Natl. J. Physiol. Pharm. Pharmacol. (2025), Vol. 15(2): 180-186

Research Article

10.5455/NJPPP.2025.v15.i2.11

Comparative study of antiulcer activity of Glycyrrhiza glabra (Liquorice) and pantaprazole in albino rats

Rupa Arun Korde^1*, Radhika Mayur Sherkhane², Rupa Arun Korde¹, Mohammed Ameeruddin Kamdod³

¹Associate Professor, Department of Pharmacology, SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwar University, Dharwad, India²Professor and Head of Department of Pharmacology, SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwar University, Dharwad, India³Retired Professor, Department of Pharmacology, SDM College of Medical Sciences and Hospital, Dharwad, India

*Corresponding Author: Rupa Arun Korde. SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwar University, Dharwad, India. Email: drrupa2 [at] yahoo.co.in

Submitted: 21/11/2024 Accepted: 18/01/2025 Published: 28/02/2025

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Abstract

Background: Peptic ulcer disease (PUD) is a common gastrointestinal disorder. Glycyrrhiza glabra (liquorice) and pantoprazole are known for their anti-ulcer properties.

Aim: To compare the anti-ulcer effects of G. glabra and pantoprazole in albino rats.

Methods: Healthy adult Wistar albino rats (150–250 g) were acclimatized for 1 week in the department after being obtained from the central animal house and were provided standard food pellets and water ad libitum. Gastric ulcers were induced using aspirin (500 mg/kg orally in 1% carboxymethyl cellulose) and ethanol (1 ml orally). Pantoprazole was administered as the standard drug at a dose of 40 mg/kg, whereas G. glabra was prepared by boiling 10 g of powder in 80 ml of distilled water, with doses of 625 mg/kg or 1.25 g/kg. The drugs were delivered orally via a mouth gag and feeding tube, and the antiulcerogenic effects of G. glabra were compared with pantoprazole in models of aspirin- and ethanol-induced gastric mucosal damage.

Results: In Groups II and VI, treated with the standard drug pantoprazole, exhibited superior antiulcer activity. The test drugs in Groups VII and VIII were comparable to those in Group VI, suggesting potential for future antiulcer applications.

Conclusion: The results demonstrated that ethanol alone and its combination with G. glabra significantly affected mean scores, with ethanol showing the highest efficacy and Pantoprazole or G. glabra combined with aspirin resulting in markedly lower scores.

Keywords: Peptic ulcer disease, Glycyrrhiza glabra (liquorice), Pantoprazole, Albino rats.

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Introduction

Nature has long been a rich source of therapeutic compounds, providing numerous medicinal plants that yield valuable phytochemicals. Licorice, scientifically known as Glycyrrhiza glabra, is a member of the Leguminosae family and is widely used in Ayurvedic medicine. This medicinal plant is found across Asia and parts of Europe (Fiore et al., 2005), and its origins are believed to have been in Iraq (Mamedov and Egamberdieva, 2019). Glycyrrhiza glabra is the most widely distributed species, and it is found in countries such as Italy, Spain, Turkey, the Caucasus region, western China, and Central Asia, whereas G. uralensis is native to Central Asia, China, and Mongolia (Hayashi et al., 2019). Licorice is commercially cultivated in many countries, including Italy, Spain, Greece, France, Iran, Iraq, Turkey, Turkmenistan, Uzbekistan, Syria, Afghanistan, Azerbaijan, India, China, the United States, and England (Sokolov and Zamotayev, 1985; Chevallier, 1996). It is one of the most economically significant plants globally, with diverse applications in the tobacco, cosmetics, food, and pharmaceutical industries (Fenwick et al., 1990). The phytochemical and pharmaceutical properties of licorice have been thoroughly studied and documented (Hayashi et al., 2019).

