Phytochemical and toxicological studies of aqueous leaves extracts of Erythrophleum africanum

Preclinical antidiabetic and antioxidant effects of Erythrophleum africanum (benth.) harms in streptozotocin-induced diabetic nephropathy

OBJECTIVES

This study investigated the antidiabetic effects of the methanolic extract of E. africanum (MEEA) stem bark on streptozotocin (STZ)-induced diabetic nephropathy (DN) in Wistar rats.

METHODS

The in vitro enzyme (α-amylase) inhibitory activity of MEEA was measured using a standard procedure. Diabetic rats with fasting blood glucose above 250 mg/dL were considered diabetic and were divided into the following groups: control (distilled water-treated), diabetic-control, diabetic metformin (100 mg/kg), diabetes + MEEA (150 mg/kg), and diabetes + MEEA (300 mg/kg) via oral gavage once daily for 14 days. At the end of the experimental period, kidney tissues were collected for biochemical and histological analyses. Kidney apoptosis and marker gene expression were measured by real-time quantitative PCR.

RESULTS

MEEA exhibited α-amylase inhibitory effects. MEEA significantly (p<0.05) reduced the STZ-induced increases in blood glucose, serum urea, serum creatinine, uric acid, alanine aminotransferase, alkaline phosphatase, and malondialdehyde and increased the STZ-induced decreases in superoxide dismutase, catalase, and reduced glutathione. In addition, MEEA protects against DN by significantly downregulating the mRNA expression of cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP-response binding protein (CREB), and cFOS and upregulating B-cell lymphoma 2 (Bcl-2), suggesting that the nephroprotective ability of MEEA is due to the modulation of the cAMP/PKA/CREB/cFOS signaling pathway. Furthermore, MEEA treatment protected against histopathological alterations observed in diabetic rats.

CONCLUSIONS

The data from this study suggest that MEEA modulates glucose homeostasis and inhibits redox imbalance in DN rats.

Succinimido–Ferrocidiphenol Complexed with Cyclodextrins Inhibits Glioblastoma Tumor Growth In Vitro and In Vivo without Noticeable Adverse Toxicity

SuccFerr (N-[4-ferrocenyl,5-5-bis (4-hydroxyphenyl)-pent-4-enyl]-succinimide) has remarkable antiproliferative effects in vitro, attributed to the formation of a stabilized quinone methide. The present article reports in vivo results for a possible preclinical study. SuccFerr is lipophilic and insoluble in water, so the development of a formulation to obviate this inconvenience was necessary. This was achieved by complexation with randomly methylated cyclodextrins (RAMEßCDs). This supramolecular water-soluble system allowed the in vivo experiments below to proceed. Application of SuccFerr on the glioblastoma cancer cell line U87 indicates that it affects the cellular cycle by inducing a blockade at G0/G1 phase, linked to apoptosis, and another one at the S phase, associated with senescence. Using healthy Fischer rats, we show that both intravenous and subcutaneous SuccFerr: RAMEßCD administration at 5 mg/kg lacks toxic effects on several organs. To reach lethality, doses higher than 200 mg/kg need to be administered. These results prompted us to perform an ectopic in vivo study at 1 mg/kg i.v. ferrocidiphenol SuccFerr using F98 cells xenografted in rats. Halting of cancer progression was observed after six days of injection, associated with an immunological defense response linked to the active principle. These results demonstrate that the properties of the selected ferrocidiphenol SuccFerr transfer successfully to in vivo conditions, leading to interesting therapeutic perspectives based on this chemistry.

Toxicity and bacterial anti-motility activities of the hydroethanolic extract of Acacia senegal (L.) Willd (Fabaceae) leaves

BACKGROUND

Acacia senegal is a plant traditionally used for its various properties, including the treatment of infectious diseases. Recently, our team has demonstrated the ability of the hydroethanolic extract of the leaves to increase the activity of phenicol antibiotics against multi-resistant bacteria. The aim of this work is to determine the toxicological effects of the extract and its capacity to inhibit the bacterial mobility of Gram-negative bacteria, in order to evaluate the level of safety use of this plant.

METHODS

The cytotoxicity test was performed using the neutral red absorption method. Acute and sub-acute oral toxicity were conducted on NMRI mice and Wistar rats. The behaviour and adverse effects were recorded during the 14 days of the acute study. For the subacute test, biochemical parameters, food and water consumption, and morphological parameters were determined. The anti-motility activities were evaluated on Pseudomonas aeruginosa PA01 and Escherichia coli AG100, using specific concentrations of Agar as required by the method.

