Short report
Antioxidant, icthyotoxicity and brine shrimp lethality
tests of
Magonia glabrata
Telma L. G. Lemos
⁎
, Luciana L. Machado, João S.N. Souza, Aluisio M. Fonseca,
Juliana L. Maia, Otilia D.L. Pessoa
Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, CP 12200, Fortaleza, Ceará, 60451-970, Brazil
Received 3 August 2004; accepted 3 April 2006 Available online 24 May 2006
Abstract
The ethanolic extract of the fruit bark fromMagonia glabratayielded shikimic acid, scopoletin, sitosterol glycoside and 2-O
-methyl-L-inositol. Antioxidant, icthyotoxicity and brine shrimp lethality activities were observed in this extract. The major constituent, 2-O-methyl-L-inositol, was found to be inactive in two assays but showed moderate activity as a radical scavenger. © 2006 Elsevier B.V. All rights reserved.
Keywords: Magonia glabrata; 2-O-Methyl-L-inositol; Ichthyotoxicity; Radical scavengers
1. Plant
Magonia glabrata St. Hill (Sapindaceae), fruit barks collected in Iraucuba, Ceará, Brazil, in January 2003, was identified by Dr. Afrânio G. Fernandes, Botanist of Universidade Federal do Ceara. A voucher specimen (N.15.198) has been deposited in the Herbarium Prisco Bezerra.
2. Uses in traditional medicine
Infusions of trunk barks are used as antiseptic. The plant in general is considered toxic, can cause death to cow when ingested, and infusions of fruits or roots are used by rural people to aid fishery by causing fish dizziness[1,2].
3. Previously isolated classes of constituents
2-O-Methyl-L-inositol and proanthocyanidins[3].
Fitoterapia 77 (2006) 443–445
www.elsevier.com/locate/fitote
⁎ Corresponding author.
E-mail address:tlemos@ufc.br(T.L.G. Lemos).
4. New-isolated constituents
Shikimic acid (0.014%), scopoletin (0.007%), sitosterol glucoside (0.004%) and 2-O-methyl-L-inositol [L-quebrachitol
(1, 0.73%)] (Fig. 1).
5. Tested materials
Dried fruit barks (1.8 kg) ethanol extract (yield: 95 g). 2-O-Methyl-L-inositol (1) was obtained by precipitation from
the extract.
6. Studied activity
6.1. Ichthyotoxicity[4]and brine shrimp lethality test
Tested material was suspended in water (200 ml) at concentrations ranging from 10 to 500 ppm, placed in a beaker with Mollinesia latipinnaof 2.0–3.0 cm size, identified in the Fishing Engineering Department, Universidade Federal do Ceará, and placed in each dish (5 per dish). Mortality was recorded after 24 h. Tap water was used as positive control. Tests were done in triplicate.
Brine shrimp lethality was tested using umbelliferone as positive reference[5].
6.2. Free radical scavenging activity
The antioxidant activity of EtOH extract and 2-O-methyl-L-inositol were assessed on the basis of the radical scavenging
effect of the stable DPPH free radical. One milliliter of a 60μM DPPH ethanol solution was added to sample solutions of different concentrations and allowed to react at r.t. After 30 min the absorbance values were measured at 517 nm and the antioxidant activity was determined[6,7].
Fig. 1. Structure of compound1. Table 1
Ichthyotoxicity activity and brine shrimp lethality (BST) of theM. glabrataethanol extract and 2-O-methyl-L-inositol
Extract/ compounds
Ichthyotoxicitya BSTa
Conc. (ppm) % mortality Conc. (ppm) % mortality
EtOH extract 10 0 1 25
50 50 10 75
100 100 100 100
1 500 0 500 0
Umbelliferone nt nt 10 25
nt nt 100 50
nt = not tested.
a Values (mean of three replicates).
7. Results
Reported inTables 1 and 2.
8. Conclusions
Ichthyotoxicity activity was observed in EtOH extracts of fruit barks with 100% mortality at the concentration up to 100 ppm and can justify the popular use of infusion of this plant by rural people of Brazil to aid fishery. A very significant brine shrimp toxicity, highest than that of umbelliferone, was observed. 2-O-methyl-L-inositol (1), the major
constituent of the extract, was inactive for both assays. A high antioxidant activity was observed with 80.60% radical scavenging activity at a concentration of 1.00 mg while it was 29.63% at concentration of 0.25 mg. Moderate activity 41.46% was observed for 2-O-methyl-L-inositol at concentration of 1.00 mg. Based on these resultsM. glabratacan be exploited for its cytotoxic and antioxidant properties[8,9].
Acknowledgments
The authors are grateful to the Brazilian Agencies CAPES, CNPq, PRONEX, and FUNCAP for fellowships and financial support.
References
[1] Correia MP. Dicionário de Plantas Úteis do Brasil, Ministério da Agricultura. Instituto Brasileiro de Desenvolvimento Florestal 1984;VI:231. [2] Braga R. Plantas do Nordeste Especialmente do Ceara. Natal: Editora Universitaria UFRN; 1960.
[3] Araujo FWL, Lemos TLG, Militão JSLT, Braz-Filho R. Quím Nova 1994;17:128. [4] Yamada K, Ryu K, Miyamoto T, Higuchi R. J Nat Prod 1997;60:798.
[5] McLaughlin JL. Methods in plant biochemistry, vol. 6. London: Academic Press; 1991. [6] Hegazi AG, Abd El Hady FK. Z Naturforsch 2002;57c:395.
[7] Usia T, Banskota AH, Tezuka Y, Midorikawa K, Matsushige K, Kadota S. J Nat Prod 2002;65:673. [8] Pimenta LPP, Pinto GB, Takahashi JÁ, Fé Silva LG, Boaventura M. Phytomedicine 2003;10:209. [9] Hou WC, Lin RD, Cheng KT, Hung YT, Cho CH, Chen CH. Phytomedicine 2003;10:170. Table 2
DPPH free radical scavenging activity ofM. glabrataethanol extract and 2-O-methyl-L-inositol (1) Treatment Concentration (mg ml−1)
1.00 0.50 0.25
Activity % Activity % Activity %
Control 0.3550 ± 0.00005 00.00 0.3550 ± 0.00005 00.00 0.3550 ± 0.00005 00.00 Trolox 0.0500 ± 0.00004 86.00 0.0870 ± 0.00005 75.51 0.0920 ± 0.00005 74.12 BHT 0.0670 ± 0.00005 81.10 0.1620 ± 0.00005 54.40 0.1680 ± 0.00005 52.72 EtOH extract 0.0690 ± 0.00005 80.60 0.2260 ± 0.00003 36.31 0.2500 ± 0.00005 29.63 1 0.1720 ± 0.00005 41.46 0.1278 ± 0.00001 37.80 0.1937 ± 0.000025 34.60 Results are expressed as mean ± S.D., **P< 0.01 vs control.
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