Antioxidant and antifungal activities in vitro of essential oils and extracts of twelve Algerian species of Thymus against some mycotoxigenic Aspergillus genera

The aim of the study was to determine the phenolic and flavonoid content of essential oils (EOs), chloroform and ethanolic extracts of 12 Algerian Thymus species and evaluate their antioxidant and antifungal activities. EOs (1.73 ± 0.30–15.00 ± 1.24 μg/mg), chloroform extracts (33.8 ± 2.42–160.93 ± 3.88 μg/mg) and ethanol extracts (27.01 ± 3.56 –148.46 ± 4.40 μg/mg) showed considerable phenolic content. Flavonoids values of chloroform extracts ranged between 3.39± 0.17 and 20.27 ± 0.29 μg/ml while ethanolic extracts values ranged between 2.81 ± 0.11 and 26.64 ± 0.18 μg/mg. Results of DPPH showed that EOs, chloroform and ethanolic extracts exhibited strong radical scavenging activity (IC50 = 21.75 ± 6.54–338.22 ± 2.99 μg/ml, 22.91 ± 5.59–90.93 ± 1.36 μg/ml, and 33.51 ± 5.72–103.80 ± 4.54 μg/ml, respectively). Inhibition of β-carotene bleaching was potentially performed by all EOs (66.48 ± 2.41–94.06 ± 2.68 %), chloroform extracts (68.98± 1.58–95.30± 1.99%), and ethanolic extracts (62.15 ± 2.51–92.36± 1.15%). The antifungal activity of EOs and extracts was tested using the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). The EOs (0.1 ± 0.00 mg/ mL – 1.06 ± 0.46 mg/mL), chloroform (0.1 ± 0.00 mg/ mL –1.06 ± 0.46 mg/mL) and ethanol (0.1 ± 0.00 mg /mL–1.6 ± 0.00 mg/mL) showed remarkable antifungal activity against mycotoxigenic Aspergillus genera. The MFC of EOs (1.0 ± 0.34 mg/mL and > 4.8 mg/mL) , chloroform (0.26 ± 0.11 mg/mL and > 1.6 mg/mL) and ethanol (0.2 ± 0.00 mg/mL and > 1.6 mg/mL) were fungicidal in nature higher than MICs. The findings of the study indicated that Thymus spp. EOs and extracts could be used as natural alternatives for food industry.

Fractionation of Sugarcane Extracts and Determination of Phenolic Compounds and their Antioxidant Activity

Crude ethanolic extracts of four cultivars of sugarcane (Saccharum officinarum L.) were firstly prepared and then fractionated using silica gel column chromatography before the determination of their oxidative substances. The fractionated extracts were then tested for antioxidant activity by various assays. Finally, high-performance liquid chromatography (HPLC) was applied for the quantitative determination of the individual phenolic compounds. Sub-fraction 2 has the highest phytochemical contents as well as antioxidant activity. All tested phytochemicals had positively correlated to antioxidant activity. HPLC analysis showed that the phytochemicals in the fractionated extracts varied by the sugarcane cultivars. The main flavonoid substances found in the fractionated extracts were epicatechin, catechin, quercetin, resveratrol, myricetin and rutin while gallic acid was the main phenolic substance. The obtained information is useful for further studies and applications.

Ethanolic extract of ocimum kilimandscharicum linnleaves: phytochemical and in vitro pharmacological activity

Using an in vitro model, the anti-thrombolytic efficacy of ethanolic extracts of Ocimum kilimandscharicum Linn was investigated. The researchers discovered that different concentrations of the extract had significant anti-thrombolytic activity in a dose-dependent manner , which was comparable to a standard drug. As a result of the presence of flavonoids and polyphenols in the plant extract, it can be concluded that it has a promising future in the treatment of thrombosis. This knowledge will be useful in the clinical development of thrombolytic therapeutics by identifying more potent anti-thrombolytic principles from natural resources..

Ameliorative potential of Crinum asiaticum Linn leaf extracts on Elevated blood glucose in Alloxan-induced Diabetic Rats

In the present investigation the glucose lowering potential of the leaf extracts of Crinum asiaticum were prepared using cold maceration technique in solvents of varying polarity. The extracts exhibited the presence of flavonoids, alkaloids, phenolics and tannins. The oral toxicity of the aqueous and ethanolic extracts was determined and these two extracts were used of evaluating the antidiabetic activity. Oral glucose tolerance test was performed and diabetes was induced using alloxan (150 mg/kg) in rats. Ethanolic and aqueous extracts at two dose levels (200 mg/kg and 400mg/kg) were used for evaluating glucose lowering capability. Both the aqueous and the ethanolic extracts were found to significantly reduce glucose levels with the aqueous extract at dose level 200 mg/kg being the most effective (50% reduction) whereas the ethanolic extract was able to reduce the blood glucose by around 35% at the same dose level.

