Improvement of microvascular complications in STZ-diabetic rats treated with Pterocarpus erinaceus Poir. extract

Pterocarpus erinaceus Poir. from Fabaceae family is a medicinal plant traditionally used in decoction or infusion to treat diabetes mellitus. Although this plant is used in treating diabetes, studies on the effectiveness of its stem bark on the complications induced by chronic hyperglycemia have not been thoroughly addressed. Thus, this study was conducted to prove the efficacy of hydroethanolic extract of stem bark of P. erinaceus on type 2 diabetes and its complications, such as renal fibrosis and retinopathy in rats. STZ diabetics. The dry extract of P. erinaceus stem bark was obtained following the hydroethanolic extraction (v/v). Diabetes was induced with streptozocin in SD rats pretreated with fructose-lard for 20 days. Then, the serum and urinary biochemical parameters were evaluated at the start and the end of the treatment. Rats with blood glucose ≥350 mg/dL and significant proteinuria were selected and treated with P. erinaceus stem bark extract and glibenclamide for 3 weeks. A complete blood count and a histopathological examination of the retina and kidneys were performed at the end of the 41st day of treatment. The results showed that P. erinaceus extract at a dose of 500 mg/kg bw and glibenclamide at a dose of 0.6 mg/kg bw caused a significant decrease (p < 0.0001) in basal blood glucose in STZ diabetic rats during treatment and improved oral glucose intolerance. At the end of the experiment, the treated rats showed a normalization in body weight, food and water consumption. Evaluating of biochemical parameters showed a significant (p < 0.001) decrease in total cholesterol, LDL-C, triglycerides, TG/HDL-C ratio, CPK and oxidative stress in treated rats. No retinal and kidney abnormalities were observed on histological sections in rats treated with plant extract and glibenclamide. In contrast, macular edema and renal fibrosis were observed in the diabetic control group. The findings showed that extract at a dose of 500 mg/kg bw improves oral glucose intolerance, and inhibits lipid deposition and retinal and renal fibrosis. Therefore, the plant extract could be exploited in the production of herbal medicines to manage diabetes and its complications.

Four Togolese plant species exhibiting cytotoxicity and antitumor activities lightning polytherapy approach in cancer treatment

Background

Cancer is leading to premature deaths across the globe. Therapeutic approaches are still being developed to enhance the survival of cancer patients. In our previous study, extracts from four Togolese plants, namely, Cochlospermum planchonii (CP), Piliostigma thonningii (PT), Paullinia pinnata (PP), and Securidaca longipedunculata (SL), actually used in traditional medicine for cancer treatment, showed beneficial health effects against oxidative stress, inflammation, and angiogenesis.

Purpose

In the present study, we aimed to investigate the cytotoxicity and antitumor activities of these four plant extracts.

Material and methods

Breast, lung, cervical, and liver cancer cell lines were exposed to the extracts, and viability was assessed using the Sulforhodamine B method. P. pinnata and S. longipedunculata with significant cytotoxicity were selected for in vivo tests. The acute oral toxicity of these extracts was assessed using BALB/c mice. The antitumor activity was evaluated using the EAC tumor bearing mice model, wherein mice were orally treated with extracts at different concentrations for 14 days. The standard drug was cisplatin (3.5 mg/kg, i.p), single dose.

Results

Cytotoxicity tests revealed that SL, PP, and CP extracts have more than 50% cytotoxicity at 150 μg/mL. The acute oral toxicity of PP and SL at 2000 mg/kg did not show any toxic signs. At therapeutic doses of 100 mg/kg, 200 mg/kg and 400 mg/kg of PP and 40 mg/kg, 80 mg/kg, and 160 mg/kg of SL, extracts showed beneficial health effects by modulating several biological parameters. SL extract significantly reduced tumor volume (P < 0.001), cell viability, and normalized hematological parameters. SL also demonstrated a strong anti-inflammatory activity similar to the standard drug. The SL extract also revealed a significant increase of the life span of treated mice. PP extract reduced the tumor volume and significantly improved the values of endogenous antioxidants. Both PP and SL extracts also exerted significant anti-angiogenic potency.

Conclusion

The study indicated that polytherapy would be a panacea for the efficient use of medicinal plant extracts against cancer. This approach will make it possible to act simultaneously on several biological parameters. Molecular studies of both extracts targeting key cancer genes in several cancer cells are currently underway.

