Evaluation of the acute and sub acute toxicity of Annona senegalensis root bark extracts

Safety assessment of crude aqueous methanol extract of Annona senegalensis stem bark: acute and sub-chronic toxicity studies

Annona senegalensis Pers., (wild custard apple), is a shrub used traditionally to treat respiratory and skin diseases. Previous studies have demonstrated its anti-malaria, anti-snake envenomation and anti-cancer activities. However, its toxicological profile remains limited, particularly in male and female animals. This study aims to evaluate the safety of crude aqueous methanol extract of Annona senegalensis stem bark (AMEAS) through acute and sub-chronic toxicity studies. The stem bark of A. senegalensis was collected, air-dried, pulverized, and extracted using 70% methanol. Phytochemical screening, elemental analysis, and acute toxicity evaluation were carried out on AMEAS. Sub-chronic toxicity study was conducted on Wistar rats of both sexes at different doses administered orally for 28 days. Elemental analysis revealed the presence of heavy metals and essential mineral elements with the highest contents being calcium (59.88%) and potassium (25.39%). Acute toxicity testing showed no mortality up to 5000 mg/kg, suggesting an LD50 greater than 5000 mg/kg. In the sub-chronic toxicity study, no mortality or significant harmful effects were observed. The blood glucose decreased from 13.68 mMol/L at 250 mg/kg to 10.71 mMol/L at 1000 mg/kg, much lower than the distilled water group (17.06 mMol/L). In conclusion, the extract appeared to be well-tolerated, with no obvious adverse effects. AMEAS is rich in Calcium (Ca) and potassium (K). It has been shown to have LD50 greater than 5000 mg/kg and is assumed to be safe. On repeated use, AMEAS may cause hypoglycemia and weight loss which may be useful in managing diabetes and obesity respectively.

Toxicological Profile of the Aqueous Extract of Tectona grandis L.F. (Verbenaceae) Leaves: A Medicinal Plant Used in the Treatment of Typhoid Fever in Traditional Cameroonian Medicine

Tectona grandis (T. grandis) is a medicinal plant widely used in Cameroon to treat typhoid fever and several other diseases. Despite its heavy use for medical purposes, no study has yet been conducted to assess its potentially toxic effects. This study aimed at evaluating the acute and subchronic toxicological profile of Tectona grandis leaf extract in rats. The acute toxicity study revealed neither behavioral disturbances nor death in rats. The lethal dose (DL₅₀) of this extract is greater than 5000 mg/kg body weight. The subchronic toxicity study showed no significant change in weight gain in rats at test doses throughout the treatment period. However, there was a significant decrease in alanine transaminase activity and serum protein levels at all doses. Alkaline phosphatase activity decreased at doses of 30, 90, and 270 mg/kg and increased at the dose of 810 mg/kg body weight. Serum and urinary urea levels increased simultaneously at doses of 270 and 810 mg/kg body weight. Repeated administration of the extract also increased total cholesterol, high-density lipoprotein levels in both sexes were compared to respective controls, and the ratio of high- to low-density lipoprotein was found to be greater than 1 in all animals. However, at the dose of 810 mg/kg, necrosis was observed on the kidney sections and vascular congestion on the liver sections of animals. Aqueous extract of T. grandis did not lead to any adverse effects in rats after acute and subchronic treatment at 30 and 90 mg/kg doses. This extract can, therefore, be used for the formulation of typhoid fever phytomedicine at the therapeutic dose of 30 mg/kg, but before this, chronic and mutagenic toxicity evaluations must be carried out.

Drosophila para bss Flies as a Screening Model for Traditional Medicine: Anticonvulsant Effects of Annona senegalensis

Epilepsy is among the most common serious neurological disorders and affects around 50 million people worldwide, 80% of which live in developing countries. Despite the introduction of several new Anti-Epileptic Drugs (AEDs) in the last two decades, one third of treated patients have seizures refractory to pharmacotherapy. This highlights the need to develop new treatments with drugs targeting alternative seizure-induction mechanisms. Traditional medicine (TM) is used for the treatment of epilepsy in many developing countries and could constitute an affordable and accessible alternative to AEDs, but a lack of pre-clinical and clinical testing has so far prevented its wider acceptance worldwide. In this study we used Drosophila melanogaster paralytic^{bangsensitive}(para^bss) mutants as a model for epileptic seizure screening and tested, for the first time, the anti-seizure effect of a non-commercial AED. We evaluated the effect of the African custard-apple, Annona senegalensis, which is commonly used as a TM for the treatment of epilepsy in rural Africa, and compared it with the classical AED phenytoin. Our results showed that a stem bark extract from A. senegalensis was significantly more effective than a leaf extract and similar to phenytoin in the prevention and control of seizure-like behavior. These results support that Drosophila constitutes a robust animal model for the screening of TM with potential value for the treatment of intractable epilepsy.

