The extract of Sclerocarya birrea, Nauclea latifolia, and Piper longum mixture ameliorates diabetes-associated cognitive dysfunction.

Diabetes-associated cognitive dysfunction is linked to chronic hyperglycemia, oxidative stress, inflammation, cholinergic dysfunction, and neuronal degeneration. We investigated the antidiabetic and neuroprotective activity of a mixture of Sclerocarya birrea, Nauclea latifolia, and Piper longum (SNP) in type 2 diabetic (T2D) rat model-induced memory impairment. Fructose (10%) and streptozotocin (35 mg/kg) were used to induce T2D in male Wistar rats. Diabetic animals received distilled water, metformin (200 mg/kg), or SNP mixture (75, 150, or 300 mg/kg). HPLC-MS profiling of the mixture was performed. Behavioral testing was conducted using the Y-maze, NORT, and Morris water mazes to assess learning and memory. Biochemical markers were evaluated, including carbohydrate metabolism, oxidative/nitrative stress, pro-inflammatory markers, and acetylcholinesterase activity. Histopathological examination of the pancreas and hippocampus was also performed. Fructose/STZ administration resulted in T2D, impaired short- and long-term memory, significantly increased oxidative/nitrative stress, pro-inflammatory cytokine levels, acetylcholinesterase activity (AChE), hippocampal neuronal loss and degeneration in CA1 and CA3 subfields, and neuronal vacuolation in DG. SNP mixture at 150 and 300 mg/kg significantly improved blood glucose and memory function in diabetic rats. The mixture reduced oxidative/nitrative stress and increased endogenous antioxidant levels. It also reduced serum IL-1ß, INF-γ and TNF-α levels and ameliorated AChE activity. Histologically, SNP protected hippocampus neurons against T2D-induced neuronal necrosis and degeneration. We conclude that the aqueous extract of SNP mixture has antidiabetic and neuroprotective activities thanks to active metabolites identified in the plant mixture, which consequently normalized blood glucose, protected hippocampus neurons, and improved memory function in diabetic rats.

Chromolaena odorata (L.) R. M. King and H. Robinson Leaves Aqueous Extract Improves the Femoral Head in Ethanol-Induced Osteonecrosis in Rats.

Chronic alcohol consumption damages bone formation and causes bone pathology, including osteonecrosis of the femoral head. The aim of this work was to evaluate the effects of the leaf aqueous extract of Chromolaena odorata (C. odorata) on the femoral head in ethanol-induced osteonecrosis in rats. Animals received alcohol (40°) at 3 g/kg for 12 weeks. A group of animals were sacrificed to attest to the instalment of osteonecrosis by using histopathological analysis. The remaining animals received alcohol concomitantly with the plant extract (150, 300, or 600 mg/kg) or diclofenac (1 mg/kg) for 28 additional days. At the end of the experimental period, biochemical parameters including total cholesterol, triglycerides, calcium, alkaline phosphatase (ALP), reduced glutathione (GSH), malondialdehyde (MDA), nitrite, superoxide dismutase (SOD), and catalase activities were measured. Histopathological and histomorphometry analyses of femurs were also assessed. The administration of alcohol, irrespective of the experimental period, induced a significant increase in total cholesterol (p < 0.05) and triglyceride (p < 0.01) and a decrease in ALP (p < 0.05) and calcium (p < 0.05-p < 0.001) levels. Intoxicated animals showed an alteration in oxidative stress parameters accompanied by a significant drop in bone cortical thickness and density with necrosis and marked bone resorption. The concomitant administration of the plant with ethanol reversed the alcohol-induced bone defect, characterized by the improvement of the lipid profile (p < 0.001), bone calcium concentration (p < 0.05), bone ALP activity (p < 0.001), oxidative stress parameters, improved cortical bone thickness (p < 0.01), and bone density (p < 0.05). These results are supported by the absence of bone resorption with an obvious effect at a dose of 300 mg/kg. The pharmacological effect of the extract on ethanol-induced osteonecrosis of the femoral head is probably due to its osteogenic, hypolipidemic, and antioxidant properties, justifying its use in Cameroonian folk medicine for articulation and bone pain management.