Anti-cholinesterase, anti-inflammatory and antioxidant properties of Combretum micranthum G. Don: Potential implications in neurodegenerative disease

Background

Brain damage is a severe and common pathology that leads to life-threatening diseases. Despite development in the research, the medical evidence of the effectiveness of potential neuroprotective medicines is insufficient. As a result, there is an immense and urgent demand for promising medication. For millennia, herbal remedies were a fundamental aspect of medical treatments. Combretum micranthum (CM), a plant of the family Combretaceae in sub-Saharan Africa, has been utilized in folklore medicine to cure diverse human ailments. In order to develop a neuroprotective phytomedicine, the current research was undertaken to explore the antioxidant, anti-inflammatory, anticholinesterase and neuroprotective potential of CM extract.

Methods

Colorimetric methods were used to determine CM antioxidant activity, in-vitro protein denaturation and membrane destabilization assays were used to evaluate its anti-inflammatory capacity, anticholinesterase activity was carried out using Ellman's method, and neuroprotective potential was assessed on brain homogenate stressed with ferric chloride and ascorbic acid (FeCl₂-AA) by assessing the lipoperoxidation biomarker malondialdehyde (MDA).

Results

In Ferric Reducing Antioxidant Power (IC₅₀ = 27.15 ± 0.06 µg/mL) and Total Antioxidant Capacity (IC₅₀ = 31.13 ± 0.02 µg/mL), CM extract demonstrated strong antioxidant activity. Anti-inflammatory effect were improved in heat-induced Egg albumin and BSA denaturation (IC ₅₀ = 46.35 ± 1.53 and 23.94 ± 1.10 µg/mL) as well as heat and hypotonia induced membrane destabilization (IC ₅₀ = 20.96 ± 0.11 and 16.75 ± 0.94 µg/mL).CM extract showed strong anticholinesterase activity (IC ₅₀ = 59.85 ± 0.91 µg/mL). In an ex-vivo neuroprotective model, CM extract showed substantial inhibition (p < 0.001) of oxidative damage caused by FeCl₂-AA in brain tissue.

Conclusion

C. micranthum may be a good candidate for its probable neuroprotective potential. Its neuroprotective benefits might be attributed to its antioxidant, anti-inflammatory and anticholinesterase effects.

Antidiabetic and antioxidant potential of total extract and supernatant fraction of the roots of Anogeissus leiocarpus in HFD-fed and Streptozocin -induced diabetic rats

The aim of this study was to evaluate the antidiabetic properties of hydro alcoholic extract and supernatant fraction of the roots of Anogeissus leiocarpus, a plant used by traditional healers to treat Diabetes mellitus. Diabetes mellitus was induced by a single intraperitoneal administration of Streptozocin to Sprague Dawley rats under a fructose-enriched fat diet. Diabetic rats were treated with 500 mg/kg of total extract and 100 mg/kg of supernatant. The antidiabetic activity was assessed by measuring blood glucose level, lipid profile, insulin and biochemical parameters together with the antioxidant potential. The administration of total extract and supernatant exhibited significant decrease (p < 0.01) of the blood glucose level in the diabetic rats after 7 days of treatment compared to the diabetic rats. A significant reduction in the serum concentrations of cholesterol (19.7 %) and triglycerides (56.7 %) was observed in the treated diabetic rats. The levels of insulin did not differ across all the groups. However, compared to diabetic rats, HOMA-IR (Homeostasis Model Assessment for Insulin-resistance) and HOMA-β (Homeostasis Model Assessment for β cell function) showed a statistical decrease in insulin resistance and an increase in pancreatic β cell function in the treated diabetic rats. Moreover, total extract and supernatant significantly increased GSH level and decreased lipid peroxidation because of their antioxidant properties. In comparison, the supernatant fraction exerted stronger antidiabetic and antioxidant effects than the total extract. Hence, the roots of Anogeissus leiocarpus are a potent antidiabetic agent that can be developed as an alternative medicine for diabetes and its complications.

Ethnopharmacological evaluation of antioxidant, anti-angiogenic, and anti-inflammatory activity of some traditional medicinal plants used for treatment of cancer in Togo/Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer is a multistep disease and its management is exceedingly expensive. Nowadays medicinal plants are gaining more attention in drug discovery and approximately 70% of anticancer drugs were developed from natural products or plants. A strong candidate from medicinal plant with anticancer potential should have four major properties: antioxidant, anti-inflammatory, anti-angiogenic, and cytotoxic activities.