Peptic ulcer disease (PUD) remains a significant health concern globally. It is characterized by the erosion of the gastric or duodenal mucosa, which is often caused by factors such as Helicobacter pylori infection, excessive use of nonsteroidal anti-inflammatory drugs, and excessive acid secretion (Lanas and Chan, 2017). Traditional therapeutic approaches to managing peptic ulcers include the use of proton pump inhibitors (PPIs) like pantoprazole, which are effective in reducing gastric acid production and promoting mucosal healing. Pantoprazole, a well-established PPI, is commonly used in the treatment of ulcer-related conditions because of its potent and selective inhibition of the H+/K+ ATPase enzyme in the gastric parietal cells (Shin and Sachs, 2008).

In recent years, interest in the potential use of herbal remedies for ulcer management has increased, with G. glabra (liquorice) emerging as a promising candidate. Glycyrrhiza glabra, known for its anti-inflammatory and mucosal protective properties, has been traditionally used in various cultures to treat gastrointestinal disorders.

This study examines the numerous chemical constituents of licorice and its significant pharmacological properties, including anticancer, antibacterial, anti-inflammatory, cardioprotective, hepatoprotective, and respiratory infection-fighting activities. Recent literature highlights the growing interest among researchers in licorice, as they work to identify its active components and understand its mechanisms of action. Flavonoids, extracted from the stem and root of licorice, have demonstrated several promising biological activities. This review explores the ethnopharmacological applications, phytochemical composition, biological activities, clinical evidence, and toxicology of licorice, serving as a valuable resource for future research. Additionally, this study focused on the molecular mechanisms and pharmacological activities of four key flavonoids in licorice—isoliquiritigenin, liquiritigenin, licochalcone, and glabridin—suggesting that licorice could offer a natural alternative for treating emerging disorders with minimal side effects. This review aims to provide systematic insights into this ancient remedy, supporting its further development and clinical application.

This study aimed to compare the anti-ulcer activity of G. glabra and pantoprazole in albino rats, assessing their efficacy in reducing ulcerative lesions and their potential to improve mucosal healing. By evaluating and contrasting these two therapeutic agents, this study seeks to provide insights into the effectiveness of G. glabra as an alternative or complementary treatment to conventional pharmacological interventions for PUD.

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Materials and Methods

Healthy adult Wistar albino rats of either sex, weighing between 150 and 250 g, were procured from the central animal house of the institution. The rats were acclimatized for one week in departmental animal housing facilities under standard laboratory conditions. During the acclimatization and experimental periods, rats were provided with ad libitum access to standard food pellets and water.

Ethical clearance for the use of the animals was obtained from the Institutional Animal Ethics Committee (certificate no. SDMIAEC: 069:2011).

Drug preparation

Aspirin (Ulcerogen): Sourced from SDM Pharmacy, aspirin was suspended in 1% carboxymethyl cellulose (CMC) in water and administered orally at a dose of 500 mg/kg via gavage to induce gastric ulcers (Parmar and Desai, 1993).

Ethanol (99.9%) (Ulcerogen): Sourced from the Department of Pharmacology, ethanol (99.9%) was administered orally at a dose of 1 ml to induce gastric ulcers (Kanter et al., 2005).

Pantoprazole (Standard drug): Dissolved in distilled water and administered at a dose of 40 mg/kg orally (Haule et al., 2012).

Glycyrrhiza glabra root (Test compound): The test compound, G. glabra root powder, was obtained from the Department of Rasayanashastra, Ayurvedic Mahavidyalaya, Hubli. The preparation of the test compound involved adding 10 g of G. glabra powder to 80 ml of distilled water, which was boiled to reduce the volume to 40 ml over 30 minutes. After boiling, the preparation was allowed to steep for 10 minutes and then filtered. The resulting solution contained 0.25 g of test compound per ml. Freshly prepared G. glabra was administered in two doses: 625 mg/kg and 1.25 g/kg (Srivastava, 2009).