Antiamnesic and Neuroprotective Effects of an Aqueous Extract of Ziziphus jujuba Mill. (Rhamnaceae) on Scopolamine-Induced Cognitive Impairments in Rats.

BACKGROUND: Alzheimer's disease is a neurological condition that affects about 44 million people worldwide. The available treatments target symptoms rather than the underlying causes. Ziziphus jujuba (Rhamnaceae) is widely used in traditional Cameroonian medicine to treat diabetes, pain, infections, and dementia. Previous studies reported that Z. jujuba aqueous macerate improves working memory impairment, but no study on the antiamnesic effect of a concoction of Z. jujuba in rats has been performed. Therefore, this study aimed to assess the antiamnesic and neuroprotective effects of an aqueous extract of Z. jujuba on scopolamine-induced cognitive impairments in rats. METHODS: Learning and memory impairments were induced in rats by administering scopolamine (1 mg/kg, i.p.) to 58 rats for 15 days. Rats that developed learning and memory impairments in Morris water maze and Y-maze paradigms were divided into 7 groups (8 rats each) and treated daily for 15 days as follows: the normal control group received distilled water (10 ml/kg, p.o.), the negative control group received distilled water (10 ml/kg, p.o.), positive control groups either received donepezil (1.2 mg/kg, p.o.) or tacrine (10 mg/kg, p.o.), and the three test groups were given the extract (29, 57, and 114 mg/kg, p.o.). At the end of treatments, learning and memory impairments were determined using the same paradigms. Animals were then euthanized, and biochemical parameters of oxidative stress, inflammation, and apoptosis were analyzed in the hippocampus and prefrontal cortex. RESULTS: On the 4th day of the acquisition phase in the Morris water maze, Z. jujuba (29 and 114 mg/kg) reduced (p < 0.001) the latency to reach the platform, while in the retention phase, Z. jujuba (57 and 114 mg/kg) decreased (p < 0.001) the time to reach the platform and increased the time in the target quadrant (p < 0.05) compared to control. Surprisingly, the extract failed to affect spontaneous alternations in the Y-maze. Furthermore, the extract (29, 57, and 114 mg/kg) reversed (p < 0.001) scopolamine-induced oxidative stress, inflammation, and apoptosis. This was supported by the reduction of neuronal alterations in the hippocampus and prefrontal cortex. CONCLUSIONS: Compared to donepezil, a standard drug against Alzheimer's disease, these findings suggest that Z. jujuba extract possesses antiamnesic and neuroprotective effects, and these effects are mediated in part through antioxidant, anti-inflammatory, and antiapoptotic activities. These findings help to explain its use in treating psychiatric disorders in Cameroon's folk medicine.

Curative effects of the aqueous extract of Tithonia diversifolia (Hemsl.) A. gray (Asteraceae) against ethanol induced-hepatotoxicity in rats.

OBJECTIVES: Tithonia diversifolia (Asteraceae) is used in Cameroonian traditional medicine for the treatment of several diseases amongst which are hepatic disorders. Anti-inflammatory, analgesic and anti-diabetic properties have been reported but, there is no scientific information on its hepato-protective effects. The aim of this study was to evaluate the curative effects of the Tithonia diversifolia (T. diversifolia) leaves aqueous extract on ethanol induced-hepatotoxicity in rats. METHODS: Ethanol 40° (4 g/kg) was administered daily by intragastric gavage for 21 days, and then the extract was administered concomitantly with ethanol for two more weeks. Some biochemical serum and tissue parameters were evaluated. Histopathologic analysis of the liver was carried out. RESULTS: The ingestion of ethanol induced a significant reduction of body weight and a significant increase in some markers of hepatic function (Alanine Amino-transferase, Aspartate Amino-transferase, alkaline phosphatase, gamma glutamyl-transferase, total bilirubin and albumin). These alterations were accompanied by a significant increase in the levels of serum triglycerides (p<0.001). Intoxicated animals were also characterized by a significant decrease of reduced glutathione and nitrites concentrations, catalase and superoxide dismutase activities as well as an increase of malondialdehyde levels. The histopathological examination showed vascular congestion, disorganized parenchyma, liver inflammation and dilation of sinusoid. The extract at the doses of 60 and 120 mg/kg reversed ethanol-induced adverse effects. CONCLUSION: Our study found that, the aqueous extract of T. diversifolia leaves has hepato-protective activity against ethanol-induced liver damages due partly to its antioxidant effect. This result justifies its empirical use for the treatment of liver problems.