AIM OF THE STUDY

In order to assess Togolese traditional healer's claims about the anticancer potential of medicinal plants and obtain candidate plants for anticancer drug discovery, some species were selected from surveys and evaluated for their antioxidant, anti-inflammatory, anti-angiogenic and cytotoxic activities.

METHODS

Four species, Cochlospermum planchonii (CP), Piliostigma thonningii (PT), Paullinia pinnata (PP), and Securidaca longipedunculata (SL) were selected and analyzed to detect the phytochemical components. The mentioned bioactivities were evaluated using in vitro, ex vivo and in vivo assays.

RESULTS

Relative to SL extract, CP and PT have shown significantly high polyphenols and flavonoids content. The DPPH, FRAP, and TAC of the extracts revealed that CP, PT, and PP have a potent antioxidant effect compared to SL. MDA analysis revealed the same antioxidant activity as CP, PT and PP showed a minor MDA level. The egg albumin denaturation assay showed that IC50 of CP and PP was significantly higher than control (P < 0.05). In contrast, the Bovine Serum Albumin (BSA) results showed a nonsignificant effect (P > 0.05). Notably, SL extract was nonsignificant to control in both Egg Albumin and BSA. Furthermore, angiogenesis assay showed that SL at 50 μg/ml and PP at 100 μg/ml effectively reduced the number of blood vessels than control and showed a potent anti-angiogenic effect (2.7-fold and 2.5-fold, respectively, P < 0.05). No cytotoxicity on PBMC was reported for CP, PP, and PT up to 1000 μg/ml, whereas SL at 1000 μg/ml exhibit benign cytotoxicity (P < 0.0001).

CONCLUSION

This study provided in vitro evidence supporting further evaluation on cancer cell lines and tumors in vivo.

Toxicological evaluation of the dried hydroethanolic extract of Amaranthus spinosus L. roots in Artemia salina larvae and Sprague Dawley rats

Background

Amaranthus spinosus is a medicinal plant used in traditional medicine to treat several diseases including diabetes and its complications. The aim of this study was to prove the safety of the plant in animal health.

Methods

The dry extract was obtained following the hydroethanolic extraction of A. spinosus roots. The cytotoxicity was evaluated in vitro by incubating Artemia salina larvae with the extract for 24 h. In vivo toxicity was assessed in Sprague Dawley rats. A single dose of 5000 mg/kg bw of extract was administered orally to female rats in acute toxicity and observed for 14 days for mortality and signs of toxicity. In subchronic toxicity, extract doses of 500 and 1000 mg/kg bw were administered orally to male and female rats for 28 consecutive days and observed for previous signs. Body weight was recorded daily and blood glucose levels every week. On day 29, blood was collected for biochemical and hematological studies. Organs were then exised for gross autopsy and histopathological examination.

Results

The in vitro study showed that the extract had a LC50 = 1.178 mg/mL in larvae and was considered to be non-cytotoxic. Oral administration of extract at a single dose of 5000 mg/kg bw did not cause any mortality or sign of toxicity in gross necropsy. In subchronic oral toxicity, repeated doses of 500 and 1000 mg/kg bw of extract, did not also cause any mortality or significant change in body weight, relative weight of vital organs. Furthermore, hematological and biochemical parameters and histopathological examination did not show any significant change. The observed decrease in blood glucose levels did not correlate with organ damage and supports the safety of the plant. However, the reduction of LDL-cholesterol has shown that the extract can prevent cardiovascular disease.

Conclusions

This finding demonstrated that A. spinosus root is non-toxic with a LD50 > 5000 mg/kg bw. Thus, the extract can be used for cutaneous and subchronic oral administration at doses ≤ 1000 mg/kg bw. However, further studies such as embryo/fetotoxicity, genotoxicity and neurotoxicity will be needed to prove the safety of chronic administration of the extract in patients and fetuses.

Nephroprotective effect of Combretum micranthum G. Don in nicotinamide-streptozotocin induced diabetic nephropathy in rats: In-vivo and in-silico experiments

ETHNOPHARMACOLOGICAL RELEVANCE

Combretum micranthum G. Don (CM) is extensively used in traditional medicine throughout West Africa and commonly known as "long-life herbal tea" or "plant to heal". Further, traditional healers frequently use the title plant to mitigate of renal disorders.

