Lawrence Sheringham Borquaye

Nutritional and anti-nutrient profiles of some Ghanaian spices

Abstract Spices are generally consumed because of the taste and flavor they add to food. Some are also consumed because of their medicinal properties. We herein report on the nutrient and antinutrient compositions of five Ghanaian spices namely Xylopia aethiopica, Piper guineense, Monodora myristica, Aframomum melegueta and Parkia biglobosa. Nutritional composition was assessed by proximate analysis, minerals by atomic absorption spectrophotometry while titrimetric methods were utilized in vitamin C and antinutrients analysis. P. biglobosa was rich in proteins (38.60%) and had highest moisture content (32.79%). The highest levels of ash, fiber, fat and carbohydrates were observed P. guineense (11.90%), A. melegueta (31.12%), M. myristica (31.01%) and X. aethiopica (50.1%) respectively. Calorific values for all spices were between 243 and 402 kcal. Calcium, magnesium, potassium and iron were the most abundant minerals with levels ranging from 2.67 to 5,381.88 mg/kg. Zinc, copper and manganese were present in trace amounts. Vitamin C levels ranged from 3.3 to 18.4 mg/100 g. Phytates were present at generally higher levels than oxalates. P. biglobosa and X. aethiopica contained the highest concentration of oxalates and phytates respectively. The results indicate that these spices are good sources of valuable nutrients. However, the high levels of antinutrients implies consumption in moderation and good processing before eating is important.

Distribution and ecological risks of toxic metals in the topsoils in the Kumasi metropolis, Ghana

Abstract The distribution, and ecological risks due to toxic metals in topsoils of an urban commercial centre of Kumasi metropolis were determined. Concentrations of heavy metals in the samples were initially screened using field portable X-ray fluorescence spectrometer prior to confirmation on an inductively coupled plasma-mass spectrometer. The results from the two instruments correlated well with high linearity (R2 > 0.70). Concentrations of metals were in the order: Fe (45246.15 mg/kg) > Mn (347.86 mg/kg) > Zn (176.40 mg/kg) > V (173.10 mg/kg) > Cr (125.12 mg/kg) > Pb (53.47 mg/kg) > Ni (43.16 mg/kg) > Cu (39.85 mg/kg) > As (4.59 mg/kg) > Sn (3.69 mg/kg) > Cd (0.46 mg/kg) > Hg (0.28 mg/kg). Multivariate and geostatistical analyses exploring various hazard indices such as geo-accumulation, contamination, pollution load and ecological risks all suggest contamination of the topsoils with toxic metals and that the contamination due to Pb, Cu, Ni, Cr and Zn is mainly derived from anthropogenic origins whereas, As, Hg, Mn, V, Sn and Cd contaminations are attributable mainly to geological and atmospheric depositions. Contamination factor (CF) suggests that the topsoils were considerably contaminated (CF 3–6) with Zn, moderately contaminated (CF 1–3) with Ni, Hg, V, Sn and Cd and least contaminated (CF < 1) with As, Pb, Cu, Cr and Mn. In general, the soils were found to be moderately contaminated (average contamination factor (1 ≤ CF < 3) with toxic metals and may pose both human and ecological risks.

Heavy metal contents of some medicinal herbs from Kumasi, Ghana

Abstract This research was conducted to assess the safety of herbs available in the Kumasi central market with regards to heavy metal contamination. A total of 15 medicinal herbs were randomly collected. The levels of iron (Fe), cadmium (Cd), lead (Pb) and zinc (Zn) were determined by atomic absorption spectrometry. The levels of the metals were in the range of 2.51–7.06 mg/kg for Fe, 0.44–0.89 mg/kg for Pb, 0.21–1.07 mg/kg for Zn and 0.11–0.53 mg/kg for Cd. This shows that most of the metal concentration levels in the herbs were within the WHO maximum permissible limits (WHO MPL) of 15 mg/kg for Fe, 100 mg/kg for Zn and 10 mg/kg for Pb. Four samples, however, had Cd levels above the WHO MPL of 0.3 mg/kg. There was a positive correlation between Cd and Zn. However, there was no correlation between the remaining metals. Considering the levels of heavy metals, the medicinal herb samples investigated are considered unsafe for human consumption.

