Inhibitory activity of plant extracts on nitric oxide synthesis in LPS‐activated macrophages

Abstract

Nitric oxide (NO) produced in large amounts by inducible nitric oxide synthase (iNOS) is known to be responsible for the vasodilation and hypotension observed in septic shock and inflammation. Inhibitors of iNOS, thus, may be useful candidates for the treatment of inflammatory diseases accompanied by overproduction of NO. We prepared alcoholic extracts of woody plants and screened the inhibitory activity of NO production in lipopolysaccharide (LPS)-activated macrophages after the treatment of these extracts. Among 83 kinds of plant extracts, 23 kinds of extracts showed potent inhibitory activity of NO production above 60% at the concentration of 80 micro g/ml. Some of potent extracts showed dose dependent inhibition of NO production of LPS-activated macrophages at the concentration of 80, 40, 20 micro g/ml. Especially, Artemisia iwayomogi, Machilus thunbergii, Populus davidiana and Populus maximowiczii showed the most potent inhibition (above 70%) at the concentration of 40 micro g/ml. Inhibitory activity of NO production was concentrated to nonpolar solvent fractions (ethyl ether and/or ethyl acetate soluble fractions) of Artemisia iwayomogi, Machilus thunbergii and Morus bombycis. These plants are promising candidates for the study of the activity-guided purification of active compounds and would be useful for the treatment of inflammatory diseases and endotoxemia accompanying overproduction of NO.

Anti-inflammatory, anticholinesterase and antioxidant activity of leaf extracts of twelve plants used traditionally to alleviate pain and inflammation in South Africa

“…(Lu et al, 2008). The inhibitory activity of NO production by medicinal plants may come from the inhibition of iNOS enzyme activity and/or expression of nitric oxide synthase (Ryu et al, 2003). Many natural compounds from medicinal plants have been known as inhibitors of expression of iNOS in LPS-activated macrophages.…”

Morpho-anatomical study of the cladodes of Homalocladium platycladum (F.J. Muell.) L.H. Bailey (Polygonaceae)

“…platycladum is a one species in genus, native to the Solomon Islands and Papau New Guinea (Liberty Hyde Bailey Hortorium, 1976). This taxum is employed in Chinese traditional therapy (Ryu et al, 2001). In Malay herbal medicine, it is named jarilipan and externally applied to skin wounds caused by arthropods (Ong;Norzalina, 1999).…”

“…In Brazil, it is popularly known as fi ta-de-moça or solitária (Lorenzi;Souza, 1999) and its indication is similar to Polygonum species. Although few studies have been carried out, mostly devoted to ecological aspects, Ryu et al (2001) prepared an alcoholic extract of H. platycladum and screened its inhibitory activity against nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages. H. platycladum, as whole plant, showed 52% of inhibitory activity on the LPS-activated NO production in RAW 264.7 cells at 50 µg.mL .…”

Anti-Inflammatory Effects of Xanthoceras sorbifolia Seeds Oil on RAW264.7 Macrophages and TPA-Induced Ear Edema Mice

“…LPS 자극에 의해 발현된 iNOS (inducible nitric oxide synthase)는 많 은 양의 NO를 생성하게 되며 이에 의한 세포독성은 염 증반응, 세포의 돌연변이 및 종양 발생 등에도 관여하는 것으로 알려져 있다. 염증반응과 관련된 조직 손상에서 NO와 iNOS의 발현이 증가되어 있음이 보고되어 있다 (Mu et al 2001;Ryu et al 2003). 생체 내 염증반응을 촉 진하는 효소 및 인자들로서 cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1 β와 신호전달경로인 nuclear factor kappa-B (NF-κB) 및 mitogen-activated protein kinase (MAPK)가 잘 알려져 있 고, 이들 효소 및 인자들을 억제하는 실험방법은 항염활 성 검정법으로 많이 사용된다 (Eum et al 2013).…”