In vitro effects of aqueous seeds extract of Acacia cyanophylla on the opsonized zymosan-induced superoxide anions production by rat polymorphonuclear leukocytes

Insights for the Valorization of Biomass from Portuguese Invasive Acacia spp. in a Biorefinery Perspective

Acacia spp. are widespread all over the Portuguese territory, representing a threat to local biodiversity and to the productivity of the forest sector. The measures adopted in some countries for their eradication or to control their propagation are expensive, have been considered unfeasible from practical and economical perspectives, and have generated large amounts of residue that must be valorized in a sustainable way. This review brings together information on the valorization of bark, wood, leaves, flowers, pods, seeds, roots, and exudates from Acacia spp., through the production of high-value bioactive extracts (e.g., antioxidant, antimicrobial, anti-inflammatory, antidiabetic, antiviral, anthelmintic, or pesticidal agents, suitable to be explored by pharmaceutical, nutraceutical, cosmetics, and food and feed industries), its incorporation in innovative materials (e.g., polymers and composites, nanomaterials, low-cost adsorbents), as well as through the application of advanced thermochemical processes (e.g., flash pyrolysis) and pre-treatments to decompose biomass in its structural components, regarding the production of biofuels along with valuable chemicals derived from cellulose, hemicellulose, and lignin. The knowledge of this research is important to encourage an efficient and sustainable valorization of Acacia spp. within a biorefinery concept, which can bring a significant economic return from the valorization of these residues, simultaneously contributing to forest cleaning and management, to reduce the risk of fires, and to improve the social-economic development of rural areas.

The effect of Acacia nilotica seed extract on the physicochemical, microbiological and oxidative stability of chicken patties

The present study investigates the effect of Acacia seed water extract (ASWE) at four levels (0, 50, 100, 150 mg/100 mL) in triplicate batch on the shelf-life and quality of chicken patties. Flavones, mainly (+)-catechin, were the predominant phenolic compounds in ASWE with high antioxidant activity. ASWE showed greater inhibition effects against gram-positive bacteria than gram-negative bacteria. ASWE incorporation had no significant effects on the chemical composition of chicken patties. The microbial load, and thiobarbituric acid reactive substances of chicken patties significantly decreased (P ≤ 0.05) and reached minimum values at 150 mg/100 mL but the pH decreased slightly. The cooking properties were significantly improved (P ≤ 0.05) at 150 mg/100 mL. Moreover, ASWE at high level (150 mg/100 mL) significantly (P ≤ 0.05) enhanced total phenolic content and free radical scavenging activity of chicken patties. The results showed that chicken patties with ASWE had better quality attributes compared to the unformulated. Shelf-life of chicken patties can therefore be prolonged for 15 days in refrigerated storage using ASWE especially at high concentration (150 mg/100 mL).

Antitumoral potency of methanolic extract from Nitraria retusa leaves via its immunomodulatory effect

Background

The purpose of this study was to assess the antitumoral effect of the methanol extract (MeOH) from Nitraria retusa leaves and to investigate its immunomodulatory activity that mediated the prevention of tumor progression in tumor-bearing mice.

Methods

Balb/c mice weighing 18–20 g were subcutaneously implanted with B16-F10 cells then injected intra-peritoneally, 7 days later with (200 mg/kg bw) of MeOH extract, for 21 days. After euthanization on day 21, the tumors were weighed. Lymphocyte proliferation, cytotoxic T lymphocyte (CTL) and NK activity were evaluated using the MTT assay. Macrophage phagocytosis was studied by measuring their lysosomal activity and nitric oxide production.

Results

The methanol extract inhibited significantly the growth of the implanted tumor, and increased remarkably splenocyte proliferation as well as NK and CTL activities, in tumor-bearing mice. It also promoted lysosomal activity of treated animal macrophages.

Conclusion

Our findings suggest that antitumoral effect of MeOH extract is related with to immunomodulatory activity.

Studies on Antimicrobial and Immunomodulatory Effects of Hot Aqueous Extract of Acacia nilotica L. Leaves against Common Veterinary Pathogens

Acacia nilotica is a plant species that is almost ubiquitously found in different parts of the world. Various preparations of it have been advocated in folk medicine for the treatment of tuberculosis, leprosy, smallpox, dysentery, cough, ophthalmia, toothache, skin cancer as astringent, antispasmodic, and aphrodisiac since immemorial times. The present study investigates the antibacterial, antifungal, antiviral, and immunomodulatory potential of hot aqueous extract (HAE) of Acacia nilotica leaves. On dry matter basis, the filtered HAE had a good extraction ratio (33.46%) and was found to have carbohydrates, glycosides, phytosterols, phenolic compounds, saponins, and flavonoids as major constituents. HAE produced dose dependent zone of inhibition against Klebsiella pneumoniae, Pseudomonas aeruginosa, E. coli, Bacillus cereus, Staphylococcus aureus, and Streptococcus uberis and fungal pathogens Aspergillus niger and Aspergillus fumigates; however, no antiviral activity was recorded against IBR virus. HAE of A. nilotica revealed both proliferative and inhibitory effects on the rat splenocytes and IL-10 release depending on the dose. Detailed studies involving wide spectrum of bacterial, fungal, and viral species are required to prove or know the exact status of each constituents of the plant extract.

