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1. Introduction
Monoterpenes, belonging to a large and diverse group of chemical compounds named “terpenes,” represent a group of naturally occurring organic compounds whose basic structure consists of two linked isoprene units, which are formed by a 5-carbon base (C5) each. They are the most representative molecules constituting 90% of the essential oils and have a great variety of structures [1], with several pharmacological properties assigned to them, including cardiovascular, antioxidant, anti-inflammatory, and analgesic [2, 3].
Borneol (C10H18O), a bicyclic monoterpenoid alcohol, one of the valuable medical material, senior aromatic spices, and chemical materials, has been used in food and also folk medicine in China and India. According to the Pharmacopoeia of China (2005), borneol is an important ingredient among about 63 herbal products [4]. This compound is considered a GRAS (generally regarded as safe) approved by the FDA (US Food and Drug Administration) as food flavor [5]. Additionally, borneol is a fragrance ingredient used in decorative cosmetics, fine fragrances, shampoos, toilet soaps, and other toiletries as well as in noncosmetic products such as household cleaners and detergents. Its use worldwide is in the region of 10–100 metric tonnes per annum [6].
Previous studies have shown that borneol has vasorelaxant effect on rat thoracic aorta [7] and neuroprotective effects [8]. Despite being inserted in pharmaceutical preparations to treat painful and inflammatory conditions, few studies have been found investigating the specific role of borneol in this regard. So, we investigated the possible antinociceptive effect of borneol in rodents.
2. Material and Methods
2.1. Animals
Male adult albino Swiss mice (25–35 g) were used throughout this study. The animals were randomly housed in appropriate cages at
2.2. Acetic-Acid-Writhing-Induced Nociception
This test was performed using the method described by Koster et al. [9]. Mice were divided into six groups of six mice each. Acetic acid (0.9% v/v) was administered i.p. in a volume of 0.1 mL/10 g. Vehicle (saline), morphine (10 mg/kg), indomethacin (INDO 20 mg/kg), and borneol (BOR 5, 25, and 50 mg/kg) were administered i.p. 30 min before the injection of acetic acid. The number of abdominal constrictions produced in each group for 5–15 min after injection was counted and compared to the response in the control group. Antinociceptive activity was calculated as the percentage inhibition of abdominal constriction.
2.3. Formalin-Induced Nociception
The method used was similar to that described by Hunskaar and Hole [10]. Twenty microliters of 2.5% formalin (in 0.9% saline, subplantar) was injected subcutaneously into the right hind paw of the mice. The time (in seconds) spent licking and biting the injected paw was measured as an indicator of pain response. Responses were measured for 5 min after formalin injection (first phase, neurogenic) and 15–30 min after formalin injection (second phase, inflammatory). Vehicle (saline), morphine (10 mg/kg), indomethacin (INDO 20 mg/kg), and borneol (BOR 5, 25, and 50 mg/kg) were administered i.p. 60 min before the injection of formalin. Mice were observed in the chambers with a mirror mounted on three sides to allow view of all of the paws. Antinociceptive activity was calculated as the percentage inhibition of licking time.
2.4. Hot Plate Test
Mice were divided into five groups of six mice each. Mice were preselected on the hot plate at
2.5. Rotarod Test
A rotarod tread mill device (Insight, Brazil) was used for the evaluation of motor coordination [12]. Initially, 24 h before the test, mice capable of remaining on the rotarod apparatus longer than 180 s (7 rpm) were selected. Thirty minutes after the administration of either borneol (BOR 5; 25, and 50 mg/kg, i.p.), vehicle (saline/Tween 80 0.2%; control group), or diazepam (DZP; 2.5 mg/kg, i.p.), each animal was tested on the rotarod apparatus at 0.5, 1, and 2 h after treatment, and the time (s) the mice were able to remain on top of the bar was recorded for up to 180 s.
2.6. Grip Strength Test
Grip strength test was performed using a grip strength meter (Model EFF-305, Insight, Ribeirão Preto-SP, Brazil) as previously described [13]. The grip strength meter consists of a force transducer with digital display and a metal plate with a trapeze. Each mouse was placed on the plate and was pulled by its tail with increasing force until it was unable to grasp the trapeze and the grip was broken. The instrument digitally captures and displays the peak pull-force achieved. Muscle strength was defined as the peak weight (g) indicated on the display. The value was determined individually as the mean of three trials and presented as group mean ± SEM. Mice were treated similarly of the rotarod test.
