Investigation of anthelmintic activity of the acetone extract and constituents of Typha capensis against animal parasitic Haemonchus contortus and free-living Caenorhabditis elegans.

This study aimed to determine in vitro anthelmintic activity of plant extracts of eleven plant species used traditionally in South Africa to treat various disorders including symptoms related to nematode infections, and to isolate bioactive compounds from the most active plant extract. Crude plant extracts were tested on different life-cycle stages of Haemonchus contortus. The cytotoxicity of the most active extracts, fractions and compounds was evaluated on Vero cells and the most potent extract, fractions and compounds were tested for their ability to kill the parasitic H. contortus and the free-living nematode Caenorhabditis elegans. Typha capensis acetone extract had the strongest egg hatching inhibitory effect with an EC50 of 184.94 µg/mL, and this extract also halted larval development of H. contortus with an EC50 of 83.30 µg/mL compared to the positive control (albendazole) with an EC50 of 2.66 µg/mL. Typha capensis crude extract and its butanol fraction had promising anthelmintic activity against both parasitic H. contortus and free-living C. elegans. Two compounds isolated from T. capensis, namely, isorhamnetin-3-O-ß-D-glucoside and isorhamnetin 3-O-rutinoside, had antioxidant activity with IC50 values of 3.16 µg/mL and 0.96 µg/mL respectively, and good anthelmintic activity against H. contortus with IC50 values of 55.61 µg/mL and 145.17 µg/mL respectively. Identification of bioactive compounds from the T. capensis crude extract supports development of this extract as a complementary or alternative treatment against haemonchosis. However, further research is necessary to confirm the anthelmintic efficacy of the plant, including in vivo studies.

Anti-inflammatory and antioxidant properties of leaf extracts of eleven South African medicinal plants used traditionally to treat inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Inflammation is a complex mechanism employed by the body to promote healing and restoration to normal function in the event of injury. Eleven plant species were selected in this study based on their use in traditional medicine against inflammation in South Africa. METHODS: Hexane, acetone, ethanol, methanol and water extracts of the powdered plants were prepared and a total of fifty-five extracts were tested for their anti-inflammatory and antioxidant activities. The anti-inflammatory activity of extracts was evaluated via the 15-lipoxygenase (15-LOX) inhibitory and the nitric oxide (NO) inhibition assays using lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophages. Total flavonoid and total phenolic contents were determined. The antioxidant activity of the extracts was performed using radical scavenging DPPH (2, 2-diphenyl-1-picrylhydrazyl) and electron reducing ABTS (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays. RESULTS: The hexane extract of Typha capensis (TC) had good lipoxygenase inhibitory activity with IC50 of 4.65 µg/mL, significantly (p < 0.05) higher than that of the positive control quercetin (IC50 = 24.60). The same extract also had good nitric oxide inhibitory activity with 86% NO inhibition and cell viability of 97% at 50 µg/mL. The TC acetone extract had the best antioxidant activity with IC50 of 7.11 and 1.91 µg/mL respectively in the DPPH and ABTS assays. Following fractionation of the TC plant material, the ethyl acetate fraction had interesting antioxidant activity and the methanol/water (35%) and hexane fractions had good 15-LOX inhibitory activity. The antioxidant and anti-inflammatory activities therefore resided in both polar and more non-polar fractions. CONCLUSION: The acetone extract of Typha capensis and its fractions had good anti-inflammatory and antioxidant activities, supporting the medicinal use of this species against inflammation. Other species including Ficus elastica, Carpobrotus edulis, Cotyledon orbiculata and Senna italica also had good activity worthy of further investigation.