RESULTS

HEASG induced inhibition of keratinocytes cell growth with an IC50 of 1302 ± 60 μg/mL. For the acute toxicity study in mice, the single dose of extract of 2000 mg/kg body weight caused no deaths and no behavioural changes were observed; therefore, the median lethal dose (LD50) of HEASG was calculated to 5000 mg/kg body weight. In Wistar rats, no mortality was observed at 250, 500 and 1000 mg/kg/day during the 28-day subacute oral toxicity study. The weights of both females and males increased globally over time, regardless of the batch. No statistically significant differences were registered for organ weights and biochemical parameters, except for chloride for biochemical parameters. Water and food consumption did not change significantly. Furthermore, no macroscopic changes in organ appearance were observed. Regarding anti-motility activity, the extract has reduced the swarming motility of PA01 and AG100 significantly at the concentration of 32 μg/mL (P < 0.001). The extract has reduced the swimming motility (P < 0.01) of PA01 but not AG100.

CONCLUSIONS

The results suggest that hydroethanolic extract of A. senegal leaves has significant activity against bacterial motility and relatively low toxicity.

Toxicological study of aqueous-methanol solvent fraction of methanol extract of Dacryodes edulis leaves

Dacryodes edulis (G. Don) H.J. Lam) is the most popular species under the genus Dacryodes. It is well known for its nutritional and ethno-medicinal uses in South-eastern and South-western Nigeria. This study was aimed to evaluate the toxicity of the aqueous-methanol fraction of crude methanol extract of Dacryodes edulis leaves (AMDE). The test rats were randomized to groups of single oral treatment of AMDE (10-5000 mg/kgbw) for the acute toxicity study. They were monitored for obvious signs of behavioural change and mortality. For the subacute toxicity study, the rats were randomized to three daily treatment groups (of 200, 400 and 600 mg/kgbw of AMDE) for 28 days. The fourth group (control) received 2.5 %v/v DMSO. At the end of the experiment, blood samples were collected for hematology and clinical chemistry evaluation. The histopathology of the livers and kidneys were assessed using the excised organs. The cytotoxicity and genotoxicity of AMDE were also evaluated using Allium cepa model. The result showed that acute administration of AMDE, up to a dose of 5000 mg/kgbw did not result in mortality of the test rats. The observed median lethal dose (LD50) was greater than 5000 mg/kgbw. The subacute oral administration of AMDE for 28 days showed no significant (p > 0.05) effect on liver function, kidney function indices, organ - body weight ratio, but significantly (p < 0.05) decreased erythrocytic indices: red blood cells, haematocrit, and haemoglobin at 600 mg/kgbw. The Allium cepa assay revealed a non-significant reduction in mitotic index and low chromosomal aberrations of the treated groups. In conclusion, the aqueous-methanol solvent fraction of methanol extract of Dacryodes edulis leaves, AMDE is relatively safe. However, there are strong indications that it may contain compounds that are cytotoxic and reduces erythrocytic indices including red blood cells at high doses. Thus, adequate care should be taken in dosing and administering the extract to avert anaemic condition.

Administration of ethanolic extract of Erythrophleum ivorense (A Chev.) stem bark to male Wistar rats alters brain areas involved in motor coordination, behavior, and memory

ETHNOPHARMACOLOGICAL RELEVANCE

Erythrophleum ivorense (A Chev.) is a common plant in the tropics. Its use as ordeal poison in folklore medicine is controversial. The incoordination and behavioral changes following consumption are often associated with guilt. This study is aimed at dispelling or upholding this belief by investigating the actions of E. ivorense on the brain and behavior using rat model.

MATERIALS AND METHODS

Sixty male Wistar rats were equally divided into five groups; control group received distilled water, test groups were administered 10, 20, 30 and 40 mg/kg ethanolic extract of E. ivorense in a daily oral dose for 28 days. Cognition (Morris water maze) depression (forced swim test), motor function (hanging wire and inverted wire mesh grid grip tests) and exploratory assessments were done. Brains were stained with H&E, Cresyl violet and immunohistochemistry was done using GFAP, anticalbindin-D28k, Iba-1 and MBP antibodies.

RESULTS

At all doses, E. ivorense significantly (P ≤ 0.05) increased escape latency in the Morris water maze compared to control. Forced swim test showed a dose-related increase in duration of immobility, significant reduction in hanging latency in hanging wire and wire mesh grid grip test was also observed. Depletion of Purkinje cells of the cerebellum and hippocampal neurons was observed with H&E and cresyl violet. Immuno-staining revealed astrocytic activation in the cerebellum, loss of dendritic spines, cortical microglial activation and demyelination in the cerebellum and dentate gyrus of the hippocampus.

