Ethnoveterinary Research plants
Many plants are used for ethnoveterinary purposes in South Africa, particularly in
rural areas. Little work appears to have been carried out concerning the evaluation
of the in vitro or in vivo efficacy of these plant preparations. In one such study [70]
extracts of 17 plant species employed to treat infectious diseases in cattle were pre-
pared using solvents of differing polarities. Antibacterial activity of the extracts was
determined against a range of bacteria and anthelmintic activity was evaluated
against the free-living nematode Caenorhabditis elegans. Cytotoxic effects were as-
sessed using the brine shrimp larval mortality test. Most of the plant extracts exhib-
ited antibacterial activity, with the best MIC being 0.1 mg mL–1. More than a third
of the extracts displayed a level of anthelmintic activity. Slightly toxic effects against
brine shrimp larvae were shown by 30% of extracts, with the lowest LC50 recorded
as 0.6 mg mL–1. The promising biological activity displayed by a number of plant
extracts may provide support for the ethnoveterinary use of these plants, but it is
clear that in vivo tests are required to substantiate their medicinal properties and
possible toxicity.
Following results obtained from this preliminary screening of ethnoveterinary
plants, an MSc study was undertaken to determine the antibacterial constituents of
Ziziphus mucronata (Rhamnaceae), a common tree in southern Africa. From the
leaves, 2,3-dihydroxylup-20-en-28-oic acid and betulinic acid (zizyberanalic acid)
were isolated [89]. The first compound displayed excellent activity against Staphylo-
coccus aureus, adding support to the use of Z. mucronata leaf paste in treating bac-
terial infections in animals as well as humans. The antibacterial activity of the iso-
lated compounds was not previously known.
116 5 Plant Extracts Used to Manage Bacterial, Fungal, and Parasitic Infections in Southern Africa
Peltophorum africanum (Fabaceae) is a deciduous tree widespread in southern
Africa. The plant has many ethnomedical and ethnoveterinary uses. The root and
bark decoctions are used to treat diarrhea, dysentery, sore throat, wounds, back and
joint pains, HIV-AIDS, venereal diseases, and infertility. Pastoralists and rural
farmers use the root and bark extracts to treat diarrhea, dysentery, infertility, and
to promote well-being and resistance to diseases in cattle. To evaluate these eth-
nobotanical leads, dried leaves, stem bark, and root bark were extracted with etha-
nol, acetone, dichloromethane, and hexane.
Polyphenols in the extract were determined by the Folin–Ciocalteu method with
gallic acid as standard. Qualitative antioxidant activity was screened by spraying
TLCs of the extracts with 0.2% 1,1-diphenyl-2-picryl hydrazyl (DPPH), and quanti-
fied with the Trolox equivalent antioxidant capacity (TEAC) assay. MIC and total
antibacterial activity (TAA) values were determined by serial microplate dilution
for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Enterococcus
faecalis, with gentamicin as standard and tetrazolium violet as growth indicator.
Acetone and ethanol extracted the largest quantity of material. The polyphenol con-
centration was 49.2% in the acetone extract of the root and 3.8% in the dichlorom-
ethane extract of the leaf. Antioxidant activity of at least five antioxidant com-
pounds as measured by TEAC ranged from 1.34 (ethanol extract of the root) to 0.01
(hexane extract of the leaf). The total antibacterial activity (volume to which active
compounds present in 1 g plant material can be diluted and still inhibit bacterial
growth) was 1263 mL g–1 for the ethanol extract of the root against S. aureus and
800 mL g–1 for the acetone extract of the root against P. aeruginosa. There was sub-
stantial activity against both Gram-positive and Gram-negative bacteria, with MIC
values of 0.08 mg mL–1 for S. aureus and 0.16 mg/ml for P. aeruginosa. There is
therefore a rationale for the traditional use of root and bark of P. africanum in treat-
ing bacterial infection-related diseases [90].
Rhizome extracts of Gunnera perpensa (Gunneraceae) are used in South Africa to
treat endometritis in animals as well as in humans. A study was conducted to in-
vestigate whether antibacterial activity could be responsible for the efficacy of the
G. perpensa extract. It was concluded that although some degree or activity was
present, the relatively weak antibacterial activity was unlikely to justify the use of
G. perpensa rhizomes in the traditional treatment of endometritis [91]. It seems
likely that the slightly antibacterial nature of the rhizomes may contribute an addi-
tive effect, along with their known uterotonic activity, to the overall efficacy of the
preparation.