In vitro and in vivo antiplasmodial activity of hydroethanolic bark extract of Bridelia atroviridis müll. Arg. (Euphorbiaceae) and lc-ms-based phytochemical analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria is a life-threatening health problem worldwide and treatment remains a major challenge. Natural products from medicinal plants are credible sources for better anti-malarial drugs. AIM OF THE STUDY: This study aimed at assessing the in vitro and in vivo antiplasmodial activities of the hydroethanolic extract of Bridelia atroviridis bark. MATERIALS AND METHODS: The phytochemical characterization of Bridelia atroviridis extract was carried out by High-Performance Liquid Chromatography-Mass spectrometry (HPLC-MS). The cytotoxicity test on Vero cells was carried out using the resazurin-based assay while the in vitro antiplasmodial activity was determined on Plasmodium falciparum (Dd2 strain, chloroquine resistant) using the SYBR green I-based fluorescence assay. The in vivo assay was performed on Plasmodium berghei-infected rats daily treated for 5 days with distilled water (10 mL/kg) for malaria control, 25 mg/kg of chloroquine sulfate for positive control and 50, 100 and 200 mg/kg of B. atroviridis extract for the three test groups. Parasitaemia was daily monitored using 10% giemsa-staining thin blood smears. At the end of the treatment, animals were sacrificed, blood was collected for hematological and biochemical analysis while organs were removed for biochemical and histopathological analyses. RESULTS: The HPLC-MS analysis data of B. atroviridis revealed the presence of bridelionoside D, isomyricitrin, corilagin, myricetin and 5 others compounds not yet identified. Bridelia atroviridis exhibited good in vitro antiplasmodial activity with the IC50 evaluated at 8.08 µg/mL and low cytotoxicity with the median cytotoxic concentration (CC50) higher than 100 µg/mL. B. atroviridis extract significantly reduced the parasitemia (p < 0.05) with an effective dose-50 (ED-50) of 89 mg/kg. B. atroviridis also prevented anemia, leukocytosis and liver and kidneys impairment by decrease of transaminases, ALP, creatinine, uric acid, and triglycerides concentrations. As well, B. atroviridis extract decreased some pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6) levels and significantly improved the anti-inflammatory status (P < 0.01) of infected animals marked by a decrease of IL-10 concentration. These results were further confirmed by the improved of antioxidant status and the quasi-normal microarchitecture of the liver, kidneys and spleen in test groups. Overall, the hydroethanolic bark extract of Bridelia atroviridis demonstrated antimalarial property and justified its use in traditional medicine to manage malaria disease.

Hydroethanolic Extract from Bridelia atroviridis Müll. Arg. Bark Improves Haematological and Biochemical Parameters in Nicotinamide-/Streptozotocin-Induced Diabetic Rats.

Bridelia atroviridis Müll. Arg. (B. atroviridis) is a plant used in Cameroonian traditional medicine to manage diabetes. The effects of hydroethanolic barks extract from B. atroviridis were evaluated on diabetes disorders including hematology, inflammatory, and oxidative stress parameters. The in vitro antioxidant capacity of the hydroethanolic bark extract (70 : 30) was evaluated. Nicotinamide-/streptozotocin-induced diabetic rats were daily treated with the B. atroviridis extract for fifteen days. Glycemia were evaluated every 5 days, insulin sensibility test was performed, and haematological, inflammatory, and oxidative stress parameters were analysed. Histomorphometry of the pancreas was realized. The extract was able to scavenge free radicals in vitro and decrease significantly the blood glucose levels. The treatment resulted in a significant alleviation of insulin resistance, anemia, leukocytopenia, and thrombocytopenia observed in untreated diabetic rats. The extract significantly decreased proinflammatory cytokines TNF-α, IL-1ß, and IL-10. The rate of reduced glutathione was increased in the pancreas, whereas the catalase activity and nitrite concentration were decreased. Diabetic control showed a reduced size of Langerhans islet, whereas the size of islets was large in treated groups. The hydroethanolic extract of B. atroviridis was able to improve glycemia and alleviate haematological and inflammatory parameters disorders observed in diabetic conditions, probably due to its antidiabetic, anti-inflammatory, and antioxidant capacities.

