Antifungal activity of plant extracts against dermatophytes

Ethanolic and aqueous extracts of 20 Palestinian plant species used in folk medicine were investigated for their antimicrobial activities against five bacterial species (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa) and one yeast (Candida albicans). The plants showed 90% of antimicrobial activity, with significant difference in activity between the different plants. The most antimicrobially active plants were Phagnalon rupestre and Micromeria nervosa, whereas, the least active plant was Ziziphus spina-christi. Only ten of the tested plant extracts were active against C. albicans, with the most active from M. nervosa and Inula viscosa and the least active from Ruscus aculeatus. Of all extracts the ethanolic extract of M. nervosa was the most active, whereas, the aqueous extract of Phagnalon rupestre was the most active of all aqueous extracts tested. The ethanolic extracts (70%) showed activity against both Gram positive and negative bacteria and 40% of these extracts showed anticandidal activity, whereas, 50% of the aqueous extracts showed antibacterial activity and 20% of these extracts showed anticandidal activity.

Triterpene and steroid saponins and sapogenins of medicinal plants (Aesculus hippocastanum L., Hedera helix L., Ruscus aculeatus L.) are claimed to be effective for the treatment/prevention of venous insufficiency. In this work we evaluated the inhibitory effects of these plant constituents on the activity of elastase and hyaluronidase, the enzyme systems involved in the turnover of the main components of the perivascular amorphous substance. The results evidence that for Hedera helix L., the sapogenins only non-competitively inhibit hyaluronidase activity in a dose-dependent fashion, showing comparable IC50 values (hederagenin IC50 = 280.4 microM; oleanolic acid IC50 = 300.2 microM); both the saponins hederacoside C and alpha-hederin are very weak inhibitors. The same behaviour is observed for serine protease porcine pancreatic elastase: the glycosides are devoid of inhibitory action, while genins are potent competitive inhibitors (oleanolic acid IC50 = 5.1 microM; hederagenin IC50 = 40.6 microM). Constituents from Aesculus hippocastanum L. show inhibitory effects only on hyaluronidase, and this activity is mainly linked to the saponin escin (IC50 = 149.9 microM), less to its genin escinol (IC50 = 1.65 mM). By contrast, ruscogenins from Ruscus aculeatus L., ineffective on hyaluronidase activity, exhibit remarkable anti-elastase activity (IC50 = 119.9 microM; competitive inhibition). The mechanism of elastase inhibition by triterpene and steroid aglycones, with a nitroanilide derivative as substrate, is discussed.