Abstract

Medicinal plants have been used as alternative treatments to health problems. Most of the natural remedies are based on medicinal plants. Many reports have demonstrated that the extracts from medicinal plants such as Nigella sativa (L.) seeds extracts have anti-elastase activity; this is mainly due to the enrichment of the extracts with many bioactive molecules mainly phenolic compounds. Neutrophil serine proteases including human neutrophil elastase are involved in many inflammatory diseases, such as chronic obstructive pulmonary disease and emphysema. Since the current therapies for these diseases are inadequate and have numerous adverse effects, there is an acute need of potential alternative therapies. The natural protease inhibitors have received increasing attention as useful tools for potential utilization in pharmacology. This review is elucidating the most important natural phenolic substances that have been reported recently for their effectiveness as natural anti-elastase molecules and hence to the possibility of their use in the field of pharmaceuticals.

Key words: Medicinal plants, phenols, elastase, anti-elastase, chronic obstructive pulmonary disease (COPD), emphysema.

Abbreviation

ARDS, Acute respiratory distress syndrome; α1-AT, α1-antitrypsin; CE, capillary electrophoresis; CF, cystic fibrosis; CMT, chemically modified tetracycline; COPD, chronic obstructive pulmonary disease; fMLP,  N-formyl-methionine-leucine-phenylalanine; GAE, gallic acid equivalents; HLE, human leukocyte elastase; HNE, human neutrophil elastase; IC₅₀, inhibitory concentration; MAE, microwave assisted extraction; MMPs, matrix metalloproteinases;   N.   sativa,   Nigella   sativa;  NSPs, neutrophil serine proteases; PAF, platelet activating factor; α1-PI, α1-protease inhibitors; PLE, pressurized liquid extraction; PMNL, polymorphonuclear leukocyte; ROS, reactive oxygen species; SFE, supercritical fluid extraction; SLPI, secretory leukoproteinase inhibitor;  SOD, superoxide dismutase; SSF, solid state fermentation; SPIs, serine protease inhibitors; TEAC, trolox equivalent anti-oxidant capacity; Thy, thymol; TQ, thymoquinone; VC, vital capacity.