The constituents of walnut (Juglans regia L.) leaves are represented by tannins, phenolics, and naphthoquinones, the characteristic compound being juglone. The content of juglone in the methanolic extract of the leaves determined by the GC/MS method was 9.9±0.2 mg/100 g; small amounts (1.3±0.02 mg/100 g) were recorded in the infusion, whereas in the decoction it was not detected. As some studies indicate toxicity of juglone, only decoctions should be recommended for therapeutic use.
AmaralJS, SeabraRM, AndradePB, ValentãoP, PereiraJA, FerreresF. (2004) Phenolic profile in the quality control of walnut (Juglans regia L.) leaves. Food Chemistry, 88, 373–379.
2.
ŁuczakS, ŚwiątekL, ZadernowskiR. (1989) Phenolic acids in leaves and pericarpium of walnut Juglans regia L. Acta Poloniae Pharmaceutica -Drug Research, 46, 494–499.
3.
PereiraAJ, OliveiraI, SousaA, ValentãoP, AndradePB, FerreiraCFR, FerreresF, BentoA, SeabraR, EstevinhoL. (2007) Walnut (Juglans regia L.) leaves. Phenolic compounds, antibacterial activity and antioxidant potential of different cultivars. Food and Chemical Toxicology, 45, 2287–2295.
4.
CarvalhoM, FerreiraPJ, MendesVS, SilvaR, PereiraJA, JerónimoC, SilvaBM. (2010) Human cancer cell antiproliferative and antioxidant activities of Juglans regia L. Food and Chemical Toxicology, 48, 441–447.
5.
PaudelP, SatyalP, DosokyNS, MaharjanS, SetzerWN. (2013) Juglans regia and J. nigra, two trees important in traditional medicine: A comparison of leaf essential oil Compositions and biological activities. Natural Product Communications, 8, 1481–1486.
6.
PrassadRBN, GülzPG. (1990) Surface waxes from leaves and fruits of walnut. Phytochemistry, 29, 2097–2099;
7.
PauliGF, FriesenJB, GödeckeT, FarnsworthNR, GlodnyB. (2010) Occurrence of progesterone and related animal steroids in two higher plants. Journal of Natural Products, 73, 338–345.
8.
GuarreraPM. (1999) Traditional antihelminthic, antiparasitic and repellent uses of plants in Central Italy. Journal of Ethnopharmacology, 68, 183–192.
9.
GuarreraPM, FortiG, MarignoliS. (2005) Ethnobotanical and ethnomedicinal uses of plants in the district of Acquapendente (Latium, Central Italy). Journal of Ethnopharmacology, 96, 429–444.
10.
RatherMA, DarBA, DarMY, WaniBA, ShahWA, BhatBA, GanaiBA, BhatKA, AnandR, QurishiMA. (2012) Chemical composition, antioxidant and antibacterial activities of the leaf essential oil of Juglans regia L. and its constituents. Phytomedicine, 19, 1185–1190.
EidiA, MoghadamJZ, MortazaviP, RezazadehS, OlamafarS. (2013) Hepatoprotective effects of Juglans regia extract against CCl4-induced oxidative damage in rats. Pharmaceutical Biology, 51, 558–655.
13.
SalimiM, MajdA, SepahderZ, AzadmaneshK, IrianS, ArdestaniyanMHH, EayatiMH, RastkariN. (2012) Cytotoxicity effects of various Juglans regia (walnut) leaf extracts in human cancer cell lines. Pharmaceutical Biology, 50, 1416–1422.
14.
AsgaryS, ParkhidehS, SolhpourA, MadaniH, Mahzouni-RahimiP. (2008) Effect of ethanolic extract of Juglans regia L. on blood sugar in diabetes-induced rats. Journal of Medicinal Food, 11, 533–538.
15.
GîrzuM, CarnatA, PrivatAM, FialipJ, CarnatAP, LamaisonJL. (1998) Sedative effect of walnut leaf extract and juglone, an isolated constituent. Pharmaceutical Biology, 36, 280–286.
16.
HosseinzadehH, ZareiH, TaghiabadiE. (2011) Antinociceptive, anti-inflammatory and acute toxicity effects of Juglans regia L. leaves in mice. Iranian Red Crescent Medical Journal, 13, 27–33.
17.
Bermejo-BescósP, Martín-AragónS, Jiménez-AliagaKL, OrtegaA, MolinaMT, BuxaderasE, OrellanaG, CsákAG. (2010) In vitro antiamyloidogenic properties of 1,4-naphthoquinones. Biochemical and Biophysical Research Communications, 400, 169–174.
18.
ÖzerÖ, MutluB, KivçakB. (2007) Antityrosinase activity of some plant extracts and formulations containing ellagic acid. Pharmaceutical Biology, 45, 519–524.
19.
MontenegroaRC, AraújoaAJ, MolinabMT, FilhoaJDBM, RochaaDD, Lopéz-MonterobE, GoulartcMOF, BentocES, AlvesdNAPN, PessoaaC, Odorico deMoraesa M, Costa-LotufoaLV. (2010) Cytotoxic activity of naphthoquinones with special emphasis on juglone and its 5-O-methyl derivative. Chemico-Biological Interactions, 18, 439–448.
20.
ThakurA. (2011) Juglone: A therapeutic phytochemical from Juglans regia L. Research Journal of Medicinal Plant, 5, 5324–5330.
21.
SugieS, OkamotoK, RahmanKMW, TanakT, KawaiK, YamaharaJ, MoriH. (1998) Inhibitory effects of plumbagin and juglone on azoxymethane-induced intestinal carcinogenesis in rats. Cancer Letter, 127, 177–183.
22.
EdenharderR, TangX. (1997) Inhibition of the mutagenicity of 2-nitrofluorene, 3- nitrofluoranthene and 1-nitropyrene by flavonoids, coumarins, quinones and other phenolic compounds. Food and Chemical Toxicology, 31, 357–372.
23.
German Commission E, monograph BAnz. no.101, 01. 06. 1990
24.
European Medicines Agency (EMEA) Juglandis folium. Available at www.emea.europa.eu. Accessed September 10. 2014.
25.
European Food Safety Authority.Compendium of botanicals that have been reported to contain toxic, addictive, psychotropic or other substances of concern. EFSA Journal. 2009; 7: 53. http://dx.doi.org/10.2903/j.efsa.2009.281 Available at www.efsa.europa.eu Accessed September 10. 2013.
ChenLJ, LebetkinEH, BurkaLT. (2005) Metabolism and disposition of juglone in male F344 rats. Xenobiotica, 35, 1019–1034.
28.
WójcikE. (1984) Spectrophotometric evaluation of the juglone content in Folium Juglandis. Farmacja Polska, 40, 523–525.
29.
BabulaP, AdamV, HavelL, KizekR. (2009) Noteworthy secondary metabolites naphthoquinones – their occurrence, pharmacological properties and analysis. Current Pharmaceutical Analysis, 5, 47–68.
30.
SolarA, JakopicJ, VebericR, StamparF. (2012) Correlations between Xanthomonas arboricola pv. Juglandis severity and endogenous juglone and phenolic acids in walnut. Journal of Plant Pathology, 94, 229–235.
31.
NourV, TrandafirI, CosmulescuS. (2013) HPLC determination of phenolic acids, flavonoids and juglone in walnut leaves. Journal of Chromatographic Sciences, 51, 883–890.
32.
International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for human use, ICH Harmonized Tripartite Guideline; Stability testing of new Drug substances and Products Q1A (R2), Step 5, ICH, Geneva, 2003.