Skip to main navigation menu Skip to main content Skip to site footer
Plant Science Today (PST)

Research Articles

Vol. 13 No. 3 (2026)

Evaluation of acute and subacute toxicity of bay laurel (Laurus nobilis) in rats

DOI
https://doi.org/10.14719/pst.12623
Submitted
6 November 2025
Published
02-07-2026 — Updated on 09-07-2026
Versions

Abstract

Laurus nobilis is an aromatic and medicinal plant widely used in traditional medicine and as a culinary herb. The present study aimed to evaluate the acute and subacute toxicity of Laurus nobilis leaves aqueous extract (LNAE) in rats.  The study was conducted at the Laboratory of Pharmacology and Pharmacognosy, Faculty of Sciences and Techniques, Errachidia, Morocco, between March and June 2024. Acute toxicity was assessed in female rats following a single oral administration of 500, 2000 and 5000 mg/kg, while subacute toxicity was evaluated in male and female rats receiving 2000 mg/kg daily for 28 days. No mortality or signs of toxicity were observed in the acute study, indicating that the LD50 is higher than 5000 mg/kg. In contrast, repeated administration at a dose of 2000 mg/kg resulted in significant alterations (p < 0.05), including changes in relative organ weight (particularly the heart, kidneys and spleen), an increase in haematological parameters such as WBC, HCT and RCDW, as well as an elevation in serum biochemical markers. In females, an increase in urea and ALT was observed, while in males, urea and ALT were also elevated. Furthermore, histopathological alterations in liver tissue were observed compared to the control group (p <0.05). These findings suggest that although LNAE is relatively safe at single high doses, repeated exposure at high doses may induce organ toxicity, particularly hepatotoxicity, indicating a potential lowest observed adverse effect level (LOAEL) at 2000 mg/kg.