Drug dosing

The doses of all drugs were calculated based on the individual body weight of each animal. The respective volumes of the drugs were administered orally using an infant feeding tube, which was passed into the esophagus with the aid of a mouth gag. In a pilot study, G. glabra at a dose of 1.25 g/kg was found to be effective in reducing gastric mucosal damage. Therefore, a lower dose of 625 mg/kg was also included for further investigation, and both doses were used in subsequent tests.

Procedure

The antiulcerogenic properties of G. glabra were evaluated in two experimental models: aspirin-induced and ethanol-induced gastric mucosal damage. The results were compared with those of pantoprazole, a known anti-ulcer drug. The rats were randomly divided into eight groups, with each group containing six animals (n=6):

1. Group I (Control): Aspirin 500 mg/kg.

2. Group II (Standard Control): 40 mg/kg of pantoprazole + aspirin 500 mg/kg.

3. Group III (Test compound A): G. glabra 625 mg/kg + aspirin 500 mg/kg.

4. Group IV (Test compound B): G. glabra, 1.25 g/kg + aspirin 500 mg/kg.

5. Group V (Control): Ethanol 1 ml (99.9%).

6. Group VI (Standard Control): 40 mg/kg of pantoprazole + ethanol 1 ml (99.9%).

7. Group VII (Test compound A): G. glabra 625 mg/kg + ethanol 1 ml (99.9%).

8. Group VIII (Test compound B): G. glabra (1.25 g/kg) + ethanol 1 ml (99.9%).

This design allowed the evaluation of the protective effects of G. glabra at two different doses in aspirin- and ethanol-induced gastric ulcer models.

Aspirin-induced gastric ulcer model

Following the method of Parmar and Desai (1993), Wistar albino rats of either sex, weighing 150–250 g, were used after being fasted for 36 hours with free access to water. Group I received aspirin suspended in 1% CMC in water and administered orally at a dose of 500 mg/kg via gastric intubation. Group II received pantoprazole (40 mg/kg) 1 hour before aspirin (500 mg/kg). Group III received G. glabra at 625 mg/kg, 1 hour before aspirin administration, while Group IV received G. glabra at 1.25 g/kg, 1 hour before aspirin administration. Four hours after aspirin administration, the animals were euthanized, their stomachs were opened along the greater curvature, washed with normal saline, and the ulcers were examined and scored (Parmar and Desai, 1993).

Ethanol-induced ulcer model

Wistar albino rats of either sex weighing between 150 and 250 g, and starved for 24 hours with water ad libitum were used. Group V received ethanol (99.9 %) in a dose of 1ml orally via gastric intubation. Group VI received 40 mg/kg of pantoprazole 2 hours before the administration of ethanol (Saini, 2009). Group VII received G. glabra 625 mg/kg of G. glabra 30 minutes before ethanol (Kanter, 2005). Group VIII received 1.25 g/kg G. glabra 30 minutes before ethanol (Kanter, 2005). The animals were sacrificed 1 hour after ethanol administration, the stomach was opened along the greater curvature, washed with normal saline, and the ulcers were examined and scored (Kanter, 2005).

In both models, during the period of fasting, the animals had free access to drinking water. 4 hours after the administration of aspirin and 1 hour after the administration of ethanol (Kanter, 2005; Parmar and Desai, 1993), the animals were sacrificed by dislocating the cervico-atlanto joint under ether anesthesia. The anterior abdominal wall was opened, and the stomach dissected out (Parmar and Desai, 1993). The stomach was opened along the greater curvature and mounted on a moist board.

Analysis

Data are analyzed using SPSS software version 21 and Excel. Categorical variables are presented as frequency tables. Continuous variables are given in Mean ± SD/Median (Min, Max) form. Normality was assessed using the Shapiro–Wilk test. For the nonparametric test, the Kruskal–Wallis test and Mann–Whitney U test were used. p 0.05 indicates statistical significance.

The ulcers were examined and scored according to the method described by Laurence and Bacharach (1964).