CONCLUSION

The ethanolic extract of E. ivorense stem bark caused a dose-dependent deficit in learning, memory and motor coordination with evidences of depression in rats. It is concluded that the plant is neurotoxic and induce several neurobehavioral changes.

In vitro and in vivo anti-diabetic and anti-oxidant activities of methanolic leaf extracts of Ocimum canum

Background:

Diabetes is a metabolic disorder with a highly complex, multifaceted and intricate etiologies and thus may require management options that proffers multimodal mechanism of action. This present study evaluated the antidiabetic and antioxidant potential of the methanolic extract/fractions of leaves of Ocimum canum.

Methods:

The antidiabetic potential was evaluated and using STZ-induced diabetic Wistar rat model (in vivo) and inhibition of α-amylase and α-glucosidase activity (in vitro). Antioxidant activity was assessed in vitro by free radical scavenging and reducing power assays and in vivo via monitoring SOD and CAT activities; GSH and MDA levels.

Results:

The total phenolic content (221.0±3.0 mg catechol/g of sample) and tannins (146.0±4.0 mg tannic acid/g of sample) of the crude extract; and flavonoid of the aqueous-methanol fraction (216.0.0±1.0 mg of rutin/g of sample) were found to be significantly higher relative to others. The crude extract and the aqueous-methanol fraction exhibited a significantly (p<0.05) higher percentage reduction in fasting blood glucose and a concomitant increase in serum insulin level relative to the diabetic control group. The highest radical scavenging activity and reducing power were observed in the aqueous-methanol fraction. The aqueous-methanol solvent fraction also significantly reversed the alterations in oxidative stress markers occasioned by the diabetic condition.

Conclusion:

In conclusion, the result of the present study has demonstrated evidently that extracts of Ocimum canum leaves ameliorates hyperglycemia and the associated oxidative stress in STZ-induced rats.

Safety against nephrotoxicity in paclitaxel treatment: Oral nanocarrier as an effective tool in preclinical evaluation with marked in vivo antitumor activity

Oral paclitaxel (PTXL) formulations freed from cremophor^® EL (CrEL) is always in utmost demand by the cancerous patients due to toxicities associated with the currently marketed formulation. In our previous investigation [Int. J. Pharm. 2014; 460:131], we have developed an oral oil based nanocarrier for the lipophilic drug, PTXL to target bioavailability issue and patient compliance. Here, we report in vivo antitumor activity and 28-day sub-chronic toxicity of the developed PTXL nanoemulsion. It was observed that the apoptotic potential of oral PTXL nanoemulsion significantly inhibited the growth of solid tumor (59.2 ± 7.17%; p < 0.001) without causing any explicit toxicity. The 6.5 mg/kg and 3 mg/kg oral PTXL nanoemulsion dose did not cause any notable alteration in haematological, biochemical/structural characteristics during 28-day sub-chronic toxicity studies in the experimental mice. Whereas, the toxicity of 12.8 mg/kg body weight dose showed decrease in RBC, haemoglobin and neutrophil counts. In contrast, marketed PTXL (Taxol^®) was found to be comparatively more toxic to the experimental animals. Taxol^® treatment resulted glomerulonephritis in histopathological examination, which could be correlated with increased level of creatinine and associated nephrotoxicity. This investigations conclude that the developed oral nanoemulsion presents a viable therapeutics bio-system to step towards clinical application as well as substitute CrEL based PTXL formulations.

Toxicological assessment of the hydroethanolic leaf extract of clerodendrum capitatum in Wistar rats

Introduction

Clerodendrum capitatum (Willd) Schumach. & Thonn (Lamiaceae) is used in African traditional medicine for the treatment of malaria, hypertension, obesity, jaundice and diabetes however there is lack of experimental data on its possible toxicity. This study investigated the acute and 28 days sub-chronic toxicity of C. capitatum in Wistar rats.

Methods

In acute toxicity tests, a single administration of the hydroethanolic C. capitatum leaf extract (5 g/kg) was given orally to 5 female rats. The general behavior, adverse effects and mortality were recorded for up to 14 days post treatment. On the 15^th day, the rats were weighed and euthanized for necropsy. In sub-chronic toxicity tests, the extract (4, 8 and 16 g/kg/day) was given orally to both male and female rats for 28 days. The animal body weight was recorded throughout the experiment, while hematological and biochemical parameters of blood and relative organs weights were evaluated on the 29^th day.

