Acute and sub-acute toxicity of a lyophilised aqueous extract of the aerial part of Spilanthes africana Delile in rats.
Spilanthes africana is a plant used in several countries for the treatment of toothache, malaria, fracture, pneumonia, and dysentery. In order to establish the safety of aerial part of the plant extract, the acute and sub-acute toxicity of the aqueous extract of this plant has been evaluated in male and female young rats.
In acute toxicity, the effects of a single oral dose (2,000 mg/kg and 5,000 mg/kg) of the lyophilised aqueous extract have been determined. General behaviour, adverse effects and mortality were determined for up to 14 days. In sub-acute treatment, the effects of the extract in daily single oral administration at the doses of 250, 500 and 1,000 mg/kg during 28 days were evaluated. One group treated at the dose of 1,000 mg/kg for 28 days was let without treatment during 14 days to assess the possible reversibility of the harmful effects of the extract. Body weight, food and water intakes, biochemical and haematological parameters were recorded. Histopathological examination of liver, kidney and lungs were assessed.
In acute study, a single administration of the aqueous extract at the doses of 2,000 mg/kg or 5,000 mg/kg did not induce mortality. Thus, the LD50 of the aqueous extract of S. africana has been estimated higher than 5,000 mg/kg. Four hours after administration of the extract, a reduction of the mobility, sensitivity to the noise and to touch has been observed. In sub-acute study, the administration of the extract during 28 days at all doses did not significantly modify the body weight. On the haematological analysis, a decrease of the rate of monocytes and a rise of lymphocytes counts were observed among the male group. In both sexes, it appeared a decrease of the rate of granulocytes two weeks after stopping the treatment. It has also been observed in different groups among the females, an increase of the mean corpuscular content and the mean concentration in haemoglobin as well as an increase of platelets. A significant decrease of transaminases, alkaline phosphatase, triglycerides, and a significant increase of total bilirubin compared to the normal group has been observed. There was a significant decrease in renal catalase in both sexes compared with different control groups. Besides, a significant increase of the kidney rates of glutathione and malondialdehyde have also been observed in the female treated at the doses of 1,000 mg/kg. Histopathological analysis has shown vascular congestion and leucocyte infiltrations in the liver of animals treated at the dose of 1,000 mg/kg. This congestion has been marked in satellite group. In the kidney female satellite group, tubular clarifications have been observed and disappear when stopping the treatment.
These results show that the aqueous extract of S. africana given by the oral route is slightly toxic. However in sub-acute treatment, higher doses could provoke functional and structural changes in the organism which could in part reversible. Thus the extract should be used with caution.
Ngueguim TF
,Djouwoug Noussi C
,Donfack JH
,Gounoue KR
,Mbatchou A
,Kamtchouing P
,Dimo T
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Acute and sub-acute toxicity of the methanolic extract of Pteleopsis hylodendron stem bark.
Pteleopsis hylodendron is one of the most popular medicinal plants in Cameroon where it is used to treat measles, chickenpox, sexually transmitted diseases, female sterility, liver and kidney disorders as well as dropsy. To date there is no documented evidence corroborating its safety. This study thus aimed to determine the toxicity profile of the methanolic extract of Pteleopsis hylodendron.
The acute and sub-chronic toxicity of the methanolic extract of Pteleopsis hylodendron were investigated by employing established methods. The acute toxicity study was done by administering single doses (2-8 g/kg body weight) of plant extract to adult mice. For the sub chronic toxicity study, doses (85-680 mg/kg bw) of plant extract were administered daily to adult rats during 28 days after which the effect on organs, the hematological and biochemical parameters was assessed.
In mice, single oral administrations of the methanolic extract of Pteleopsis hylodendron caused dose-dependent general behaviour adverse effects and mortality. The LD50 values were 3.00 and 3.60 g/kg bw for males and females respectively. In rats, daily single oral doses of the methanolic extract of Pteleopsis hylodendron provoked significant (p < 0.05) growth retardation in rats at all tested doses after 28 days of dosing. Haematological parameters showed a significant decrease in white blood cells count and significant increases red blood cells count; irrespective of the sex, all biochemical parameters studied, except triglycerides significantly (p < 0.001) increased with dose. However, a dose-dependent significant (p < 0.007) increase in HDL was observed only in male rats. Increases in liver enzymes (ALT and AST), proteins and creatinine levels correlate the observed histopathological damages (i.e. inflammation and vascular congestions) in the liver and kidneys.
The overall results of this study indicate that the methanolic extract of Pteleopsis hylodendron stem bark possesses hepatotoxic and nephrotoxic effects at doses ≥ 85 mg/kg bw, suggesting that this plant should be used with caution.
Nana HM
,Ngane RA
,Kuiate JR
,Mogtomo LM
,Tamokou JD
,Ndifor F
,Mouokeu RS
,Etame RM
,Biyiti L
,Zollo PH
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Evaluation of acute and subacute toxicity of aqueous extract of Crassocephalum rubens leaves in rats.
Crassocephalum rubens is found throughout tropical Africa including the Indian Ocean islands. The leaves are commonly eaten in form of soups and sauces in South-Western Nigeria, also in other humid zones of Africa. Traditionally, it is used as an antidote against any form of poisoning; used to treat stomach and liver complaints; and externally to treat burns, sore eyes, earache, leprosy and breast cancer. In this study, acute and subacute toxicity of aqueous extract of C. rubens leaves was evaluated in rats in order to assess its safety profile.
In acute toxicity study, rats were given a single oral administration of aqueous extract of C. rubens leaves at graded doses (250-5000mg/kg). The animals were monitored for behavioural changes and possible mortality over a period of 24h and thereafter, for 14 days. In the subacute toxicity study, rats of both sexes were administered C. rubens orally at doses of 250mg/kg, 500mg/kg, 750mg/kg and 1000mg/kg body weight daily, for 28 days. Rats were observed weekly for any changes in general behaviour and body weights. In addition, other relevant parameters were assayed at the end of the main and reversibility study periods.
There was no observed adverse effect; including mortality in the animals. The extract caused no significant difference in the body weights as well as organs weights of treated groups when compared with the control groups. Haematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological assessments were normal in liver and kidney.
It can therefore be suggested based on the results from this study that aqueous extract of C. rubens leaves, at dosage levels up to 1000mg/kg, is non-toxic and could also offer protection on some body tissues. Aqueous extract of C. rubens could therefore, be considered safe. This study supports the application of Crassocephalum rubens in traditional medicine.
Adewale OB
,Onasanya A
,Anadozie SO
,Abu MF
,Akintan IA
,Ogbole CJ
,Olayide II
,Afolabi OB
,Jaiyesimi KF
,Ajiboye BO
,Fadaka AO
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