Alterations of Antioxidant Status and Mitochondrial Succinate Dehydrogenase Activity in the Liver of Wistar Strain Albino Rats Treated with by Ethanol Extracts of Annona senegalensis Pers (Annonaceae) Stem Bark

Numerous ethnomedicinal uses have been attributed to different parts of Annona senegalensis (ASE), including its uses as food and food additives. The present study investigated toxicological and antioxidant effects of 28 days administration of ethanol extracts of ASE stem bark to Wistar strain albino rats. Acute toxicity test was done to determine lethal dose in Wistar rats while sub-acute toxicity test was conducted on rats divided into four groups (A - control, B - 50 mg/kg, C - 100 mg/kg, D - 150 mg/kg, respectively and treated for 28 days. Oxidative stress markers in liver and kidney as well as hepatic succinate dehydrogenase activity in the mitochondrial and post mitochondrial fractions (PMF) were evaluated. The LD₅₀ value of ASE was > 2,000 mg/kg. White blood cell counts gradually increased, but red blood cell counts and haematocrits level decreased significantly (p < 0.05) by about 50%. Liver enzymes in the serum and mitochondrial succinate dehydrogenase activity increased significantly (p < 0.05). Superoxide dismutase and catalase activities also increased in liver mitochondria and PMF while malondialdehyde (MDA) and reduced glutathione levels increased only in the PMF. Furthermore, only MDA levels increased significantly in the kidney after 28 days extract administration. Histopathological examination showed hepatic necrosis and no obvious signs of nephrotoxicity. Anona senegalensis is relatively safe, but prolonged ingestion could induce oxidative stress and impair ATP synthesis through the modulation of the activity of mitochondrial succinate dehydrogenase.

Plants used to treat skin diseases in northern Maputaland, South Africa: antimicrobial activity and in vitro permeability studies

CONTEXT

Ethnobotanical claims of medicinal plants used in northern Maputaland are limited. Objectives To establish scientific validity for a selection of the plants used in Maputaland to treat skin diseases.

MATERIALS AND METHODS

Aqueous and dichloromethane-methanol extracts were prepared from 37 plant species which were collected from four rural communities in Maputaland. Antimicrobial screening was performed on extracts against 12 dermatological relevant pathogens using the micro-titre plate dilution assay. Their combined effect was evaluated by determining the sum of the fractional inhibitory concentrations (ΣFICs). Chemical analysis was undertaken using reverse-phase high-performance liquid chromatography (RP-HPLC) and investigated in vitro across excised intact porcine skin using the ILC07 automated system.

RESULTS

The organic extract of Garcinia livingstonei T. Anderson (Clusiaceae) was found to be the most antimicrobially active displaying an average broad-spectrum MIC value of 270 μg/mL. The combination of Sclerocarya birrea (A. Rich.) Hotsch. (Anacardaceae) with Syzygium cordatum Hochst. ex C. Krauss (Myrtaceae) displayed synergistic effects. The four antimicrobially active organic extracts were found to possess mainly anthraquinones, flavonoids, tannins and saponins. The organic extracts of Kigelia africana (Lam.) Benth. (Bignoniaceae) and S. cordatum were found to have more compounds capable of permeating intact skin after 10 min of exposure.

CONCLUSION

More than 80% of the organic extracts tested displayed a correlation between the antimicrobial efficacy and the reported traditional uses of the plants. Furthermore, the traditional use of topically applied plant preparations is validated as some compounds from the active plants are capable of permeating the skin in vitro.

Therapeutic potency of bee pollen against biochemical autistic features induced through acute and sub-acute neurotoxicity of orally administered propionic acid

Background

It is now well documented that postnatal exposure to certain chemicals has been reported to increase the risk of autism spectrum disorder. Propionic acid (PA), as a metabolic product of gut microbiotaandas a commonly used food additive, has been reported to mediate the effects of autism. Results from animal studies may help to identify environmental neurotoxic agents and drugs that can ameliorate neurotoxicity and may thereby aid in the treatment of autism. The present study investigated the ameliorative effects of natural bee pollen against acute and sub-acute brain intoxication induced by (PA) in rats.

