Plant-derived anti-inflammatory compounds

Furst, R. and 1. Zundorf, Plant-Derived Anti-Inflammatory Compounds Hopes and Disappointments regarding the Translation of Preclinical Knowledge into Clinical Progress. Mediators Inflamm., 2014. 2014 p. 146832. 

The balance between the anabolism and catabolism of HA is maintained by the inhibitors of hyaluronidases. Heparin is a known and well-characterized inhibitor of hyaluronidase [132]. Chitosan inhibits HA degradation by venom and bovine testicular hyaluronidases [133]. Cis-unsaturated fatty acids can also inhibit the hyaluronidase activity [134]. Certain anti-inflammatory drugs including saly-cylates, indomethacin and dexamethasone are also known to exert anti-hyaluronidase activity [133, 135]. Ascorbic acid [136], as well as plant derived bioactive compounds, such as flavonoids, tannins, pectins, curcumins, cou-marins, gylcyrrhizin are used to block hyaluronidase activity [100]. 

Phenolics and their functional derivatives are widely found throughout the plant kingdom. One defining characteristic of these compounds is that their aromatic ring usually contains at least one hydroxyl substituent. In a broad sense, phenolics, which are classified according to their structural skeleton, are basically derivatives from simple phenols and phenolic acids, phenylpropanoids including coumarins and lignans, flavonoids and related compounds, and stilbenes. Some of these compounds which show anti-inflammatory activity are reviewed in this section. 

A current compilation of Mexican medicinal plants indicates that no pharmacological studies have been carried out to test the presumed properties of the decoction [13]. Chemical studies of the aerial parts of Penstemon barbatus have afforded four aucubin iridoid glycosides catalpol (53), scutellarioside (54), globularin (55) and barbatoside (56) "Fig. (15)." The two former compounds were isolated as their acetate derivatives [101]. Several iridoid glycosides have shown anti-inflammatory activity in experimentally induced edema in mice best results were obtained when administered topically. The most active compounds were two catalpol derivatives, besides aucubine, verbalin and loganin these compounds induced a 72 to 80% edema inhibition when applied at a dose of 1 mg/ear [102]. 

Interest in these naturally occurring and synthetic lactones, podolactones, and related podocarpic acid derivatives has been mainly due to the novel structures of these compounds and the various types of biological activity possessed by them. Octahydrophenanthrene lactones (II) and related podocarpic acid derivatives (III) have been reported to possess hormonal and anti-inflammatory properties (4). Other similar podolactones have been shown to inhibit the expansion and division of plant cells (IV) (5-10), to have antileukemic activity (V) (11), to have antibacterial activity (12), to have insect toxicity properties (13-15), and to exhibit antitumor activity (16-19). 

The large family of medicines known as nonsteroidal anti-inflammatory drags (NS AID, 3.3) today also owes its existence to primitive observations about the effect of the willow Salix in Latin). In this case, it was not the original compound, but a chemical derivative that became a blockbuster drag. The taste of willow bark is bitter, and similar to the taste of the bark of a South American plant Cinchona, which is an effective treatment against malaria. As well as the taste, the effect was also similar willow bark seemed to possess an antifever property. Today, it has been established that salicin is the active ingredient, but a simpler derivative named acetylsalicylic acid proved to be more potent (— 3.25), and is currently sold under the trade name Aspirin. 

Indole and its derivatives are found in many natural products as plant alkaloids that have antimicrobial [150], anti-inflammatory [151], antibacterial [152], and antidepressive activities. Many sulfur-containing compounds such as sulfates, sulfones, and sulfonomides exhibit insecticidal, germicidal, antimicrobial, and antibacterial activities [153,154] and certain phenyl sulfones show fungicidal properties [155]. 

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