Biology, Medicine, & Natural Product Chemistry  ISSN 2089-6514 (paper) 

Volume 13, Number 1, April 2024 | Pages: 271-275 | DOI: 10.14421/biomedich.2024.131.271-275 ISSN 2540-9328 (online) 
 

 

 

 

Antiepileptic Potential of Justicia insularis Leaf Extract in Swiss Mice 

 
Nancy Elkanah1, Michael Chuks Nnumolu1,*, Jude Effiom Okokon1, Uduak Peter Ise2 

1Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Uyo, Uyo, Nigeria. 
2Department of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Bingham University, Karu, Nassarawa State, Nigeria. 

 

 

Corresponding author* 
michaelnnumolu@gmail.com 

 

 
Manuscript received: 21 September, 2023. Revision accepted: 14 March, 2024. Published: 08 August, 2024. 

 

 

Abstract 

 

Epilepsy is a prevalent neurological condition characterized by repetitive seizures, necessitating the exploration of efficacious treatments. 

Justicia insularis, a plant with a historical use in treating convulsions and epilepsy, has garnered attention as a potential antiepileptic 

agent. This study aimed to investigate the antiepileptic properties of Justicia insularis leaf extract, focusing on generated seizure models in 

mice. The analysis of variance (ANOVA), specifically one-way ANOVA, was utilized to assess the statistical significance of the data. 

Seizure models were employed to evaluate the antiepileptic effects of Justicia insularis leaf extract. The p-values obtained from the one-

way ANOVA were significant, with values of ap<0.005, bp<0.01, and cp<0.001. These results suggest the statistical significance of the 

observed effects in the seizure models. This study provides valuable insights into the therapeutic potential of Justicia insularis leaf extract 

as a treatment for epilepsy. The significant findings underscore the importance of further research into the use of natural medicines for 

managing epilepsy, potentially offering new avenues for treatment. 

 

Keywords: Justicia insularis; antiepileptic; seizures; convulsion; GABAA receptor; flavonoids. 

 

 

INTRODUCTION 
 

Epilepsy is a persistent neurological condition 

characterised by the occurrence of repetitive seizures. 

This event can potentially influence individuals across 

various age groups and substantially influence their 

overall well-being. Despite various antiepileptic 

treatments, many persons diagnosed with epilepsy 

encounter insufficient seizure management and often 

endure unfavourable prescription side effects. his has 

increased interest in alternative therapies, including 

herbal remedies (Espinosa-Garcia et al., 2021). 

Justicia insularis, sometimes called "African Water 

Willow", is classified under the Acanthaceae botanical 

family. It has been widely used in many traditional 

medicinal practices in diverse cultural contexts. Justicia 

insularis is often grown within the home gardens of West 

and Central Africa, with particular prevalence in 

countries such as Guinea, Sierra Leone, Ghana, Togo, 

Benin, Nigeria, Cameroon, and the Democratic Republic 

of Congo (Christian et al., 2020). Justicia insularis has 

been used as a traditional cure for convulsions, epilepsy, 

and associated ailments across several African groups. In 

Senegal, providing a leaf decoction derived from J. 

insularis to pregnant women during the last month of 
their pregnancy is common practice to alleviate the 

discomfort associated with labour (Christian et al., 2020). 

In the Western area of Cameroon, the use of it is seen in 

conjunction with the foliage of three other botanical 

species (Aloe buettneri, Hibiscus macranthus, and 

Dicliptera verticillata) to manage dysmenorrhoea and 

some instances of female infertility (Meguem et al., 

2021). Additionally, in Togo and Northeast Ghana, the 

cooked leaves of J. insularis are administered to infants 

to facilitate bowel movement, and the leaves are also 

used topically to enhance the healing process of wounds 

(Irinmwinuwa et al., 2023). Nevertheless, it is well 

observed that traditional knowledge frequently lacks 

empirical substantiation via scientific methods. Hence, 

the primary objective of this investigation was to conduct 

a scientific assessment of the antiepileptic properties of 

Justicia insularis leaf extract via the use of 

pentylenetetrazole, aminophylline and isoniazid-induced 

mice. 