Methods

Twenty-four young male Western Albino ratswere enrolled in the present study. They were classified into four equal groups, eachwith6 rats. The control group received only phosphate buffered saline; the oral buffered PA-treated groups (II and III) received a neurotoxic dose of 750 mg/kg body weight divided in 3 dose of 250 mg/kg body weight/day serving asthe acute group and 750 mg/kg body weight divided in 10 equal dose of 75 mg/kg body weight/day as the sub-acute group. The fourth group received 50 mg bee pollen for 30 days after PA-acute intoxication.

Results

The obtained data showed that the PA-treated groups demonstrated multiple signs of brain toxicity, as indicated by a depletion of serotonin (5HT), dopamine and nor-adrenaline, together withan increase in IFN-γ and caspase 3. Bee pollen was effective in ameliorating the neurotoxic effect of PA. All measured parameters demonstrated minimal alteration in comparison with thecontrol animal than did those of acute and sub-acute PA-treated animals.

Conclusions

In conclusion, bee pollen demonstrates anti-inflammatory and anti-apoptotic effects while ameliorating the impaired neurochemistry of PA-intoxicated rats.

Acute and Sub-Acute Toxicity Evaluation of the Methanolic Extract of Alstonia scholaris Stem Bark

Alstonia scholaris has been used by traditional medicine practitioners since the medieval ages for the treatment of diseases. The aim of this research was to evaluate the acute and sub-acute oral toxicity of its methanolic extract. The acute toxicity test was conducted using Sprague Dawley (SD) rats. The methanolic extract of Alstonia scholaris stem bark (ASME) was administrated in a single dose of 2000 mg/kg via oral gavage; and the animals were observed for any behavioral changes or mortality. In the sub-acute toxicity study, SD rats received three doses of ASME (250, 500 and 1000 mg/kg) for 28 days via oral gavage. During these 28 days of treatment, the rats were observed weekly for toxicity symptoms. Following the 28-day treatment, the rats were sacrificed for hematological, biochemical and histopathology studies. In the acute toxicity study, Alstonia scholaris was found to be non-toxic at a dose of 2000 mg/kg b.w. In the sub-acute toxicity study, significant variations in body weight, hematological and biochemical parameters were observed in the experimental groups at the dose of 500 and 1000 mg/kg with the death of two female rats being recorded at the highest dose (1000 mg/kg b.w.). Histopathological studies revealed slight degeneration (lesion) and centrilobular necrosis in the liver, which was most expressed in the highest-dose group. These results demonstrate that, while a single dose and short term oral intake of Alstonia scholaris bark extract caused no toxicity up to a dose of 2000 mg/kg b.w., toxic effects manifested in the long term treatment at the highest dose (500 and 1000 mg/kg). The long-term toxic effect was found to be associated with alterations in hematological compositions and end-organ damage to the liver. Thus, prolonged use of high doses of ASME orally should be discouraged and lower doses encouraged.

Toxicity profile of ethanolic extract of Azadirachta indica stem bark in male Wistar rats

OBJECTIVE

To investigate the toxic implications of ethanolic stem bark extract of Azadirachta indica (A. indica) at 50, 100, 200 and 300 mg/kg body weight in Wistar rats.

METHODS

Fifty male rats of Wistar strains were randomly grouped into five (A-E) of ten animals each. Animals in Group A (control) were orally administered 1 mL of distilled water on daily basis for 21 days while those in Groups B-E received same volume of the extract corresponding to 50, 100, 200 and 300 mg/kg body weight.

RESULTS

The extract did not significantly (P>0.05) alter the levels of albumin, total protein, red blood cells and factors relating to it whereas the white blood cell, platelets, serum triacylglycerol and high-density lipoprotein cholesterol decreased significantly (P<0.05). In contrast, the final body weights, absolute weights of the liver, kidney, lungs and heart as well as their organ-body weight ratios, serum globulins, total and conjugated bilirubin, serum cholesterol, low-density lipoprotein cholesterol and computed atherogenic index increased significantly. The spleen-body weight ratio, alkaline phosphatase, alanine and aspartate transaminases, sodium, potassium, calcium, feed and water intake were altered at specific doses.

CONCLUSIONS

Overall, the alterations in the biochemical parameters of toxicity have consequential effects on the normal functioning of the organs of the animals. Therefore, the ethanolic extract of A. indica stem bark at the doses of 50, 100, 200 and 300 mg/kg body weight may not be completely safe as an oral remedy and should be taken with caution if absolutely necessary.