Medicinal plant vasaka could be a therapeutic option for the management of COVID-19 symptoms

Abstract

Introduction: Corona virus disease 19 (COVID-19) outbreak is a current pandemic that causes acute respiratory syndrome with huge mortality worldwide. The chief clinical features of COVID-19 is the presence of respiratory symptoms, with severe cardiovascular and renal complications in some patients. This study explores the potentiality of Vasaka (Adhatoda vasica Nees) in the prevention and management of symptoms associated with COVID-19. Vasaka is a well-known natural shrub in Ayurveda system of medicine which has a beneficial effects, particularly in respiratory disorders. Methods: First, we reviewed various researches on Vasaka, and its use in the management of respiratory system related diseases, viral diseases and other diseases in various journals and Ayurveda classical texts. Second, a survey based study was conducted to assess the effectiveness of Vasaka in the prevention and management of respiratory related problems. Results: The literature review revealed that Vasaka has been widely studied for its pharmacological activities. It has various action like antiviral, hepatoprotective, antibacterial, anti-inflammatory, cardioprotective, antitubercular and antioxidant. The survey results of the study indicated that only 15% of the sampled respondents used Vasaka in the treatment of respiratory related diseases. Nevertheless, among the respondents who used the plants, 97% stated that the use of Vasaka was useful in the treatment of diseases. Interestingly, 36.4% of the sampled respondents reported that they were completely recovered from the respiratory related diseases. Conclusions: Due to Vasaka multi-modal therapeutic effects and the findings from the survey-based research indicate the potentiality of its use in the management of COVID-19 symptoms.

Full text

~ 44 ~
Journal of Medicinal Plants Studies 2020; 8(5): 44-48
ISSN (E): 2320-3862
ISSN (P): 2394-0530
NAAS Rating: 3.53
www.plantsjournal.com
JMPS 2020; 8(5): 44-48
© 2020 JMPS
Received: 13-07-2020
Accepted: 23-08-2020
Dr. Hari Khanal
PG Scholar, PG Department of
Kayachikitsa, National Institute
of Ayurveda, Jaipur, Rajasthan,
India
Dr. Uttam Khanal
PhD, Agriculture Victoria,
Horsham, VIC 3400, Australia
Jyoti Koirala
B. Pharmacy, Little Buddha
College of Health Science,
Minbhavan, Kathmandu, Nepal
Corresponding Author:
Dr. Hari Khanal
PG Scholar, PG Department of
Kayachikitsa, National Institute
of Ayurveda, Jaipur, Rajasthan,
India
Medicinal plant vasaka could be a therapeutic
option for the management of COVID-19
symptoms
Dr. Hari Khanal, Dr. Uttam Khanal and Jyoti Koirala
Abstract
Introduction: Corona virus disease 19 (COVID-19) outbreak is a current pandemic that causes acute
respiratory syndrome with huge mortality worldwide. The chief clinical features of COVID-19 is the
presence of respiratory symptoms, with severe cardiovascular and renal complications in some patients.
This study explores the potentiality of Vasaka (Adhatoda vasica Nees) in the prevention and management
of symptoms associated with COVID-19. Vasaka is a well-known natural shrub in Ayurveda system of
medicine which has a beneficial effects, particularly in respiratory disorders.
Methods: First, we reviewed various researches on Vasaka, and its use in the management of respiratory
system related diseases, viral diseases and other diseases in various journals and Ayurveda classical texts.
Second, a survey based study was conducted to assess the effectiveness of Vasaka in the prevention and
management of respiratory related problems.
Results: The literature review revealed that Vasaka has been widely studied for its pharmacological
activities. It has various action like antiviral, hepatoprotective, antibacterial, anti-inflammatory,
cardioprotective, antitubercular and antioxidant. The survey results of the study indicated that only 15%
of the sampled respondents used Vasaka in the treatment of respiratory related diseases. Nevertheless,
among the respondents who used the plants, 97% stated that the use of Vasaka was useful in the
treatment of diseases. Interestingly, 36.4% of the sampled respondents reported that they were
completely recovered from the respiratory related diseases.
Conclusions: Due to Vasaka multi-modal therapeutic effects and the findings from the survey-based
research indicate the potentiality of its use in the management of COVID-19 symptoms.
Keywords: Ayurveda; Corona Virus; Medicinal plants; Respiratory syndrome; Vasaka, Adhatoda
vasica, Justicia adhatoda.
1. Background
The widespread of the coronavirus (COVID-19) is unique and unprecedented threat for human
health all over the globe. Corona viruses (2019-nCoV/SARS-CoV2) is a single stranded,
enveloped, positive sense RNA viruses which belong to family Coronaviridae, [1]. Despite the
huge effort and investment, there are no standard medicine developed to treat the disease. Due
to its high rate of transmission and unavailability of specific medicine and vaccine for its
treatment WHO declared it as a pandemic disease [2]. Coronaviruses have been the cause
behind severe acute respiratory diseases in human [3]. This study provides an empirical
investigations on the potential and possibilities of Ayurveda based medical system in the
management of the disease symptoms.
Ayurveda is the world’s oldest medical system and is equipped with varieties of treatment
modalities to handle various type of deadly diseases. According to Ayurveda the Sareera
(Body) is composed of Dosha (humours like Vata, Pitta and Kapha), Dhatu (Tissues like Rasa,
Rakta, Mamsa etc.) and Mala (waste products like fecal matter, Urine and Sweat) [4]. Ayurveda
describes health as a state of equilibrium of Dosha, Dhatu, Mala and normal function of Agni
(Digestive fire) along with well-being of mind, sense organs and soul [5] and in other hand
disequilibrium of Dosha, Dhatu and Mala leads to the disease [6]. Ayurveda focuses on treating
different disease by balancing these three pillars of life. The general causes for diseases are
Asatmyendriyartha samyoga (Abuse of senses), Pragyaparadha (abuse of intellect) and
Kala/Parinama (Seasonal variation) [7]. The diseases generally classified as Nija (endogenous)
and Agantuja [8] (exogenous) which can be compared with Communicable and Non-
Communicable diseases respectively according to Ayurveda.

