Alzheimer’s disease is first characterised by memory loss related to the central cholinergic system alteration. Available drugs provide symptomatic treatment with known side effects. The present study is aimed to evaluate the properties of Carissa edulis aqueous extract on a Scopolamine mouse model as an attempt to search for new compounds against Alzheimer’s disease-related memory impairment. Memory impairment was induced by administration of 1 mg/kg (i.p.) of Scopolamine for 7 days, and mice were treated with Carissa edulis aqueous extract. Behavioural studies were performed using T-maze and novel object recognition task for assessing learning and memory and open field test for locomotion. Brain acetylcholinesterase enzyme (AChE) activity was measured to evaluate the central cholinergic system. The level of MDA, glutathione, and catalase activity were measured to evaluate the oxidative stress level. Administration of Scopolamine shows a decrease in learning and memory enhancement during behavioural studies. A significant decrease in the time spent in the preferred arm of T-maze, in the time spent in the exploration of the novel object, and in the discrimination index of the familiar object was also observed. The significant impairment of the central cholinergic system was characterised in mice by an increase of AChE activity to 2.55±0.10 mol/min/g with an increase in oxidative stress. Treatment with the different doses of Carissa edulis (62.8, 157, 314, and 628 mg/kg orally administrated) significantly increased the memory of mice in T-maze and novel object recognition tests and also ameliorated locomotion of mice in the open field. Carissa edulis aqueous extract treatment also decreases the AChE activity and brain oxidative stress. It is concluded that administration of Carissa edulis aqueous extract enhances memory of mice by reducing AChE activity and demonstrating antioxidant properties. This could be developed into a novel therapy against memory impairment related to Alzheimer’s disease.

Carissa edulis is a plant used in the management of oxidative stress and inflammatory related disorders such as malaria, rheumatism inflammation, and cardiovascular diseases. The present study evaluates the total phenolic content, antioxidant capacity (DPPH, ABTS, and FRAP), and the bioactive compounds present in the various extracts of C. edulis (HEC, MEC, AEC, and PC). An HPLC analysis determined the different compounds present in the extracts. High concentration of total phenolic content was observed in aqueous and methanolic extracts more than in the hydroethanolic extract though not significantly different. Flavonoids were higher in the hydroethanolic and methanolic extracts, respectively, with 14.84 mg RE/g extract and 12.02 mg RE/g extract. Tannins were also found in large amounts in the same two extracts with 26.76 mg TAE/g extract and 34.67 mg TEE/g extract. The percentage radical scavenging activity DPPH ranged between 58.63% and 94.67% for aqueous extract and for ABTS between 51.39% and 94.12% for the methanolic extract. The highest FRAP was obtained in the methanolic extract (6.73 g AAE/100 g extract). HPLC analysis revealed the presence of quercetin, rutin, and gallic acid in the different extracts. C. edulis represents a potential source of bioactive components with antioxidant capacity.

Psychotria densinervia hydro-ethanolic leaf extract (PHELE) and bark extract (PHEBE) were evaluated for antioxidant, anti-inflammatory, and inhibition of digestive enzymes activities. The antioxidant activity was characterized by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), total phenolic content (TPC), and total flavonoid content (TFC) assays. The anti-inflammatory activity was characterized by protein denaturation and antiproteinase tests, while the inhibition of the enzymes was assessed using α-amylase, α-glucosidase, lipase, and cholesterol esterase activities. PHELE presented low ( ) IC₅₀ (59.09 ± 5.97 μg/ml) for DPPH compared with ascorbic acid (71.78 ± 6.37 μg/ml) and PHEBE (115.40 ± 1.21 μg/ml). The IC₅₀ of PHELE (262.4 ± 4.46 μg/ml) and PHEBE (354.2 ± 1.97 μg/ml) was higher ( ) than that of catechin (33.48 ± 2.02 μg/ml) for ABTS. PHELE had high ( ) FRAP (341.73 ± 21.70 mg CE/g) than PHEBE (150.30 ± 0.32 mg CE/g). PHELE presented ( ) high TPC (270.05 ± 7.53 mg CE/g) and TFC (23.43 ± 0.032 mg CE/g) than PHEBE (TPC: 138.89 ± 0.91 and TFC: 20.06 ± 0.032 mg CE/g). PHELE showed antiprotein denaturation with IC₅₀ (257.0 ± 7.51 μg/ml) ( ) and antiproteinase activity (74.37 ± 1.10 μg/ml) lower than PHEBE (316.1 ± 6.02 μg/ml and 177.6 ± 0.50 μg/ml), respectively. Orlistat inhibited lipase ( ) activity with IC₅₀ (37.11 ± 4.39 μg/ml) lower than PHELE and PHEBE (50.57 ± 2.89 μg/ml and 62.88 ± 1.74 μg/ml, respectively). PHELE inhibited cholesterol esterase with IC₅₀ (34.75 ± 3.87 μg/ml) lower than orlistat (54.61 ± 2.56) and PHEBE (80.14 ± 1.71 μg/ml). PHELE inhibited α-amylase IC₅₀ (6.07 ± 4.05 μg/ml) lower than PHEBE (19.69 ± 6.27 μg/ml) and acarbose (20.01 ± 2.84 μg/ml). Acarbose inhibited α-glucosidase ( ) activity with IC₅₀ (4.11 ± 3.47 μg/ml) lower than PHELE (24.41 ± 2.84 μg/ml) and PHEBE (38.81 ± 2.46 μg/ml). PHELE presented better antioxidant, anti-inflammatory, and enzyme inhibition activity than PHEBE.

