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Most of the current cancer chemotherapeutics are associated with harsh and undesirable side effects, including toxicity and chemoresistance, driving the need for safer and more effective alternatives. In this study, the antiproliferative activities of the methanolic extract of Tetrapleura tetraptera fruits and nine different fractions (C1–C9) from the column chromatographic separation of the extract against leukemia (Jurkat) and human breast cancer (MCF-7) cell lines were investigated using a tetrazolium-based colorimetric assay. Phytochemical screening of the extract and fractions found alkaloids, carbohydrates, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids in the methanolic extract. Most of the fractions exhibited antiproliferative activity (>100 μg/mL) with the Jurkat cells being more susceptible than the MCF-7 cells. Four of the collected fractions C4, C3, C5, and C2 had good selective indices in decreasing order of activity, in the case of Jurkat cells. Liquid chromatography-mass spectrometry analysis of all samples (except for C4 and C9) revealed that C1, C2, C3, and C5 each had a single component. More importantly, fractions C2, C3, and C5, which were selective to Jurkat cells, also had the same retention time of 1.846 min. Fractions C6 and C8 had two components, with C7 having four components. This study serves as a basis for further work to isolate and characterize potential anticancer agents from the fractions of extracts of T. tetraptera fruits.

Dichapetalum madagascariense Poir (Dichapetalaceae) is traditionally used to treat bacterial infections, jaundice, urethritis and viral hepatitis in Africa. Its root contains a broad spectrum of biologically active dichapetalins. To evaluate the plant's effect on human MCF-7 cells and its' antibacterial and antiparasitic potentials, we isolated and identified the known dichapetalins A and M from the roots. Both dichapetalins were tested on six bacterial strains (Shigella flexneri, Bacillus cereus, Salmonella paratyphi B, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus) and two parasite strains; Trypanosoma brucei brucei, and Leishmania donovani using the Alamar Blue assay system. Dichapetalins A and M were more potent against B. cereus with IC50 values of 11.15 and 3.15 μg/ml, respectively, compared to the positive control ampicillin (IC50 = 19.50 μg/ml). Dichapetalins A (IC50 = 74.22 μg/ml) and M (IC50 = 72.34 μg/ml) were less active against T. b. brucei, compared to the standard Suramin (IC50 = 4.96 μg/ml). Dichapetalin M showed moderate activity against L. donovani (Amphotericin B: IC50 = 0.21 μg/ml) with an IC50 of 16.80 μg/ml. In human MCF-7 cells expressing the NR1I2 receptor, the activity of dichapetalin M was higher (IC50 = 4.71 μM and 3.95 μM) for 48 and 72 h of treatment, respectively compared to Curcumin with IC50 of 17.49 μM and 12.53 μM for 48 and 72 h of treatment, respectively. Results from in vitro expression studies with qPCR confirmed an antagonistic effect of dichapetalin M on PXR (NR1I2) signaling; supporting the PXR signaling pathway as a possible mode of action of dichapetalin M as predicted by in silico results. These findings confirm previous studies that D. madagascariense can be a source of potential lead compounds for development of novel antibiotic, antiparasitic and anticancer medicines, and provide further insights into the mechanism of action of the dichapetalins.

Two new bisbibenzyls, heudelotol A (1) and B (2), along with the known bibenzyls, (E)-combretastatin A-1 (3) and combretastatin B-1 (4) have been isolated from the ethyl acetate extract of the roots of Dichapetalum heudelotii. Structure elucidation of all four isolated compounds was achieved using UV, IR, 1D and 2D NMR spectroscopy and HR-Mass Spectrometry. The compounds exhibited varying antiproliferative activity against six cancer cell lines using the CellTiter-Glo® Luminiscent Cell Viability Assay. Compound 3 was found to be the most active with sub-micromolar growth inhibition concentrations against all the cell lines (GI50 0.03-0.72μM). However, it was about ten-fold less active than the positive control, taxol. The new bisbibenzyls heudelotol A and B exhibited good activity against human pancreatic adenocarcinoma (GI50 9.04μM) and Burkitt's lymphoma (GI50 4.67μM) respectively, and average activity against the other cancer cell lines.

The common narrative on e-waste recycling in contemporary Ghana refers to a sector that is primarily a marginalised, ‘survival entity’ involving excess workers living in poor urban neighbourhoods. Other narratives highlight the environmental health challenges associated with e-waste recycling management practices. In this paper, we explore how such recycling in Accra, notwithstanding the health and environmental externalities, also involves a vibrant entrepreneurial part of the urban economy. This case-study-based article was conducted through community asset mapping and 17 key informants' interviews. The study identified within the e-waste economy a network of worlds of work that intersect with both formal and international industries. Based on our findings, we propose that when properly nurtured, regularised and managed, e-waste recycling can foster economic growth and job creation. In conclusion, we highlight three foci that can enrich theory, practice and research, all three of which are in need of broader understandings. These foci will also support progress towards achieving a democratic account of everyday life and work complexities within the informal economy in Ghana.

The informal sector in developing countries plays a particularly important role in the overall economic development, yet due to epistemological neglect, its conceptualization focuses on the prism of poverty and social exclusion, hence overshadowing its embedded innovativeness, adaptability and contributions to job creation, poverty alleviation and environmental management. This paper contributes in bridging this knowledge dearth by focusing on how informal e-waste recyclers negotiate the challenges of contemporary political economy contexts. Using an urban mining lens, this paper shows how crucial this sector is for the success of any municipal waste management system and Accra’s local economy in general. It is contended that the continuous denial of the sector’s virtues in the economy is a poor situational analysis and the research emphasizes instead the need to consider as well as harness the sector’s potential in order to create not only employment for the poor but also to bring e-waste recycling into mainstream waste management scholarship.