 

 

MATERIALS AND METHODS 
 

Experimental Animals 

Swiss mice of either sex used for these experiments were 

obtained from the Faculty of Pharmacy Animal House, 

University of Uyo, Uyo. The animals were housed in 

standard cages and were maintained on standard pelleted 
feed (Guinea feed) and water ad libitum. Permission and 

approval for animal studies were obtained from the 

College of Health Sciences Animal Ethics Committee, 

https://doi.org/10.14421/biomedich.2024.131.271-275
mailto:michaelnnumolu@gmail.com


 

 
 

272 Biology, Medicine, & Natural Product Chemistry 13 (1), 2024: 271-275 

 

 

University of Uyo. All animal experiments complied 

with the National Institute of Health Guide for Care and 

Laboratory Animals (pub. No. 85-23, revised 1985). 

 

Plant Collection and Identification 

The plant material Justicia insularis (leaves) was 

collected from the University of Uyo premises, Akwa 

Ibom State, Nigeria, in March 2023. The plant was 

identified and authenticated by a taxonomist in the 

Department of Botany and Ecological Studies, University 

of Uyo, Uyo, Nigeria.  

 

Preparation of Extract 

The leaves were washed and shade-dried for two weeks. 

The dried plants' materials were chopped into small 

pieces and reduced to powder using an electric grinder. 

The powdered leaves material (1.5 kg) was soaked for 72 

h in ethanol (50%). This was later filtered, and the liquid 

filtrate was concentrated and evaporated to dryness in 

vacuo 40˚C using a rotary evaporator (BuchiLab, 

Switzerland). The extract was stored in a refrigerator at -

4˚C until used for the proposed experiments.  

 

Experimental Design 

Table 1 illustrates the experimental design used for the 

three seizure models. The design of the models was the 

same across all models, with the exception of the 

administration of different standard drugs for each kind 

of convulsion. Specifically, phenobarbital (40 mg/kg) 

was used as the standard drug for pentylenetetrazole and 

aminophylline-induced convulsions, while diazepam (5 

mg/kg) was employed as the standard drug for isoniazid-

induced convulsions. The different doses of the extract 

and standard drugs were administered to the mice an 

hour before induction of convulsion. 

 
 

 

Table 1. Experimental design of experimentally induced convulsion in Swiss mice. 
 

GROUPS AGENT DOSAGE (mg/kg/day) 

I Normal Saline 10 mL/kg 

II Low dose of the ethanol leaf extract of Justicia insularis 150 

III Middle dose of the ethanol leaf extract of Justicia insularis 300 

IV High dose of the ethanol leaf extract of Justicia insularis 450 

V Phenobarbital 40 

Source: Field data (2023) 

 

 

Statistical Analysis and Data Evaluation 

The results were analysed using the statistical software 

package for social sciences (SPSS) version 16.0 for 

Windows. Analysis of variance (ANOVA) was used to 

compare means, and all results were presented as Mean ± 

SEM. 
 
 

RESULTS AND DISCUSSION 
 

Results 

PTZ –induced convulsion 

Administration of leaf extract of Justicia insularis (150-

450 mg/kg) provided a considerable degree of protection 

for the mice against seizure induced by 

pentylenetetrazole. The leaf extract prolonged the onset 

of myoclonic convulsion in a dose-dependent fashion, 

but the effect was insignificant (p>0.05) compared to the 

control. Similarly, the leaf extract exerted a significant 

(p<0.05) prolongation of time for the onset of tonic 

convulsion in a dose-dependent manner, which was 

significant (p<0.05) at the higher doses (300 and 450 

mg/kg) (Table 2). The time of death of treated animals 

was dose-dependently and insignificantly (p>0.05) 

prolonged compared with the control. The standard drug, 

phenobarbital, offered 33.33% protection to the treated 

animals (Table 2). 

 

 

Table 2. Effect of ethanol leaf extract of Justicia insularis on Pentylenetetrazole-induced convulsion. 

