Five plant species (Ricinus communis, Carpobrotus edulis, Senna italica, Cotyledon orbiculata and Gomphocarpus fruticosus) were selected in this study based on their use in traditional medicine against inflammation and helminthiasis in South Africa. The leaves from each plant were extracted using different solvents of varying polarity (hexane, ethyl acetate, acetone, ethanol and methanol) and tested for their total phenolic content, total flavonoid content, in vitro antioxidant activity using diphenyl-1-picrylhydrazyl (DPPH), 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and anti-inflammatory activity against the 15-lipoxygenase (15-LOX) enzyme. The extracts were also tested against the parasitic sheep nematode Haemonchus contortus in the egg hatch assay (EHA) and larval development assay (LDA). The C. edulis acetone extract had good phenolic content (23.95 mgGAE/g where GAE = gallic acid equivalent) and total flavonoid content with 31.12 mgRE/g (where RE = rutin equivalent). C. edulis also had very good antioxidant activity with an IC50 of 1.11µg/mL compared to the positive controls vitamin C (IC50 = 0.32 µg/mL) and Trolox (0.69 µg/mL), as well as very good activity against 15-LOX with an IC50 value of 9.84 µg/mL compared to the positive control quercetin (IC50 = 24.6 µg/mL). Anthelmintic activity testing against H. contortus showed that R. communis had the best activity with an LC50 = 18.55 µg/mL for EHA compared to the positive control albendazole (LC50 = 1.99 µg/mL). R. communis also had good activity in the LDA with an LC50 value of 10.64 µg/mL compared to albendazole (LC50 = 5.48 µg/mL). C. edulis extracts were not active against H. contortus. This study revealed that C. edulis had good antioxidant and anti-inflammatory activity, and these results showed a good correlation with the phenolic and flavonoid contents. R. communis had good activity against H. contortus in the EHA and LDA. Therefore C. edulis and R. communis could be a potential source of new compounds with anti-inflammatory and anthelmintic activities.