Influence of mycorrhiza and fly ash on the survival, growth and heavy metal accumulation in three Acacia species grown in Cu-Ni mine soil.

Acacia albida, Acacia luederitzii, and Acacia tortilis are dominant acacia species in Botswana and have the potential to rehabilitate the heavy metal degraded environment. To establish this claim, experiments to assess the influence of mycorrhizal inoculation and fly ash amendments on the survival, growth and heavy metal accumulation of these species in mine tailings were conducted. A two-factor (AM inoculation × fly ash) in CRD was done on each of the three Acacia species consisting of four treatments: control (no mycorrhizal, no fly ash coded as - AM/- FA), with mycorrhizal but no fly ash (+ AM/- FA), no mycorrhizal but with fly ash (- AM/+ FA), and with mycorrhizal and with fly ash (+ AM/+ FA). After 24 weeks, results showed that the survival and dry matter yield of all Acacia species were enhanced by 10% with fly ash amendments. However, mycorrhiza inoculation alone improved the survival of A. albida and A. luederitzii but reduced that of the A. tortilis in mine tailings. Fly ash amendments increased the pH of the mine tailings, reduced the availability of Cu, Ni, Pb, Mn and Zn and consequently reduced the concentration of these metals in shoots. On the other hand, it increased the availability of As in the mine tailings. In addition, mycorrhizal inoculation reduced the concentration of these metals in shoots regardless of fly ash amendments. Overall, combined mycorrhizal inoculation and fly ash amendment enhanced the establishment of A. luederitzii in heavy metal-contaminated soils by reducing the heavy metal availability and metal uptake, thus increasing the survival and dry matter yield of plants.

Albidosides H and I, two new triterpene saponins from the barks of Acacia albida Del. (Mimosaceae).

Two new triterpene saponins, albidosides H (1) and I (2), along with the three known saponins were isolated from the barks of Acacia albida. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies and mass spectrometry. Albidosides H (1) and I (2) were assayed for their cytotoxicity against HeLa and HL60 cells using MTT method.

Triterpene saponins from the roots of Acacia albida Del. (Mimosaceae).

Seven previously undescribed bidesmosidic triterpenoid saponins named albidosides A - G, were isolated from a methanol extract of the roots of Acacia albida. Their structures were elucidated using 1D and 2D NMR spectroscopy and mass spectrometry and determined to be bidesmosides of oleanolic acid and of 16α-hydroxyoleanolic acid. Albidosides B - G were assayed for their cytotoxicity against HeLa and HL60 cells using MTT method and microscopic observation.

Evaluation of antioxidant activities of the edible and medicinal Acacia albida organs related to phenolic compounds.

This study compared phenolic contents and antioxidant activity in different organs of Acacia albida (leaves and bark) and focuses on identification of phenolic compounds of leaves by HPLC-DAD. The analysed organs exhibited differences in total polyphenol contents (100 and 59.5 mg GAE g(-1) DW). Phenolic contents of leaves were two times higher than those in bark. Ethanolic extracts exhibited good antioxidant activities with IC50 = 26 µg mL(-1) for DPPH and EC50 = 50 µg mL(-1) for FRAP. Identification by HPLC-DAD revealed the presence of nine phenolic compounds known for their high antioxidant activity. The results suggested that this species can be used as source of natural antioxidants.

Effects of aqueous extracts of Acacia albida stem bark on Wistar albino rats infected with Trypanosoma evansi.

The effect of aqueous extract of Acacia albida stem bark was investigated in Wistar albino rats infected with Trypanosoma evansi. The extract showed highest reduction in parasitemia at the dose of 600 mg/kg body weight (bw). A dose of 300 mg/kg bw improved packed cell volume the most by 14.35%. The group treated with 150 and 600 mg/kg bw of the extract showed significant decrease (P < 0.05) in alanine transaminase and aspartate transaminase levels which were lower than those of the group treated with diminazene aceturate. The group treated with 150 mg/kg bw of the extract showed the least urea, albumin and protein level and lowest relative organ weight. There was a significant difference (P < 0.05) in the levels of catalase and Thiobarbituric acid reactive substances in liver and kidney of the animals in the infected-untreated group and the extracts-treated groups. The results of this study show that the extracts of A. albida have antitrypanosomal activity against T. evansi infection.