The roots of Dichapetalum madagascariensis have yielded the new dichapetalin M, together with the previously reported dichapetalin A. This brings to nine, the total number of dichapetalins so far isolated from the roots of the plant, and to thirteen, the total number of dichapetalins isolated from the Dichapetalaceae. Dichapetalin M exhibited greater toxicity towards brine shrimp larvae than dichapetalin A, which has demonstrated cell inhibition against various cancer cell lines.

Dichapetalum filicaule Breteler (Dichapetalaceae) is a rare species occurring only in Côte d'Ivoire and Ghana. Although research on several species of the genus has produced interesting bioactive compounds, particularly the Dichapetalins, a novel class of triterpenoids with antineoplastic properties, there is virtually no information on the ethnobotanical uses and chemical constituents of D. filicaule.The phytochemical and anthelminthic activities of the constituents of D. filicaule were investigated.Chemical constituents of the petroleum ether, chloroform-acetone, and methanol root extracts of D. filicaule were isolated by column chromatography and characterized by their physico-chemical properties, 1-D and 2-D NMR spectroscopy and mass spectrometry. In vitro anthelminthic activity of the extracts and compounds against the human hookworm, Necator americanus, Stiles 1902 (Nematoda: Ancylostomatidae) was determined within a concentration range of 2500-250 μg/ml using the Egg Hatch Inhibition (EHI) Assay. The hookworm species were identified using a published polymerase chain reaction (PCR) method.A new dichapetalin, dichapetalin X (1), together with the known dichapetalin A (2), pomolic acid (3), glycerol monostearate (4), D:A-friedooleanan-3β-ol (5), and D:A-friedooleanan-3-one (6) were isolated. Compounds 1, 2, and 4 exhibited EHI with IC50 values of 523.2, 162.4, and 306.0 μg/ml, respectively, against the hookworm. The positive control albendazole gave an IC50 value of 93.27 μg/ml.This is the first report of the phytochemical investigation of D. filicaule. The study has yielded a new dichapetalin and also demonstrated the potential anthelminthic properties of the constituents.

The lack of appropriate infrastructure and legislation regarding the proper way of handling ewastes has encouraged informal recycling as in the case of the Agbogbloshie e-waste site. The burning and dumping of these wastes at the bank of the Odaw River eventually end up in the river. To ascertain the level of trace metal contamination in the Odaw River, 15 sediment samples collected from five different locations were analyzed for their trace metals. The locations were chosen to represent areas near to heavy e-waste activities and areas with no apparent ewaste activities, and analysis carried out using Atomic Absorption Spectrophotometry. The results indicated that mean concentrations of the trace metals (Cu, Cd, Pb, Fe, Cr and Ni) were highest at locations near burning and dumping sites (L1 and L2 respectively). This was attributed to the result of e-waste activities and the configuration of the river. With the exception of Cu and Cd at L1, the rest of the metals were below the recommended Canadian interim sediment quality guideline (ISQG) while none was above the Probable Effect Level (PEL), an indication that the levels of trace metal contamination were below the concentration at which frequent adverse effects are expected to occur. The results have confirmed that e-waste recycling activities along the banks of the Odaw River contribute to the contamination of the river. Keywords : E-waste, sediment, metal, contamination, recycling

The Dichapetalaceae (syn. Chailletiaceae) is a small family of plants comprising 3 genera and about 165 species. Dichapetalum Thouars is the most prominent genus, with 124 species, and is mostly found in the world’s tropical and subtropical regions. Irvine lists eight species as occurring in West Africa and Ghana. D. madagascariensis (syn. D. guineense) and D. toxicarium are the commonest and most widely distributed (Irvine, 1961). Hall and Swaine also describe eight species as occurring in Ghana and other parts of West Africa, four of which D. barteri, D. crassifolium, D. filicaule and D. heudelotii were not mentioned by Irvine. The first two are likely to be new species identified after Irvine. According to Hall and Swaine, D. heudelotii includes D. johnstonii and D. kumansiense which appear on Irvine’s list while D. filicaule also includes D. cymulosum described by Irvine (Hall and Swaine, 1981). Irvine’s D. oblongum is not mentioned by Hall and Swaine. Several species of the Dichapetalum are poisonous to livestock due to the presence of fluorinated compounds, mainly fluorocarboxylic acids (Hall, 1972; O’Hagan et al., 1993). These include D. toxicarium, D. cymosum, D. tomentosum and to a lesser extent D. barteri.

Phytochemical investigation of the ethanol extract of the whole plant of Scoparia dulcis, has resulted in the isolation of 4, 5, 7-trihydroxy-6-methoxyflavone, commonly called hispidulin and a steroidal glycoside, β-sitosterol-β-D-glucoside. This is the first isolation of the two compounds from S. dulcis. Also isolated and characterized were the previously reported 6-me-thoxybenzoxazolinone, friedelan-3-one and scopadulcic acid B. Structural elucidation was done on the basis of spectroscopic data interpretations (IR, UV, NMR and EIMS). Using the Tetrazolium-based colorimetric selective assay, hispidulin was found to be inactive against HIV-1/IIIB in MT-4 cells whereas the same test on the aqueous extract of the plant was positive.