Merwilla natalensis (Hyacinthaceae)
Introduction
Merwilla natalensis (Planch.) Speta, also known as Scilla natalensis planch, Merwilla plumbea (Lindl.) is indigenous to South Africa and is distributed throughout the eastern part of South Africa including Lesotho, KwaZulu-Natal, Free-State, Swaziland, and the Northern Province [100]. Merwilla natalensis is traditionally known as “inguduza” which means “searching the body for the cause of the ailment” [101]. The extracts of the bulb are known for their antibacterial, anthelmintic, anti-inflammatory, and antischistosomal medicinal activity and use as ointment for wounds, scarifications, as a laxative, and as an enema [10]. Merwilla is sought after for its traditional and medicinal properties to such an extent that there is a risk of extinction [102].
Pelargonium sidoides (Geraniaceae)
Introduction
The taxonomic classification of Pelargonium species is noted with some difficulty hence the numerous revisions in the past. Nonetheless, the genus Pelargonium is highly esteemed by traditional healers for its therapeutic and palliative effects in the treatment of gastrointestinal disorders [120]. Pelargonium sidoides DC. is native to the coastline regions of South Africa and Lesotho [2]. The small perennial herb has long-stalked leaves which are slightly aromatic, heart-shaped, and velvety. The characteristic dark, reddish-purple tubular flowers are present throughout most of the year but occur most frequently from late spring to summer [2, 121]. In the early 20th century, Charles Henry Stevens was treated in South Africa by a traditional health practitioner who claimed that he cured his tuberculosis with a natural remedy containing P. sidoides. “Umckaloabo” is the name used by Stevens for his tuberculosis medicine, a name that still persists today. The term “Umckaloabo” may actually be an origination of Stevens, based on South African languages, intended to create an enigmatic image for his remedy to increase its marketability. In the first half of the 20th century, a product made from the root was used in Europe to treat tuberculosis [2]. A summary of the fascinating history of the commercial development of “Umckaloabo” in Europe is presented in Brendler and van Wyk [122].
http://pt.wikipedia.org/wiki/Pelargonium_sidoides
Sclerocarya birrea (Anacardiaceae)
Introduction
The name Sclerocarya is derived from the Greek word for hard (skleros) and nut (karyon) [2].Sclerocarya birrea (A.Rich.) Hochst. subsp. caffra, also known as marula, is widely distributed in northern and western parts of Africa, but only the subspecies caffra is found in southern Africa [10]. Owing to its ability to provide two fundamental needs, namely, food and medicine [130], S. birrea is also referred to as the “tree of life” and is one of the most important trees of the southern African region. It is regarded sacred and protected in communal lands under the local chiefs [2]. Marula is a medium-sized deciduous tree of up to 15 meters in height with the male and female flowers habitually appearing on separate trees. The flowers are small, with red sepals and yellow petals [4]. The fruit, which averages around 20–30 g, is yellow when ripe with a white juicy flesh which clings to a hard stone, inside which are 2-3 seeds [2]. It is considered a drought-tolerant medicinal plant species with potential role in land rehabilitation [131].
Siphonochilus aethiopicus (Zingiberaceae)
Introduction
Siphonochilus aethiopicus (Schweinf.) B. L. Burtt is commonly known as wild ginger or African ginger, with a restricted distribution in South Africa where it is only found in Mpumalanga and the Northern Province and has become extinct in KwaZulu-Natal [10]. It also grows in Zimbabwe, Malawi, and Zambia. Wild ginger is regarded as one of the most important medicinal plant species of South Africa [15]. The rhizomes and roots are used for a variety of ailments, including coughs, colds, asthma, headache, candida, malaria, and influenza, but also for hysteria, pain and several other traditional and cultural practices [10, 15, 38, 147]. Wild ginger is the main commercial species that is relatively known as a result of its popularity in traditional medicine and concerns about its conservation status [147].
