Curcuma zanthorrhiza Roxb.

Scientific Name

Curcuma zanthorrhiza Roxb.

Synonyms

No documentation.

Vernacular Name

MalaysiaTemu kuning, kuncur [1], temu raya [2], temu lawas [3]
EnglishGiant curcuma and false turmeric [1]
ChinaShu gu jiang huang [1], yin ni e zhu [2]
IndiaMenjal (Tamil) [1]; kaliyaka [4]
IndonesiaTemu lawak (Java) [2]; konèng gĕdè (Sunda Island) [3].

Geographical Distributions

No documentation.

Botanical Description

Curcuma zanthorrhiza is a member of Zingiberaceae family. It is a robust, erect herb that could reach up to 2 m tall. [5]

The rhizomes have a few branched, ovate, with both palmate and pendulous tubers deep/dark yellow, orange or orange-red inside, paler on younger parts, has pungent smell and bitter taste. [5][6]

The leaves are semi erect, sessile on their green sheaths, broad lanceolate and oblong. The leaf sheaths are up to 75 cm long. The leaf margin is medium wavy. The leaf blade is green with purple midvein, oblong with distinct purple strip beside main green midrib, size of 10-18 x 30-80 cm, and glabrous. The ligule is small and petiole is measure ca. 10 cm. [5][6][7][8]

The inflorescense of C. zanthorrhiza is up to 25 cm, on separate shoots arising from rhizomes. The peduncle and spike is measure of 15-25 cm and 16-25 x 8-10 cm, respectively. The fertile bracts are pale green ca. 1.4 cm, pubescent, apex 3-toothed. The corolla tube is ca. 3.5 cm, lobes pale purple, ovate, ca. 1.7 x 1.5 cm. The coma is large, and of deep purple, or crimson, whereas coma bracts are dark pink in colour. [5][6][7][8]

The flowers are yellow with pinkish corolla lobes whereas the exterior border of the corolla is red in colour. The lateral staminodes are yellowish and tinged with purple colour, oblong that measure of ca. 1.7 x 1 cm. the labellum is yellowish with deeply coloured, median band, square shape that measure of ca. 2 x 2 cm. the anther is ca. 4 mm, base with spurs ca. 3 mm. [5][6][7][8]

Cultivation

No documentation.

Chemical Constituent

Ethyl acetate extract of C. zanthorrhiza rhizome has been found to contain curcuminoids (e.g. bisdemethoxycurcumin, demethoxycurcumin, curcumin). [9]

Acetone extract of C. zanthorrhiza rhizome has been found to contain curcuminoid (e.g. curcumin). [10]

Ethanol extract of C. zanthorrhiza rhizome has been found to contain monoterpene (e.g. camphor), sesquiterpenes (e.g. zingiberene, γ-elemene, trans β‐farnesene, Ar-curcumene, α‐cedrene, β‐elemenone), sesquiterpenoid (e.g. xanthorrhizol) and others (e.g. curcumin, benzofuran). [11][12]

Essential oil of C. zanthorrhiza rhizome has been found to contain monoterpenes (e.g. borneol, δ-terpineol, camphene, α-pinene, α-thujene, β-pinene, myrcene, linalool, cis-pinene, α-phellandrene, α-terpinene, (Z)-β-ocimene, β-ocimene, p-cymene, γ-terpinene, camphor, α-terpineol, terpinen-4-ol, limonene, terpinolene, ρ-cymene-8-ol, cis-dehydro-β-terpineol), curcuminoids (e.g. curcumin), sesquiterpenes (e.g. α-curcumene, zingiberene, α-cubebene, β-humulene, humulene, (Z)-β-farnesene, γ-elemene, (E)-β-farnesene, Ar-curcumene, γ-curcumene, β-bisabolene, (Z)-γ-bisabolene, β-curcumene, β-sesquiphellandrene, caryophyllene oxide, thujopsan-2-α-ol, sesquithuriferol, 1,10-di-epi-cubenol, β-bisabolol, Ar-curcumen-15-al, (E, Z)-farnesol, α-bisabolol oxide A, β-elemene, β-caryophyllene, humuleneoxide, curzerenone, trans-α-bergamotene, germacrone), sesquiterpenoids (e.g. xanthorrhizol, cubenol, α-eudesmol, α-cis-bergamotene), monoterpenoids (1,8-cineole, 6,7-epoxymyrcene), phenylpropene (e.g. (Z)-isoeugenol,), esters (e.g. methyl undecanoate, (E)-ethyl cinnamate, butyl dodecanoate), and others (e.g. ethyl-4E-octenoate, dihydro citronellol acetate, methyl perillate, 1,10-decanediol, (Z)-isoeugenol acetate, citronellyl pentanoate, cis-cadin-4-en-7-ol, (E)-amyl-cinnamic alcohol, (E)-citronellyl tiglate, 1-phenyl-hepta-1,3,5-triyne, 4-hydroxy-3-methoxycinnamaldehyde, chamazulene, α-p-dimethylstyrene, 2-nonanol). [13][14][15][16][17][18]