Antimicrobial and antioxidant activities of ethyl acetate and methanol extracts of Littorina littorea and Galatea paradoxa

Abstract The aquatic environment is a vital resource for bioprospecting pharmacologically important natural products. Molluscs are known to harbour compounds with antimicrobial, antitumor and antioxidant activities. This study evaluated the antimicrobial and antioxidant properties of ethyl acetate and methanol tissue extracts of two molluscs, Littorina littorea (L. littorea) and Galatea paradoxa (G. paradoxa). Agar diffusion and broth dilution assays were used to test for antimicrobial activity against nine microbes. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) method was used to determine antioxidant activity of the extracts. Extracts of both molluscs showed significant activity against all the bacteria strains tested but were inactive towards the fungus. The best antibacterial activity was recorded by methanol extract of L. littorea towards Pseudomonas aeruginosa. In comparison to ethyl acetate extracts, methanol extracts were more efficient in scavenging the DPPH radical. Methanol extracts of L. littorea had an IC50 of 0.37 mg/mL which was closer to that of the standard ascorbic acid drug (0.0048 mg/mL) than any of the other extracts. The findings of this work indicate that the tissue extracts of L. littorea and G. paradoxa are promising sources of antimicrobial and antioxidant agents that can be utilized for pharmaceutical and nutraceutical purposes.

Human Risk Assessment of Organochlorine Pesticide Residues in Vegetables from Kumasi, Ghana

The use of organochlorine pesticides has been banned worldwide due to their toxicities. However, some farmers use them illegally because of their potency. The aim of this study was to assess the level of organochlorine pesticide (OCP) residues and the potential health risk associated with vegetables, soil, and groundwater obtained from farms in Ayigya, Nsenie, Gyenyase, and Kentinkrono in Kumasi, Ghana. A total of 15 samples were analyzed using a gas chromatograph equipped with an electron capture detector. The highest mean concentration of 184.10 ± 12.11 µg/kg was recorded for methoxychlor in cabbage from Ayigya. Beta-hexachlorocyclohexane (beta-HCH) recorded the lowest mean concentration of 0.20 ± 0.00 µg/kg in cabbage from Ayigya. The combined risk index showed significant health risk to children than adults. The soil samples mainly contained methoxychlor followed by dichlorodiphenyltrichloroethane (DDT), aldrin, and other OCPs. Concentrations of total HCHs, total DDTs, and total OCPs in the soil samples ranged from 10−6, posing a potentially serious cancer risk to consumers. Moreover, the hazard quotients (HQs) of aldrin exceeded the threshold value of one, indicating that daily exposure is a potential concern.

Assessment of the quality of the Owabi reservoir and its tributaries

Abstract Physicochemical properties, nutrient concentrations, microbial properties and concentrations of heavy metals in water and sediments from the Owabi reservoir and its tributaries, namely Atafua, Sukobri and Owabi rivers as well as the outflow of the reservoir, were determined as indicators of the extent of pollution of the reservoir. The samples were collected in December 2015, which falls within the dry season in Ghana. Nutrient concentrations in water and sediments were within permissible limits. The heavy metals (Cu, Mn, Cd, Pb and Fe) in sediments were determined using X-ray fluorescence and that in water using flame atomic absorption spectrometer. Water from the reservoir and its feeder tributaries was heavily polluted with faecal coliforms, Escherichia coli and faecal enterococci. Physicochemical properties were within the World Health Organisation’s (WHO) permissible concentrations for drinking water except for turbidity, which was significantly higher (P < 0.05). The pH of the water samples ranged from 7.68 to 7.84 in the tributaries whilst that of the dam water ranged from 8.87 to 9.01. The turbidity of the Owabi dam and its tributaries ranged from 5.98 to 42.25 NTU. The turbidity of all the water samples was significantly higher (P < 0.05) than the WHO’s threshold for potable water (5 NTU). Manganese was detected in all the water samples and ranged from 0.19 to 0.61 mg L−1. Lead concentrations in the water samples ranged from below detection limit to 0.3 mg L−1. Cd was present in only one water sample from the Sukobri River. Cu and Fe were below detection limit in all the water samples. Geo-accumulation index of Cu, Mn and Pb was less than 1 with their enrichment factors also being less than 0.5. The geo-accumulation index and enrichment factor for Cd in Sukobri River sediment were 6.41 and 11.41, respectively. Sediments from the Owabi reservoir recorded no Cd geo-accumulation indices and enrichment factors, indicating no Cd contamination in it. The reservoir was chemically unpolluted but had high levels of pathogens which pose a health risk.