2.7. Leukocyte Migration to the Peritoneal Cavity
The leukocyte migration was induced by the injection of carrageenan (500 μg/cavity, i.p., 500 μL) into the peritoneal cavity of mice 1 h after administration of borneol (5, 25, and 50 mg/kg, i.p.) or aspirin (200 mg/kg, i.p.) by the modification of the technique previously described by Bastos et al. [14] and Leite et al. [15]. The animals (
2.8. Statistical Analysis
All data obtained were evaluated by one-way analysis of variance (ANOVA) followed by Dunnett’s test. Differences were considered to be statistically significant when
3. Results and Discussion
The present study demonstrates that borneol (5, 25 and 50 mg/kg) is capable of strongly preventing acetic-acid-writhing-induced nociception in mice when injected into intraperitoneally (i.p.) route before 30 min acetic acid administration (Figure 1). This is a classical model widely used to screen new agents with analgesic profile where both neurogenic and/or inflammatory pain is involved [17]. In acetic-acid-induced abdominal writhing, pain is elicited by the injection of an irritant such as acetic acid into the peritoneal cavity which produces episodes of characteristic stretching (writhing) movements, and inhibition of the number of episodes by analgesics is easily quantifiable [9]. Drugs-like analgesics can inhibit this nociceptive behavior [12].
[figure omitted; refer to PDF]The systemic administration of borneol, all doses, significantly reduced
[figures omitted; refer to PDF]
Since acute treatment with borneol elicited a significantly reduction of painful behavior induced by formalin (in the first phase), this result indicates a possible neurogenic (central) component in analgesic profile of monoterpene. Thus, we conducted a hot plate test to evaluate possible involvement of supraspinal component in this response. This test consists of introducing a mouse into an open-ended cylindrical space with a floor consisting of a metallic plate that is heated by a thermode or a boiling liquid [19]. A plate heated to a constant temperature produces two behavioral components that can be measured in terms of their reaction times, namely, paw licking and jumping. Both are considered to be supraspinally integrated responses [17]. The borneol-treated mice lack reduces the painful behavior only in higher dose and at time 0.5 or 2 h after treatment (Table 1). This inconsistent response may have occurred due to a lack effect of borneol on opioid system; after all, the hot plate test is more useful to evaluate opioids drugs [17]. Additionally, this results support the hypothesis that many monoterpenes do not exhibit dose-dependent effects [3]; thereby, it is necessary to find the most appropriate dose range that shows effectiveness.
Table 1
Effect of borneol and morphine on hot plate test in mice.
Groups | Dose (mg/kg) | Latency time (s) | |||
---|---|---|---|---|---|
0.5 h | 1 h | 1.5 h | 2 h | ||
Vehicle | — | 4.43 ± 0.48 | 7.52 ± 0.74 | 6.07 ± 0.70 | 6.52 ± 0.76 |
Borneol | 5 | 7.07 ± 0.42 | 9.77 ± 1.28 | 8.48 ± 0.83 | 7.47 ± 0.41 |
25 | 8.16 ± 0.89 | 7.58 ± 0.73 | 9.79 ± 0.48 | 8.27 ± 0.59 | |
50 | 9.86 ± 0.83* | 9.18 ± 0.65 | 8.89 ± 0.91 | 9.84 ± 0.92* | |
Morphine | 10 | 13.79 ± 2.52** | 12.19 ± 1.67* | 12.34 ± 1.75** | 12.80 ± 1.17** |
Values are mean ± SEM,
Anyway, according to Granger et al. [20], while many possible mechanisms for the actions of sedative borneol have been proposed, these monoterpenes have been primarily linked, in electrophysiology studies, with functions associated with the neurotransmitter GABAA. Additionally, Quintans-Júnior et al. [21] reinforce this effect demonstrating that borneol possess anticonvulsant and sedative properties due to the modulation of the GABA system. Several studies demonstrate the hole of GABA system in pain modulation [22, 23]. Thus, we do not disregard the possibility that the antinociceptive profile of intraperitoneal injected borneol might involve, at least, others central nervous system (CNS) effects like anticonvulsant or anxiolytic activities and a possible involvement of GABA system.
On the other hand, in order to clarify if the pharmacological effects of borneol would be consequent to a central activity interference on motor function or motor coordination, the activity of borneol was also evaluated on rotarod and grip strength meter apparatus that are classical models for screening CNS or myorelaxant actions providing information about psychomotor performance. As shown in Figures 3 and 4 borneol-treated mice did not cause any motor disturbance on rotarod and grip strength meter test. This effect corroborates that analgesic profile demonstrated by borneol is a direct action in modulate pain by an understanding mechanism.
[figure omitted; refer to PDF] [figure omitted; refer to PDF]Since borneol produced a marked analgesic effect in acetic acid writhing-induced nociception and in later phase of formalin test, such that this phase has a strong participation of inflammatory mediators, we investigate the possible effect of borneol on leukocytes migration. Cell recruitment during inflammation depends on the orchestrated release of local mediators that are responsible for local vascular and tissue changes as well as for the recruitment of host defense cells [24]. The inflammation induced by carrageenan involves cell migration, plasma exudation, and production of mediators, such as nitric oxide, prostaglandin E2, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF-α) [25]. Borneol, in higher doses, reduced leukocyte migration induced by i.p. injection of inflammatory agent (carrageenan) in peritonitis model (Figure 5).