Results

Clerodendrum Capitatum did not cause any death or any hazardous symptoms of acute toxicity, showing an LD₅₀ higher than 5 g/kg. Sub-chronic administration of C. capitatum resulted in no noticeable changes in weight gain and water or food consumption. White blood cells and hemoglobin increased while urea concentration, liver enzymes, total cholesterol and glucose concentrations significantly decreased in treated animals. No changes in macroscopical aspect of organs were observed in the animals.

Conclusion

These results showed that acute or sub-chronic oral administration of the hydroethanolic leaf extract of Clerodendrum capitatum may be considered as relatively free of toxicity.

The Potential of Sub-Saharan African Plants in the Management of Human Immunodeficiency Virus Infections: A Review

Acquired immunodeficiency syndrome, caused by human immunodeficiency virus (HIV), is a leading cause of mortality and morbidity in Sub-Saharan Africa, particularly in Southern Africa. Phytomedicines are an integral part of African health care. The Southern African flora is composed of at least 23 400 taxa. Despite this richness, only a handful of botanical products have been assessed for activities against HIV. This study aimed to summarize the potential of Sub-Saharan African plants, based on their composition and the established bioactivities, as sources of agents to manage HIV symptoms and as retroviral therapy. At least 109 plant species from 42 families and 94 genera that are found in Southern Africa were shown to have potential or actual activities against HIV. Only 12 of these plant species from 6 families and 10 genera were shown to harbour anti-HIV properties. Phytochemicals that include β-sitosterols, terpenoids, glycosides, saponins, flavonoids, triterpenoids, tannins and alkaloids, which harbour anti-HIV properties, were found to have a near cosmopolitan presence across the plant families in the region. Bioactivities of multiple phytochemicals are comparable to those for standard allopathic antiretroviral drugs. Research to determine the anti-HIV activities of the identified and other plants, including clinical trials, is long overdue.

Toxicity assessment of Erythrophleum ivorense and Parquetina nigrescens

Erythrophleum ivorense and Parquetina nigrescens are found growing in tropical regions and they are used in African traditional medicine to treat various ailments including wounds, boils and anaemic conditions. Some species of plant in the Erythrophleum genus are also known to be poisonous and toxic to several livestock. However, there is no information on the toxicity of E. ivorense and P. nigrescens. This study is to determine the cytotoxicity and subchronic toxicity properties of methanol leaf extract (EIML) and methanol stem barks extract (EIMB) of E. ivorense and methanol leaf and aerial part extract of P. nigrescens (PNML). Concentrations from 0.1 to 100 μg/mL of the extracts were used to determine the influence of the extracts on the release of lactate dehydrogenase (LDH) from HaCaT keratinocytes. The EIML and EIMB extracts showed increase in LDH released from HaCaT keratinocytes at 0.1-10 μg/mL and 1-100 μg/mL for the PNML extracts (p > 0.05). Wistar rats were orally administered with 100, 300 and 1000 mg/kg body weight of the extracts (EIML, EIMB and PNML, respectively) for 35 days. Tissues from the kidney and liver of the rats treated with lower doses (100-300 mg/kg body weight) of EIML extract showed highly vascularized kidneys with numerous glomerular tufts, healthy hepatocytes and sinusoids in liver. However, there were persistent renal tissue inflammation and glomerular degeneration in kidney, and increased inflammatory infiltrates with few vacuolations and scarrings in liver in rats treated with higher extract dose of 1000 mg/kg body weight of rat. The rats treated with EIMB extract showed persistent renal and hepatocyte inflammations with glomerular and hepatocyte necrosis at all administered doses (100, 300 and 1000 mg/kg body weight) which are indications of renal and hepatic toxicities. Though rats administered with 100 and 300 mg/kg of PNML extract showed renal haemorrhage and inflammation and hepatic inflammation, the rats administered with 1000 mg/kg body weight showed restoring glomerular tufts and improved vasculature and liver with reduced inflammatory infiltrates with healthy hepatocytes. Phytochemical screening of EIML, EIMB and PNML extracts revealed the presence of alkaloids, tannins, flavonoids, sterols, cardiac glycosides and terpenoids.