Plant Part Used

Rhizomes [9][10][11][12]

Traditional Use

Traditionally, infusion of C. zanthorriza with two Zingibers and peppercorns is used for indigestion and rheumatism. It is also used as emmenagogue in amenorrhoea, as a tonic after childbirth and also applied to the body after childbirth in the form of paste. The rhizome can also cure the liver disease and sliced or grated and infused to cure gall-stones. [19]

Preclinical Data

Pharmacology

Antimetastatic activity

Xanthorrhizol isolated from rhizome of C. zanthorriza when given intraperitoneally daily to six-week-old C57BL6 mice inoculated with 2×105 B16BL6 melanoma cells suppressed the formation of intra-abdominal tumour mass with dosage 0.2 mg/kg (71% reduction) and 0.5 mg/kg (97% reduction) after 2 weeks. Xanthorrhizol (0.1-1.0 mg/kg/day) given intravenously for two weeks to Balb/c mice induced with murine colon cancer CT26 cells significantly reduced the formation of lung tumour nodules at concentration 0.1 and 1.0 mg/kg (p < 0.005) and at concentration 0.2 and 0.5 mg/kg (p < 0.0001) as compared to CT26 cell alone-treated group. [20]

Antifungal activity

Xanthorrhizol isolated from ethyl acetate fraction of methanol extract of C. zanthorrhiza rhizome (0.125-64.0 µg/mL) inhibited the growth of Aspergillus flavus (minimum inhibitory concentration (MIC) 2 µg/mL; minimum fungicidal concentration (MFC) 4 µg/mL), Aspergillus fumigatus (MIC 2 µg/mL; MFC 4 µg/mL), Aspergillus niger (MIC 2 µg/mL; MFC 4 µg/mL), Fusarium oxysporum (MIC 4 µg/mL; MFC 8 µg/mL), Rhizopus oryzae (MIC 1 µg/mL; MFC 2 µg/mL) and Trichophyton mentagrophytes (MIC 1 µg/mL; MFC 2 µg/mL) by using in vitro susceptibility test. [21]

Xanthorrhizol (4.0 µg/mL) isolated from C. zanthorrhiza extract inhibited the conidial germination of R. oryzae (18%) and T. mentagrophytes (22%). The dose of 8.0 µg/mL inhibited the germination of A. flavus (22%), A. fumigatus (18%) and A. niger (16%) while the dose of 16.0 µg/mL inhibited the germination of F. oxysporum (24%) by using conidial germination assay. [21]

Essential oil of C. zanthorrhiza rhizome inhibited the growth of Candida albicans (inhibition zone = 9 mm), Kluyveromyces (7 mm), A. flavus (8 mm) and Penicillium chrysogenum (8 mm) by using disc diffusion assay. [13]

Xanthorrhizol isolated from ethyl acetate fraction of methanol extract of C. zanthorrhiza rhizome inhibited the growth of 18 clinical isolates of Candida albicans with sessile minimum inhibitory concentrations (SMIC50) of 4 to 16 g/mL by using 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay after 24 hours of incubation. [22]

Xanthorrhizol isolated from ethyl acetate fraction of methanol extract of rhizome of C. zanthorrhiza inhibited the growth of C. albicans(MIC of 1.0–15.0 mg/L), C. glabrata (1.0–10 mg/L), C. guilliermondii (2.0–8.0 mg/L), C. krusei (2.5–7.5 mg/L), C. parapsilosis (5.0–25 mg/L) and C. tropicalis (2.0–8.0 mg/L) byusing National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 broth microdilution assay after 48 hours of incubation. [23]

