The Aqueous Extract from the Stem Bark of Garcinia lucida Vesque (Clusiaceae) Exhibits Cardioprotective and Nephroprotective Effects in Adenine-Induced Chronic Kidney Disease in Rats.

Chronic kidney disease (CKD) is a serious health problem with high morbidity and mortality, mainly attributable to cardiovascular risk. Garcinia lucida is traditionally used in Cameroon for the management of cardiovascular diseases. The aim of this study was to evaluate the cardioprotective and nephroprotective effects of the aqueous extract from the stem bark of G. lucida (AEGL). The in vitro antioxidant effect of AEGL was assessed at concentrations ranging 1-300 µg/mL against DPPH, lipid peroxidation, and AAPH-induced hemolysis. The reducing power and phenolic and flavonoids contents were also determined. CKD was induced by intraperitoneal bolus injection of adenine (50 mg/kg/day) for 4 consecutive weeks to male Wistar rats. AEGL (150 and 300 mg/kg/day) or captopril (20 mg/kg/day) was concomitantly administered with adenine per os. Bodyweight and blood pressure were monitored at baseline and weekly during the test. At the end of the experiment, plasma creatinine, urea, AST, and ALT were quantified. Proteinuria, creatinine excretion, and creatinine clearance were also assessed. The effect on GSH, CAT, and SOD activity was evaluated in cardiac and renal homogenates. Sections of the heart and kidney were stained with hematoxylin and eosin. AEGL exhibited a potent in vitro antioxidant activity and was shown to possess a large amount of phenolic compounds. Adenine alone increased blood pressure, cardiac and kidney mass, proteinuria, protein to creatinine ratio, plasma creatinine, AST, and urea levels (p < 0.05, 0.01, and 0.001). Besides, the bodyweight and creatinine clearance were significantly reduced (p < 0.05 and p < 0.01). All these alterations were blunted by the plant extract, except the bodyweight loss. In addition, AEGL improved GSH levels and CAT and SOD activities. AEGL attenuated adenine-induced glomerular necrosis, tubular dilatation, and cardiac inflammation. AEGL exhibits cardioprotective and nephroprotective effects that may be ascribed to its antihypertensive and antioxidant activities.

Medicinal Uses and Natural Availability of Three Plant Species in Selected Ecosystems in Cameroon.

In many developing countries traditional medicine constitutes a major part of health care because of its local availability and affordability compared to modern medicine. However, little is known about the specific uses and availability of medicinal plants. In this research an exploratory study was conducted to determine the uses of three medicinal plants in Cameroon, and to examine their relative distribution and abundance in specific habitats. From a questionnaire administered to traditional healers, we and found that three species of medicinal plants including: Alstonia boonei, Picralima nitida and Sarcocephalus latifolius that are commonly used, either singly or in mixtures to treat human diseases such as muscle and joints pains, hyperthermia, hypertension, hepatitis, jaundice and rheumatism. Fresh or dry barks of the tree plants and fresh fruits of Picralima nitida, as well as various ethnopharmacological preparations (decoctions, maceration, infusion and powder) are widely commercialized. Findings from our ecological study revealed that Alstonia boonei was represented by 2, or 1 % of total individuals recorded in 0.5 ha, implying 3 individuals and 6 trees/ha. This tree was well represented and was sometime among the forests. Picralima nitida was represented by 0.6 % of total trees recorded in 0.5 ha, implying 0.70 tree and 1 tree/ha. This tree was poorly represented and was not a dominant species in its habitats. Sarcocephalus latifolius belonged to a group of 72 plants with a recovery < 5% corresponding to Braun- Blanquet scale1. Hence, this plant was not densely represented in the Sudono-Guinean and Sahelian savannahs. It is the most harvested species of the three species that has undergone a strong anthropogenic destruction. Therefore these three plants, and especially Sarcocephalus latifolius, need to be protected through a sustainable management of their habitats in Cameroon.

In vitro anti-hyperglycemic and antioxidant properties of extracts from the stem bark of Ceiba pentandra.

BACKGROUND: The goal of the study was to determine the antidiabetic mechanisms and the antioxidant effects of aqueous (decoction and maceration) and methanol extracts from the stem bark of Ceiba pentandra. METHODS: These extracts were tested in vitro on glucose uptake by skeletal muscles and liver slices and on glucose release by liver slices. The antioxidant activities of C. pentandra extracts were investigated at concentrations ranging from 1 to 300 µg/mL on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2)-induced hemolysis, H2O2-induced brain lipid peroxidation, hydroxyl (˙OH) radical as well as their reducing power. RESULTS: The decoction similarly to insulin exhibited a significant glucose lowering activity. In a hyperglycemic milieu, it significantly increased glucose uptake by the liver by 56.57% and in the skeletal muscle by 94.19%. In a hypoglycemic milieu, it significantly reduced glucose release by the liver by 33.94%. The decoction, maceration and methanol extracts exhibited a significant radical scavenging activity on DPPH with respective EC50 of 87.84, 54.77 and 6.15 µg/mL versus 2.24 µg/mL observed with ascorbic acid. All the extracts showed a significant antioxidant effect on hydroxyl radical, against lipid peroxidation and H2O2-induced hemolysis. The decoction showed the greatest antihemolytic effect with a maximum inhibition of 77.57% at the concentration of 100 µg/mL. C. pentandra extracts also showed a concentration-dependent reducing power. CONCLUSIONS: These results suggest that the antidiabetic effect of C. pentandra is due to its ability to increase glucose uptake and to reduce glucose release by target organs. The antioxidant properties of C. pentandra extracts are additional benefit for their antidiabetic effects.

In vitro antiplasmodial activities and synergistic combinations of differential solvent extracts of the polyherbal product, Nefang.

Nefang, a polyherbal product composed of Mangifera indica (bark and leaf), Psidium guajava, Carica papaya, Cymbopogon citratus, Citrus sinensis, and Ocimum gratissimum (leaves), is a potential therapy against P. falciparum malaria. In vitro antiplasmodial activities of its constituent solvent extracts were analyzed on CQ-sensitive (3D7) and multidrug resistant (Dd2) P. falciparum strains. The interactions involving the differential solvent extracts were further analyzed using a variable potency ratio drug combination approach. Effective concentration 50 (EC50) values were determined by nonlinear regression curve-fitting of the dose-response data and used in calculating the fractional inhibitory concentration 50 (FIC50) and combination indices (CI) for each pair. The derived EC50 values (3D7/Dd2, µ g/mL) are Nefang-96.96/55.08, MiB-65.33/34.58, MiL-82.56/40.04, Pg-47.02/25.79, Cp-1188/317.5, Cc-723.3/141, Cs-184.4/105.1, and Og-778.5/118.9. Synergism was obtained with MiB/Pg (CI = 0.351), MiL/Pg (0.358), MiB/Cs (0.366), MiL/Cs (0.482), Pg/Cs (0.483), and Cs/Og (0.414) when analyzed at equipotency ratios. Cytotoxicity testing of Nefang and the solvent extracts on two human cell lines (Hep G2 and U2OS) revealed no significant toxicity relative to their antiplasmodial activities (SI > 20). Taken together, our data confirm the antimalarial activities of Nefang and its constituent plant extracts and identified extract pairs with promising synergistic interactions for exploitation towards a rational phytotherapeutic and evidence-based antimalarial drug discovery.