Oxidised palm oil and sucrose induced hyperglycemia in normal rats: effects of Sclerocarya birrea stem barks aqueous extract.

BACKGROUND: Consumption of foods rich in carbohydrates and fats, result in an increase in obesity and consequently type 2 diabetes. The present study was carried out to evaluate the effects of oxidised palm oil and sucrose (SOPO +S) on some metabolic parameters and to investigate the effects of aqueous extract from barks of Sclerocarrya birrea on SOPO + S induced damages. METHODS: During 16 weeks, animals received every day a supplement of oxidised palm oil (10 %) and 10 % sucrose as drinking water). Control rat received standard diet and drinking water without sucrose. At the end of this period, animal presenting intolerance in glucose test and insensitivity to insulin were continuously feed with hypercaloric diet along with the administration of the plant extract (150 or 300 mg/kg) or glibenclamide (10 mg/kg) during three weeks. OGTT was performed; insulin sensitivity was assessed by performing insulin tolerance test and determining insulin sensitivity index (Kitt). Several parameters were evaluated including body weight, abdominal fat mass, blood glucose levels, blood pressure, serum lipid profile, and serum transaminases (ALT and AST). Oxidative parameters were measured by MDA levels, nitrites levels, SOD levels, reduced glutathione content and by enzyme activities of SOD and catalase. RESULTS: Animal receiving a supplement of oxidised palm oil and sucrose showed hyperglycaemia, glucose intolerance, insulin resistance and a significant increase in body weight and abdominal fat mass compared to normal rats. In addition, there was a significant increase of SOD in aorta and heart, nitrites in liver and kidney, malondialdehyde (MDA) in heart, liver and kidney. It was also observed a significant reduction in the activities of the SOD and catalase in liver, kidney and reduced glutathione levels in heart. Concomitant treatment of plant extract with SOPO + S brought glycaemia and blood pressure towards normal value, restored glucose tolerance and insulin sensitivity. The plant extract prevent the increase or decrease in the activity of the enzyme depending to the organ, reduced MDA and nitrites levels. CONCLUSION: These results highlighted the hyperglycaemic and oxidant character of SOPO + S diet and confirm the hypoglycaemic, and antioxidant action of sclerocarya birrea aqueous extract in diabetes.

Ethanol extract of Peperomia pellucida (Piperaceae) promotes fracture healing by an anabolic effect on osteoblasts.

ETHNOPHARMACOLOGICAL RELEVANCE: The whole plant or some part of Peperomia pellucida (L.) HBK is used in some parts of Cameroon as a treatment for fracture healing. AIM OF THE STUDY: To evaluate the effect of ethanolic extracts of Peperomia pellucida (L.), a Cameroonian medicinal plant on bone regeneration following bone and marrow injury, and determine the mode of action. MATERIALS AND METHODS: Ethanol extract of Peperomia pellucida was administered at 100 and 200mg/kg doses orally to adult female Sprague-Dawley rats having a drill hole injury (0.8mm) in the femur diaphysis. Vehicle (gum-acacia in distilled water) was given to the control group. After 12 days of treatment, animals were euthanized and femur bones collected. Confocal microscopy of calcein labeling at the drill hole site was performed to evaluate bone regeneration. 3-D microarchitecture of drill hole site was analyzed by micorocomputed tomography. Osteogenic effects of the extract were evaluated by assessing mineralized nodule formation of bone marrow stromal cells and expression of osteogenic genes (mRNA level of type-1 collagen, bone morphogenetic protein-2 and osteocalcin genes) in the femur. RESULTS: Ethanol extract from Peperomia Pellucida (L.) dose-dependently induced bone regeneration at the fracture site. At 200mg/kg dose, the extract significantly increased mineral deposition compared to controls. The extract also improved microarchitecture of the regenerating bone evident from increased bone volume fraction, trabecular thickness, trabecular number, and decreased trabecular separation and structure model index. In addition, the extract increased the formation of mineralized nodules from the bone marrow stromal cells. Furthermore, the extract induced the expression of osteogenic genes in the femur including type 1 collagen, osteocalcin and BMP-2, compared to control. CONCLUSION: Ethanolic extract of P. pellucid (L.) accelerates fracture repair in rats via stimulatory effects on osteoblast differentiation and mineralization, thereby justifying its traditional use.