Antibacterial activity

Essential oil of C. zanthorrhiza rhizome inhibited the growth of Escherichia coli (inhibition zone = 14 mm), Bacillus amyloliquefaciens (14 mm), Klebsiella pnuemoniae (12 mm), Shigella sonnei (11 mm), Enterobacter aerogens (10 mm), Pseudomonas aeruginosa (9 mm), Salmonella thypi (9 mm), Xanthomonas campestris (9 mm), Mycobacterium sp. (8 mm),Proteus vulgaris (8 mm), Streptococcus thermophiles (8 mm), Staphylococcus aureus (8 mm) and Bacillus megaterium (7 mm) by using disc diffusion assay. [13]

Xanthorrhizol isolated from C. zanthorrhiza rhizome (50 µmol/L) significantly (p < 0.05) inhibited biofilm formation at adherent phase of Streptococcus mutans growth (76%) after 60 min by using polystyrene microtitre plate assay. [24]

Xanthorrhizol isolated from C. zanthorrhiza rhizome completely inhibited biofilm formation by Streptococcus mutans within 60 min of exposure to the xanthorrhizolat adherent phases (5-50 µmol/L) and active accumulated phase (50 µmol/L only). [24]

Antioxidant activity

Methanol extract of C. zanthorrhiza rhizome inhibited low density lipoprotein (LDL) oxidation with IC50 of 0.78 ± 0.03 µg/mL by using thiobarbituric acid reactive substances assay. Essential oil of the rhizome had IC50 of 2.2 ± 0.1 µg/mL while xanthorrhizol (isolated from the essential oil) had IC50 of 0.4 ± 0.1 µg/mL by using the same assay. [15]

Freeze-dried curcuminoids isolated from ethyl acetate extract of C. zanthorrhiza rhizome (10 mg) inhibited lipid peroxidation with (98.4%) comparable to butylated hydroxyltoluene (BHT) (99.7%) by using ferric thiocyanate (FTC) value FTC assay, TBA value (99.7 ± 0.001%) comparable to quercetin (98.3 ± 0.010%). However, the extract has a lower DPPH scavenging activity (IC50) 62.7 ± 0.014 µg/mL compared to ascorbic acid (8.48 ± 0.012 µg/mL). [9]

Anticancer activity

Xanthorrhizol isolated from C. zanthorrhiza rhizome reduced the viability of human breast cancer cell line MCF-7 with EC501.71 ± 0.16 µg/mL using MTT method after 72 hours of incubation. The xanthorrhizol also reduced the viability of other malignant cell lines such as T-47D (ductal breast cancer cell), HepG2 (liver cancer cell), HM3KO (melanoma cell) and MG-63 (osteosarcoma cell) with EC50 < 5 µg/mL. The xanthorrhizol (10 µg/mL) also reduced the viability 47% of MCF-7 cells compared to untreated cells as quantified by flow cytometry analyser after annexin-V binding assay. Nuclear morphology of xanthorrhizol-treated MCF-7 cells (5 µg/mL and 10 µg/mL) using Hoechst 33258 assay showed shrinkage of cells, DNA condensations, nuclear and plasma membrane convolution and nuclear fragmentation. [25]

Xanthorrhizol isolated from C. zanthorrhiza rhizome reduced the viability of HepG2 cell (IC50 4.17 ± 0.03 µg/mL), non-malignant Chang’s liver cell (IC50 8.7 ± 0.0065 µg/mL) and Vero cell (IC50 6.6 ± 0.061 µg/mL). The xanthorrhizol (4 µg/mL) also increased the level of apoptosis on HepG2 cells compared to untreated cells with apoptotic index 72% after 24 hours using Tdt-mediated dUTP nick end labelling (TUNEL) assay. The TUNEL assay also demonstrated increased intensity of fluorescence and more DNA fragmentation (apoptotic index 84%) after 48 hours treatment. [26]

Xanthorrhizol isolated from C. zanthorrhiza rhizome showed antiproliferative activity on cervical cancer HeLa (HPV 18-positive) cells (EC50 = 6.16 µg/mL) using methylene blue assay. Xanthorrhizol (6 µg/mL) significantly increase apoptosis in HeLa cells as determined from nuclear morphology (using Hoechst 33258 staining) and DNA fragmentation (using TUNEL assay). The presence of P53 and Bax (pro-apoptosis proteins) was identified using Western blot analysis. [27]