Pesticide Residues in Honey from the Major Honey Producing Forest Belts in Ghana

Concentrations of pesticides residues in honey sampled from the major honey producing forest belts in Ghana were determined. Samples were purposively collected and extracted using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method and analysed for synthetic pyrethroids, organochlorine, and organophosphate pesticide residues. Aldrin, γ-HCH, β-HCH, ∑endosulfan, cyfluthrin, cypermethrin, deltamethrin, permethrin methoxychlor, ∑DDT, chlorpyrifos, fenvalerate, malathion, dimethoate, and diazinon were all detected at the concentration of 0.01 mg/kg, while cyfluthrin and permethrin were detected at mean concentrations of 0.02 and 0.04 mg/kg, respectively. All the pesticide residues detected were very low and below their respective maximum residue limits set by the European Union. Hence, pesticide residues in honey samples analyzed do not pose any health risk to consumers.

Veterinary antibiotics in dairy products from Kumasi, Ghana

Abstract Consumption of traces of veterinary drug residues through dairy products could have adverse effects on human health. There is, therefore, the need for routine monitoring of drug residues in dairy products on the market. In this study, fresh milk, cheese, and yogurt being sold at different points in the Kumasi metropolis were analyzed for residues of chloramphenicol, sulfathiazole, sulfamethoxazole, and oxytetracycline — four commonly used veterinary drugs in the country. The concentrations found were generally very low and close to the method detection limit of 0.1 μg/kg. Concentration of chloramphenicol in yogurt (0.8 μg/L) was the highest among all the residues studied. However, with the residue levels being hundred folds lower than the maximum residue limit, they are highly unlikely to pose any health risks to the consumers. Therefore, as far as chloramphenicol, sulfathiazole, sulfamethoxazole, and oxytetracycline in fresh milk, cheese, and yogurt are concerned, this study did not indicate any risk of consumption.

Anti-inflammatory activities of extracts from Oliva sp., Patella rustica, and Littorina littorea collected from Ghana’s coastal shorelines

Abstract Inflammation is one of the means the human body uses to defend itself in the event of infection, trauma, or exposure to toxic substances and it is closely associated with a number of disease symptoms. Steroidal and non-steroidal anti-inflammatory agents have been the drugs of choice for managing inflammation. However, reports of unpleasant side effects have necessitated a search for new anti-inflammatory agents which have minimal side effects. Marine-derived natural products continue to make significant contributions in the pharmaceutical, nutraceutical, and cosmeceutical industries and a number of extracts and compounds from marine origin have shown promise as anti-inflammatory agents. In Ghana, extracts that have been screened for their potential anti-inflammatory effects have almost exclusively come from plants. In this work, the anti-inflammatory activities of extracts from three different marine mollusks (Oliva sp., Patella rustica, and Littorina littorea) were evaluated. Extracts were obtained by cold maceration. The carrageenan-induced paw edema model in seven-day old chicks was used to evaluate anti-inflammatory potentials. Of the extracts tested, the ethyl acetate fraction of Oliva sp. was the most potent, with an ED50 of 10.16 mg/kg. The ethanol extract of L. littorea proved to be least effective in reducing inflammation, with an ED50 value of 119.80 mg/kg. When compared, extracts from Oliva sp. seemed to possess greater anti-inflammatory potentials than either P. rustica or L. littorea counterparts. The ethyl acetate fraction of Oliva sp. was a potent and promising anti-inflammatory agent and could be explored for anti-inflammatory lead compounds.