Commentary on: Evaluation of spice and herb as phyto-derived selective modulators of human retinaldehyde dehydrogenases using simple in vitro method

It is commonly known that aldehyde dehydrogenases (ALDHs) are a promising therapeutic target in many diseases. Bui et al. - the authors of the paper I am discussing here (Biosci Rep (2021) 41(5): BSR20210491; DOI: https://doi.org/10.1042/BSR20210491) - point that there is a lack of research on the use of spices and herbs as the sources of naturally occurring modulators of ALDH activity. In order to carry out this type of research, the authors prepared ethanolic extracts of 22 spices and herbs. The main objective of the study was to investigate retinaldehyde dehydrogenases (RALDHs), of which retinal is the main substrate and ALDH2, the mitochondrial isoform, having acetaldehyde as the main substrate. The obtained results indicated that the tested extracts exhibited differential regulatory effects on RALDHs/ALDH2 and some of them showed a potential selective inhibition of the activity of RALDHs.

Investigating the Effects of Aqueous and Alcoholic Extracts of Allium Hirtifolium and Allium Jesdianum on Keratinase Activity of Trichophyton Mentagrophytes

Background: Trichophyton spp., as pathogenic species to humans and animals, cause different forms of dermatophytosis through the production of particular enzymes, playing an essential role in tissue invasion. Among these, herein, keratinase was investigated, for the specific case of Trichophyton mentagrophytes, as a target of the effects of Allium hirtifolium and Allium jesdianum extracts, thus pharmacological potential of these plants was studied against keratinase activity. Methodology: Sampling was carried out on 20 bald patients from medical diagnostic laboratories and mycology centers, with suspected dermatophytosis of scalp. For confirming the presence of Trichophyton mentagrophytes in the specimens, different laboratory procedures were applied. Trichophyton mentagrophytes isolates were cultured on a screening medium containing keratin to verify production of the keratinase enzyme. The best enzyme-producing isolate was selected by measuring diameter of transparent halo around colony to be used in subsequent stages. Afterwards, the optimized conditions maximizing enzyme production and activity were determined. Finally, the inhibitory effect of different dilutions of aqueous and alcoholic extracts of Allium jesdianum and Allium hirtifolium on extracellular keratinase activity was studied. Results : Sixteen out of 20 fungal isolates were identified as the Trichophyton mentagrophytes. The most desirable reduction on keratinase activity was reported for dilution values of 50 and 100 mg/ml of both aqueous and ethanolic extracts of A.jesdianum, though much more significant decrease belonged to the latter, and for dilution values of 25 and 100 mg/ ml of both aqueous and ethanolic extracts of A.hirtifolium. Conclusion : Concerning our results, it is suggested that paying special attention to these natural compounds for the treatment of dermatophytosis could be remarkably effective, considering significant production of keratinase observed in T. mentagrophytes, and they are beneficial, as they have no side effects and offer an alternative to currently available medications, which are under the restriction of drug resistance.

Trypanocidal effect of aqueous and ethanolic extracts of Strychnos spinosa on white mice infected with Trypanosoma brucei brucei

The emergence of trypanocidal resistance has led to a change in the behavior and use of local plants for the treatment of parasites. The trypanocidal activity of Strychnos spinosa aqueous and ethanolic extracts on Trypanosoma brucei brucei was evaluated during ten days of treatment. Thus, the smear was used to monitor the parasitaemia of mice treated with Strychnos spinose aqueous and ethanolic extracts by gavage at doses of 250, 500, 1000 mg/kg (test groups); with 10 ml/kg of distilled water (negative control) and 1mg/kg of isometamidium chloride (positive control). The results of the pharmacological studies on the trypanocidal potential of the plant showed that On day ten (D10) a mortality rates of 32 %, 39 % and 62 % respectively for the doses 250, 500 and 1000 mg/kg with the ethanolic extract while the aqueous extract induced a mortality rates of 32 %, 37 % and 56 % respectively. Isometamidium chloride induced the highest mortality rate of 85 %. The lethal doses were 218.07 and 225.79 mg/kg for the aqueous and ethanolic extracts respectively. All these results justify at least in part the use of this plant in traditional medicine for the treatment of trypanosomiasis. Keywords: Ethanolic extracts - Aqueous extracts - Trypanocidal potential - Trypanosomes - Inhibition of parasitaemia.