Xanthorrhizol isolated from C. zanthorrhiza rhizome inhibited the growth of human colon carcinoma HCT 116 cells with IC5054.8 µM using MTT assay after 3 days. The cell cycle analysis by flow cytometry showed that xanthorrhizol-treated HCT 116 cells was highly arrested (68.5%) in the sub-G0/G1 phase at dose of 75 µM compared to 50 µM (7.8%) after 48 hours of incubation. [28]

Antitumour activity

Both chloroform and ethanol extracts of C. zanthorrhiza rhizome (40 µg/mL and 160 µg/mL, respectively) inhibited antitumour promoter activity with 100% inhibitory effect by using the short-term assay of inhibition of 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) in Raji cells. [29]

Anti-inflammatory activity

Freeze-dried methanol (75%) extract of C. zanthorrhiza rhizome (5.0 mg) was topically applied on the right ear of female ICR mice (aged five to six weeks) 30 minutes prior to edema induction by TPA. A significant (p < 0.05) edema inhibition was observed in treated mice compared to untreated group. [30]

The freeze-dried methanol (75%) extract (1-5 mg) were topically applied on shaven back of female ICR mice (aged six weeks) 30 minutes prior to edema induction by TPA. A dose-dependent decrease in ornithine decarboxylase level was observed in treated mice. [30]

Antiplatelet activity

Methanol extract of C. zanthorrhiza rhizome (18.2 µg/mL) inhibited the binding of platelet-activating factor to receptor on rabbit platelets by 57%. [31]

1-methoxy-2-methyl-5-(1’,5’-dimethylhex-4’enyl)benzene isolated from the chloroform extract of C. xanthorrhiza rhizome inhibited the binding of platelet-activating factor to receptor on rabbit platelets with IC50 value of 40.9 µM. [31]

Immunostimulating activity

Ethanol (100%) extract of C. zanthorrhiza rhizome (10-50 µg/mL) significantly (p < 0.01) increased the production of nitric oxide (100-160%), hydrogen peroxide (6-14 µM), prostaglandin E2 (PGE2) (303.67-320.98%) and tumor necrosis factor-α (TNF-α) (100-140%), compared to untreated control (40% NO production; <1 µM hydrogen peroxide; 100% PGE2 production; <1% TNF-α). [32]

The ethanol extract (5-50 µg/mL) also significantly (p < 0.01) increased phagocytic activity (133%-350%) and PGE2(284%-320%) compared to untreated control (100%). [32]

Antinociceptive activity

Absolute ethanol extract of C. zanthorrhiza rhizome (200 and 400 mg/kg body weight) was administered subcutaneously in the subplantar of right hind paw of Sprague Dawley male rats 30 minutes before the induction of neurogenic pain using formalin. A significant (p < 0.05) dose dependent reduction in licking time was observed in the early phase (neurogenic pain) (10-60 s) and late phase (inflammatory pain) (30-50 s), compared to untreated control (70 s in early phase and 90 s in late phase). [12]

Estrogenic activity

Methanol (75%) extract of C. xanthorrhiza rhizome (1-10 µM) had estrogenic activity by increasing luciferase activity of ERα-transfected COS-7 cells (266-517%) and luciferase activity of ERβ-transfected COS-7 cells (333-832%), compared to DMSO-control (100%). [33]

Toxicity

Mutagenicity

Methanol (75%) extract of C. zanthorrhiza rhizome (2.5 µg/plate) significantly (p < 0.001) inhibited the 7,12-dimethylbenz[a]anthracene (DMBA)-induced bacterial mutagenesis of Salmonella typhimurium TA98 (64%) and TA100 (62%). The extract (2.5 µg/plate) significantly (p < 0.001) inhibited S. typhimurium TA102 bacterial mutagenesis induced by H2O2 (80%) while the concentration of 50 µg/plate inhibited the mutagenesis induced by t-BOOH (97%). [30]

Acute toxicity

Oral single dose acute toxicity study on female Sprague Dawley rats (aged between 8 to 12 weeks old) using aqueous mixture of powderedC. zanthorrizarhizome showed no toxic effect on the parameters observed which included behaviours, body weight, food and water intake. All rats were observed for 14 days and no death was found throughout the study period (LD50 > 2000 mg/kg). [34]

Hepatotoxicity

Absolute ethanol extract of C. zanthorrhizarhizome (500 mg/kg/day) administered orally for 7 days to male Sprague-Dawley rats before induction of hepatotoxicity by ethanol significantly prevented the increase of liver enzymes (p < 0.05) compared to ethanol control group (without extract pre-treatment). Histopathologically, the hepatocytes in pre-treated extract group showed less ballooning compared to the ethanol control group. [35]

Clinical Data

No documentation.