[figure omitted; refer to PDF]4. Conclusions
In summary, it can be concluded that borneol is endowed with peripheral and centrally acting analgesic properties (without producing motor deficit) as well as anti-inflammatory profile. However, a more in-depth evaluation of the mechanisms involved should be performed. Our results also support that borneol has a therapeutic potential for painful and inflammatory disorders.
Acknowledgments
This work was supported by grants from the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq/Brazil) and the Fundação de Apoio à Pesquisa e à Inovação Tecnológica do Estado de Sergipe (FAPITEC-SE/Brazil).
[1] F. Bakkali, S. Averbeck, D. Averbeck, M. Idaomar, "Biological effects of essential oils: a review," Food and Chemical Toxicology, vol. 46 no. 2, pp. 446-475, DOI: 10.1016/j.fct.2007.09.106, 2008.
[2] M. R. V. Santos, F. V. Moreira, B. P. Fraga, D. P. De Sousa, L. R. Bonjardim, L. J. Quintans-Junior, "Cardiovascular effects of monoterpenes: a review," Brazilian Journal of Pharmacognosy, vol. 21 no. 4, pp. 764-771, 2011.
[3] A. G. Guimaraes, J. S. S. Quintans, L. J. Quintans Junior, "Monoterpenes with analgesic activity: a systematic review," Phytotherapy Research, vol. 27 no. 1, 2013.
[4] L. Chen, J. Su, L. Li, B. Li, W. Li, "A new source of natural D-borneol and its characteristic," Journal of Medicinal Plants Research, vol. 5 no. 15, pp. 3440-3447, 2011.
[5] Q. Shen, X. Li, W. Li, X. Zhao, "Enhanced intestinal absorption of daidzein by borneol/menthol eutectic mixture and microemulsion," AAPS PharmSciTech, vol. 12, pp. 1044-1049, 2011.
[6] S. P. Bhatia, C. S. Letizia, A. M. Api, "Fragrance material review on borneol," Food and Chemical Toxicology, vol. 46, pp. S77-S80, DOI: 10.1016/j.fct.2008.06.031, 2008.
[7] J. C. Silva-Filho, N. N. P. M. Oliveira, D. D. R. Arcanjo, L. J. Quintans-Júnior, S. C. H. Cavalcanti, M. R. V. Santos, R. C. M. Oliveira, A. P. Oliveira, "Investigation of mechanisms involved in (-)-Borneol-induced vasorelaxant response on rat thoracic aorta," Basic and Clinical Pharmacology and Toxicology, vol. 110, pp. 171-177, 2011.
[8] R. Liu, L. Zhang, X. Lan, L. Li, T. T. Zhang, J. H. Sun, G. H. Du, "Protection by borneol on cortical neurons against oxygen-glucose deprivation/reperfusion: Involvement of anti-oxidation and anti-inflammation through nuclear transcription factor κ appaB signaling pathway," Neuroscience, vol. 176, pp. 408-419, DOI: 10.1016/j.neuroscience.2010.11.029, 2011.
[9] R. Koster, M. Anderson, E. J. Beer, "Acetic acid for analgesic screening," Federation Proceedings, vol. 18, pp. 412-418, 1959.
[10] S. Hunskaar, K. Hole, "The formalin test in mice: dissociation between inflammatory and non-inflammatory pain," Pain, vol. 30 no. 1, pp. 103-114, 1987.
[11] J. R. G. S. Almeida, J. T. Lima, H. R. Oliveira, M. R. Oliveira, P. R. M. Meira, A. S. S. C. Lucio, J. M. Barbosa-Filho, L. J. Quintans-Junior, "Antinociceptive activity of discretamine isolated from Duguetia moricandiana," Natural Product Research, vol. 25 no. 20, pp. 1908-1915, 2011.
[12] P. G. S. de Sá, X. P. Nunes, J. T. de Lima, J. A. de Siqueira-Filho, A. P. Fontana, J. S. Siqueira, L. J. Quintans-Jْnior, P. K. F. Damasceno, C. R. C. Branco, A. Branco, J. R. G. S. Almeida, "Antinociceptive effect of ethanolic extract of Selaginella convoluta in mice," BMC Complementary and Alternative Medicine, vol. 12 no. 187, 2012.
[13] O. A. Meyer, H. A. Tilson, W. C. Byrd, M. T. Riley, "A method for the routine assessment of fore- and hindlimb grip strength of rats and mice," Neurobehavioral Toxicology and Teratology, vol. 1 no. 3, pp. 233-236, 1979.