 

TREATMENT DOSE (mg/kg) 
Onset of myoclonic 

(Min) 

Onset of tonic 

(Min) 

Time of death 

(Min) 
No. of death 

Control (normal saline) - 0.32 ±0.04 1.35 ± 0.06 1.68±0.37 6/6 

Phenobarb 40 1.23 ±0.09c 18.28±1.82c 30.09±0.01c 2/6 

leaf extract 

150 0.33 ±0.01 1.32± 0.14 3.89±0.32 6/6 

300 0.34 ±0.06 2.06± 0.25a 2.99±0.38 6/6 

450 0.46± 0.04 2.57±0.02a 3.64±0.63 6/6 

Data are expressed as MEAN ± SEM, Significant at ap<0.005; bp<0.01; cp < 0.001, compared to control. (n=6). 

 
 

Aminophylline-induced convulsion 

Administration of the leaf extract of J. insularis (150-450 

mg/kg) caused a significant (p<0.01-0.001) delay in the 

onset of seizure induced by aminophylline in a dose-

dependent fashion. The delay was significant (p<0.01-

0.001) in both myoclonic and tonic convulsions, 



 

 
 

 Elkanah et al. – Antiepileptic Potential of Justicia insularis Leaf Extract in … 273 
 

 

especially at higher doses (300 and 450 mg/kg) of the 

extract (Table 3). The time of death of the treated 

animals was dose-dependently and significantly (p<0.05-

0.01) prolonged at higher doses (300 and 450 mg/kg) of 

the extract when compared with the control. The standard 

drug, Phenobarbital, offered 100% protection to the 

treated mice.  

 

 

Table 3. Effect of ethanol leaf extract of Justicia insularis on Aminophylline-induced convulsion. 

 

TREATMENT DOSE (mg/kg) 
Onset of myoclonic 

(Min) 
Onset of tonic (Min) 

Time of death 

(Min) 
No. of death 

Control (normal saline) - 10.42 ± 0.36 12.31 ± 4.27 15.30 ± 5.45 6/6 

Phenobarb 40 12.96 ± 0.76c 0.00 ± 0.00c 0.00 ± 0.00c 6/6 

leaf extract 

150 10.94 ± 1.82 12.37 ± 2.41 16.79 ± 5.21 6/6 

300 14.62 ± 2.66 22.82 ± 1.39a 26.65 ± 1.91a 6/6 

450 22.77 ± 3.19c 26.49 ±3.66a 30.22 ± 4.36b 6/6 

Data are expressed as MEAN ± SEM, Significant at ap<0.005; bp<0.01; cp < 0.001, compared to control. (n=6). 

 

 

Isoniazid-induced convulsion 

Administration of the leaf extract of Justicia insularis 
(150-450 mg/kg) caused a significant (p<0.01-0.001) 

delay in the onset of seizure induced by isoniazid in a 

non-dose-dependent fashion. The delay was significant 

(p<0.01-0.001) in both myoclonic and tonic convulsions, 

especially at the lower doses (150 and 300 mg/kg) (Table 

4). The time of death of the treated animals was 

prolonged significantly (p<0.05) at the lowest dose (150 

mg/kg) of the extract when compared with the control, 

while the standard drug, diazepam, also offered a more 

significant (p<0.01) prolongation of the time of death to 

the mice treated with it (Table 4). 

 

 

Table 4. Effect of ethanol leaf extract of Justicia insularis on Aminophylline-induced convulsion. 
 

TREATMENT DOSE (mg/kg) 
Onset of myoclonic 

(Min) 
Onset of tonic (Min) 

Time of death 

(Min) 
No. of death 

Control (normal saline) - 13.73±3.90 29.08± 1.23 34.95±1.64 6/6 

Diazepam 5 41.17±0.10b 26.19± 0.53b 84.09±4.05b 6/6 

leaf extract 

150 41.81±1.23b 55.77± 1.72b 56.39±1.86a 6/6 

300 26.96±0.59a 40.73±3.05a 47.64±6.25 6/6 

450 13.73±3.90 29.08±1.23 35.95±1.44 6/6 

Data are expressed as MEAN ± SEM, Significant at ap<0.005; bp<0.01; cp < 0.001, compared to control. (n=6). 

