Growth Inhibitory, Bactericidal, and Morphostructural Effects of Dehydrocostus Lactone from Magnolia sieboldii Leaves on Antibiotic-Susceptible and -Resistant Strains of Helicobacter pylori

Abstract

Helicobacter pylori is associated with various diseases of the upper gastrointestinal tract, such as gastric inflammation and duodenal and gastric ulcers. The aim of the study was to assess anti-H. pylori effects of the sesquiterpene lactone dehydrocostus lactone (DCL) from Magnolia sieboldii leaves, compared to commercial pure DCL, two previously known sesquiterpene lactones (costunolide and parthenolide), (–)-epigallocatechin gallate, and four antibiotics. The antibacterial activity of natural DCL toward antibiotic-susceptible H. pylori ATCC 700392 and H. pylori ATCC 700824 strains (MIC, 4.9 and 4.4 mg/L) was similar to that of commercial DCL and was more effective than costunolide, parthenolide, and EGCG. The activity of DCL was slightly lower than that of metronidazole (MIC, 1.10 and 1.07 mg/L). The antibacterial activity of DCL was virtually identical toward susceptible and resistant strains, even though resistance to amoxicillin (MIC, 11.1 mg/L for PED 503G strain), clarithromycin (49.8 mg/L for PED 3582GA strain), metronidazole (21.6 mg/L for H. pylori ATCC 43504 strain; 71.1 mg/L for 221 strain), or tetracycline (14.2 mg/L for B strain) was observed. This finding indicates that DCL and the antibiotics do not share a common mode of action. The bactericidal activity of DCL toward H. pylori ATCC 43504 was not affected by pH values examined (4.0–7.0). DCL caused considerable conversion to coccoid form (94 versus 49% at 8 and 4 mg/L of DCL for 48 h). The Western blot analysis revealed that urease subunits (UreA and UreB) of H. pylori ATCC 43504 were not affected by 10 mM of DCL, whereas UreA monomer band completely disappeared at 0.1 mM of (–)-epigallocatechin gallate. Global efforts to reduce the level of antibiotics justify further studies on M. sieboldii leaf-derived materials containing DCL as potential antibacterial products or a lead molecule for the prevention or eradication of drug-resistant H. pylori.

Dehydrocostus lactone attenuates osteoclastogenesis and osteoclast‐induced bone loss by modulating NF‐κB signalling pathway

“…DHE is a naturally occurring sesquiterpene lactone reported to have many biological effects, including anticancer, bactericidal and antioxidative stress properties. 9,14,15 However, there has been no report examining the effects of DHE on osteoclasts. In this study, we investigated its effects on RANKL-induced osteoclast formation and function, and determined the underlying mechanism in vitro.…”

Transformation of Helicobacter pylori into Coccoid Forms as a Challenge for Research Determining Activity of Antimicrobial Substances

“…In a set of eleven studies [45][46][47][48][49][50][51][52][53][54][55] determining an activity and morphological effect of plant extracts and plant-derived compounds on H. pylori, four of them reported a bacteriostatic activity [45][46][47][48] and six indicated a bactericidal effect [49][50][51][52][53][54] of the tested compounds. In one case, the use of this classification was avoided [55].…”

“…The six studies indicated the bactericidal effect of the tested compounds on H. pylori [49][50][51][52][53][54]. A capacity to completely inhibit growth was only proven in half of them [49,51,52], which was achieved in a range of 18 h [49] to 72 h [51] with MICs. A relationship between the decrease in viability and number of spherical forms was particularly well illustrated in the Lee et al article [51].…”

A novel approach for isolation of essential oil from fresh leaves of Magnolia sieboldii using microwave-assisted simultaneous distillation and extraction

“…provinces, because of its medicinal and ornamental values. It is an important Chinese traditional medicinal plant that is used frequently as stomachic, analgesic and anthelmintic in folk medicines [1], due to its pharmacological activities, such as antiinflammatory [2], anti-tumor [3], and anti-bacterial activity [4]. Phytochemical and pharmacological studies have illustrated that Magnoliaceae are full of many kinds of biologically active substances such as magnolol, honokiol, magnoshinin and magnosalin [1,5], in addition, the essential oil of Magnoliaceae has been researched [6,7].…”