Antioxidant activity of extracts from six different Sudanese plant materials

Hydrolyzable tannins (ellagitannins), flavonoids, pentacyclic triterpenes and their glycosides in antimycobacterial extracts of the ethnopharmacologically selected Sudanese medicinal plant Combretum hartmannianum Schweinf

In Sudanese traditional medicine, decoctions, macerations, and tonics of the stem and root of Combretum hartmannianum are used for the treatment of persistent cough, a symptom that could be related to tuberculosis (TB). To verify these traditional uses, extracts from the stem wood, stem bark, and roots of C. hartmannianum were screened for their growth inhibitory effects against Mycobacterium smegmatis ATCC 14468. Methanol Soxhlet and ethyl acetate extracts of the root gave the strongest effects (MIC 312.5 and 625 µg/ml, respectively). HPLC-UV/DAD and UHPLC/QTOF-MS analysis of the ethyl acetate extract of the root led to the detection of 54 compounds, of which most were polyphenols and many characterized for the first time in C. hartmannianum. Among the major compounds were terflavin B and its two isomers, castalagin, corilagin, tellimagrandin I and its derivative, (S)-flavogallonic acid dilactone, punicalagin, and methyl-ellagic acid xylopyranoside. In addition, di-, tri- and tetra-galloyl glucose, combregenin, terminolic acid, cordifoliside D, luteolin, and quercetin-3-O-galactoside-7-O-rhamnoside-(2→1)-O-β-D-arabinopyranoside were characterized. Luteolin gave better growth inhibition against M. smegmatis (MIC 250 µg/ml) than corilagin, ellagic acid, and gallic acid (MIC 500-1000 µg/ml). Our study justifies the use of C. hartmannianum in Sudanese folk medicine against prolonged cough that could be related to TB infection. This study demonstrates that C. hartmannianum should be explored further for new anti-TB drug scaffolds and antibiotic adjuvants.

Characterization of thermo-oxidative behavior of ethylcellulose oleogels

The thermo-oxidative behavior crucial to the applicability of ethylcellulose (EC) oleogels is characterized. Not only did we take into account the composition of the gel network in relation to textural attributes, but also the dynamic chemical changes occurred during formation, heating, and holding of the gels. EC oleogel oxidative stability showed that at 6.0% EC100 concentration in the oleogels the movement of liquid oil trapped in the gel network was hindered by its high viscosity and stable gel network, thus retarding oxidation. Processing temperature ≤ 120 °C for <2 h was recommended when incorporated in food systems to minimize oxidation. As for the measurement of oxidative stability in general, p-AnV was found suitable in depicting oxidation of EC oleogels. Meanwhile, both R_ao and R_ad acquired from ¹H NMR spectra could serve as reliable oxidative indicators to gauge total oxidation of EC oleogels during storage.

Microwave-assisted extraction for recovery of polyphenolic antioxidants from ripe mango (Mangifera indica L.) peel using lactic acid/sodium acetate deep eutectic mixtures

The present study investigates recovery of polyphenolic compounds from ripe mango ( Mangifera indica L.) peel using deep eutectic solvents based on microwave-assisted extraction method. Lactic acid/sodium acetate/water (3:1:4) screened out from eight different types of deep eutectic solvent systems was used as extractant. A Box–Behnken design along with response surface methodology was applied to optimize the effect of microwave power (W), time (min), and liquid-to-solid ratio (mL g−1) on polyphenol extraction. The optimized conditions determined were power of 436.45 W, time of 19.66 min, and liquid-to-solid ratio of 59.82 mL g−1. Under the optimal conditions, the recovery of total phenolic content, ferric reducing antioxidant power, and 2,2-diphenyl-1-picrylhydrazyl scavenging activity was 56.17 mg gallic acid equivalent g−1 dw, 683.27 µmol ascorbic acid equivalent g−1 dw, and 82.64 DPPHsc%, respectively. High Performance Liquid Chromatography (HPLC) analysis revealed mangiferin as the prominent phenolic compound in the mango peel extracts. Microwave-assisted deep eutectic solvent extraction showed remarkable effects on the extraction efficiency of phenolic compounds as revealed from scanning electron microscopy analysis. Rancimat test results revealed that the oxidative stability almost doubled upon addition of purified mango peel extracts to the sunflower oil and thus paving way for the use of mango peel waste as a potential source of antioxidants.

In vitro and in vivo antimicrobial activity of Algerian Hoggar Salvadora persica L. extracts against microbial strains from children's oral cavity

ETHNOPHARMACOLOGICAL RELEVANCE

Salvadora persica L. (miswak) is traditionally used to ensure oral hygiene Muslim people in developing countries where it is growing. The antibacterial properties of Salvadora persica L. originating from various geographic areas have already been reported. However, they have never been tested for samples originating from Hoggar, where extreme weather conditions could lead to different properties for this Salvadora persica L. ecotype.

AIM OF THE STUDY

To assess the in vitro and in vivo antimicrobial activities of methanolic extract of Algerian Hoggar Salvadora persica L. (miswak) on some isolated and identified strains from the oral cavity of school children aged from 6 to 12 with (n=20) and without (n=20) caries.

MATERIALS AND METHODS

After a qualitative and quantitative analysis of dental plaque samples from the selected children, the effect of methanolic extract of Hoggar miswak against oral bacterial and fungal strains isolated from the oral cavity of children with caries was tested by both agar disc diffusion and microdilution methods. The stability and physicochemical parameters of Hoggar Salvadora persica L. mouthwash were also assessed compared. The in vivo antimicrobial effect of Hoggar miswak rinse on dental plaque samples was also tested over a week.

RESULTS

Four bacterial genera (Staphylococcus, Streptococcus, Escherichia and Lactobacillus) were commonly identified in all subjects at different colonization levels. A statistically significant difference in colonization levels between the two groups of children was recorded. Hoggar miswak extract more significantly inhibited the growth of Gram negative bacteria from the dental plaque than Gram positive ones. Hoggar Salvadora persica L. mouthwash was stable at 4 °C and 25 °C over the period of conservation (one week) while a temperature of 40 °C induced variations in the physicochemical parameters and considered not suitable for preservation. The in vivo study revealed a significant reduction in bacteria of the oral cavity using miswak mouthwash as compared to placebo.

CONCLUSION

Hoggar miswak extract displayed a strong antimicrobial effect both in vitro and in vivo. Its use as a mouthrinse could therefore be recommended as a preventive measure to preserve from tooth decay.