0. Normal

1. Scattered haemorrhagic spots

2. Deeper hemorrhagic spots and some ulcers

3. Hemorrhagic spots and ulcers

4. Perforation

The ulcer index was calculated for each group using the method of Jain and Santani (1996).

$\begin{array}{l}\text{<b>Ulcer index</b>}=\\ \begin{array}{l}\text{Arithmetic means of}\\ \text{the intensity in a group}\end{array}\end{array}+\frac{\text{Ulcer positive No}\mathrm{x}2}{\text{Total number of animals}}$

In each group, the total score, mean score, SD, SEM, p value, ulcer index, and ulcer incidence were calculated.

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Results

Table 1 presents the measurements of six Albino rats treated with various antiulcer agents.

Table 1. Distribution according to the scores of different groups.

Table 2 presents the comparison of various scores across Groups 1–4. There was a significant difference in mean scores between Groups I to IV.

Table 2. Mean comparison of different scores between Groups I to IV.

Table 3 presents the mean scores across the different groups. There was a significant difference in the means between Groups I and II, Groups I and III, and Groups I and IV.

Table 3. Mean comparison of different scores between groups.

Table 4 presents the mean comparison of various scores among Groups V–VIII. There was a significant difference in the mean scores between these groups.

Table 4. Mean comparison of different scores between Groups V to VIII.

Table 5 presents the mean comparison of different scores between groups.

From the Mann–Whitney U test, it can be observed that there is a significant difference in the mean of Groups V and VI, Groups V and VII, and Groups V and VIII. In addition, a significant difference in the mean can be observed between Groups VI and VII, and Groups VII, and VIII.

Table 5. Mean comparison of different scores between groups.

Figure 1 shows the effects of drugs on gastric mucosal damage.

Fig. 1. Effects of drugs on gastric mucosal damage.

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Discussion

The present study aimed to evaluate and compare the anti-ulcer activity of G. glabra (licorice) and pantoprazole in albino rats. The anti-ulcerogenic properties of these substances were tested in models of gastric mucosal damage induced by aspirin and ethanol.

Pantoprazole, a well-established PPI, was used as the standard reference drug. In both aspirin- and ethanol-induced ulcer models, pantoprazole significantly mitigated gastric mucosal damage, demonstrating its effectiveness in reducing ulcer severity. This finding aligns with its known mechanism of action, which involves the suppression of gastric acid secretion, thereby providing a protective effect on the gastric mucosa.

Glycyrrhiza glabra administered at doses of 625 mg/kg and 1.25 g/kg also exhibited notable anti-ulcer activity. The higher dose of G. glabra exerted significant protective effects comparable to those of pantoprazole. The results suggest that G. glabra possesses substantial antiulcerogenic properties, potentially due to its mucosal protective and anti-inflammatory effects. This is consistent with previous studies highlighting its role in enhancing mucosal defense and reducing gastric acid secretion. Liquorice has been identified as a highly effective herb for ulcer treatment (Nugroho et al., 2016). Numerous researchers have indicated that Liquorice plays a significant role in wound healing (Tanideh et al., 2014).

The results reveal notable differences in mean scores across various groups, indicating varying levels of performance or responses in the present study.

In this study, the standard drug, pantoprazole, used in Groups II and VI, demonstrated superior anti-ulcer activity. It is noteworthy that Groups III and VII exhibited outcomes comparable to the standard, indicating their potential use as future antiulcer agents. Similarly, Groups VII and VIII showed similar efficacy as Group VI, suggesting a level of activity comparable to that of pantoprazole. These findings align with the positive effects observed by Gut Gard and ALE in Aly et al. (2005) and Mukherjee et al. (2010). Mukherjee et al. (2010) specifically highlighted the high efficacy of Gut Gard in significantly reducing gastric mucosal lesions.

