Potential Anti-Stress, Anxiolytic and Antidepressant Like Activities of Mono-Hydroxybenzoic Acids and Aspirin in Rodents: A Comparative Study

Research Article

Austin J Pharmacol Ther. 2015; 3(3).1073.

Potential Anti-Stress, Anxiolytic and Antidepressant Like Activities of Mono-Hydroxybenzoic Acids and Aspirin in Rodents: A Comparative Study

Saba Anjum Khan¹, Shyam Sunder Chatterjee2,3 and Vikas Kumar¹*

¹Neuropharmacology Research Laboratory, Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, India

²Stettiner Straße, Germany

³Retired Head of Pharmacology Research Laboratories, Dr. Willmar Schwabe GmbH & Co. KG, Germany

*Corresponding author: : Vikas Kumar, Neuropharmacology Research Laboratory, Department of Pharmaceutics, Indian Institute of Technology, Banaras Hindu University, Varanasi, India

Received: July 20, 2015; Accepted: August 17, 2015; Published: August 27, 2015


Objective: To compare efficacies of aspirin and mono-hydroxybenzoic acids as anti-stress and potential anxiolytic and antidepressant agents.

Methods: Antidepressant and stress response suppressing effective daily oral doses of aspirin and 3-hydroxybenzoic acid were estimated in tail suspension test using foot shock stressed mice. Efficacies of 20 mg/kg daily oral doses of aspirin and mono-hydroxybenzoic acids in elevated plus maze and forced swimming tests were compared with those of diazepam (5 mg/kg/day) in foot shock stressed rats. Apart from stress triggered alterations in body weights and core temperatures, pretreatment effects on plasma glucose, cortisol and insulin levels and weights of adrenal gland and spleen were also compared in the rat experiment.

Results: Daily 3mg/kg oral doses of aspirin and 3-hydroxybenzoic acid protected mice against stress triggered alterations in body weights and core temperatures, whereas their minimally effective daily doses in tail suspension test were 30 and 3mg/kg respectively. Unlike low dose aspirin, none of the monohydroxybenzoic acids were active in rat forced swimming test for antidepressants, and diazepam like anxiolytic activity in stressed rats was observed for aspirin and 2-hydroxybenzoic acid only. All quantified stress triggered alterations in both mice and rats were either absent or less pronounced in all aspirin or monohydroxybenzoic acid treated groups.

Conclusion: Aspirin and all mono-hydroxybenzoic acids are stress response desensitizers, but only low dose aspirin and salicylic acid possess diazepam like effects in stressed rats. Unlike mono-hydroxybenzoic acids, aspirin possess antidepressants like activities in both stressed mice and rats after its low daily oral doses.

Keywords: Aspirin; Mono-hydroxybenzoic acids; Diazepam; Stresstriggered- hyperthermia; Anxiolytic; Anti-depressant


Structurally diverse hydroxybenzoic acid derivatives are common constituents of plant derived food and other products regularly used for health maintenance or for recreational and therapeutic purposes. Amongst them the 2-, 3- and 4-hydroxylated benzoic acids are structurally the simplest ones, and they have been identified as bioactive constituents of numerous edible and other medicinal plants often used in Ayurvedic and other traditionally known systems of medicine and health care, or as ultimate or penultimate metabolites of structurally diverse aromatic phytochemicals, including those of some essential aromatic acids. However, the questions concerning their roles in traditionally known medicinal used herbal remedies still remain unanswered, or at the best can be speculative answered only.

It is now well recognized though, that 2-hydroxybenzoic acid (salicylic acid) possess a broad spectrum of therapeutically interesting bioactivities potentially useful for prevention and cure of diverse metabolic and other chronic diseases, including cancer, and that its bioactivity profile and side effect potentials depend on its daily doses and treatment regimen used [1-4]. Salicylic acid with bactericidal and antiseptic properties has since long been used as a food preservative [5], and such uses of easily hydrolysable esters of 4-hydroxybenzoic acid (Parabens) are still fairly common. Together with other phenolic acids, 3-hydroxybenzoic acid is also encountered in several common edible plants and in a GRAS food additives castoreum. More recent reports indicate also that like salicylic or nicotinic acids, 3-hydroxybenzoic acid could also have therapeutic potentials for treatment diabetes and other metabolic disorders [6-9].

Numerous observations made in our laboratories and elsewhere have consistently reconfirmed that fairly low repeated daily oral doses of herbal extracts and some of their bioactive constituents possess stress response modulating, antidepressant, anxiolytic and diverse other therapeutically interesting bioactivities in rodent models [10]. Recently we have reported also that fairly low daily oral doses of salicylic and 4-hydroxybenzoic acids desensitizes mice against foot shock stress triggered body weight losses and thermoregulatory disturbances, and also posses anxiolytics and antidepressant activities in stressed mice [11]. However, the questions whether aspirin (a pro-drug of salicylic acid) and 3-hydroxybenzoic acid also possess analogous stress response modulating activities after their low oral doses still remained unanswered. Therefore, aim of the two mice experiments reported in this communication was to assess dose ranges and treatment regimen of aspirin and 3-hydroxybenzoic acid in the same mouse bioassay used earlier for the other two mono-hydroxybenzoic acids. Results of these experiments revealed that like salicylic and 4-hydoxybenzoic acids, both aspirin and 3-hydroxybenzozic acid also possess stress response suppressing as well as antidepressant and anxiolytics like activities after their repeated daily fairly low oral doses. Therefore, the third reported experiment was conducted to compare anti-stress, and anxiolytics and antidepressants like effects of aspirin in an analogous bioassay using rats as experimental animals. Results of these experiments are described and discussed in this communication. Implications of the reported observations for better defining bioactive constituents of traditionally known medicinal herbs, or for obtaining novel therapeutic leads from hydroxybenzoic acids and their metabolic precursors are also pointed out.

Materials and Methods


Adult male Wistar rats (150±50 g) and male Swiss mice (20±5g) were obtained from Central Animal House of Institute of Medical Sciences, Banaras Hindu University, Varanasi (Registration number 542/AB/CPCSEA). They were acclimatized to constant laboratory conditions for at least one week before starting the experiments. They were randomly selected and group-housed (six animals per cage) in poly propylene cages (28×19×12.5 cm) and maintained at an ambient temperature (25±1oC) and relative humidity (50±10%) with a 12:12 h light /dark cycle (light on at 6:00 and off at 18:00). All cages were provided with husk, and except for observation periods all animals have always free access to standard rodent diet and tap water. Prior approval from the Central Animal Ethical Committee of the Banaras Hindu University was obtained (Dean/2014/CAEC/607; dated May 30, 2014) for the experimental protocol. All the experimental groups were tested on the same days of a given experiment, and they were handled, weighed and observed by blind observers using the same lab equipments.

Drugs and chemicals

Aspirin, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, and fluoxetine were purchased from-HiMedia Laboratories Pvt. Ltd. Mumbai, India. Carboxymethyl Cellulose (CMC) was obtained from Central Drug House Pvt. Ltd., New Delhi, India and diazepam was acquired from Lupin Ltd., Jammu, India.

Animal grouping and drug administration

In mice dose finding experiments, the animals were randomly allotted to different experimental groups of six animals each. Standard drugs fluoxetine (10 mg/kg), diazepam (5 mg/kg) and graded oral doses (3, 10, 30, 100 and 300 mg/kg) of test agents were suspended in 0.3% CMC and orally administered for 11 consecutive days (application volume 10 ml/kg). Other details of bioassay procedure used were similar to those reported earlier [11], and are summarized in Figure 1(a).