Planta Med 2005; 71(10): 904-909
DOI: 10.1055/s-2005-871234
Original Paper
Pharmacology
© Georg Thieme Verlag KG Stuttgart · New York

An Anti-Inflammatory ent-Kaurane from the Stems of Annona squamosa that Inhibits Various Human Neutrophil Functions

Shang-Hsin Yeh1 , Fang-Rong Chang2 , Yang-Chang Wu2 , Yu-Liang Yang2 , Shi-Kai Zhuo1 , Tsong-Long Hwang1
  • 1Graduate Institute of Natural Products, Chang Gung University, Taoyuan, Taiwan
  • 2Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
Further Information

Publication History

Received: January 1, 2005

Accepted: April 1, 2005

Publication Date:
29 July 2005 (online)

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Abstract

We have previously shown that 11 ent-kauranes isolated from the stems of Annona squamosa exhibited immunomodulating effects in leukocytes. In this study, a cellular model using isolated human neutrophils, which are important in the pathogenesis of rheumatoid arthritis, ischemia-reperfusion injury, chronic obstructive pulmonary disease, asthma and other inflammatory diseases, was established in order to elucidate the anti-inflammatory functions of 16β,17-dihydroxy-ent-kauran-19-oic acid (1). Reactive oxygen species (ROS) and granule proteases produced by neutrophils contribute to the pathogenesis of inflammatory diseases. Compound 1 inhibited the generation of superoxide anion, the formation of ROS, and the release of elastase in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated human neutrophils in a concentration-dependent manner with IC50 values of 3.95 ± 0.68, 12.20 ± 2.16, and 12.52 ± 2.26 μM, respectively. The anti-inflammatory actions were not attributable to cytotoxicity because incubation of the neutrophils with 1 did not result in lactate dehydrogenase release. Compound 1 did not display antioxidant or superoxide anion-scavenging activity. Furthermore, neither subcellular NADPH oxidase activity nor cAMP-dependent pathways were altered by 1. Compound 1 significantly inhibited rapid calcium release from internal calcium stores induced by FMLP but not by thapsigargin. In summary, the presented results indicate that the inhibitory effects of 1 on respiratory burst and degranulation of human neutrophils are through the inhibition of cytosolic calcium mobilization, but not via the cAMP-dependent pathways.

Abbreviations

AC:adenylate cyclase

cAMP:cyclic adenosine 3′,5′-monophosphate

DPPH:1,1-diphenyl-2-picrylhydrazyl

FMLP:formyl-L-methionyl-L-leucyl-L-phenylalanine

O2 ·-:superoxide anion

PDE:phosphodiesterase

PKA:protein kinase A

LDH:lactate dehydrogenase

SOD:superoxide dismutase

WST-1:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt

References

Dr. Tsong-Long Hwang

Graduate Institute of Natural Products

College of Medicine

Chang Gung University

259 Wen-Hwa 1st Road

Kweishan 333

Taoyuan

Taiwan, R.O.C.

Phone: +886-3-211-8506

Fax: +886-3-211-8506

Email: htl@mail.cgu.edu.tw