AIM OF THE STUDY

To explore the nephroprotective property of standardised hydroalcoholic extract of Combretum micranthum in nicotinamide-streptozotocin induced diabetic nephropathy in rats. In addition, in-silico computational experiments were performed with bioactive compounds of the title plant against PPARα and PPARγ.

MATERIAL AND METHODS

Male rats were made diabetic by a single intraperitoneal (ip) injection of STZ (50 mg/kg), 15 min after ip administration of NA (100 mg/kg) dissolved in normal saline. The diabetic rats received CM extract (200 and 400 mg/kg p.o.) daily, for eight weeks. Body weights and blood glucose (non-fasting and fasting) of rats were measured weekly. Daily food and water consumption were also measured. After 8 weeks of treatment, urine biochemical parameters such as N-Acetyl-β-D-Glucosaminidase (NAG), urea (UR), uric acid (UA), creatinine (CRE), and serum markers of diabetes, kidney damage and liver damage such as insulin, lipid parameters), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (γGT), albumin (Alb), magnesium (Mg²⁺), calcium (Ca²⁺), phosphorus (P), were estimated. Blood glycosylated hemoglobin (HbA1_C) were also estimated. kidney and liver were used for biochemical estimation of oxidative stress markers such as lipid peroxidation, superoxide dismutase (SOD) activity and glutathione peroxidase (GPx) activity. The kidney and pancreas were used for histopathological study. Further, HPLC chemoprofiling of CM extract and in-silico molecular simulation experiments were performed.

RESULTS

At the end of eight weeks, renal damage induced by the consequence of prolong diabetic condition was confirmed by altered levels of serum and urine kidney and liver function markers, oxidative stress markers and histopathological variations in kidney. Treatment with CM extract ameliorated the diabetes mellitus-induced renal biochemical parameters and histopathological changes. Further, HPLC-UV & MS experiments revealed that CM extract contains several bioactive compounds including hyperozide (62.35 μg/mg of extract) and quercitrin (19.07 μg/mg of extract). In-silico experiment exhibited cianidanol (-17.133), epicatechin (-15.107) exhibited higher docking score against PPARα and luteoforol (-11.038), epigallocatechin (-10.736) against PPARγ. Based on docking and drug likeness score, four bioactive compounds were selected for molecular dynamic experiments. Cianidanol and epigallocatechin out of the 30 compounds are concluded as a potential candidate for the treatment of DN through activating PPARα and PPARγ target protein.

CONCLUSIONS

Taken together, the present study provided the scientific footage for the traditional use of Combretum micranthum.

Acute and subchronic oral toxicity assessments of Combretum micranthum (Combretaceae) in Wistar rats

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Acute and subchronic oral toxicity assessments of Combretum micranthum leaves extract were evaluated in Wistar rats of both sexes.

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In acute oral toxicity assessment, LD50 of Combretum micranthum leaves extract is greater than 5000 mg/kg.

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In subchronic oral toxicity assessment at doses of 500 and 1000 mg/kg/day for 28 days, No significant changes in food consumption, body weight gain, organ weights and in biochemical parameters.

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The level of PLT increased in female rats in the sub-chronic study but the immune system was not affected.

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No treatment related pathology was identified during histopathology.

Background

Combretum micranthum (CM) (Combretaceae) is widely used in traditional medicine throughout West Africa for the treatment of diabetes, hypertension, inflammation, malaria and liver ailments. In our recent research we demonstrated that CM has nephroprotective potentials in diabetes mellitus, hypertension and renal disorders. However, to the best of our knowledge, no systematic study concerning its toxicity profile has been reported.

Aim of the study

The study carried out to evaluates the potential toxicity of the hydroalcoholic extract from leaves of the CM, through the method of acute and sub-chronic oral administration in rats.

Materials and methods

During the acute toxicity study, male and female rats were orally administrated with CM extract at single doses of 5000 mg/kg (n = 5/group/sex). Abnormal behaviour, toxic symptoms, weight, and death were observed for 14 consecutive days to assess the acute toxicity. For sub-chronic toxicity study, the extract was administered orally at doses of 500 and 1000 mg/kg (n = 5/group/sex) daily to Wistar rats for 28 days. The general behaviour and body weight of the rats was observed daily. A biochemical, haematological, macroscopical and histopathological examinations of several organs were conducted at the end of the treatment period. The CM extract was subjected to Fourier transform infrared spectrophotometric examination in order to detect the presence or absence of cyanide toxic compounds.