References

  1. 1. World Health Organization. WHO Traditional Medicine Strategy 2002-2005. Geneva: WHO; 2002.
  2. 2. Gurib-Fakim A. Medicinal plants: traditions of yesterday and drugs of tomorrow. Mol Aspects Med. 2006;27(1):1–93. https://doi.org/10.1016/j.mam.2005.07.008
  3. 3. Ekor M. The growing use of herbal medicines: issues relating to adverse reactions and challenges in monitoring safety. Front Pharmacol. 2014;4:177. https://doi.org/10.3389/fphar.2013.00177
  4. 4. da Silva Moreira S, Tamashiro LK, Jorge BC, da Silva Balin P, Heredia-Vieira SC, de Almeida GL, et al. Toxicological safety evaluation in acute and 28-day studies of aqueous extract from Serjania marginata Casar. (Sapindaceae) leaves in rats. J Ethnopharmacol. 2019;231:197–204. https://doi.org/10.1016/j.jep.2018.11.024
  5. 5. amargo J, Le Heuzey JY, Mabo P. Narrow therapeutic index drugs: a clinical pharmacological consideration to flecainide. Eur J Clin Pharmacol. 2015;71:549–67. https://doi.org/10.1007/s00228-015-1832-0
  6. 6. Paparella A, Nawade B, Shaltiel-Harpaz L, Ibdah M. A review of the botany, volatile composition, biochemical and molecular aspects and traditional uses of Laurus nobilis. Plants. 2022;11(9):1209. https://doi.org/10.3390/plants11091209
  7. 7. Awada F, Hamade K, Kassir M, Hammoud Z, Mesnard F, Rammal H, et al. Laurus nobilis leaves and fruits: a review of metabolite composition and interest in human health. Appl Sci. 2023;13(7):4606. https://doi.org/10.3390/app13074606
  8. 8. Altın S, Işık M, Alp C, Dikici E, Köksal E, Kırboğa KK, et al. Therapeutic potential of Laurus nobilis extract by experimental and computational approaches: phenolic content and bioactivities for antioxidant, antidiabetic and anticholinergic properties. Front Chem. 2025;13:1541250. https://doi.org/10.3389/fchem.2025.1541250
  9. 9. Layachi N, Berrezeg A. Phytochemical composition, antioxidant and anti-inflammatory activities of Laurus nobilis leaf extracts using solvent fractionation. J Angiother. 2025;9:1–8. https://doi.org/10.25163/angiotherapy.9110175
  10. 10. L Al-Mammori F, Qasem AMA, Al-Tawalbeh D, Abuarqoub D, Hmedat A. The therapeutic potential of Laurus nobilis L. leaves ethanolic extract in cancer therapy. Molecules. 2025;30(19):4012. https://doi.org/10.3390/molecules30194012
  11. 11. Bouadid I, Amssayef A, Eddouks M. Study of the antihypertensive effect of Laurus nobilis in rats. Cardiovasc Hematol Agents Med Chem. 2023;21(1):42–54. https://doi.org/10.2174/1871525720666220512154041
  12. 12. Mohammed RR, Omer AK, Yener Z, Uyar A, Ahmed AK. Biomedical effects of Laurus nobilis L. leaf extract on vital organs in streptozotocin-induced diabetic rats: experimental research. Ann Med Surg (Lond). 2021;61:188–97. https://doi.org/10.1016/j.amsu.2020.11.051
  13. 13. Basak SS, Candan F. Effect of Laurus nobilis L. essential oil and its main components on α-glucosidase and reactive oxygen species scavenging activity. Iran J Pharm Res. 2013;12(2):367–78.
  14. 14. Khodja YK, Bachir-Bey M, Belmouhoub M, Ladjouzi R, Dahmoune F, Khettal B. The botanical study, phytochemical composition and biological activities of Laurus nobilis L. leaves: a review. Int J Secondary Metabol. 2023;10(2):269–96. https://doi.org/10.21448/ijsm.1171836
  15. 15. Lewis RW, Billington R, Debryune E, Gamer A, Lang B, Carpanini F. Recognition of adverse and nonadverse effects in toxicity studies. Toxicol Pathol. 2002;30(1):66–74. https://doi.org/10.1080/01926230252824725
  16. 16. Park YC, Cho MH. A new way in deciding NOAEL based on the findings from GLP-toxicity test. Toxicol Res. 2011;27:133–5. https://doi.org/10.5487/tr.2011.27.3.133
  17. 17. Zarn JA, Engeli BE, Schlatter JR. Study parameters influencing NOAEL and LOAEL in toxicity feeding studies for pesticides: exposure duration versus dose decrement, dose spacing, group size and chemical class. Regul Toxicol Pharmacol. 2011;61(2):243–50. https://doi.org/10.1016/j.yrtph.2011.08.004
