A review of preclinical evidence of Cryptolepis nigrescens (Wennberg) L. Joubert. and Bruyns., Prosopsis africana (Guill. and Perr.) Taub. and Pterygota macrocarpa K. Schum. traditionally used to manage tumours in Ghana

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer stands as one of the leading causes of death worldwide according to the World Health Organization (WHO), and it has led to approximately 10 million fatalities in 2020. Medicinal plants are still widely used and accepted form of treatment for most diseases including cancer in Ghana. This review presented Cryptolepis nigrescens (Wennberg) L. Joubert. and Bruyns., Prosopsis africana (Guill. and Perr.) Taub. and Pterygota macrocarpa K. Schum. as medicinal plants that are traditionally used to treat tumour growth, amongst other diseases, in the Ashanti region of Ghana.

AIM OF REVIEW

This paper aims to present a comprehensive review on the botanical description, ecological distribution, ethnomedicinal uses, phytochemical composition and ethnopharmacological relevance of C. nigrescens, P. africana and P. macrocarpa.

MATERIALS AND METHODS

The review covers works published between 1962 and 2023 from various countries. Published books, thesis, scientific and medical articles on C. nigrescens, P. africana and P. macrocarpa were collected from the following databases: 'Scopus', 'Science Direct', 'Medline', 'PubMed', 'Research Gate' 'Google Scholar, and 'Springer link' using the keywords.

RESULTS

Phytochemical analysis of C. nigrescens, P. africana and P. macrocarpa revealed the presence of some prominent bioactive compounds such as convallatoxin, 7,3,4-trihydroxy-3-methoxyflavanone and dioxane, respectively. Plant extracts and isolated compounds of these medicinal plants exhibited a wide range of ethnopharmacological activities including antimicrobial, anti-inflammatory, antioxidant, analgesic, cytotoxic, antimalarial, antipyretic, haematinic, hepato-protective, aphrodisiac and antihypertensive properties.

CONCLUSION

The present review on C. nigrescens , P.africana and P. macrocarpa provided a credible summary of the ethnopharmacological research conducted on these medicinal plants till date. The data also highligted the potential therapeutic profiles of these plants in Ghana that could serve as foundation for future studies. Additionally, the information significantly supported the traditional and commercial use of these plants among the people.

Mining-induced changes in ecosystem services value and implications of their economic and relational cost in a mining landscape, Ghana

The surge in mining operations to meet the global demand for mineral resources adversely impacts ecosystem services and dependent households, but the issue barely attracts attention. This study evaluated the dynamics of mining-induced changes in the value of ecosystem services (ES) and the consequent economic and relational cost to rural households in the Ahafo region of Ghana. Face-to-face structured interviews with 200 householders were conducted in three mining communities. We determined relational values in the landscape through focus group discussion and the economic cost of the ecosystem services lost by applying replacement and contingency cost estimations. Old-growth forests, degraded forests, teak plantations, cultivated land, wetlands, and grassland were ecosystems identified in the mining landscape. The most valued ecosystem was old-growth forest, while the least was grassland. Provisioning service was the most valued ES, while supporting service was the least. Provisioning ES was rated the most impacted by the mine, whereas cultural services were the least affected. Mining activities caused a significant loss of 14 ecosystem services (including crops, livestock, capture fisheries, wild food, bush meat, biomass fuel, and freshwater) that were of priority to the communities. The affected households experienced relatively high monthly economic costs, approximating $300 per household, from the loss of priority ecosystem services. Canonical correspondence analysis revealed connections between ecosystem services valuation and the socio-demographic characteristics of the respondents. There was a perceived mine-adverse effect on the relational values of the people relating to cultural identity, sovereignty, symbolic value, security, subsistence and livelihood, sense of place, social cohesion, social memory, female emotional/mental health, and womanhood training opportunities. Actors in the mining industry should consider policies and management interventions that will limit ecosystem services loss, widely ascertain ecosystem benefits, and comprehensively mitigate the impact of their loss on households.

Phytoremediation of wastewater with Limnocharis flava, Thalia geniculata and Typha latifolia in constructed wetlands

Phytoremediation is thought to be the most sustainable wastewater treatment option for developing countries. However, its application is often limited by unavailability of suitable candidate species. In the present study, the potentials of Limnocharis flava, Thalia geniculata and Typha latifolia for remediation of heavy metal contaminated wastewater with a constructed wetland system were evaluated. The wetland consisted of three treatment lines each planted with sufficient and equal number of a species. Duplicate plant and water samples were collected bi-monthly and analyzed for Fe, Cu, Zn, Pb, and Hg using the atomic absorption spectrophotometer over a six month period. Bioaccumulation rates generally increased over time and varied among plants for these metals, with Fe (456-1549 mg kg1 roots; 20-183 mg kg(-1) shoot) being the most sequestered and Pb (1.2-7.6 mg kg(-1) roots; 1.55-3.95 mg kg(-1) shoot) the least. Translocation factors differed among the species but generally remained stable over time. L flava showed potential for hyperaccumulating Hg. Removal efficiencies varied for the studied metals (approximately 20-77 %) and were generally related to metal uptake by the plants. These results demonstrate the suitability of the species for phytoremediation, and the usefulness of the technique as an option for improving irrigation water quality in Ghana.