Dosage

No documentation.

Poisonous Management

No documentation.

Line drawing

The line drawing of . Curcuma zanthorrhiza Roxburgh. [6]

References

  1. Dalimartha S. Atlas tumbuhan obat Indonesia Jilid 2. Jakarta: Niaga Swadaya, 2000; p. 182-190.
  2. Quattrocchi U. CRC world dictionary of medicinal and poisonous plants: Common names, scientific names, eponyms, synonyms, and etymology. Volume II C-D. Boca Raton, Florida: CRC Press; 2012. p. 544.
  3. Hanelt P, Buttner R. Mansfeld’s encyclopedia of agricultural and horticultural crops. Berlin: Springer-Verlag, 2001; p. 2383.
  4. Wise TA. Commentary on the Hindu system of medicine: New Issue. London: Trubner & Co., 1860; p. 138.
  5. Flora of China. Curcuma zanthorrhiza Roxburgh. No date [cited 2016 Apr 20]. Available from: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=240001178.
  6. Wardini TH, Prakoso B. Curcuma xanthorrhiza Roxb. In: de Padua LS, Bunyapraphatsara N, Lemmens RHMJ, editors. Plant resources of South-East Asia No. 12(1): Medicinal and poisonous plants 1. Leiden, Netherlands: Backhuys Publisher, 1999; p. 217-218.
  7. Ong HC. Rempah-ratus: khasiat makanan & ubatan. Kuala Lumpur: Utusan publication & distributors, 2008; p. 206-207.
  8. Mahendra B. 13 Jenis tanaman obat ampuh. Jakarta: Penebar Swadaya, 2005; p.95.
  9. Ruslay S, Abas F, Shaari K, et al. Characterization of the components present in the active fractions of health gingers (Curcuma xanthorrhiza and Zingiber zerumbet) by HPLC-DAD-ESIMS. Food Chem. 2007;104(3):1183-1191.
  10. Nurvita DL. Pengaruh jenis pelarut pada ekstraksi kurkuminoid dari rimpang temulawak (Curcuma xanthorrhiza Roxb.). Chem Info Journal. 2013;1(1):101-107.
  11. Ab Halim MR, Zabri TMSM, Ismail S, Mahmud R. Standardization and phytochemical studies of Curcuma xanthorrhiza Roxb. Int J Pharm Pharm Sci. 2012;4(3):606-610.
  12. Devaraj S, Esfahani AS, Ismail S, Ramanathan S, Yam MF. Evaluation of the antinociceptive activity and acute oral toxicity of standardized ethanolic extract of the rhizome of Curcuma xanthorrhiza Roxb. Molecules. 2010;15(4):2925-2934.
  13. Mary HPA, Susheela GK, Jayasree S, Nizzy AM, Rajagopal B, Jeeva S. Phytochemical characterization and antimicrobial activity of Curcuma xanthorrhizaRoxb. Asian Pac J Trop Biomed. 2012;2(2 SUPPL.):S637-S640.
  14. Jantan IB, Ahmad AS, Ali NAM, Ahmad AR, Ibrahim H. Chemical composition of the rhizome oils of four Curcuma species from Malaysia. J Essent Oil Res. 1999;11(6):719-723.
  15. Jantan I, Saputri FC, Qaisar MN, Buang F. Correlation between chemical composition of Curcuma domestica and Curcuma xanthorrhiza and their antioxidant effect on human low-density lipoprotein oxidation. Evid Based Compl Alt Med. 2012;2012:1-10.
  16. Yasni S, Imaizumi K, Sin K, Sugano M, Nonaka G, Sidik. Identification of an active principle in essential oils and hexane-soluble fractions of Curcuma xanthorrhiza Roxb. showing triglyceride-lowering action in rats. Food Chem Toxicol. 1994;32(3):273–278.
  17. Jarikasem S, Thubthimthed S, Chawananoraseth K, Suntorntanasat T. Essential oils from three Curcumaspecies collected in Thailand. Bayer KHC, Franz G, Canigural S, Demirci F, Craker LE, Gardner ZE, editors. Proceeding WOCMAP lll, Vol. 3: Perspectives in natural product chemistry. Acta Hort. 2005;677:37-41.
  18. Zwaving JH, Bos R. Analysis of the essential oils of five Curcuma species. Flavour Frag J. 2006;7(1):19–22.
