Anti-Helicobacter pylori activity and oxidative burst inhibition by the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

Abstract

Abstract:Helicobacter pylori is a bacterium recognized as the major cause of chronic gastritis and peptic ulcers. Infection by H. pylori induces inflammatory responses and pathological changes in the gastric microenvironment. The host immune cells (especially neutrophils) release inflammatory mediators and large amounts of reactive oxygen species (ROS), which are associated with an increased risk of developing gastric cancer. In this study, we evaluated the anti-H. pylori and antioxidant activities of a 1,4-naphthoquinone-5-methoxy-3,4-dehydroxanthomegnin. The antimicrobial activity was assessed using a spectrophotometric microdilution technique, and antioxidant activity was assessed by noting the effect of 5-methoxy-3,4-dehydroxanthomegnin on the neutrophil oxidative burst using luminol-and lucigenin-amplified chemiluminescence. The results showed that 5-methoxy-3,4-dehydroxanthomegnin is a potent anti-H. pylori compound (MIC 64 µg/mL and MBC 128 µg/mL) and a strong antioxidant. 5-Methoxy-3,4-dehydroxanthomegnin decreased luminol-and lucigenin-amplified chemiluminescence, with ED50 values of 1.58±0.09 µg/mL and 5.4±0.15 µg/mL, respectively, reflecting an inhibitory effect on the oxidative burst. These results indicate that 5-methoxy-3,4-dehydroxanthomegnin is a promising compound for the prevention and treatment of diseases caused by H. pylori infection, such as gastritis, peptic ulceration, and gastric cancer, because reactive oxygen intermediates are involved in the pathogenesis of gastric mucosal injury induced by H. pylori infections.

Evaluation of mutagenicity and metabolism-mediated cytotoxicity of the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

“…Previous studies have shown that this compound has antitumor and immunomodulatory effects (Kitagawa et al, 2011), as well as anti-Helicobacter pylori and antioxidant properties http (Kitagawa et al, 2012). The antitumor effect of 5-methoxy-3,4-dehydroxanthomegnin may be enhanced by association with ascorbic acid as demonstrated by a significant cytotoxic index (CI) for McCoy cells.…”

Natural Products for the Prevention and Management of Helicobacter pylori Infection

“…Methanol extract 15 clinical isolates MICs: 0.063 to 1.0 mg/mL MBCs: 0.098 to 12.5 mg/mL (Ndip et al, 2007) Paepalanthus latipes 5-Methoxy-3,4dehydroxanthomegnin H. pylori ATCC 43504 MIC: 64 μg/mL MBC: 128 μg/mL (Kitagawa et al, 2012).…”

“…Ethyl acetate extract HEp-2 cells Significantly inhibited invasion (Chaichanawongsaroj et al, 2010). Anti-oxidative stress activity Paepalanthus latipes 5-Methoxy-3,4dehydroxanthomegnin Peritoneal neutrophils Inhibited oxidative burst (Kitagawa et al, 2012).…”

Synthesis, molecular docking and biological evaluation of 3-arylfuran-2(5H)-ones as anti-gastric ulcer agent

“…[9][10] However, the acquisition of antibiotic resistance by H. pylori has severely weakened eradication therapy and presents a serious problem such as allergy to antibiotics, severe complications (liver and/or kidney dysfunction). [11][12] To develop more effective and safer therapies, many substances from natural products with good potency against H. pylori are reported, such as 5-methoxy-3,4-dehydroxanthomegnin (a naphthoquinone from Paepalanthus latipes) 13 , epigallocatechin gallate (a major compound of Catechins) 14 and 2-hydroxy-4-methoxy benzaldehyde from Decalepis hamiltonii. 15 2-Furanone framework is a part of many natural and synthetic compounds, which possesses useful biological activities, including anti-inflammatory and HIV-1 integrase inhibitory activities.…”