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author:("annand, koff")
1.  The heavy metal contents of some selected medicinal plants sampled from different geographical locations 
Pharmacognosy Research  2013;5(2):103-108.
The levels of 5 minerals namely; lead, arsenic, mercury, cadmium, and aluminum were assessed in 10 medicinal plants sampled from 5 different geographical locations to determine the effect of location on the plants’ mineral content.
Materials and Methods:
Atomic absorption spectrophotometry (wet digestion) was used for the analyzes, and content of the minerals per sample was expressed as μg/g. The levels of minerals were compared to their limit specification for herbs and daily total intake of these minerals. A two-way analysis of variance, which tends to look at the effect of the location and the medicinal plant itself on the plants mineral content, was used in the statistical analysis.
Lead (Pb) was present in all plant species examined, except Ocimum gratissimum. One plant exceeded the maximum safety limit for lead. Cadmium was also detected in some of the medicinal plant species (44%) whilst majority were below the detection limit (0.002) representing 56%. 40% of the plant species exceeded the limit for cadmium. Mercury and arsenic in all the plant species were below the detection limit (0.001). Significant variation existed in mineral content for the various locations (P ≤ 0.05).
The findings generally suggest the variation in mineral levels for the various locations. Thus, our study has shown that same species of medicinal plants, growing in different environments, accumulates different levels of heavy metals.
PMCID: PMC3685757  PMID: 23798884
Geographical locations; heavy metals; medicinal plants; minerals
2.  Antibiotic producing microorganisms from River Wiwi, Lake Bosomtwe and the Gulf of Guinea at Doakor Sea Beach, Ghana 
BMC Microbiology  2012;12:234.
Microorganisms have provided a wealth of metabolites with interesting activities such as antimicrobial, antiviral and anticancer. In this study, a total of 119 aquatic microbial isolates from 30 samples (taken from water bodies in Ghana) were screened by the agar-well diffusion method for ability to produce antibacterial-metabolites.
Antibacterial activity was exhibited by 27 of the isolates (14 bacteria, 9 actinomycetes and 4 fungi) against at least one of the indicator microorganisms: Enterococcus faecalis (ATCC 29212), Bacillus thuringiensis (ATCC 13838), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Proteus vulgaris (NCTC 4635) and Bacillus Subtilis (NCTC 10073). A sea isolate MAI2 (identified as a strain of Pseudomonas aeruginosa) exhibited the highest antibacterial activity (lowest zone of inhibition = 22 mm). The metabolites of MAI2 extracted with chloroform were stable to heat and gave minimum inhibitory concentrations ranging between 250 and 2000 μg/ml. Bioautography of the extract revealed seven active components.
This study has therefore uncovered the potential of water bodies in the West African sub-region as reservoirs of potent bioactive metabolite producing microorganisms.
PMCID: PMC3493300  PMID: 23072432
Aquatic microorganisms; Antibiotics; Ghana; Multi-drug resistance
3.  In vitro anti-plasmodial activity of three herbal remedies for malaria in Ghana: Adenia cissampeloides (Planch.) Harms., Termina liaivorensis A. Chev, and Elaeis guineensis Jacq 
Pharmacognosy Research  2012;4(4):225-229.
Herbal remedies of Adenia cissampeloides, Terminalia ivorensis, and Elaeis guineensis among others have been used in Ghana for the treatment of various ailments including malaria. However, most of these remedies have not been scientifically investigated.
This study, therefore, seeks to investigate the anti-plasmodial activity of these plants.
Materials and Methods:
The ethanolic extracts of A. cissampeloides stem, T. ivorensis stem bark, and E. guineensis leaves were tested for in vitro anti-plasmodial activity against chloroquine-resistant strains of Plasmodium falciparum. Thin blood films were used to assess the level of parasitemia and growth inhibition of the extracts.