Many plants are used for ethnoveterinary purposes in South Africa, particularly in
rural areas. Little work appears to have been carried out concerning the evaluation
of the in vitro or in vivo efficacy of these plant preparations. In one such study [70]
extracts of 17 plant species employed to treat infectious diseases in cattle were pre-
pared using solvents of differing polarities. Antibacterial activity of the extracts was
determined against a range of bacteria and anthelmintic activity was evaluated
against the free-living nematode Caenorhabditis elegans. Cytotoxic effects were as-
sessed using the brine shrimp larval mortality test. Most of the plant extracts exhib-
ited antibacterial activity, with the best MIC being 0.1 mg mL–1. More than a third
of the extracts displayed a level of anthelmintic activity. Slightly toxic effects against
brine shrimp larvae were shown by 30% of extracts, with the lowest LC50 recorded
as 0.6 mg mL–1. The promising biological activity displayed by a number of plant
extracts may provide support for the ethnoveterinary use of these plants, but it is
clear that in vivo tests are required to substantiate their medicinal properties and
possible toxicity.
Following results obtained from this preliminary screening of ethnoveterinary
plants, an MSc study was undertaken to determine the antibacterial constituents of
Ziziphus mucronata (Rhamnaceae), a common tree in southern Africa. From the
leaves, 2,3-dihydroxylup-20-en-28-oic acid and betulinic acid (zizyberanalic acid)
were isolated [89]. The first compound displayed excellent activity against Staphylo-
coccus aureus, adding support to the use of Z. mucronata leaf paste in treating bac-
terial infections in animals as well as humans. The antibacterial activity of the iso-
lated compounds was not previously known.
116 5 Plant Extracts Used to Manage Bacterial, Fungal, and Parasitic Infections in Southern Africa
Peltophorum africanum (Fabaceae) is a deciduous tree widespread in southern
Africa. The plant has many ethnomedical and ethnoveterinary uses. The root and
bark decoctions are used to treat diarrhea, dysentery, sore throat, wounds, back and
joint pains, HIV-AIDS, venereal diseases, and infertility. Pastoralists and rural
farmers use the root and bark extracts to treat diarrhea, dysentery, infertility, and
to promote well-being and resistance to diseases in cattle. To evaluate these eth-
nobotanical leads, dried leaves, stem bark, and root bark were extracted with etha-
nol, acetone, dichloromethane, and hexane.
Polyphenols in the extract were determined by the Folin–Ciocalteu method with
gallic acid as standard. Qualitative antioxidant activity was screened by spraying
TLCs of the extracts with 0.2% 1,1-diphenyl-2-picryl hydrazyl (DPPH), and quanti-
fied with the Trolox equivalent antioxidant capacity (TEAC) assay. MIC and total
antibacterial activity (TAA) values were determined by serial microplate dilution
for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Enterococcus
faecalis, with gentamicin as standard and tetrazolium violet as growth indicator.
Acetone and ethanol extracted the largest quantity of material. The polyphenol con-
centration was 49.2% in the acetone extract of the root and 3.8% in the dichlorom-
ethane extract of the leaf. Antioxidant activity of at least five antioxidant com-
pounds as measured by TEAC ranged from 1.34 (ethanol extract of the root) to 0.01
(hexane extract of the leaf). The total antibacterial activity (volume to which active
compounds present in 1 g plant material can be diluted and still inhibit bacterial
growth) was 1263 mL g–1 for the ethanol extract of the root against S. aureus and
800 mL g–1 for the acetone extract of the root against P. aeruginosa. There was sub-
stantial activity against both Gram-positive and Gram-negative bacteria, with MIC
values of 0.08 mg mL–1 for S. aureus and 0.16 mg/ml for P. aeruginosa. There is
therefore a rationale for the traditional use of root and bark of P. africanum in treat-
ing bacterial infection-related diseases [90].
Rhizome extracts of Gunnera perpensa (Gunneraceae) are used in South Africa to
treat endometritis in animals as well as in humans. A study was conducted to in-
vestigate whether antibacterial activity could be responsible for the efficacy of the
G. perpensa extract. It was concluded that although some degree or activity was
present, the relatively weak antibacterial activity was unlikely to justify the use of
G. perpensa rhizomes in the traditional treatment of endometritis [91]. It seems
likely that the slightly antibacterial nature of the rhizomes may contribute an addi-
tive effect, along with their known uterotonic activity, to the overall efficacy of the
preparation.
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