DPPH antiradical scavenging, anthelmintic and phytochemical studies of Cissus poulnea rhizomes

Objective: To investigate the phytochemical constituents, antioxidant and anthelmintic activities of the crude methanol extract of Cissus populnea (C. populnea) rhizomes. Methods: Phytochemical screening was performed using standard protocols, and column chromatography of silica gel was used for the compounds isolation. DPPH antiradical scavenging assay was performed in order to evaluate the antioxidant activity. Total phenolic content was evaluated using the Folin-Ciocalteu assay. The anthelmintic activity was screened on the bovine adult male forms of parasitic nematode Onchocerca ochengi, by the in vitro evaluation of the inhibition of adult worm motility and mortality. Worms were incubated in the presence of different concentrations of the plant extract and effects on survival were monitored after 24 and 48 h. Results: The preliminary phytochemical screening revealed the presence of phenolic compounds, saponins, steroids, tannins, and terpenoids. Bergenin and a mixture of phytosterol, β -sitosterol and stigmasterol were isolated from this extract and were identified by nuclear magnetic resonance, mass spectrometry and by comparison with published data. The crude methanol extract of C. populnea rhizomes showed a strong DPPH antiradical activity with a good amount of total phenolic content ((20.69±2.13) g gallic acid equivalent/100 g of extract) and significant anthelmintic activity comparable to the standard drug ivermectin. Bergenin was found to be inactive even after 72 h of incubation. Conclusions: This study constitutes the first report on the anthelmintic activity of this plant and supports the traditional use of C. populnea as a natural antioxidant and anthelmintic.

DPPH antiradical scavenging, anthelmintic and phytochemical studies of Cissus poulnea rhizomes

Objective:To investigate the phytochemical constituents, antioxidant and anthelmintic activities of the crude methanol extract of Cissus populnea (C. populnea) rhizomes.Methods:Phytochemical screening was performed using standard protocols, and column chromatography of silica gel was used for the compounds isolation. DPPH antiradical scavenging assay was performed in order to evaluate the antioxidant activity. Total phenolic content was evaluated using the Folin–Ciocalteu assay. The anthelmintic activity was screened on the bovine adult male forms of parasitic nematode Onchocerca ochengi, by the in vitro evaluation of the inhibition of adult worm motility and mortality. Worms were incubated in the presence of different concentrations of the plant extract and effects on survival were monitored after 24 and 48 h.Results:The preliminary phytochemical screening revealed the presence of phenolic compounds, saponins, steroids, tannins, and terpenoids. Bergenin and a mixture of phytosterol, β -sitosterol and stigmasterol were isolated from this extract and were identified by nuclear magnetic resonance, mass spectrometry and by comparison with published data. The crude methanol extract of C. populnea rhizomes showed a strong DPPH antiradical activity with a good amount of total phenolic content ((20.69±2.13) g gallic acid equivalent/100 g of extract) and significant anthelmintic activity comparable to the standard drug ivermectin. Bergenin was found to be inactive even after 72 h of incubation.Conclusions:This study constitutes the first report on the anthelmintic activity of this plant and supports the traditional use of C. populnea as a natural antioxidant and anthelmintic.

Anti-convulsivant and sedative like-effect of Abyssinone V-4’ methyl ether Isolated from Erythrina droogmansiana (Leguminosae).

Erythrina droogmansiana is used in traditional medicine in Cameroon to treat epilepsy, insomnia and headaches. From this plant, many secondary metabolites are extracted including alcaloids, tannins, flavonoids, etc. Amongst the flavonoid, abyssinone V-4’ methyl ether is used in this manipulation. Animal models of epilepsy: pentylenetetrazol (PTZ), picrotoxine (PIC) and pilocarpine (PILO)-induced convulsions or turning behavior were used to evaluate anticonvulsant activity while diazepam-induced sleep test was used to evaluate sedative activity of the extract. Four doses of extracts were used for each group test (12.5, 25, 50 and 100 mg/kg). Abyssinone V-4' methyl ether protected 100% of mice against the convulsions induced by the pentylenetetrazole at the dose of 100 mg/kg. Abyssinone V-4’ methyl ether protected 100% of mice at the doses of 25 and 100 mg/kg and 80% at the doses of 12.5 and 50 mg/kg against generalized convulsions induced by picrotoxine. This flavonoid protected 100% of mice at the doses 25 and 50 mg/kg and 80% at the doses of 12.5 mg/kg against generalized convulsions induced by pilocarpine. Moreover, for the test of induction of convulsions by pilocarpine, Abyssinone V-4’ methyl ether protected 100% of mice at doses of 25 and 50 mg/kg and 71.43% at the doses of 12.5 and 100 mg/kg against death after 1h and 24h respectively. Abyssinone V-4’ methyl ether has anticonvulsivant properties and not sedative properties. These results explain the use of Erythrina droogmansiana to treat epilepsy.

