Search

Ethnopharmacological relevance Traditional remedies from plants have been use to treat male reproductive related disorders for ages in South Africa. Aim This study reviewed the current status of medicinal plants used in male reproductive healthcare as well as their effectiveness as a mode of treatment. Methodology A detailed literature search was done by consulting books, peer-reviewed papers, scientific databases such as Scopus, Science direct and PubMed, and Google scholars. Keywords such as aphrodisiacs, conception, erectile dysfunction, fertility, infertility and sterility in relation to medicinal plants were used during the search. Plant species were selected based on their traditional use in different aspects of male reproductive healthcare. Results A total of 61 plants species were found to be used in treating male impotency or as aphrodisiacs. However, only six species have been evaluated scientifically and these plants showed significant activities either in promoting conception by improving fertility and promoting erection or in contraception by decreasing sperm motility, virility and membrane integrity. Conclusion The importance of herbal products in the treatment of male infertility and related sexual disorders is undeniable. Scientific evaluations of the six species have proved the empirical use of these plants in the improvement of male sexual disorders as well as validating their traditional uses.

Ethnopharmacological relevance Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest complaints, arthritis, rheumatism, venereal diseases and distemper in dogs. Aims of the study To investigate the antioxidant, anti-inflammatory and anti-tyrosinase activities of four Podocarpus species, Podocarpus elongatus, Podocarpus falcatus, Podocarpus henkelii and Podocarpus latifolius, used in traditional medicine in South Africa. Phytochemical analysis to determine the phenolic contents was also carried out. Materials and methods DPPH, FRAP and β-carotene-linoleic acid assays were used to determine the antioxidant/radical scavenging activities of these species. Anti-inflammatory activity of these species was assayed against two cyclooxygenase enzymes (COX-1 and COX-2). Tyrosinase inhibition activity was analysed using the modified dopachrome method with l -DOPA as the substrate. Phenolics were quantitatively determined using spectrophotometric methods. Results Stems of Podocarpus latifolius exhibited the lowest EC50 (0.84 μg/ml) inhibition against DPPH. The percentage antioxidant activity based on the bleaching rate of β-carotene ranged from 96% to 99%. High ferric reducing power was observed in all the extracts. For COX-1, the lowest EC50 value was exhibited by stem extracts of Podocarpus elongatus (5.02 μg/ml) and leaf extract of Podocarpus latifolius showed the lowest EC50 against COX-2 (5.13 μg/ml). All extracts inhibited tyrosinase activity in a dose-dependent manner with stem extract of Podocarpus elongatus being the most potent with an EC50 value of 0.14 mg/ml. The total phenolic content ranged from 2.38 to 6.94 mg of GAE/g dry sample. Conclusion The significant pharmacological activities observed support the use of these species in traditional medicine and may also be candidates in the search for modern pharmaceuticals in medicine, food and cosmetic industries.

The genus Podocarpus sensu latissimo (s.l.) was initially subdivided into eight sections. However, based on new information from different morphological and anatomical studies, these sections were recognised as new genera. This change in nomenclature sometimes is problematic when consulting ethnobotanical data especially when selecting plants for pharmacological screening, thus there is a need to clear any ambiguity with the nomenclature. Species of Podocarpus s.l. are important timber trees in their native areas. They have been used by many communities in traditional medicine and as a source of income. Podocarpus s.l. is used in the treatment of fevers, asthma, coughs, cholera, distemper, chest complaints and venereal diseases. Other uses include timber, food, wax, tannin and as ornamental trees. Although extensive research has been carried out on species of Podocarpus s.l over the last decade, relatively little is known about the African species compared to those of New Zealand, Australia, China and Japan. Phytochemical studies have led to the isolation and elucidation of various terpenoids and nor- and bis-norditerpenoid dilactones. Biflavonoids of the amentoflavone and hinokiflavone types have also been isolated. Nor- and bis-norditerpenes are said to be taxonomic markers for this genus. Recent in vitro and in vivo studies have shown antitumor, antimicrobial, anti-inflammatory, antioxidant, larvicidal, plant and insect growth regulation activities. Various studies have yielded important natural bioactive products and two of them are worth mentioning. Taxol, a significant anticancer agent has been isolated from Podocarpus gracilior and totarol, a diterpenoid isolated from various species and now commercially produced as a potent antibacterial and antioxidant agent. Findings from this review supports the use of an ethnobotanical and chemotaxonomical approach in selecting plants for pharmacological screening since most of the species in the different morphological groups have similar uses. Also the isolated compounds have chemotaxonomic value amongst the groups. Some of the biological activities identified from extracts and compounds isolated from Podocarpus s.l. support the rationale behind the medicinal uses of these species.

In South Africa, heavy metal contamination of agricultural soils is on the increase primarily due to excessive application of fertilizers, sewage disposal and mining activities. The aim of this study was to investigate the effect of cadmium (Cd) on plant growth and biological activity. The medicinal plant Merwilla plumbea [Syn. Merwilla natalensis (Syn. Scilla natalensis)] was selected due to the high demand for its bulbs in the traditional medicine markets. Low levels of Cd (2 mg/L) significantly reduced fresh mass of leaves, bulbs and roots in comparison to the control. Although most of the Cd was stored in the roots, the bulbs, which are used medicinally, accumulated 7.1, 5.9 and 11.6 mg/kg when grown in sand watered weekly with 2, 5 and 10 mg Cd/L respectively. The bulbs of M. plumbea contained 24-fold more Cd than the World Health Organization guideline of 0.3 mg Cd/kg, when irrigated with 2 mg Cd/L. The bulb extracts showed increased antibacterial activity against the Gram-positive bacterium Bacillus subtilis at 2 mg Cd/L. The plants treated with 10 mg Cd/L showed an increased antibacterial activity against B. subtilis, Klebsiella pneumoniae and Staphylococcus aureus in comparison to non-Cd-treated plants (control). However, there was no change in antibacterial activity of the various extracts against the Gram-negative bacterium Escherichia coli. The ability of M. plumbea to accumulate Cd not only raises concern for consumer safety, but also the quality of medicinal plants sold may be in question.