 

 

Discussion 

The efficacy of the leaf extract derived from Justicia 

insularis, a botanical species often used in traditional 

medicine for managing convulsions and epilepsy, was 

assessed in relation to its potential to mitigate 

experimentally induced convulsions. The leaf extract was 

found to possess significant activity against seizures 

induced by pentelyenetetrazole, aminophylline and 

isoniazid, offering considerable protection in some cases, 

with lower doses being more potent. The precise 

mechanisms of aminophylline-induced seizures seem 

multifaceted, including various intricate pathways that 

remain uncertain. The available evidence indicates that 

seizures caused by aminophylline may be attributed to 

two mechanisms: adenosine receptor antagonism and 

suppression of cerebral nucleotidase activity (Tescarollo 

et al., 2020). These mechanisms decrease adenosine 

levels in the brain, ultimately leading to disinhibition. 

However, according to a paper by Sharma and Sandhir 
(2010), it was shown that diphenylhydantoin, which is a 

potent inhibitor of adenosine absorption, did not show 

efficacy in avoiding these seizures. In addition to its non-

specific inhibition of adenosine receptors (Maleki-

Sadeghi et al., 2022), aminophylline is believed to have 

inhibitory effects on adenosine production. Nevertheless, 

a study by Ray et al. (2005) has shown that seizures 

triggered by aminophylline may be attributed to 

oxidative stress resulting from the production of free 

radicals and reactive oxygen species. The leaf extract has 

demonstrated notable antioxidant capabilities (Adeyemi 

& Babatunde, 2014). This activity may be attributed to 

the ability of its phytochemical ingredients to scavenge 

free radicals. The leaf extract may have also facilitated 

adenosine production, contributing to its anticonvulsant 

properties. 

Shrivastava et al. (2022) explain that the 

anticonvulsant action of pentylenetetrazole (PTZ) may be 

attributed to its ability to block the activity of gamma-

aminobutyric acid (GABA) at GABAA receptors. 

Gamma-aminobutyric acid (GABA) is a prominent 

inhibitory neurotransmitter involved in the 

pathophysiology of epilepsy. The modulation of GABA 
neurotransmission may reduce or intensify convulsions 

(Akyuz et al., 2021). Phenobarbitone and diazepam, 

commonly used medications for epilepsy, have been 

shown to exert their antiepileptic properties by 



 

 
 

274 Biology, Medicine, & Natural Product Chemistry 13 (1), 2024: 271-275 

 

 

augmenting GABA-mediated inhibition inside the brain 

(Okokon et al., 2021). The efficacy of phenytoin in 

preventing PTZ-induced seizures was limited, perhaps 

due to its mechanism of action, including the inhibition 

of sodium ion influx into brain cells, hence impeding the 

production of repetitive action potentials (Okokon et al., 

2021). The observed delay in PTZ-induced convulsion 

and protective effects on animals resulting from the 

administration of J. insularis leaf extract provide 

evidence supporting its central nervous system 

depressive properties and its capacity to increase GABA-

mediated inhibition inside the brain. 

Isoniazid, a pharmaceutical agent used to treat 

tuberculosis, has been found to induce status epilepticus, 

a prolonged seizure activity, by reducing Gamma-

Aminobutyric Acid (GABA) levels in the brain. GABA 

is a crucial inhibitory neurotransmitter in the mammalian 

brain. This effect is achieved by inhibiting pyridoxal-5-

phosphate-dependent Glutamic Acid Decarboxylase 

(GAD), an enzyme involved in GABA synthesis. 

Pyridoxal-5-phosphate is the biologically active form of 

pyridoxine, functioning as a cofactor for glutamic acid 

decarboxylase (GAD), an essential enzyme involved in 

the manufacture of gamma-aminobutyric acid (Ghatge et 

al., 2021). Recurrent seizures characteristic of status 

epilepticus result from reduced GABA levels (Rho and 

Boison, 2022). Despite the limited efficacy of existing 

anticonvulsant medications in treating seizures generated 

by isoniazid, intravenous diazepam continues to be 

utilised for seizure management in the absence of 

pyridoxine (Okokon et al., 2021). The administration of 

Justicia insularis leaf extract demonstrated a substantial 

protective effect against isoniazid (INH)-induced 

convulsions in the treated mice. The observed behaviour 

might be attributed to the extract's capacity to augment 

GABA production in the brain through the actions of its 

phytoconstituents. 