Pentacyclic triterpenes and crude extracts with antimicrobial activity from Cameroonian brown propolis samples.

The aim of this study was to isolate compounds from Cameroonian propolis extracts and to test their activities against bacteria isolated from carcass at the Yaoundé slaughterhouse. The n-hexane, ethyl acetate and ethanol extracts of propolis samples from Ngaoundal and Tala-Mokolo were separated by successive silica gel column chromatography to give six triterpenes. Their structures were determined as 25-cyclopropyl-3β-hydroxyurs-12- ene (7), cycloart-3β-hydroxy-12, 25(26)-diene (8), lup-20(29)-en-3-one (9), olean-12-en-3β, 28-diol (10), lup- 20(29)-en-3β-oate (13) and 3β-hydroxylup-20(29)-ene (14). Compounds 7 and 8 were new triterpene derivatives while 10 and 13 were isolated for the first time from propolis. The structures of all the compounds were established on the basis of spectroscopic analysis. Phytochemical screening of the methanol extract (5) revealed the presence of alkaloids, reducing compounds, coumarins, saponins and tannins accounting for its broad spectrum antibacterial activities. The six isolated compounds and crude extracts were tested for antimicrobial activity against some Gram negative bacteria. The methanol extract (5) of propolis samples was active against Escherichia coli and Pseudomonas aeruginosa (MIC: 0.2 mg/ml) whereas the isolated compounds 7, 8 and 10 exclusively exhibited antimicrobial activity against Salmonellas pp (MIC: 0.1-0.15 mg/ml). The MIC values of all the four propolis products were greater than that of the standard drug (Amoxicillin): 0.1-0.2 mg/ml versus 0.4 mg/ml. Nevertheless, further pharmacological and toxicity studies on experimental animals are necessary to establish the safety of the propolis products for its use as topical antimicrobial agents.

Antimicrobial Activity of Phenylpropanoyle from the Rhizome of Zingiber officinale Roscoe (Zingiberaceae).

Aim: This study was carried out to determine the phytochemical and the antimicrobial activities of Zingiber officinale (Zingiberaceae) Rhizome. Methodology: The air-dried and powdered rhizome (1.0 kg) of Z. officinale was extracted with ethyl acetate (1.5 L) at room temperature for 72 h. After evaporation under reduced pressure, 46.5 g of crude extract was obtained. The CH2Cl2 extract was purified by column chromatography over silica gel 60 (230-400 mesh) and preparative TLC using a gradient system of hexane, ethyl acetate and MeOH. Agar diffusion test plates with Escherichia coli CIP 548, Listeria monocytogenes CIP 82110, Enterococcus faecalis CIP 76117, Bacillus cereus CIP 6624, Staphylococcus aureus CIP 7625, Pseudomonas fluorescents CIP 6913, Bacillus substilis ATCC 6636, Candida lusitaniae ATCC 200950, Candida tropicalis ATCC 750, Cryptococcus neoformans CIP 95026, Aspergillus flavus, and Aspergillus parasiticus as test strains were performed. Results: A new nonyl-3-phenylpropanoate (1), together with known compounds, 8- hepthyl-12- propyldecanol (2) were isolated from the ethyl acetate extract of the rhizome of Zingiber officinale. The structures of the two compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral data, chemical reactions, and comparison with previously known analogue. The two compounds isolated from ethyl acetate extract showed antibacterial and antifungal activity and the Minimal Inhibitory Concentration (MIC) against the test fungi varied from 3.34 mM to 5.08 mM for compound 1 and from 3.81 mM to 5.08 mM for compound 2. Conclusion: One new compound, nonyl-3-phenylpropanoate, isolated from ethyl acetate extract of Zingiber officinale rhizome exhibited antibacterial and antifungal activities.