Immunomodulatory and cellular anti-oxidant activities of an aqueous extract of Limoniastrum guyonianum gall

ETHNOPHARMACOLOGICAL RELEVANCE

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses to disease/infection/etc. or to ameliorate immune based pathologies (i.e., inflammation, autoimmune associated diseases, etc.). In this particular study, the immunomodulatory potential of gall aqueous extract from Limoniastrum guyonianum Boiss. (Zita) was assessed in vitro.

MATERIALS AND METHODS

The effect of G extract on splenocytes proliferation and NK activity were assessed by MTT test. The induction of NO production and the phagocytic activity of macrophages were evaluated in vitro. Activation of the cellular anti-oxidant activity in splenocytes was determined by measuring the fluorescence of the DCF product.

RESULTS

The studies first demonstrated that the extract could enhance lysosomal enzyme activity and nitrite oxide production in murine peritoneal macrophages, suggesting a potential role in activation of these cells. In studies to assess potential effects on humoral immunity, the results indicated that the extract could significantly promote LPS-stimulated splenocyte proliferation implying a potential activation of B-cells and enhanced humoral immune responses in hosts given this natural product. In studies to assess any effects of extract on cellular immunity, the results showed that the extract significantly enhanced the killing activity of isolated NK cells but had negligible effects on mitogen-induced proliferation of splenic T-cells. Considerable effects were also observed on the cellular anti-oxidant activity.

CONCLUSION

We conclude from these studies that aqueous extract from L. guyonianum gall exhibited an immunomodulator effect which could be ascribed, in part, to its cytoprotective effect via its anti-oxidant capacity. Furthermore, these results suggest that L. guyonianum gall extract contains potent components such as flavonoids which should be potentially used to modulate immune cell functions in physiological and pathological conditions.

Immunostimulatory effects of Uncaria perrottetii (A. Rich.) Merr. (Rubiaceae) vinebark aqueous extract in Balb/C mice

AIMS OF THE STUDY

Crude extract of Uncaria perrottetii (A. Rich.) Merr. vinebark was evaluated for its immunomodulating activity in Balb/C mice. Initially, the immunomodulatory potential of the plant extract was evaluated using in vitro immune response assays at different concentrations of the plant extract (10 μg/mL, 20 μg/mL, 50 μg/mL and 100 μg/mL). Using the optimum concentration determined in the in vitro assays, the protective effect of the plant extract was assessed against drug-induced immunosuppression in vivo.

MATERIALS AND METHODS

For the in vivo experiment, thirty-six (36) mice were divided into 3 groups of 12 mice each: (1) cyclophosphamide drug-induced (30 mg/kg BW) immunosuppressed mice (Cy group) served as the positive control; (2) Uncaria perrottetii extract and Cy-treated mice (U+Cy); and (3) PBS-injected mice as the negative control group [(-) CTRL].

RESULTS

The optimum concentration was determined to be 50 μg/mL in the in vitro assays. At this concentration, Uncaria perrottetii extract stimulated peritoneal phagocyte activation, produced a significant increase in the activity of phagocytic cells from the spleen and promoted splenic cellular proliferation with or without lipopolysaccharide (LPS) when compared with the PBS-treated cells (negative control). Moreover, cells treated with 50 μg/mL of Uncaria perrottetii increased macrophage respiratory burst activity that was comparable to that of the phorbol myristate acetate-stimulated splenic macrophages. In all immune assays undertaken in the in vivo experiment, the Cy-treated mice showed significantly lower response when compared with the PBS-treated mice. Significant improvement in peritoneal cell activation, phagocytic activity and cellular proliferation was exhibited by the U+Cy-treated mice when compared with Cy-injected mice. The extract from Uncaria perrottetii also significantly enhanced respiratory burst and plasma lysozyme activity compared with the Cy-injected mice.

CONCLUSIONS

Based on the results of both in vitro and in vivo trials, Uncaria perrottetii extract has immunopotentiating activities on the innate immunity of Balb/C mice and the extract could potentially reverse the immunosuppressive effects of Cy. However, the potential of the plant as source of bioactive products and metabolites for drug development still has to be fully investigated.

Screening of antimutagenicity via antioxidant activity in different extracts from the leaves of Acacia salicina from the center of Tunisia

The effect of extracts obtained from Acacia salicina on genotoxicity and SOS response induced by Benzo(a)pyrene (B[a]P) as well as nifuroxazide was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. Preparations obtained from the leaves of A. salicina exhibited no genotoxicity either with or without the external S9 activation mixture. However, all extracts significantly decreased the genotoxicity induced by (B[a]P) and nifuroxazide. Ethyl acetate, methanol and TOF extracts exhibited the highest inhibition level of the SOS response induced by the direct mutagen nifuroxazide. Whereas, aqueous, ethyl acetate and methanol extracts displayed the greatest level of protection towards the indirect mutagen, (B[a]P), induced response. In addition to their antigenotoxic activity, TOF, aqueous, methanol and chloroform extracts showed an important free radical scavenging activity towards the 1,1-diphenyl 2-picrylhydrazyl (DPPH) free radical. These extracts showed IC(50) value of 36, 73, 65, and 87μg/ml respectively. Taken together, our finding showed that A. salicina exhibits significant antioxidant and antigenotoxic activities.