Determination of Functional Properties of Sri Lankan Ambarella (Spondias dulcis Forst. syn. Spondias cytherea Sonn.) Fruit and Development of Vacuum Dried Ambarella Fruit Powder and Incorporated Soup Mix

Objective: To develop vacuum dried (VD) Ambarella fruit powder and Ambarella fruit incorporated soup mix from large and miniature Ambarella and investigation of antioxidants and anti-diabetic properties. Methods: Ethanolic extracts of two Ambarella varieties were analyzed for antioxidant potential in terms of total phenolic content (TPC), total flavonoid content (TFC), ferrous reducing antioxidant power (FRAP), radical scavenging activities of DPPH and ABTS and α-amylase inhibitory activity. Results: Fresh dwarf Ambarella showed a significantly (p<0.05) high TPC (3.35±0.10 mgGAE/g) while fresh large Ambarella showed a significantly (p<0.05) high FRAP (0.71±0.13 mgTE/g) and DPPH (3.57±0.31 mg TE/g). In comparison of ethanolic extracts of VD Ambarella powders, a significantly (p<0.05) higher antioxidant potential in terms of FRAP (4.19±0.06 mgTE/g) exhibited in dwarf variety while significantly (p<0.05) higher ABTS (4.03±0.27 mgTE/g) and DPPH (3.00±0.49mgTE/g) exhibited in large Ambarella. Alpha amylase inhibition activities of fresh fruits of large and dwarf were 46.30±4.07% and 49.55±3.18% where as in VD powders were 27.59±5.03% and 15.58±5.86% respectively. An instant soup mixture was developed incorporating 20% of VD powder from large variety due its abundance. The antioxidant potential of ethanolic extract of the soup mixture in terms of TPC, TFC, ABTS, and FRAP were 0.55±0.00 mgGAE/g, 0.04±0.00 mgQE/g, 1.65±0.06 mgTE/g, and 0.04±0.15 mgTE/g. Alpha amylase inhibition activity of soup mixture was 39.49±0.29%. Conclusion: The both types of fresh fruits exhibited higher antioxidant potential except FRAP and higher anti-amylase inhibition than VD Ambarella powder.

Richardia brasiliensis Collected in Southern-Benin: Phytochemical Screening, Antimicrobial Activity and Toxicity

Aims: The aim of this study is to evaluate the antimicrobial activity of the R. brasiliensis aerial part extracts collected in southern-Benin. Methodology: The phytochemical screening was performed by a differential precipitation staining method. Aqueous and ethanolic extracts were made using conventional method with water and ethanol as solvent. The obtained extracts were used to evaluate their antimicrobial activity on Staphylococcus aureus strains isolated from skin infections and ten reference strains by the solid-medium diffusion method. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined by the liquid macro-dilution method. The cytotoxic effect of the extracts was evaluated on Artemia salina larvae obtained by hatching. Results: The phytochemical screening showed a strong presence of tannins, flavonoids, terpenes, steroids and a medium presence of alkaloids, anthocyanins and mucilage’s. The extraction yields vary according to the solvent: water (15.5%) and ethanol (10.30%). The two extracts variously (p<0.001) inhibited the growth of Staphylococcus aureus strains isolated from skin infections and four reference strains (Staphylococcus aureus ATCC29213, Pseudomonas aeruginosa ATCC27853, Proteus mirabilis A24974, Escherichia coli ATCC25922). However, there is no difference (p > 0.05) in inhibition of strains growth between 24h and 48h. The largest diameter (21±0.75 mm) of inhibition with the reference strains was obtained with P. aeruginosa by action of the aqueous extract. Regarding Staphylococcus aureus strains isolated from skin infections, the largest diameter of inhibition is about 19.25±2.75 mm obtained with strains isolated from ulcers. The average mics of 2.81 mg/ml and 2.08 mg/ml were obtained respectively for the aqueous and ethanolic extracts in the presence of the reference strains. The LC50 determination obtained using the regression line is 0.36 mg/ml for the aqueous extract and 1.16 mg/ml for the ethanolic extract. Conclusion: The aqueous extract is more effective because of its action spectrum. This extract can be used for the development of a soap or ointment to fight against skin infections.