  18. 18. Ajebli M, Eddouks M. Buxus sempervirens L improves streptozotocin-induced diabetes mellitus in rats. Cardiovasc Haematol Disord Drug Targets. 2017;17(2):142–52. https://doi.org/10.2174/1871529x17666170918140817
  19. 19. Ajebli M, Eddouks M. Pharmacological and phytochemical study of Mentha suaveolens Ehrh in normal and streptozotocin-induced diabetic rats. Nat Prod J. 2018;8(3):213–27. https://doi.org/10.2174/2210315508666180327120434
  20. 20. OECD. Test No. 423: acute oral toxicity-acute toxic class method. OECD Guidelines for the Testing of Chemicals, Section 4. Paris: OECD; 2002. https://doi.org/10.1787/9789264071001-en
  21. 21. OECD. Test No. 407: repeated dose 28-day oral toxicity study in rodents. In: OECD Guidelines for the Testing of Chemicals, Section 4. Paris: OECD; 2008. https://doi.org/10.1787/9789264071049-en
  22. 22. Nalimu F, Oloro J, Peter EL, Ogwang PE. Acute and sub-acute oral toxicity of aqueous whole leaf and green rind extracts of Aloe vera in Wistar rats. BMC Complement Med Ther. 2022;22(1):16. https://doi.org/10.1186/s12906-021-03470-4
  23. 23. Kang S, Johnston TV, Ku S, Ji GE. Acute and sub-chronic (28-day) oral toxicity profiles of newly synthesized prebiotic butyl-fructooligosaccharide in ICR mouse and Wistar rat models. Toxicol Res. 2020;9(4):484–92. https://doi.org/10.1093/toxres/tfaa055
  24. 24. Wu JY, Chan YC, Guo H, Chen YJ, Liu YX, Yi H, et al. Twenty-four-week oral dosing toxicities of Herba Siegesbeckiae in rats. BMC Complement Med Ther. 2020;20:1–9. https://doi.org/10.1186/s12906-020-03137-6
  25. 25. Salmerón-Manzano E, Garrido-Cardenas JA, Manzano-Agugliaro F. Worldwide research trends on medicinal plants. Int J Environ Res Public Health. 2020;17(10):3376. https://doi.org/10.3390/ijerph17103376
  26. 26. Sofowora A, Ogunbodede E, Onayade A. The role and place of medicinal plants in the strategies for disease prevention. Afr J Tradit Complement Altern Med. 2013;10(5):210–29. https://doi.org/10.4314/ajtcam.v10i5.2
  27. 27. Anywar G, Kakudidi E, Byamukama R, Mukonzo J, Schubert A, Oryem-Origa H, et al. A review of the toxicity and phytochemistry of medicinal plant species used by herbalists in treating people living with HIV/AIDS in Uganda. Front Pharmacol. 2021;12:615147.
  28. 28. Asare G, Addo P, Bugyei K, Gyan B, Adjei S, Otu-Nyarko L, et al. Acute toxicity studies of aqueous leaf extract of Phyllanthus niruri. Interdiscip Toxicol. 2011;4(4):206–10. https://doi.org/10.2478/v10102-011-0031-9
  29. 29. Takahashi K, Hike N, Ogura H, Okamura T, Yamamoto D, Sato J. Body weight loss without reduction in food consumption observed in cynomolgus monkeys during non-clinical toxicity studies. Exp Anim. 2026;75(2):121–30. https://doi.org/10.1538/expanim.25-0047
  30. 30. Bariweni MW, Yibala OI, Ozolua RI. Toxicological studies on the aqueous leaf extract of Pavetta crassipes (K. Schum) in rodents. J Pharm Pharmacogn Res. 2018;6(1):1–16. https://doi.org/10.56499/jppres17.225_6.1.1
  31. 31. Kluwe WM. Renal function tests as indicators of kidney injury in subacute toxicity studies. Toxicol Appl Pharmacol. 1981;57(3):414–24. https://doi.org/10.1016/0041-008x(81)90239-8
  32. 32. Sellers RS, Mortan D, Michael B, Roome N, Johnson JK, Yano BL, et al. Society of Toxicologic Pathology position paper: organ weight recommendations for toxicology studies. Toxicol Pathol. 2007;35(5):751–5. https://doi.org/10.1080/01926230701595300
  33. 33. Nigatu TA, Afework M, Urga K, Ergete W, Makonnen E. Toxicological investigation of acute and chronic treatment with Gnidias tenophylla Gilg root extract on some blood parameters and histopathology of spleen, liver and kidney in mice. BMC Res Notes. 2017;10:1–13. https://doi.org/10.1186/s13104-017-2964-3
  34. 34. Luka J, Badau SJ, Mbaya AW, Gadzama JJ, Kumshe HA. Acute toxicity study and effect of prolonged administration (28 days) of crude ethanolic root extract of Diospyros mespiliformis Hochst (Ebenaceae) on clinical, haematological and biochemical parameters of albino rats. J Ethnopharmacol. 2014;153(1):268–73. https://doi.org/10.1016/j.jep.2014.02.033