  19. Burkill IH. A dictionary of the economic products of the Malay Peninsula. Volume 1. London; Published on behalf of the governments of the Straits settlements and Federated Malay states by the Crown agents for the colonies, 1935; p. 713-714.
  20. Choi MA, Kim SH, Chung WY, Hwang JK, Park KK. Xanthorrhizol, a natural sesquiterpenoid from Curcuma xanthorrhiza, has an anti-metastatic potential in experimental mouse lung metastasis model. Biochem Biophys Res Commun. 2005;326(1):210-217.
  21. Rukayadi Y, Hwang JK. In vitro antimycotic activity of xanthorrhizol isolated from Curcuma xanthorrhizaRoxb. against opportunistic filamentous fungi. Phytother Res. 2007;21(5):434-438.
  22. Rukayadi Y, Hwang JK. In vitro activity of xanthorrhizol isolated from the rhizome of Javanese turmeric (Curcuma xanthorrhiza Roxb.) against Candida albicans biofilms. Phytother Res. 2013;27(7):1061-1066.
  23. Rukayadi Y, Yong D, Hwang JK. In vitro anticandidal activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. J Antimicrob Chemother. 2006;57(6):1231-1234.
  24. Rukayadi Y, Hwang JK. In vitroactivity of xanthorrhizol against Streptococcus mutans biofilms. Lett Appl Microbiol. 2006;42(4):400-404.
  25. Cheah YH, Azimahtol HLP, Abdullah NR. Xanthorrhizol exhibits antiproliferative activity on MCF-7 breast cancer cells via apoptosis induction. Anticancer Res. 2006;26:4527-4534.
  26. Handayani T, Sakinah S, Nallappan M, Pihie AHL. Regulation of p53-, Bcl-2- and caspase-dependent signaling pathway in xanthorrhizol-induced apoptosis of HepG2 hepatoma cells. Anticancer Res. 2007;27(2):965-971.
  27. Ismail N, Lope Pihie AH, Nallapan M. Xanthorrhizol induces apoptosis via the up-regulation of Bax and p53 in HeLa cells. Anticancer Res. 2005;25(3 B):2221-2227.
  28. Kang YJ, Park KK, Chung WY, Hwang JK, Lee SK. Xanthorrhizol, a natural sesquiterpenoid, induces apoptosis and growth arrest in HCT116 human colon cancer cells. J Pharmacol Sci. 2009;111(3):276-284.
  29. Vimala S, Norhanom AW, Yadav M. Anti-tumour promoter activity in Malaysian ginger rhizobia used in traditional medicine. Br J Cancer. 1999;80(1-2):110-116.
  30. Park JH, Park KK, Kim MJ, Hwang JK, Park SK, Chung WY. Cancer chemoprotective effects ofCurcuma xanthorrhiza. Phytother Res. 2008;22(5):695-698.
  31. Jantan I, Pisar M, Sirat HM, et al. Inhibitory effects of compounds from Zingiberaceae species on platelet activating factor receptor binding. Phytother Res. 2004;18(12):1005-1007.
  32. Kim AJ, Kim YO, Shim JS, Hwang JK. Immunostimulating activity of crude polysaccharide extract isolated from Curcuma xanthorrhiza Roxb. Biosci Biotechnol Biochem. 2007;71(6):1428-1438.
  33. Anggakusuma, Yanti, Lee M, Hwang JK. Estrogenic activity of xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. Biol Pharm Bull. 2009;32(11):1892-1897.
  34. Teh BP, Hamzah NF, Rosli SNS, Yahaya MAF, Zakiah I, Murizal Z. Acute oral toxicity study of selected Malaysian medicinal herbs on Sprague Dawley rats. HMRC IMR. 2012.
  35. Devaraj S, Ismail S, Ramanathan S, Marimuthu S, Fei YM. Evaluation of the hepatoprotective activity of standardized ethanolic extract of Curcuma xanthorrhiza Roxb. J Med Plants Res. 2010;4(23):2512-2517.
in this scope
Malaysian Herbal Monograph​
Medicinal Herbs & Plants Monographs​
Traditional Chinese Medicine Herbs (Professional Data)
Herbal Medicines Compendium (HMC) - U.S​