Results

The absence of absorbance peaks between the 2220−2260 cm⁻¹ region of FT-IR spectrum of CM, indicating the absence of cyanide groups. This suggested that the CM extract may not contain toxic substances. During the acute toxicity test, no mortality or adverse effects were noted at the dose of 5000 mg/kg. In the subchronic study, the CM extract induced no mortality or treatment-related adverse effects with regard to body weight, general behaviour, relative organ weights, hematological, and biochemical parameters. Histopathological examination of vital organs showed normal architecture suggesting no morphological alterations.

Conclusion

The present study revealed that oral administration of CM extract for 28 days, at dosage up to 1000 mg/kg did not induce toxicological damage in rats. From acute toxicity study, the median lethal dose (LD₅₀) of the extract was estimated to be more than 5000 mg/kg.

Nephroprotective activity of Combretum micranthum G. Don in cisplatin induced nephrotoxicity in rats: In-vitro, in-vivo and in-silico experiments

Nephrotoxicity is known to be a major complication during cisplatin chemotherapy in cancer patients. In the present study, the protective effect of a hydroalcoholic extract of Combretum micranthum (CM) against cisplatin (CP)-induced renal damage was evaluated using in-vitro human embryonic kidney (HEK)-293 cells and in-vivo experiments. Further, in-silico molecular docking and dynamic experiments were carried out with bioactive compounds of the title plant against nuclear factor kappa B (NF-κB) and soluble epoxide hydrolase (sEH). Incubation of HEK-293 cells with cisplatin resulted in a significant increase in cell death with changes in normal cellular morphology. Co-treatment of HEK-293 cells with CP and CM extract at varying concentrations resulted in significant enhancement of cell growth compared to CP treatment indicating the cytoprotective activity of CM with an EC₅₀ 8.136 μg/mL. In vivo nephroprotective activity was evaluated by administering CM (200 and 400 mg/kg, p.o) to rats for 10 days followed by single intraperitonial injection of CP (7.5 mg/kg) on the 5th day of the experiment. Nephrotoxicity induced by CP was apparent by elevated levels of serum and urine kidney function markers, transaminases, oxidative stress markers and histopathological alterations in kidney. Pre-treatment with CM normalized the renal function at both the doses by ameliorating the CP-induced renal damage markers, oxidative stress and histopathological variations. In-silico studies showed that, out of the thirty bioactive compounds, isovitexin and gallic acid exhibited a higher docking score of -22.467, -21.167 kcal/mol against NF-κB. Cianidanol and epicatechin exhibited a higher docking score of -14.234, -14.209 kcal/mol against sEH. The protective effect of CM extract in CP-induced nephrotoxicity might be attributed to its antioxidant, anti-inflammatory activity by inhibiting NF-κB and sEH upregulation.

Natural occurrence of mycotoxins in maize and sorghum in Togo

Mycotoxins are fungal secondary metabolites frequently affecting agronomical crops and consequently imposing a major challenge for food safety and public health. In this study, a total of 67 raw cereals (55 maize and 12 sorghum) were collected from the market of Togo. The samples were investigated on the occurrence of 21 mycotoxins using state-of-the-art high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The most frequent occurring mycotoxins were fumonisins (88 and 67% for maize and sorghum respectively) with concentrations ranging from 101 to 1838 μg/kg for maize and 81.5 to 361 μg/kg for sorghum, respectively. Aflatoxin B1 was detected in 38% of the maize samples with maximum contamination levels of 256 μg/kg, and 25% of the sorghum samples (range 6-16 μg/kg). The concentrations of aflatoxins were high in maize, with some cases exceeding the maximum legislative limits (EU) for unprocessed maize placed on the market. In addition to these high contamination levels, the co-occurrence of three classes of mycotoxins (i.e., aflatoxins, fumonisins, and trichothecenes) was observed in this study. For the first time, the multi-mycotoxins occurrence in agronomical crops in Togo was reported.