  35. 35. Alelign T, Chalchisa D, Fekadu N, Solomon D, Sisay T, Debella A, et al. Evaluation of acute and sub-acute toxicity of selected traditional antiurolithiatic medicinal plant extracts in Wistar albino rats. Toxicol Rep. 2020;7:1356–65. https://doi.org/10.1016/j.toxrep.2020.10.001
  36. 36. Feng GH, Li HP, Li QL, Fu Y, Huang RB. Red blood cell distribution width and ischaemic stroke. Stroke Vasc Neurol. 2017;2(3):146–51. https://doi.org/10.1136/svn-2017-000071
  37. 37. Adeyomoye OI, Akintayo CO, Omotuyi KP, Adewumi AN. The biological roles of urea: a review of preclinical studies. Indian J Nephrol. 2022;32(6):539–45. https://doi.org/10.4103/ijn.ijn_88_21
  38. 38. Thangavelu L, Balusamy SR, Shanmugam R, Sivanesan S, Devaraj E, Rajagopalan V, et al. Evaluation of the sub-acute toxicity of Acacia catechu Willd seed extract in a Wistar albino rat model. Regul Toxicol Pharmacol. 2020;113:104640. https://doi.org/10.1016/j.yrtph.2020.104640
  39. 39. Olayode OA, Daniyan MO, Olayiwola G. Biochemical, hematological and histopathological evaluation of the toxicity potential of the leaf extract of Stachytarpheta cayennensis in rats. J Tradit Complement Med. 2020;10(6):544–54. https://doi.org/10.1016/j.jtcme.2019.05.001
  40. 40. Nigam PK. Serum lipid profile: fasting or non-fasting? Indian J Clin Biochem. 2011;26:96–7. https://doi.org/10.1007/s12291-010-0095-x
  41. 41. Alves-Bezerra M, Cohen DE. Triglyceride metabolism in the liver. Compr Physiol. 2018;8(1):1–22. https://doi.org/10.1002/cphy.c170012
  42. 42. Hongnak L, Pongchaidecha A, Lungkaphin A. Renal lipid metabolism and lipotoxicity in diabetes. Am J Med Sci. 2020;359(2):84–99. https://doi.org/10.1016/j.amjms.2019.11.004
  43. 43. Huang S, Zhang Z, Cui Y, Yao G, Ma X, Zhang H. Dyslipidemia is associated with inflammation and organ involvement in systemic Lupus erythematosus. Clin Rheumatol. 2023;42(6):1565–72. https://doi.org/10.1007/s10067-023-06539-2
  44. 44. Farooque U, Lohano AK, Dahri Q, Arain N, Farukhuddin FN, Khadke C, et al. The pattern of dyslipidemia in chronic liver disease patients. Cureus. 2021;13(2):e12913. https://doi.org/10.7759/cureus.13259
  45. 45. Dongmo OL, Epoh NJ, Tadjoua HT, Yousuf S, Telefo PB, Tapondjou LA, et al. Acute and sub-acute toxicity of the aqueous extract from the stem bark of Tetrapleura tetraptera Taub. (Fabaceae) in mice and rats. J Ethnopharmacol. 2019;236:42–9.https://doi.org/10.1016/j.jep.2019.02.026
  46. 46. Ugwah-Oguejiofor CJ, Okoli CO, Ugwah MO, Umaru ML, Ogbulie CS, Mshelia HE, et al. Acute and sub-acute toxicity of aqueous extract of aerial parts of Caralluma dalzielii NE Brown in mice and rats. Heliyon. 2019;5(1):e01106. https://doi.org/10.1016/j.heliyon.2019.e01179
  47. 47. Kazeem MJ. Hypolipidemic and toxicological potential of aqueous extract of Rauvolfia vomitoria Afzel root in Wistar rats. J Med Sci. 2013;13:253–60. https://doi.org/10.3923/jms.2013.253.260
  48. 48. Raeisel GK, Menegati SE, Dos Santos AC, Souza RI, Boas GR, Justi PN, et al. Oral acute and subchronic toxicity studies of the oil extracted from pequi (Caryocar brasiliense, Camb.) pulp in rats. Food Chem Toxicol. 2016;97:224–31. https://doi.org/10.1016/j.fct.2016.09.018
  49. 49. Diallo A, Eklu-Gadegbeku K, Amegbor K, Agbonon A, Aklikokou K, Creppy E, et al. In vivo and in vitro toxicological evaluation of the hydroalcoholic leaf extract of Ageratum conyzoides L. (Asteraceae). J Ethnopharmacol. 2014;155(2):1214–8. https://doi.org/10.1016/j.jep.2014.07.005
  50. 50. Araújo MC, Barcellos NM, de Abreu Vieira PM, Gouveia TM, Guerra MO, Peters VM, et al. Acute and sub-chronic toxicity study of aqueous extract from the leaves and branches of Campomanesia velutina (Cambess) O. Berg. J Ethnopharmacol. 2017;201:17–25. https://doi.org/10.1016/j.jep.2017.02.043
  51. 51. Fu PP, Yang YC, Xia Q, Chou MW, Cui YY, Lin G. Pyrrolizidine alkaloids—tumorigenic components in Chinese herbal medicines and dietary supplements. J Food Drug Anal. 2002;10(4):198–211. https://doi.org/10.38212/2224-6614.2743

Downloads

Download data is not yet available.