Background. Cafeteria diet is known to induce excessive body fat accumulation (obesity) that could cause metabolic and cardiovascular changes and even death. The increase in prevalence over time and the failure in treatment options make obesity a real public health problem. The present study assessed the preventive effect of the hydro-ethanolic extract of the Piper nigrum leaf on the development of metabolic and cardiovascular changes in cafeteria diet fed Wistar rats. Methods. Thirty-six male rats were divided into 5 groups of 6 rats each: a normal control group (Nor.), a negative control group (Neg.), two groups administered different doses of extract in mg/kg (E250 and E500), and a group administered atorvastatin 10mg/kg (Ator., reference drug). The animals were fed with experimental diets (standard and cafeteria) for a period of 5 weeks. Food and water intake were assessed daily, and the body weight assessed weekly. At the end of the feeding, plasma lipid profile and markers of hepatic and renal function were assessed. Furthermore, the relative weights of the adipose tissue and the organs were assessed. The liver, kidneys, and heart homogenates were assessed for markers of oxidative stress while the aorta was histopathologically examined. Results. Cafeteria diet-induced weight gain of 30 and increased triglyceride, total cholesterol, and low-density lipoprotein cholesterol level of more than 50. Equally, an increase in the relative weight of accumulated adipose tissues of more than 90, oxidative stress, and alteration in the organ structure were visible in cafeteria diet fed rats (Neg). Treatment with P. nigrum extract significantly prevented weight gain, dyslipidemia, oxidative stress, and alteration in the architecture of the aorta. The effect of P. nigrum extract was comparable to that of the reference drug. Conclusion. Piper nigrum leaf may prevent weight gain and possess cardioprotective activity with a strong antioxidant activity.

Antiretroviral therapy (ART) has revolutionized the lives of people living with HIV/AIDS by overall improving their quality of life and increasing life expectancy. However, ART-associated hepatotoxicity and metabolic disorders in HIV/AIDS patients are growing concerns to clinicians, especially due to the long-term use of the drugs. This study reported on the phytochemical and pharmacological profile of hydroethanolic extracts of Piper nigrum stem (PNS) and evaluated its protective effect against tenofovir/lamivudine/efavirenz (TLE)-induced hepatotoxicity and dyslipidemia in Wistar rats. Cytotoxic, antioxidant, and anti-inflammatory assays were performed on PNS. Thirty-six rats divided into 6 groups of 6 animals/group were administered: distilled water, 17 mg/kg TLE, 17 mg/kg TLE and 100 mg/kg silymarin, 17 mg/kg TLE, and Piper extract (200 mg/kg, 400 mg/kg, or 800 mg/kg) orally for 28 days. The body weight of animals was recorded every 7 days. On Day 29, the rats were sacrificed, and blood samples were collected for hematological and biochemical tests. Portions of the liver and kidneys were collected for histological evaluation, while liver homogenates were prepared from the rest to measure antioxidant enzymes. PNS possessed in vitro cytotoxic, antioxidant, and anti-inflammatory activities. A significant decrease in the body weight of rats treated with PNS was observed. A significant high platelet count was observed in the PNS800 mg/kg group. A considerable decrease in alkaline phosphatase and triglycerides was observed in the silymarin and PNS group compared to the TLE-only group. The findings also show a significant increase in catalase and glutathione in the TLE-only group compared to the normal group, while SOD decreased. Histological observations revealed normal hepatic and renal tissues in the silymarin, and PNS-treated groups compared to the normal control, while leucocyte infiltration was observed in the TLE-only group. These results suggest that PNS extract possessed antioxidant activity that alleviated TLE-induced toxicity. Further studies are necessary to understand the pharmacokinetic interactions between ART and PNS.

This study reports the extraction of phenolic compound from shells and kernels of the Raphia farinifera fruit and the biological activities of the extract. A face-centered composite design was established to optimize the extraction conditions: ethanol/water ratio (0-100%), solvent/powder ratio (10-30 mL/g), and extraction time (90-180 min). Subsequently, the extracts obtained under the optimal conditions were used for the evaluation of the radical scavenging capacity, the capacity to chelate ferric ions, and the antimicrobial and anti-inflammatory activities. The optimal extraction conditions for the shells are an extraction time of 134.24 min, 65% ethanol in water, and a solvent/substrate ratio of 21.16 mL/g, and for the kernel, an extraction time of 180 min, 94.3% ethanol in water, and a solvent/substrate ratio of 18.6 mL/g. In these conditions, the phenolic compounds were 95.36 mg EAG/L for the shell extract and 139.72 mg EAG/L for the kernel extract. The antioxidant activity revealed that the half-maximal inhibitory concentrations (IC₅₀) of the kernel extracts are 22.32 μg/mL and 55.73 g/mL for the shells. A reducing activity of Fe ³⁺ ions with an activity of 308.39 μg EAA/mg for the kernel extracts and 293 μg EAA/mg for the shells was observed. B. cereus was the most sensitive microorganism with a minimum inhibitory concentration (MIC) equal to the minimum bactericidal concentration (MBC) with a value of 156.25 ppm for the kernel extract while the shell extract showed MIC of 625 ppm and MBC of 2500 ppm. The IC₅₀ values for the denaturation of proteins by extracts of shells and kernels are 0.76 μg/mL and 0.56 g/mL, respectively. Membrane stabilization revealed IC₅₀ values of 1054.54 g/mL and 1339 g/mL for the shell and kernel extracts, respectively. This work has shown the potential of Raphia farinifera extracts for the food industry and cosmetics.