Phytochemical studies and antioxidant activity of two South African medicinal plants traditionally used for the management of opportunistic fungal infections in HIV/AIDS patients

<p>Abstract</p> <p>Background</p> <p>It has been observed that perturbations in the antioxidant defense systems, and consequently redox imbalance, are present in many tissues of HIV-infected patients. Hence, the exogenous supply of antioxidants, as natural compounds that scavenge free radicals, might represent an important additional strategy for the treatment of HIV infection. The aim of this study was therefore to analyse the phytochemical constituents and antioxidant potential of <it>Gasteria bicolor </it>Haw and <it>Pittosporum viridiflorum </it>Sims., two South African plants traditionally used for the management of opportunistic fungal infections (OFIs) in AIDS patients.</p> <p>Methods</p> <p>The <it>in vitro </it>antioxidant properties of the two plants were screened through DPPH (1,1-diphenyl-2-picrylhydrazyl), NO (nitric oxide), H₂O₂(hydrogen peroxide) radical scavenging effects and reducing power assays. Phytochemical studies were done by spectrophotometric techniques.</p> <p>Results</p> <p>There were no significant differences in the flavonoid and proanthocyanidins contents between the leaves and bark extracts of <it>Gasteria bicolor </it>and <it>Pittosporum viridiflorum </it>respectively, while the total phenolic content of the bark extract of <it>P. viridiflorum </it>was significantly higher than that of <it>G. bicolor </it>leaf. The acetone extracts of both plants indicated strong antioxidant activities.</p> <p>Conclusion</p> <p>The results from this study indicate that the leaves and stem extracts of <it>Gasteria bicolor </it>and <it>Pittosporum viridiflorum </it>respectively possess antioxidant properties and could serve as free radical inhibitors, acting possibly as primary antioxidants. Since reactive oxygen species are thought to be associated with the pathogenesis of AIDS, and HIV-infected individuals often have impaired antioxidant defenses, the inhibitory effect of the extracts on free radicals may partially justify the traditional use of these plants in the management of OFIs in HIV patients in South Africa.</p

Evaluation of antioxidant activity, antimicrobial and fungicidal effects of organic extracts of cork oak acorns infested by carpophagous insects

International audienceThe Algerian cork oak forest is constituted with numerous essences (Quercus faginea, Quercus coccifera, Quercus suber). This last one establishes an essential element of the physical, climatic and especially socioeconomic balance of the populations of the rural zones and the country in general. An appeal to the regeneration would be indispensable for the rehabilitation of these forests, where from the importance of acorns, which play a major role in the regeneration of this essence. The purpose of this work is to estimate antioxidant activity, antimicrobial and fungicidal effect of the essential oil of organic extracts of the cork oak acorns attacked with the procession of insects called Carpophagous Insects. We extracted acorns of cork oak infested with insects by using organic solvents as the acetone, the chloroform, the ethanol and also extract of water. We measured at first the total lipids according to Goldsworthy's method (1972). The antioxidant activity of samples was determined by two methods, the one based on the discoloration of a solution of cation ABTSo +. The original product, ABTS is going to generate cations ABTSo + which are free radicals and the other one based on the discoloration of a solution of β-carotene (β-carotene bleaching method). Extracts, obtained were individually estimated against some phytopathogenes: Penicillium digitalum, Penicillium italicum, Botrytis fabae, Botrytis cinera, Ascophyta fabae, Fusarium oxysporum, as well as against pathogenic microorganisms such as Geotrichum candidum, Aspergillus, Candida galbrata, Candida albicans, and Saccharomyces cerevisiae. Extracts were so individually estimated against a sample group of 4 bacteria including: Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212 and Escherichia coli ATCC 25922. Results show that all the extracts stemming from attacked acorns contain less lipids than the extracts of the healthy acorns. These same extracts present an antioxidant activity, a significant antimicrobial and fungicidal effect. This biologic activity is a function of various used solvents

Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE) to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa), whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa). The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves

Quercus based coffee-like beverage: effect of roasting process and functional characterization

Coffee is one of the world’s most widely consumed beverages but intake it is not encouraged in consumers with some health conditions. In this way, with the growing interest in developing healthier substitutes, a coffee-like beverage obtained from Quercus ilex and Quercus suber acorn´s species, was elaborates maintaining the flavor. Although, this beverage is a promising coffee alternative, little is known about effects of roasting process in its composition. To that end the antioxidant capacity and toxicity of the developed coffee were analyzed and phenolic compounds and fatty acids (esterified and free forms) were characterized through HPLC-DAD and GC-FID, respectively. The results showed that Quercus based beverages presented antioxidant capacity related to their phenolic content, mainly to ellagic acid as the primary phenolic compound identified. Due to this composition, the beverage also presented antimutagenic activity. The main fatty acids in the esterified lipids were mainly oleic, linoleic, palmitic, stearic and cis vaccenic. In the free fatty acids fraction (FFA) they were oleic, linoleic and palmitic acids. Heat processing produced a reduction in total fatty acid concentration in TG and FFA fraction of Q. ilex. Nevertheless, for Q. suber alterations were only found for FFA. Coffee production did not form genotoxic or cytotoxic compounds. Overall, these results show the feasibility of Quercus acorn-based foodstuffs and its potential to produce a functional coffee-like beverage.info:eu-repo/semantics/publishedVersio