Antioxidant and nephroprotection activities of Combretum micranthum: A phytochemical, in-vitro and ex-vivo studies

Management of chronic renal failure is exceedingly expensive. Despite of encouraging experimental outcomes, there is a lack of potent nephroprotective drugable molecules in a clinics or market. To develop a nephroprotective phytomedicine, the present study was designed to do a literature survey on reported phytochemical and biological analysis of Combretum micranthum and to carry out chemoprofiling, in-vitro antioxidant and ex-vivo nephroprotective capacity of the title plant. The phytochemical and biological activity survey of C. micranthum has reveals the presence of many bioactive compounds such as flavonoids, terpenoids, steroids and alkaloids with many biological activities. Phytochemical investigation re-confirmed the presence of these compounds. Hydroalcoholic extract of C. micranthum (CM extract) showed a strong antioxidant activity by scavenging AAPH, DPPH, nitric oxide, hydrogen peroxide and chelating metal ions. CM extract exhibited significant (P < 0.001) dose dependent inhibition of ferric chloride-ascorbic acid induced lipid peroxidation. Diabetic nephropathy is a serious and common complication leading to end stage renal disease. Therefore, in the present study, glucose-induced toxicity was also studied in human embryonic kidney cells (HEK-293) as an in vitro model for diabetic nephropathy. The results showed that exposure of cells to high glucose (100 mM) for 72 h significantly reduced the cell viability resulting in morphological changes such as cell shrinkage, rounded cell shape and cytoplasmic vacuolation. Treatment with CM extract at 10 and 25 μg/mL resulted in significant improvement in cell viability from 10 to 23% compared to the high glucose control. This study demonstrated the potential antioxidant and nephroprotective properties of C. micranthum, justifying its traditional use in the treatment of various diseases.

In vivo and in vitro toxicological evaluation of the hydroalcoholic leaf extract of Ageratum conyzoides L. (Asteraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

In African traditional medicine, Ageratum conyzoides has been used as purgative, febrifuge, anti-ulcer and wound dressing. To date there is no safety information about long term use of Ageratum conyzoides which contains pyrrolizidine alkaloids, a class of hepatotoxic and carcinogenic phytochemicals. This study aims to evaluate the 90 days subchronic toxicity and in vitro toxicity of Ageratum conyzoides.

MATERIALS AND METHODS

Three groups of 8 rats (4 males and 4 females) received distilled water (control), 500 and 1000 mg/kg of the extract daily for 90 consecutive days by oral gavage. The animals were observed daily for abnormal clinical signs and death. Body weight, relative organ weight, haematological and biochemical parameters of blood as well as heart, kidney, liver and spleen tissues histology were evaluated.

RESULTS

After 90 days administration, Ageratum conyzoides increased significantly (p<0.05) the relative weight of the liver, the spleen and kidney as compared to control group. Ageratum conyzoides increased also significantly (p<0.05) ALP, ALT, AST and blood glucose. Furthermore, an increase in the number of platelets associated with a normocytic and normochromic anaemia was observed. The cytotoxicity, determined by the MTT test and neutral red assay, has shown that the cytotoxicity of hydroalcoholic extract of Ageratum conyzoides and its total alkaloids was very close.

CONCLUSIONS

Our results have shown that Ageratum conyzoides at 500 and 1000 mg/kg can induce liver, kidney and haematological disorders. These toxics effects can be attributed to its total alkaloids especially to pyrrolizidine alkaloids which are present in this plant.

Effect of Bridelia ferruginea Benth (Euphorbiaceae) ethyl acetate and acetone fractions on insulin resistance in fructose drinking mice

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Bridelia ferruginea is traditionally used as a treatment for type 2 diabetes. The present study was investigated to evaluate the effect of Bridelia ferruginea root bark fractions on some markers of type 2 diabetes on fructose drinking mice.

MATERIALS AND METHODS

Mice received a solution of fructose 15% during 42 days ad libitum; at the 15th day to the 42nd day, they received distilled water for fructose drinking control group, metformin 50 mg/kg per day or fractions 50 mg/kg per day for treatment groups. The normal control group received only distilled water during the experiment. After 6 weeks of experiment, OGTT, fasting blood glucose, plasma insulin, triglycerides (TG), total cholesterol, AST and ALT levels were measured.

RESULTS

Fructose drinking control group (F) showed significant (p<0.001) increase of glucose tolerance, plasma levels of total cholesterol, triglycerides and insulin index for insulin resistance (Homeostasis Model Assessment ratio HOMA-IR) as compared to normal control mice. In treated groups, there was a significant reduction of glucose intolerance respectively 74% (p<0.001), 25% (p<0.5) and 92% (p<0.001) for ethyl acetate fraction, acetone fraction and metformin at the same dose of 50 mg/kg per day during 4 weeks administration. In ethyl acetate fraction and metformin treated groups, biochemical parameters and insulin index were significantly (p<0.001) lower than that of fructose drinking control group.