Group VI consistently had the lowest mean ulcer score, indicating strong therapeutic efficacy. Groups VII and VIII displayed intermediate efficacy, suggesting a notable but less pronounced anti-ulcer activity. This positions Groups III, IV, VII, and VIII as promising candidates for effective treatment, in line with the outcomes reported by Mukherjee et al. (2010) and Aly et al. (2005). Both studies emphasized the protective effects of flavonoid-rich extracts and glycyrrhizic acid in promoting gastric mucosal health and healing.

In contrast, Groups II, IV, and VI, with comparatively lower mean scores, may reflect less effective interventions or control conditions, mirroring the outcomes seen with less potent treatments or placebos in similar studies. The consistently high efficacy observed in Groups I and V further supports the therapeutic potential of related compounds. These findings resonate with studies by Mukherjee et al. (2010) and Aly et al. (2005), which demonstrated the significant impact of flavonoid-rich compounds on gastric mucosal protection.

Additionally, research by Ligha et al. (2009) corroborates these findings, showing that extracts from liquorice seeds offered substantial protection against ethanol-induced gastric mucosal damage in animal models. The observed ulcer reductions were attributed to mechanisms such as increased mucus production or the prevention of mucus depletion following exposure to harmful agents.

Overall, these results highlight the potential of Groups III, VI, VII, and VIII as effective antiulcer treatments. Future investigations could focus on optimizing these interventions to maximize therapeutic outcomes and explore their underlying mechanisms of action.

Mukherjee et al., (2010) study reported that Gut Gard, a flavonoid-rich extract of G. glabra had a significant inhibitory effect on gastric mucosal lesions caused by indomethacin in rats. The cytoprotective effect was attributed to its flavonoid content and its ability to scavenge reactive oxygen species. The results indicate that Gut Gard effectively reduces mucosal damage and promotes healing due to its antioxidant and flavonoid content.

Aly et al., (2005) study compared aqueous licorice extract (ALE), famotidine (FT), and a combination of ALE and FT in an indomethacin-induced rat peptic ulcer model. It was found that glycyrrhizic acid from ALE increased the local concentration of prostaglandins, which in turn promoted mucous secretion and cell proliferation, thus accelerating ulcer healing. ALE’s glycyrrhizic acid contributes to enhanced mucosal protection and accelerated healing of ulcers, highlighting its therapeutic potential.

Glycyrrhiza glabra, commonly known as sweet wood or licorice, contains compounds like flavonoids, saponins, tannins, and phytosterols (Rizzato et al., 2017). It has been shown to possess antioxidant, anti-inflammatory, neuroprotective, anticancer, antimutagenic, hepatoprotective, and antimicrobial properties (Chakotiya et al., 2017; Waang et al., 2017; Yang et al., 2017; Yin et al., 2017; Pastorino et al., 2018). A previous study investigated the effects of low (100 mg/kg) and high (200 mg/kg) doses of ALE on stress-induced gastric ulcers in rats, revealing a dose-dependent response. The high dose led to a nearly normal gastric lining, with the licorice-treated group showing a lower ulcer index and reduced inflammation compared with the untreated group (Mathur et al., 2019).

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Conclusion

Glycyrrhiza glabra is a significant natural alternative for the management of gastric ulcers, and it exhibits anti-ulcer effects comparable to those of conventional treatments like pantoprazole. The established efficacy of this agent, coupled with a rich history of traditional medicinal use, makes it an attractive option for future research aimed at developing safe and effective antiulcer therapies. Exploring G. glabra further could not only enhance our understanding of its therapeutic potential but also promote the integration of herbal medicine into modern healthcare practices, ultimately benefiting patients seeking holistic and natural treatment options for gastric ulcers.

Future direction

The promising results of G. glabra in this study warrant further investigation into its detailed mechanism of action. Additionally, exploring the long-term effects, safety profile, and potential interactions with other medications could provide valuable insights into its practical applications. Comparative studies involving other ulcerogenic models and chronic administration protocols could also help establish a comprehensive understanding of G. glabra therapeutic potential.

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