Pharmacognosy Magazine

ORIGINAL ARTICLE
Year
: 2016  |  Volume : 12  |  Issue : 46  |  Page : 206--212

Evaluation of xanthine oxidase inhibitory potential and In vivo hypouricemic activity of Dimocarpus longan lour. extracts


Shi-Yuan Sheu1, Yuan-Tsung Fu2, Wen-Dar Huang3, Yung-Ann Chen4, Yi-Chih Lei4, Chun-Hsu Yao5, Feng-Lin Hsu6, Tzong-Fu Kuo7 
1 School of Medicine, Chung Shan Medical University; Department of Integrated Chinese and Western Medicine, Chung Shan Medical University Hospital; Department of Occupational Therapy, Asia University, Taichung Branch, Taiwan
2 Department of Chinese Medicine, Buddhist Tzu Chi General Hospital; School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Taichung Branch, Taiwan
3 Department of Agronomy, National University, Taichung Branch, Taiwan
4 School of Veterinary Medicine, National University, Taichung Branch, Taiwan
5 School of Chinese Medicine, China Medical University; Department of Biomedical Imaging and Radiological Science, China Medical University; Department of Biomedical Informatics, Asia University, Taichung Branch, Taiwan
6 College of Pharmacy, School of Pharmacy, Taipei Medical University; Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan
7 School of Veterinary Medicine, National University; Department of Post-Baccalaureate Veterinary Medicine, Asia University, Taiwan

Correspondence Address:
Chun-Hsu Yao
School of Chinese Medicine, China Medical University, Taichung 404
Taiwan
Feng-Lin Hsu
Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei 101
Taiwan
Tzong-Fu Kuo
School of Veterinary Medicine, National Taiwan University, Taipei 106
Taiwan

Background: Longan is a fruit tree known to contain many phenolic components, which are capable of protecting people from oxidative damage through an anti-inflammatory mechanism. It may be also worthwhile to study the effect on lowering uric acid activity. Materials and Methods: This study investigates the lowering of uric acid using longan extracts, including flowers, pericarps, seeds, leaves, and twigs, on potassium-oxonate-induced hyperuricemia mice and its inhibitory actions against xanthine oxidase (XO) activities. Results: The findings revealed that ethyl acetate fraction of longan extracts exhibited strong XO-inhibitory activity, and the flower extracts (IC50 = 115.8 μg/mL) revealed more potent XO-inhibitory activity to those of pericarps (118.9 μg/mL), twigs (125.3 μg/mL), seeds (262.5 μg/mL), and leaves (331.1 μg/mL) in vitro. In addition, different dosages of longan extract (50–100 mg/kg) were administered to hyperuricemic mice. The lowering effect of longan extracts on uric acid at 75 mg/kg markedly reduced plasma uric acid levels in decreasing order: Flowers (80%) > seeds (72%) > pericarps (64%) > twigs (59%) > leaves (41%), compared with allopurinol (89%). Finally, 10 isolated phytochemicals from longan flowers were then examined in vitro. The results indicated that proanthocyanidin A2 and acetonylgeraniin A significantly inhibited XO activity in vitro. This is the first report providing new insights into the urate-reducing effect of phenolic dimer and hydrolyzable tannin, which can be developed to potential hypouricemic agents. SUMMARY
  • Longan flower extracts possess more potent XO-.inhibitory activity than pericarps, twigs, seeds, and leaves in vitro
  • The lowering effect of longan flowers and seeds extracts markedly reduced plasma uric acid levels as compared to allopurinol in vivo
  • The extract proanthocyanidin A2 and acetonylgeraniin A were demonstrated potent XO inhibitory activity in vitro.
Abbreviations used: PO: Potassium-oxonate, XO: xanthine oxidase, HE: n-hexane, EA: ethyl acetate, i.p.: intraperitoneal, PBS: phosphate-buffered saline, AP: allopurinol, PUA: plasma uric acid.



How to cite this article:
Sheu SY, Fu YT, Huang WD, Chen YA, Lei YC, Yao CH, Hsu FL, Kuo TF. Evaluation of xanthine oxidase inhibitory potential and In vivo hypouricemic activity of Dimocarpus longan lour. extracts.Phcog Mag 2016;12:206-212


How to cite this URL:
Sheu SY, Fu YT, Huang WD, Chen YA, Lei YC, Yao CH, Hsu FL, Kuo TF. Evaluation of xanthine oxidase inhibitory potential and In vivo hypouricemic activity of Dimocarpus longan lour. extracts. Phcog Mag [serial online] 2016 [cited 2019 Nov 15 ];12:206-212
Available from: http://www.phcog.com/article.asp?issn=0973-1296;year=2016;volume=12;issue=46;spage=206;epage=212;aulast=Sheu;type=0