Phytoceramides and acylated phytosterol glucosides from Pterospermum acerifolium Willd. seed coat and their osteogenic activity.

Phytochemical investigation of seed coats of Pterospermum acerifolium afforded two phytoceramides (1, 2) and two acylated phytosterol glucosides (3, 4) together with five known compounds (5-9). Their structures were elucidated on the basis of extensive spectroscopic analysis using 1D, 2D NMR and Mass spectrometry. Compounds 1, 2, 3, and 4 were assessed for their osteogenic activity using primary cultures of osteoblasts harvested from neonatal rat calvaria. Among these compounds, 1 and 2 markedly stimulated osteoblast differentiation assessed by alkaline phosphatase production and osteoblast mineralization by alizarin red-S staining.

Evaluation of Cameroonian plants towards experimental bone regeneration.

ETHNOPHARMACOLOGICAL RELEVANCE: Elephantopus mollis, Spilanthes africana, Urena lobata, Momordica multiflora, Asystasia gangetica and Brillantaisia ovariensis are used in Cameroonian traditional medicine for the treatment of bone diseases and fracture repair. The aim of this study was to evaluate the effect of ethanolic extracts of six Cameroonian medicinal plants on bone regeneration following bone and marrow injury. MATERIALS AND METHODS: Ethanol extract of Cameroonian medicinal plants were administered (each extract at 250, 500 and 750mg/kg doses) orally to adult female Sprague-Dawley rats having a drill hole injury (0.8mm) in the femur diaphysis. Vehicle (gum-acacia in distilled water) was given to the control group. After 12 days of treatment, animals were euthanized and femur bones collected. Confocal microscopy of fractured bone was performed to evaluate bone regeneration (calcein labeling). Only active plant extracts were used for further experiments. Thus, callus was analyzed by microcomputed tomography. Osteogenic effects of the extracts were evaluated by assessing mineralized nodules formation of bone marrow stromal cells and osteoblast recruitment at drill hole site by immunohistochemistry. RESULTS: Ethanolic extract of the leaves and twigs of Elephantopus mollis (EM) and whole plant of Spilanthes africana (SA) dose-dependently stimulated bone regeneration at the drill hole site. EM at 250 and 750mg/kg doses and SA at 750mg/kg dose significantly increased mineral deposition compared to controls. Both extracts at 500 and 750mg/kg doses improved microarchitecture of the regenerating bone evident from increased bone volume fraction, trabecular thickness, trabecular number, and decreased trabecular separation and structure model index. EM and SA extracts increased the formation of mineralized nodules from the bone marrow stromal cells. In addition, EM and SA extracts increased osteoblast recruitment at the drill hole site evident from increased Runx-2 positive cells following their treatments compared to control. CONCLUSION: Ethanolic extracts of EM and SA accelerate fracture repair in rats via stimulatory effects on osteoblast differentiation and mineralization, thereby justifying their traditional use.

Acute and chronic anti-inflammatory properties of the stem bark aqueous and methanol extracts of Sclerocarya birrea (Anacardiaceae).

Sclerocarya birrea is used in folk medicine for the treatment of inflammatory disorders. The effect of the stem bark aqueous and methanol extracts of S. birrea (150 or 300 mg/kg) was evaluated on carrageenan-, histamine- or serotonin-induced paw oedema in rats. The methanol extract of S. birrea (300 mg/kg) being the most active, exhibited a maximum inhibition of 75.45 and 55.31% on carrageenan- and histamine-induced inflammation, respectively. When administered at 300 mg/kg, the methanol extract of S. birrea also exhibited 80.68% inhibition on the 10th day and 54.43% inhibition on the 21st day in formalin- or complete Freund's adjuvant (CFA)-induced paw oedema in rats. GSH level was significantly increased (75.14%), while MAD level was significantly decreased (31.22%) in the liver of CFA rats treated with S. birrea (300 mg/kg). The results suggest that the anti-inflammatory activity of the aqueous and methanol extracts of S. birrea is due to the inhibition of histamine and prostaglandin pathways and to its antioxidant activity.