The antiepileptic effect of flavonoids, which are 

secondary metabolites found in plants, has been 

extensively documented in many studies. These 

compounds have been shown to modulate the GABAA-

Cl-channel complex, similar to benzodiazepines, 

indicating their potential therapeutic use in 

treating epilepsy (Choudhary et al., 2011). The 

antiepileptic effect of flavonoids is attributed to their 

ability to modulate the GABAA-Cl-channel 

complex, facilitated by their structural resemblance to 

benzodiazepines (Choudhary et al., 2011). Additionally, 

the compound apigenin, which belongs to the class of 

flavonoids, has been identified as a ligand that acts on the 

central nervous system, like benzodiazepines. It has also 

shown effectiveness in mitigating convulsions generated 

by picrotoxin (Jäger et al., 2009). Extracts derived from 

Justicia insularis leaves have a high concentration of 

flavonoids and other phenolic compounds known for 

their potent antioxidant properties, and these metabolites 

function by scavenging free radicals and regulating the 

GABAA-Cl-channel complex inside the central nervous 

system (CNS), demonstrating their anticonvulsant 

properties (Oyomah et al., 2019). 

The results of this study have confirmed the 

anticonvulsant potential of leaf extract of Justicia 
insularis and justify its use traditionally in the treatment 

of convulsion. 

 

 

CONCLUSION 
 

The findings presented in this study provide scientific 

support for the traditional use of Justicia insularis as an 

antiepileptic remedy. The leaf extract demonstrated 

significant anticonvulsant effects across various induced 

seizure models, indicating its potential as a natural 

therapy for epilepsy management. Interactions with 

GABAA receptors and antioxidant mechanisms likely 

mediate the observed effects. Further research is 

warranted to elucidate the specific compounds 

responsible for these effects and to explore their 

mechanisms of action in more detail. The study 

contributes to the growing knowledge surrounding herbal 

remedies for epilepsy and underscores the importance of 

integrating traditional knowledge with modern scientific 

approaches. 

 

 

Acknowledgements: The authors thank Mr Nsikan 

Malachy from the Animal House Department of 

Pharmacology and Toxicology at the University of Uyo 

for providing technical assistance. 

 

Authors' Contribution: Conceptualisation: Jude Effiom 

Okokon, Data curation: Michael Chuks Nnumolu, 

Formal analysis: Jude Effiom Okokon, Funding 

acquisition: Nancy Elkanah, Investigation: Jude Effiom 

Okokon, Nancy Elkanah, Methodology: Jude Effiom 

Okokon, Project administration: Nancy Elkanah, 

Supervision: Jude Effiom Okokon, Validation: Uduak 

Peter Ise, Jude Effiom Okokon, Writing–Original 

Draft: Nancy Elkanah, Writing–Review & Editing: 

Michael Chuks Nnumolu. 

 

Competing Interests: The authors declare that there are 

no conflicts of interest concerning this manuscript. 

 

Funding: The study was self-funded. 

 

 

REFERENCES 
 
Espinosa-Garcia, C., Zeleke, H. and Rojas, A. (2021). Impact of 

Stress on epilepsy: Focus on neuroinflammation—A mini 

review. International journal of molecular sciences. 2021 Apr 

14;22(8):4061. 

Christian A. G., Ugochi, O. A., Azubuike, E. J., Uchenna, M. A., 

John, A. D., Amarachi, I. L. and Alozie, O. O. (2020). Acute 

and Sub-Acute Toxicity Effect of the Ethanol Leaf Extract of 



 

 
 

 Elkanah et al. – Antiepileptic Potential of Justicia insularis Leaf Extract in … 275 
 

 

Justicia Insularis in Wistar Rats Saudi Journal of Medical and 

Pharmaceutical Sciences. 

Meguem, S. O., Lienou, L. L., Goka, M. S., Tagne, R. S., Yemele, 

D. M., and Telefo, P. B. (2021). Effects of the aqueous extract 

of Dicliptera verticillata on fertility and different stages of 

gestation in female rats. Zygote. 2021 Aug;29(4):307-13. 

