceae

The Hyacinthaceae (sensu APGII), with approximately 900 species in about 70 genera, can be divided into three main subfamilies, the Hyacinthoideae, the Urgineoideae and the Ornithogaloideae, with a small fourth subfamily the Oziroëoideae, restricted to South America. The plants included in this family have long been used in traditional medicine for a wide range of medicinal applications. This, together with some significant toxicity to livestock has led to the chemical composition of many of the species being investigated. The compounds found are, for the most part, subfamily-restricted, with homoisoflavanones and spirocyclic nortriterpenoids characterising the Hyacinthoideae, bufadienolides characterising the Urgineoideae, and cardenolides and steroidal glycosides characterising the Ornithogaloideae. The phytochemical profiles of 38 genera of the Hyacinthaceae will be discussed as well as any biological activity associated with both crude extracts and compounds isolated. The Hyacinthaceae of southern Africa were last reviewed in 2000 (T. S. Pohl, N. R. Crouch and D. A. Mulholland, Curr. Org. Chem., 2000, 4, 1287-1324; ref. 1); the current contribution considers the family at a global level.

An overview of the evidence and mechanisms of herb-drug interactions

Despite the lack of sufficient information on the safety of herbal products, their use as alternative and/or complementary medicine is globally popular. There is also an increasing interest in medicinal herbs as precursor for pharmacological actives. Of serious concern is the concurrent consumption of herbal products and conventional drugs. Herb-drug interaction (HDI) is the single most important clinical consequence of this practice. Using a structured assessment procedure, the evidence of HDI presents with varying degree of clinical significance. While the potential for HDI for a number of herbal products is inferred from non-human studies, certain HDIs are well established through human studies and documented case reports. Various mechanisms of pharmacokinetic HDI have been identified and include the alteration in the gastrointestinal functions with consequent effects on drug absorption; induction and inhibition of metabolic enzymes and transport proteins; and alteration of renal excretion of drugs and their metabolites. Due to the intrinsic pharmacologic properties of phytochemicals, pharmacodynamic HDIs are also known to occur. The effects could be synergistic, additive, and/or antagonistic. Poor reporting on the part of patients and the inability to promptly identify HDI by health providers are identified as major factors limiting the extensive compilation of clinically relevant HDIs. A general overview and the significance of pharmacokinetic and pharmacodynamic HDI are provided, detailing basic mechanism, and nature of evidence available. An increased level of awareness of HDI is necessary among health professionals and drug discovery scientists. With the increasing number of plant-sourced pharmacological actives, the potential for HDI should always be assessed in the non-clinical safety assessment phase of drug development process. More clinically relevant research is also required in this area as current information on HDI is insufficient for clinical applications.

An approach to the synthesis and attachment of scillabiose to steroids

Hellebrin and transvaalin are two naturally occurring saponins with biological activity. In the present paper, we describe a high yielding route to the synthesis and coupling of their shared glycone, scillabiose, to a model steroid. A convergent coupling strategy utilizing a scillabiose-based glycosyl donor was devised for the glycosylation. This convergent approach is appealing due to its high efficiency and simple deprotection procedure and may find further use in total synthesis of naturally occurring saponins and related compounds sharing the same glycone. Due to the widespread occurrence of this glycone in nature, the complete NMR spectroscopic characterization of all compounds prepared herein is provided as reference material. In addition, glycosylations were performed with the monosaccharide constituents of scillabiose, thereby providing a limited series of glycosylated steroids for potential future evaluation of the effects of the glycone on the overall biological activity.

Poisonous plants of veterinary and human importance in southern Africa

Southern Africa is inherently rich in flora, where the habitat and climatic conditions range from arid environments to lush, sub-tropical greenery. Needless to say, with such diversity in plant life there are numerous indigenous poisonous plants, and when naturalised exotic species and toxic garden varieties are added the list of potential poisonous plants increases. The economically important poisonous plants affecting livestock and other plant poisonings of veterinary significance are briefly reviewed. In addition, a synopsis of the more common plant poisonings in humans is presented. Many of the plants mentioned in this review are also used ethnobotanically for treatment of disease in humans and animals and it is essential to be mindful of their toxic potential.

Effects of Urginea sanguinea, a traditional asthma remedy, on embryo neuronal development

The Southern African plant, Urginea sanguinea Shinz (Hyacinthaceae) (US), is a well-known traditional herbal medicine and it is used for many different ailments, including asthma. Pregnant women also use this plant and little is known regarding the toxic effects of this plant material on the developing foetus. US contains the cardiac glycoside (CG) Transvaalin; CGs are known to cross the placenta and blood-brain barrier and therefore may have a negative effect on the foetal development. To address this, in vitro cytotoxicity of this preparation as well as its effect on chick embryo neural development was investigated. Water extracts of US were shown to be cytotoxic in cell cultures of L929 cell and primary embryonic neural cell cultures. Electron microscopy studies following in ovo exposure revealed altered neuron morphology with patterns of cell damage either associated with apoptosis or necrosis. CGs are known to inhibit membrane bound Na(+)/K(+)-ATPase in conducting tissues, causing disruption of the calcium pathways, mitochondrial calcium overload leading to either apoptosis or necrosis or where both occur, a process of necrapoptosis. The in ovo effects observed strongly indicate that US causes necrapoptosis in chick embryonic neurons.