Sutherlandia frutescens (Fabaceae)
Introduction
Sutherlandia frutescens (L.) R.Br. belongs to the family Fabaceae commonly known as the legume, pea, or bean family. With the genus being restricted to southern Africa [10], this soft-wooded shrub with reedy stems is found in Botswana, Namibia, and South Africa [25]. The large red flowers, around 3 cm long, are followed shortly by bladder-like fruits [25]. Sutherlandia frutescens is commonly known as the cancer bush because of the reported use by Khoi-San and Cape Dutch people against internal cancers since 1895 [155, 156]. However, because of its adaptability, S. frutescens has several other vernacular names referring to its ethnomedicinal significance. These include “petola” (Setswana) which means “it changes,” implying that the plant changes the course of many illnesses towards a positive outcome and “lerumo-lamadi” (Northern Sesotho) meaning “the spear for the blood,” indicating that Sutherlandia is a powerful blood-purifier and all-purpose tonic [157]. Sutherlandia along with H. hemerocallidea are the two main African medicinal plants used for treatment of HIV/AIDS and are endorsed by the South African Ministry of Health for HIV management [87].
Conclusion
South Africa is home to thousands of plant species, each an industry for unique and useful chemical compounds. However, more pragmatic information on medicinal plants would enhance their value in agricultural landscapes by helping farmers improve their livelihoods and ensure environmental sustainability [130]. While it is anticipated that commercialization of certain medicinal plant species will bring financial remunerations to communities, this should not impair the subsistence sector, or sustainability of the resource itself [160]. A drawback of using nonrenewable parts such as bark as a source for the medicinal trade is that removal of bark can lead to the death of the plant. If bark can be traded for a high price, valuable plant populations may be collected to extinction in nature [136]. Traditional medicine has been used for treating diseases over centuries, and scientific studies have revealed that many of them are potentially toxic. The use of more polar solvents could be the reason for plant extracts being less toxic as the toxic compounds will be only extracted in more apolar solvents [115]. Drug-drug interactions are well-known phenomena, and the risks have long been realised. For example, interactions involving the concurrent use of sildenafil, a drug used for erectile dysfunction with nitrates and nitrites, can produce profound hypotension leading to decreased coronary perfusion and myocardial infarction. This potentially fatal drug interaction also led to the withdrawal of several sildenafil-containing herbal medications from the market [161]. The use of herbs may mimic, magnify, or oppose the effect of drugs and should therefore be used with care, and proper consultation and information should be provided by health care practitioners when mixing herbs and pharmaceutical drugs as interaction with most drugs is not known. Some examples of already identified herb-drug interactions include bleeding when warfarin is combined with ginkgo (Ginkgo biloba), mild serotonin syndrome in patients who mix St John’s wort (Hypericum perforatum) with serotonin-reuptake inhibitors, and potentiation of oral and topical corticosteroids by liquorice (Glycyrrhiza glabra) and soluble fibres (including guar gum and psyllium) which can decrease the absorption of drugs. An example of South African herb-drug interactions is the use of devil’s claw with the use of warfarin resulting in puprura [162]. In addition, H. hemerocallidea and S. frutescens showed a negative interaction with antiretroviral medication, thus patients may be at risk from treatment failure, viral resistance, or drug toxicity [163].
Intellectual property rights (IPRs) can both positively and negatively impact the interests of primary producers. In order to appreciate benefits from the use of IPRs, communities need substantial financial and technical support [146]. Bioprospecting and regulation thereof has been heavily debated in the past years to minimize exploitation of South African resources without benefit and recognition for knowledge holders. This regulation has been observed by the scientific community as another hurdle in promoting and developing bioactives [164]. A more contemporary avenue for bioactives is the use of plants as vehicles to make recombinant proteins and other molecules for use as therapeutics. However, this is not well explored in Africa probably because few research laboratories are equipped to do this work [6].
The paper addressed just a few applications of the chemical components of the identified plants and the use as food, beverages, various medicinal uses, cosmetic industry, flavor, and fragrance industry to name a few. Some well-known plants and applications such as rooibos, marula, and buchu oil are already contributing to local communities’ upliftment by creating enterprises both from wild harvesting and by cultivation of material. Others such as wild ginger, cancer bush, and the African potato still have potential to become international pharmaceutical and herbal products, and the full potential has not yet been exploited.
Link:
Nenhum comentário:
Postar um comentário