CONCLUSIONS

This indicates that Bridelia ferruginea root bark ethyl acetate fraction improved insulin resistance as metformin significantly in type 2 diabetes.

Survey of pesticide application on vegetables in the Littoral area of Togo

Vegetable production in Togo is seriously affected by pests attack. To reduce damage, farmers indiscriminately use pesticides. Various studies have reported high concentrations of pesticide residues more than acceptable limits in vegetables and other edible food. The aim of the presented study is to study the attitudes and practices developed by vegetable growers about pesticides applications. A standardized questionnaires which included socio-professional factors, provisions and operations concerning the use of varieties of pesticides were addressed to 150 growers in vegetable farms along the Littoral of Togo. In order to complete data concerning pesticides, seven runoff private companies and agents of the 'Direction de la Protection des Végétaux' were interviewed. Data were statistical treated using Sphinx Plus. The survey showed that vegetable growers have an acceptable educational level (36% have more than 7 years of formal education) to exploit instructions concerning pesticide use, but more than 97% do not use recommended tools. Only 21% of them received training for pesticide use. Moreover, 84% of them did not usually wear gloves, and less than 30% used oro-nasal masks. Failure to observe minimum intervals between pesticide application and sale is worrying because extremely hazardous (Carbofuran and Cadusaphos) or moderately toxic (Cypermethrin, Dimethoate, Endosulfan, Chlorpyrifos-ethyl, Fipronil) are the products currently used. The presented study indicates that pesticides application in the survey area represents a potential risk for the environment, farmers and consumers. More investigations are needed to quantify pesticides residues on the vegetables currently con,umed and moreover, to determine the potential effect of those products on human and animals health.

Acute and sub-chronic (28days) oral toxicity evaluation of hydroethanolic extract of Bridelia ferruginea Benth root bark in male rodent animals

The present investigation was carried out to evaluate the safety of hydro-ethanol extract of Bridelia ferruginea Benth (Euphorbiaceae) root bark. For acute toxicity study, a single dose of 2000 and 5000 mg/kg of the B. ferruginea root bark extract was given orally to healthy male Wistar rats and Balb/c mice. The animals were observed for mortality and clinical signs for 3 h and then daily for 14 days. In the sub-chronic toxicity study, the extract was administered orally at doses of 250, 500 and 1000 mg/kg/day for 28 days to male Wistar rats. Animals were sacrificed to examine their organs, and urine and blood serum were analyzed. In the acute toxicity study, B. ferruginea root bark extract caused neither significant visible signs of toxicity, nor mortality in Wistar rats and Balb/c mice. In sub-chronic toxicity study, administration of the B. ferruginea root bark extract at 250, 500, and 1000 mg/kg for 28 consecutive days to Wistar rats did not produce mortality. No significant differences were found in relative organ weights, biochemical studied parameters in treated groups compared to control group. No obvious histological changes were observed in organs of B. ferruginea extract treated animals compared to controls.

Preliminary evaluation of the wound healing effect of Vitex doniana sweet (Verbenaceae) in mice

Vitex doniana is traditionally used in Togo to treat various diseases including wounds. The aim of this work was to evaluate the efficiency of Vitex doniana on cutaneous wound healing. Wounds were induced in ICR mice divided into four groups as following: Group I received carbopol 974P NF empty gel, Groups II and III were treated topically with carbopol gel containing 2.5% and 5% of Vitex doniana extract. Group IV received Betadine® 10% as standard drug. The efficacy of treatment was evaluated by planimetry and histological analysis. We secondary used the gel containing Vitex doniana at 2.5% and the pure extract at 10 mg/ml on the model of ear edema induced by xylene. Skin toxicity test was performed with the gel containing Vitex doniana at 5% and the pure extract at 30 mg/ml. Vitex doniana at 5% and 2.5% provided better wound contraction (91.14% and 86.38%) at day 12 post-excision when compared to control (51.15%). The results of histological evaluation supported the outcome of excision wound model. Moreover Vitex doniana inhibited significantly edema induced by xylene when compared to control (p< 0.05). In skin toxicity test, no abnormal symptoms were developed over 14 day-time period. Vitex doniana inhibits the topical inflammation and accelerate cutaneous wound repair.