Safety assessment of methanol extract of red dragon fruit (Hylocereus polyrhizus): acute and subchronic toxicity studies

Recently, the fruits of Hylocereus polyrhizus, known as red dragon fruit, have received much attention from growers worldwide. However, there is little toxicological information regarding the safety of repeated exposure to these fruits. The present study evaluated the potential toxicity of a methanol extract of H. polyrhizus fruit after acute and subchronic administration in rats. In the acute toxicity study, single doses of fruit extract (1250, 2500 and 5000 mg/kg) were administered to rats by oral gavage, and the rats were then monitored for 14 days. In the subchronic toxicity study, the fruit extract was administered orally to rats at doses of 1250, 2500 and 5000 mg/kg/day for 28 days. There was no mortality or signs of acute or subchronic toxicity. There was no significant difference in body weight, relative organ weight or hematological parameters in the subchronic toxicity study. Biochemical analysis showed some significant changes, including creatinine, globulin, total protein and urea levels. No abnormality of internal organs was observed between treatment and control groups. The lethal oral dose of the fruit extract is more than 5000 mg/kg and the no-observed-adverse-effect level (NOAEL) of the extract for both male and female rats is considered to be 5000 mg/kg per day for 28 days.

Acute and subchronic oral toxicity of Coriolus versicolor standardized water extract in Sprague-Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Coriolus versicolor, which is known as Yun Zhi, is one of the commonly used Chinese medicinal herbs. Recent studies have demonstrated its antitumor activities on cancer cells which led to its widespread use in cancer patient. However, little toxicological information is available regarding its safety. The present study evaluated the potential toxicity of Coriolus versicolor standardized water extract after acute and subchronic administration in rats.

MATERIALS AND METHODS

In acute toxicity study, Coriolus versicolor water extract was administered by oral gavage to Sprague-Dawley (SD) rats (6 males, 6 females) at single doses of varying concentrations 1250, 2500 and 5000 mg/kg. In subchronic toxicity study, the extract was administered orally at doses of 1250, 2500 and 5000 mg/kg/day for 28 days to male and female SD rats respectively. General behavior, adverse effects and mortality were determined throughout the experimental period. Haematological and biochemical parameters, relative organ weights and histopathological were evaluated at the end of the experiment.

RESULTS

There were no mortality and signs of toxicity in acute and subchronic toxicity studies. In the single dose acute toxicity and repeated dose 28-day subchronic toxicity studies, there were no significant difference in body weight, relative organ weight, haematological parameters, clinical chemistry, gross pathology and histopathology between treatment and control groups.

CONCLUSIONS

Coriolus versicolor water extract did not cause remarkable adverse effect in SD rats. The oral lethal dose of Coriolus versicolor water extract is more than 5000 mg/kg and no-observed-adverse-effect level (NOAEL) of the extract for both male and female rats is 5000 mg/kg per day for 28 days.

Acute and subchronic oral toxicity assessment of the aqueous extract from the stem bark of Erythrina senegalensis DC (Fabaceae) in rodents

AIM OF THE STUDY

The decoction of the stem bark of Erythrina senegalensis (EAES) is traditionally used in the Western region of Cameroon against liver disorders. The present study evaluated the potential toxicity of this decoction after acute and sub-chronic administration in rodents.

MATERIALS AND METHODS

In acute study, a single administration of EAES was given orally to mice at doses ranging from 1.25 to 12.5 g/kg. General behaviour, adverse effects and mortality were determined for up to 14 days post treatment. In the sub-chronic study, EAES was given orally as a single administration to Wistar rats at doses of 300, 600 and 1,200 mg/kg/day for 28 days. Animal body weight was observed throughout the experimental period while haematological and biochemical parameters of blood and urine, as well as kidney and liver tissues histology were evaluated at the end of the experiment.

RESULTS

In the acute study in mice, none of the doses used induced mortality or significant behavioural changes. In the sub-chronic study in rats, daily oral administration of EAES at the dose of 600 mg/kg resulted in a significant increase in the relative body weight at the last week of treatment. The relative weights of organs were not affected by the treatment. No haematological changes were observed a part of a significant increase in WBC count at the dose of 600 mg/kg. Serum AST, ALT, ALP, total protein, total cholesterol and triglycerides decreased significantly while total and conjugated bilirubin significantly increased. Renal function indices assay in blood showed significant modification in all the treated groups compared to control while, in urine, only urea excretion markedly reduced at a dose of 1,200 mg/kg. Histological analysis did no show any liver or kidney alteration.

CONCLUSION

These results demonstrated that there is a wide margin of safety for the therapeutic use of EAES and further corroborated the traditional use of this extract as a hepatoprotective agent.