Antidiabetic potential of methanol extracts from leaves of Piper umbellatum L. and Persea americana Mill

Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana) (traditionally used in Cameroon against diabetes) on α-glucosidase, β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC

In vivo anti-salmonella activity of aqueous extract of Euphorbia prostrata Aiton (Euphorbiaceae) and its toxicological evaluation

OBJECTIVE: To investigate the in vivo anti-salmonella activity and the safety of aqueous extract of Euphorbia prostratra (E. prostratra), a plant commonly used in Cameroon by traditional healers. METHODS: A Salmonella typhimurium-infected rat model was used for the study. The physiological, biochemical and histopathological markers of possible side effects of this extract were studied using standard methods. RESULTS: The extract had a significant effect on the number of viable Salmonella typhimurium recovered from faeces, and could stop salmonellosis after 8 and 10 days of treatment for male and female rats, respectively, with non-toxic doses. However, the biochemical and histopathological analyses revealed that at relatively high doses (≥ 73.48 mg/kg for female and ≥ 122.71 mg/kg for male) the extract could induce liver damage, as illustrated by a rise of serum transaminases' levels and significant inflammation of the parenchyma and portal vein. Side effects were also observed on the kidneys, as shown by both serum and urinary creatinine, and urinary proteins. CONCLUSIONS: The overall results indicate that the aqueous extract of E. prostrata has the potential to provide an effective treatment for salmonellosis, including typhoid fever. However, it is necessary to extrapolate these results in large animals, in further studies.

Antidermatophytic and toxicological evaluations of dichloromethane-methanol extract, fractions and compounds isolated from Coula edulis

Coula edulis Bail [Olacaceae], is an evergreen tree growing to a height of 25-38 m. This study aimed at evaluating the antidermatophytic and toxicological properties of the stem bark of C. edulis extract as well as fractions and compounds isolated from it. The plant extract was prepared by maceration in CH[2]Cl[2]-MeOH [1:1 v/v]. The fractionation of this extract was done by silica gel column chromatography. Antidermatophytic activities were assayed using agar dilution method. The acute and sub-acute toxicities of oral administrations of the extract were studied in rodents. The crude extract of C. edulis displayed antidermatophytic activity against the tested microorganisms with highest activity against Microsporum audouinii and Trichophyton mentagrophytes. The fractionation enhanced the antidermatophytic activity in fraction F[3] [MIC=0.62-1.25 mg/ml] compared to the crude extract [MIC=1.25-5 mg/ml]. Further fractionation and purification of the fractions F[2] and F[3] gave respectively 3-O- beta -D-glucopyranoside of sitosterol [MIC=0.20-0.40 mg/ml] and a mixture of beta -sitosterol, stigmasterol and n-hexadecanoid acid [MIC=0.80 mg/ml]. The median lethal doses [LD[50]] of the crude extract were 16.8 and 19.6 g/kg body weight [BW] in male and female mice, respectively. At 200 mg/kg BW, there was a decrease in body weight gain, food and water consumptions. Gross anatomical analysis revealed white vesicles on the liver of the rats treated with the extract at 200 mg/kg BW. This dose also induced significant [P<0.05] changes on hematological and biochemical parameters in rats after 28 days of treatment. These data suggest that the CH[2]Cl[2]-MeOH [1:1 v/v] extract of C. edulis stem bark possesses antidermatophytic properties. They also show that at high doses [>/= 200 mg/kg BW], the extract has significant hepatotoxic and nephrotoxic activities

Antibacterial agents from the seeds of Peucedanum zenkeri L. [Umbelliferae]

In a search for natural substances with potential for the treatment of typhoid fevers and urogenital infections, the methylene chloride extract of the seeds of Peucedanum zenkeri was investigated. The extract was subjected to column chromatography leading to the isolation of seven compounds. Their structures were determined using modern 2D NMR techniques and by comparison with published NMR data. These compounds were tested against Salmonella typhi, Salmonella paratyphi B, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus, using both agar diffusion and broth dilution techniques. The compounds isolated were umbelliprenin [1], prangenin [2], imperatorin [3], isopimpinellin [4], bergapten [5], cnidilin [6] and stigmasterol [7]. Among the above seven compounds, only two [1 and 2] exhibited antibacterial activity. For compound 1, the MIC value was 300 micro g/ml against P. aeruginosa, S. aureus, S. typhi and S. paratyphi B. For compound 2, the MIC values varied between 200 and 300 micro g/ml against all the bacteria strains tested. These data suggest that Peucedanum zenkeri seed extract contains antibacterial agents which are active against Salmonella species causing typhoid and paratyphoid fevers, and some bacteria strains causing urogenital infections. The antibacterial activity of compound 2 appears to be due to the epoxide group present in its structure