Gastroprotective Effect of Hydroalcoholic Extract of Aloe buettneri

Aloe buettneri A. Berger is commonly used in traditional Togolese medicine to treat inflammatory and gastric ulcers. The present study examined the gastro-protection effect of the hydro-alcoholic extract of A. buettneri on mucus production and gastric pH. A gastric ulcer is induced by ethanol 95° alone (1 mL/kg body weight), after pre-treatment with indomethacin (300 mg/kg) or by utilising L-NAME (40 mg/kg IV). In addition gastric mucus was removed by scraping and subsequently weighed. The experiment focused entirely on rats that had been subjected to fasting. The hydro-alcoholic extract of A. buettneri (500 mg/kg) significantly inhibited ulcers that were induced by ethanol, indomethacin or L-NAME pre-treatment. A. buettneri was shown to increase the production of gastric mucus. Furthermore L-arginine significantly decreased the size of the induced ulcers. The results achieved in the study carried out suggest that A. buettneri posses gastro-protective properties.

In vitro inhibitory effect of West African medicinal and food plants on human cytochrome P450 3A subfamily

AIM OF THE STUDY

In Africa, medicinal plants are used intensively and concomitantly with allopathic medicines in the treatment of opportunity diseases by many patients or by healthy person to prevent diseases. However, there is little information about the interactions between medicines and botanical products used currently in West Africa area. Therefore, the aim of the present investigation is to study the effect of some plant products on CYP3A4, CYP3A5 and CYP3A7, three individual enzymes of CYP3A subfamily, in vitro.

MATERIALS AND METHODS

Teas and ethanolic extracts of medicinal, food and co-administered plants were evaluated on CYP3A4, CYP3A5 and CYP3A7 individual enzymes in vitro using fluorometric assays.

RESULTS

Extracts of adjuvant plants such as Aframomum cuspidatum, and Aframomum melegueta, as well as one medicinal plant (Harrisonia abyssinica) inhibited CYP3A4, CYP3A5 and CYP3A7 activity more than 90%. Phyllanthus amarus showed high inhibition of CYP3A5 and CYP3A7. Food plants (Solanum macrocarpon and Talinum triangulare) inhibited CYP3A4 and CYP3A5 less than 20%.

CONCLUSION

These results indicate that plants tested in this study affect in vitro the activity of the main three CYP3A subfamily enzymes. These active plants could interfere with the metabolism at phase I of conventional drugs in vivo as well act as pharmacoenhancers in herbal mixtures.

[Effect of Morinda lucida Benth. (Rubiaceae) and Newbouldia leavis P. Beauv. (Bignoniaceae) on sickling of red blood cells]

The purpose of this study was to evaluate the In vitro anti-sickling activity of two plants widely used for treatment of sickle cell disease in Togo, i.e., Morinda lucida et Newbouldia leavis. A concentration-dependent decrease in the rate of sickling was observed after incubation of red blood cells with plant extracts and 2% sodium metabisulfite as compared to incubation with 0.9% NaCl. On samples with a SS blood genotype the inhibition rate of Morinda lucida was 17.30% at a concentration of 1 mg/ml and 92.31% at a concentration of 30 mg/ml. On samples with an AS blood genotype, the inhibition rate of Morinda lucida 48.10% at a concentration of 1 mg/ml and 99.34% at a concentration of 30 mg/ml. Using Newbouldia leavis the inhibition rates at concentrations of 1 mg/ml and 30 mg/ml were 15.66% and 90.42% respectively on samples with a SS blood genotype and 64.03% and 99.02% respectively on samples with an AS blood genotype. The study protocol appeared to be adequate for both SS and AS blood genotypes since the Pearson correlation coefficient between rates measured on the two types of samples was 0.92 for Newuboulida and 0.89 for Morinda. These findings show that these two plants have clear-cut in vitro anti-sickling activity and support their use in traditional medicine.

The effect of Mangifera indica stem bark and Pluchea ovalis roots on tracheal smooth muscle in vitro

Aqueous extract of the stem bark of Mangifera indica and ethanolic extract of the roots of Pluchea ovalis has been studied on rat tracheal smooth muscle in vitro. The extract of M. indica at 1, 2 and 4 mg/ml and that of P. ovalis at 0.25, 0.5 and 1 mg/ml relaxed, dose-dependently, the rat tracheal smooth muscle strip previously contracted by acetylcholine at 0.055 mmol/l.