Comparative analysis of the phytochemical and antibacterial activity of the root extracts of Euphorbia heterophylla and Vitellaria paradoxa

Background: Over time, herbal plants and their various components have been major sources of therapeutic medicine for man. A comparative study was carried out to determine the phytochemical components and antibacterial activities of the different crude extracts of Euphorbia heterophylla and Vitellaria paradoxa roots on four enteric bacteria; Salmonella typhi, Shigella flexneri, Escherichia coli and Proteus vulgaris. Methodology: Root samples of E. heterophylla and V. paradoxa were collected, washed, air dried and processed to fine powder in the microbiology laboratory of Federal University of Technology, Minna, Nigeria. Crude extract of the root samples was done by the cold maceration technique using four solvents (chloroform, methanol, petroleum ether and water). Phytochemical analysis of the extracts was done using previously described technique, and in vitro antibacterial activities of different concentrations of the extracts (50-200 mg/ml) and a standard antibiotic (ciprofloxacin) were tested on four enteric bacteria (S. typhi, S. flexneri, E. coli, P. vulgaris) by the agar diffusion test. In vivo antibacterial activities of the two plants were also tested by daily oral administration of 2000 mg/kg bodyweight (for 7 days) of each extract on inbred mice infected through intraperitoneal inoculation of an infective dose of each of the four enteric bacteria. Data were computed as mean ± standard error and analysed by the Statistical Analysis System (SAS) version 9.4. Associations between variables were determined using analysis of variance (ANOVA), with p < 0.05 considered as significant value. Results: Phytochemical analysis of the crude extracts of both plants revealed the presence of cardiac glycosides, saponins, alkaloids, flavonoids, and tannins but V. paradoxa contain more carbohydrates and starch, and less phlobatannins, compared to E. heterophylla. In vitro assay showed dose-dependent antibacterial activity of the methanol, aqueous and chloroform (but not petroleum ether) extracts of the two plant roots. The in vitro antibacterial activities of the different extracts of V. paradoxica extracts were significantly higher (higher mean diameters of inhibition zones) than those of E. heterophylla (p<0.05), and methanol extracts gave the highest antibacterial effects. However, the root extract of E. heterophylla gave a higher antibacterial activity with the in vivo assay on inbred mice than V. paradoxa, and methanol extracts of the two plant extracts gave the highest in vivo activity, followed by aqueous extract and least activity was obtained with the chloroform extract. Conclusion: Crude extracts of E. heterophylla and V. paradoxa roots produce antibacterial activity against enteric Gram-negative bacteria pathogens involved in diarrhoea illnesses. Further researches should be directed towards isolation and characterization of the active compounds in the crude extracts.

Vitellaria paradoxa nutshells from seven sub-Saharan countries as potential herbal medicines for treating diabetes based on chemical compositions, HPLC fingerprints and bioactivity evaluation / 中国天然药物

The aim of the study was to determine the feasibility of the Vitellaria paradoxa nutshell as a new medicinal resource for treating diabetes. A total of forty-one compounds were identified by HPLC-DAD-Q-TOF-MS and phytochemical methods in V. paradoxa nutshell methanol extract. Based on HPLC fingerprints, four characteristic constituents were quantified and the origin of twenty-eight V. paradoxa nutshells from seven sub-Saharan countries was compared, which were classified into three groups with chemometric method. Twenty-eight samples contained high total phenolic content, and exhibited moderate-higher antioxidant activity and strong α-glucosidase inhibitory activity. Furthermore, all fractions and isolated compounds were evaluated for their antioxidant and α-glucosidase inhibitory activities, and α-glucosidase inhibitory action mechanism of four characteristic constituents including protocatechuic acid, 3, 5, 7-trihydroxycoumarin, (2R, 3R)-(+)-taxifolin and quercetin was investigated via molecular docking method, which were all stabilized by hydrogen bonds with α-glucosidase. The study provided an effective approach to waste utilization of V. paradoxa nutshell, which would help to resolve waste environmental pollution and provide a basis for developing potential herbal resource for treating diabetes.

Total phenolic contents and bioactivities of defatted Vitellaria paradoxa kernels from different origin / 中国药科大学学报

@#Total phenolic contents, antioxidant, cytotoxic and Epstein-Barr virus early antigen(EBV-EA)inhibitory activities of twenty-six methanol extracts from defatted Vitellaria paradoxa kernel at different sites were investigated. Furthermore, the correlation between total phenolic contents and bioactivities was discussed. The total phenolic contents were determined spectrometrically and antioxidant activities were evaluated by 1, 1-diphenyl-2-picrylhydrazyl(DPPH), 2, 2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid(ABTS)radical scavenging activity and ferric-reducing antioxidant power(FRAP)methods. The cytotoxic activities against human leukemia HL60 cells, lung cancer A549 cells and breast cancer SK-BR-3 cells were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide(MTT)assay and the inhibitory effect on EBV-EA was assayed by the indirect immunofluorescence technique. Results showed that the total phenolic contents of twenty-six methanol extracts were different(25. 8 - 265. 7 mg GAE/g DW). In addition, some of the extracts had potent antioxidant activities(DPPH: IC50 3. 4 - 54. 9 μg/mL, ABTS: 1. 11- 4. 09 mmol TE/g, FRAP: 1. 24 - 1. 93 mmol TE/g), toxicities against one or more of HL60, A549 and SK-BR-3 cells(IC50 25. 1- 95. 5 μg/mL)and inhibitory effect on EBV-EA(85. 8%- 94. 9% at 100 μg/mL). A significant correlation was observed between total phenolic contents and antioxidant activities(r=0. 750-0. 837, P< 0. 01).