[14] L. F. Bastos, L. A. Merlo, L. T. Rocha, M. M. Coelho, "Characterization of the antinociceptive and anti-inflammatory activities of doxycycline and minocycline in different experimental models," European Journal of Pharmacology, vol. 576 no. 1–3, pp. 171-179, DOI: 10.1016/j.ejphar.2007.07.049, 2007.
[15] B. L. Leite, R. R. Bonfim, A. R. Antoniolli, S. M. Thomazzi, A. A. S. Araújo, A. F. Blank, C. S. Estevam, E. V. F. Cambui, L. R. Bonjardim, R. L. C. Albuquerque Júnior, L. J. Quintans-Júnior, "Assessment of antinociceptive, anti-inflammatory and antioxidant properties of Cymbopogon winterianus leaf essential oil," Pharmaceutical Biology, vol. 48 no. 10, pp. 1164-1169, DOI: 10.3109/13880200903280000, 2010.
[16] W. Reanmongkol, K. Matsumoto, H. Watanabe, S. Subhadhirasakul, S. I. Sakai, "Antinociceptive and antipyretic effects of alkaloids extracted from the stem bark of Hunteria zeylanica," Biological and Pharmaceutical Bulletin, vol. 17 no. 10, pp. 1345-1350, 1994.
[17] D. Le Bars, M. Gozariu, S. W. Cadden, "Animal models of nociception," Pharmacological Reviews, vol. 53 no. 4, pp. 597-652, 2001.
[18] A. Tjølsen, O. G. Berge, S. Hunskaar, J. H. Rosland K Hole, "The formalin test: an evaluation of the method," Pain, vol. 51 no. 1, 1992.
[19] N. B. Eddy, D. Leimbach, "Synthetic analgesics: II. Dithenylbutenyl and dithienyl-butylamines," Journal of Pharmacological and Experimental Therapeutics, vol. 107, pp. 385-393, 1953.
[20] R. E. Granger, E. L. Campbell, G. A. R. Johnston, "(+)- And (-)-borneol: Efficacious positive modulators of GABA action at human recombinant α 1 β 2 γ 2L GABA A receptors," Biochemical Pharmacology, vol. 69 no. 7, pp. 1101-1111, DOI: 10.1016/j.bcp.2005.01.002, 2005.
[21] L. J. Quintans-Júnior, A. G. Guimarães, B. E. S. Araújo, G. F. Oliveira, M. T. Santana, F. V. Moreira, M. R. V. Santos, S. C. H. Cavalcanti, W. de Lucca Jú, M. A. Botelho, L. A. A. Ribeiro, F. F. F. Nóbrega, R. N. Almeida, "Carvacrol, (-)-borneol and citral reduce convulsant activity in rodents," African Journal of Biotechnology, vol. 9 no. 39, pp. 6566-6572, 2010.
[22] J. Sawynok, "GABAergic mechanisms of analgesia: An update," Pharmacology Biochemistry and Behavior, vol. 26 no. 2, pp. 463-474, 1987.
[23] L. Jasmin, M. V. Wu, P. T. Ohara, "GABA puts a stop to pain," Current Drug Targets, vol. 3 no. 6, pp. 487-505, DOI: 10.2174/1568007043336716, 2004.
[24] A. D. Luster, R. Alon, U. H. von Andrian, "Immune cell migration in inflammation: present and future therapeutic targets," Nature Immunology, vol. 6 no. 12, pp. 1182-1190, DOI: 10.1038/ni1275, 2005.
[25] D. Salvemini, Z. Q. Wang, P. S. Wyatt, D. M. Bourdon, M. H. Marino, P. T. Manning, M. G. Currie, "Nitric oxide: a key mediator in the early and late phase of carrageenan-induced rat paw inflammation," The British Journal of Pharmacology, vol. 118 no. 4, pp. 829-838, 1996.
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Abstract
Borneol, a bicyclic monoterpene, has been evaluated for antinociceptive and anti-inflammatory activities. Antinociceptive and anti-inflammatory activities were studied by measuring nociception by acetic acid, formalin, hot plate, and grip strength tests, while inflammation was prompted by carrageenan-induced peritonitis. The rotarod test was used to evaluate motor coordination. Borneol produced a significant (
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Details

1 Núcleo de Estudos e Pesquisas de Plantas Medicinais, Universidade Federal do Vale do São Francisco, 56.304-205 Petrolina, PE, Brazil
2 Laboratório de Farmacologia Pré-Clínica, Universidade Federal de Sergipe, 49.000-100 São Cristóvão, SE, Brazil
3 Departamento de Farmácia, Universidade Federal de Sergipe,49.000-100 São Cristóvão, SE, Brazil