Irinmwinuwa, E. O., Adolphus, M. C., Opute, R. E., Oyate, G. B., 

Chinedu, J. O., Afonne, O. J. and Unekwe, P. C. (2023). 

Review of herbal plant associated with anti-anemic property 

and mechanism of action. International Journal of Science and 

Research Archive. 2023;8(2):589-601. 

Tescarollo, F. C., Rombo, D. M., DeLiberto, L. K., Fedele, D. E., 

Alharfoush, E., Tomé, Â. R., Cunha, R. A., Sebastião, A. M. 

and Boison, D. (2020). Role of adenosine in epilepsy and 

seizures. Journal of caffeine and adenosine research. 2020 Jun 

1;10(2):45-60. 

Sharma, A. and Sandhir, R. (2010). Oxidative stress after lithium-

pilocarpine induced status epilepticus in mice brain. Annals of 

Neurosciences. 2010 Nov 2;13(1):1-4. 

Maleki-Sadeghi, N., Rahmani, P., Aghsaeifard, Z. and Heidari, G. 

(2022). Effects of aminophylline on the levels of neutrophil 

gelatinase-associated lipocalin (NGAL) in asphyxiated term 

neonates. Archives of Physiology and Biochemistry. 2022 Jul 

4;128(4):1105-10. 

Ray, A., Gulati, K., Anand, S. and Vijayan, V. K. (2005). 

Pharmacological studies on mechanisms of aminophylline-

induced seizures in rats. Indian Journal of Experimental 

Biology. 43: 849-853. 

Adeyemi, O. T. and Babatunde, O. (2014). Chemical composition 

and antioxidant capacity of the leaf extract of Justicia insularis. 

International Journal of Physical Sciences. 2014 Oct 

30;9(20):454-8. 

Shrivastava, A,. Gupta, J. K. and Goyal, M. K. (2022). Flavonoids 

and antiepileptic drugs: a comprehensive review on their 

neuroprotective potentials. Journal of Medical Pharmaceutical 

and Allied Sciences. 2022;11:4179-86. 

Akyuz, E., Polat, A. K., Eroglu, E., Kullu, I., Angelopoulou, E. 

and Paudel, Y. N. (2021). Revisiting the role of 

neurotransmitters in epilepsy: An updated review. Life 

sciences. 2021 Jan 15;265:118826. 

Okokon, J., Davies, K., Edem, U. A., Bassey, A. I. (2021). 

Anticonvulsant activity of leaf extract of Heinsia crinata: 

BIOLOGICAL ACTIVITY OF HEINSIA CRINATA. 

Nigerian Journal of Pharmaceutical and Applied Science 

Research. 2021 Mar 31;10(1):20-5. 

Ghatge, M. S., Al Mughram, M., Omar, A. M. and Safo, M. K. 

(2021). Inborn errors in the vitamin B6 salvage enzymes 

associated with neonatal epileptic encephalopathy and other 

pathologies. Biochimie. 2021 Apr 1;183:18-29. 

Rho, J. M. and Boison D. (2022). The metabolic basis of epilepsy. 

Nature Reviews Neurology. 2022 Jun;18(6):333-47. 

Choudhary, N., Bijjem, K. R. and Kalia, A. N. (2011). 

Antiepileptic potential of flavonoids fraction from the leaves 

of Anisomeles malabarica. Journal of Ethnopharmacology. 

2011 May 17;135(2):238-42. 

Jäger, A. K., Krydsfeldt, K., Rasmussen, H. B. (2009). 

Bioassay‐guided isolation of apigenin with 

GABA‐benzodiazepine activity from Tanacetum parthenium. 

Phytotherapy research. 2009 Nov;23(11):1642-4. 

Oyomah, G. O., Odoemena, C. S., Ogede, R. O. and Bala, D. 

(2019). Analgesic and Anti-Inflammatory Activities of The 

Ethanol Leaf Extract of Justicia Insularis (T. Anders) on 

Albino Rats. Journal of Advanced Research in Biology. 2019 

Dec 30;1(2):1-6. 

 

 



 

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