The IC 50 of A. cissampeloides, T. ivorensis, and E. guineensis were 8.521, 6.949, and 1.195 μg/ml, respectively, compared to artesunate with IC50 of 0.031 μg/ml.
The result of this study appears to confirm the folkloric anti-malarial use these plants.
PMCID: PMC3510876  PMID: 23225967
Adenia cissampeloides; anti-plasmodial; Elaeis guineensis; herbal remedies; Terminalia ivorensis
4.  Acaricidal effect of an isolate from Hoslundia opposita vahl against Amblyomma variegatum (Acari: Ixodidae) 
Pharmacognosy Research  2011;3(3):185-188.
Hoslundia opposita Vahl. (Lamiaceae), a common local shrub in Ghana, is traditionally known not only for its pharmacological benefits but also for its insecticidal properties. Its acaricidal property, however, has not been investigated.
To test the acaricidal effects of the crude extract and fractions of H. opposita leaves as well as to isolate and characterize the acaricidal principles.
Materials and Methods:
The crude methanolic extract, pet. ether, ethyl acetate and aqueous fractions of the leaves of H. opposita were tested against the larvae of the cattle tick, Amblyomma variegatum, using the Larval Packet Test. A bioassay-guided isolation was carried out to identify the acaricidal principle obtained from the ethyl acetate fraction.
The active principle was characterised as ursolic acid, a triterpene previously isolated from the leaves of the same plant. The extract and fractions were less potent than the control, malathion (LC50 1.14 × 10-4 mg/ml). Among the plant samples however the crude methanolic extract exhibited the highest effect against the larvae (LC50 5.74 × 10-2 mg/ml), followed by the ethyl acetate fraction (LC50 8.10 × 10-2 mg/ml). Ursolic acid, pet. ether and aqueous fractions however showed weak acaricidal effects with LC50 values of 1.13 mg/ml, 8.96 × 10-1 mg/ml and 1.44 mg/ml, respectively.
Ursolic acid was not as potent as the crude methanolic extract and the ethyl acetate fraction from which it was isolated. The overall acaricidal effect of H. opposita may have been due to synergy with other principles having acaricidal properties.
PMCID: PMC3193619  PMID: 22022167
Acaricide; Larval Packet Test; ticks; ursolic acid
5.  Profile of heavy metals in some medicinal plants from Ghana commonly used as components of herbal formulations 
Pharmacognosy Research  2010;2(1):41-44.
The levels of some heavy metals in 27 medicinal plant species from Ghana were studied in order to evaluate their health implications. These plant species, especially those used in the treatment of diseases such as hypertension, diabetes and asthma may require long term usage. The metals were copper, zinc, iron, manganese, nickel and cadmium. Atomic Absorption Spectrophotometry (wet digestion) was used for the analyses, and content of metals per sample was expressed as percent µg/g. Daily total intake of these metals is discussed based on the recommended daily intake of the medicinal plants or their corresponding formulations. From the results of the study zinc, copper and cadmium were present in all the plant species examined. Manganese was present in all species except V. amygdalina. Iron was found in all except five species (82%), whilst nickel was (rather rare) detected in only eight (30%) of the plant species. Significant variations in metal content existed (P<0.05) among the medicinal plant species with respect to the heavy metals evaluated. The concentrations of copper, zinc, cadmium and manganese were within their respective maximum permissible daily levels. However, some species, especially Ocimum canum (8), Clausena anisata and Rauwolfia vomitoria had levels of iron higher than the maximum permissible level of 1000 µg/day and may require care to avoid iron toxicity. The results also highlighted the differences in contents of minerals in Lippia multiflora obtained from different locations in Ghana. The findings generally suggest that the use of these plant species for the management of diseases will not cause heavy metal toxicity and may be beneficial to the users in cases of micronutrient deficiency, as these metals were found to be present in readily bioavailable form.
PMCID: PMC3140128  PMID: 21808538
Health implications; heavy metals; herbal formulations; medicinal plant

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