~ 45 ~
Journal of Medicinal Plants Studies http://www.plantsjournal.com
The therapeutic potential of alternative medicine is not really
being considered during this crisis and global search for
effective preventive and treatment measures. In Ayurveda
different treatment principles for communicable disease are
described in detail. Specific measures like Sthana parityaga
(change of place of living), Homa-Dhupana (Fumigation)
Niyama (observing rules and regulations), Panchakrma,
therapy (body purification), Rasayana chikitsa (Rejuvenation)
and Aushadha (Medicine) has been mentioned which are
useful in communicable disease and in Janapadodhwamsa
Janya Vyadhi (epidemic condition) [9]. Along with other
measures Aushadha (Medicine) mainly prepared from a
medicinal plants play a key role in the management of
different disease. Different medicinal plants are described in
Ayurveda for the treatment of such type of pandemic disease
among them Vasaka is one of them. In the present study, we
have chosen Vasaka as herbal medicine which has been used
since the vedic period in the treatment of different respiratory
system related disease, This study further explores the
potentiality of this plant parts in the management of COVID-
19 related symptoms.
2. Materials and Methods
This study followed two approaches. First, we conducted a
systematic review of literature published in peer reviewed
journals and Ayurveda classical texts. The literature was
explored through online internet searches, including database
such as Google Scholar, Scopus, PubMed, Science direct and
CrossRef. The main keywords used for searching articles
included: Adhatoda vasica, Justicia adhatoda, Vasaka,
Coronavirus, SARS coV 2, CoVID-19 and Antiviral.
Second, a survey based study was conducted to assess the
effectiveness of Vasaka plant parts in the prevention and
management of respiratory related problems such as common
cold, cough, and difficulty in breathing. The study was
undertaken in the Tanahun district of Nepal. Ward number 1
of the Myagde rural municipality in the Tanahun district was
purposively selected due to two reasons. First, the principal
investigator of this study is originally from the respective area
so that it is easier to contact local leaders and then the
potential respondents of the study. Second, the principal
investigator is aware that Vasaka plant is widely found in the
area.
The selection of respondents from the study area was by
means of systematic random sampling. First, we obtained the
list of people living in the study site. This was obtained from
the Nepal government website
(http://www.election.gov.np/election/np/voter-list.html)
where there is a list of voters for the previous election. From
the total of 2391 individuals in the list, we selected every fifth
person by following the systematic random sampling
procedure. This yielded 478 individuals. Out of the total 478
selected persons, we were able to make contact via phone to
257 respondents. The phone numbers were obtained from
local leaders in respective villages. Among those 257, we
were able to get information from 215 individuals. The
information was collected through phone interviews using a
structured set of questions (Table 1). The interviews were
conducted from 10 to 25 June, 2020. On average, an interview
took 5 minutes to complete.
Table 1: Questions used in the interview
1. What gender do you identify as?
Male… Female…
2. How old are you?
… years
3. What is your education level?
… years
4. Are you employed?
Employed… Not
employed…
5. What is the distance from your home to the nearest hospital in minutes by commonly used means of
transportation
… minutes
6. Have you ever used medicinal plants in the treatment of any diseases?
Yes… No…
7. Have you ever used Vasaka (Asuro) plant parts to treat any respiratory diseases such as common cold,
cough, bronchitis, difficulty in breathing etc?
Yes… No…
8. How effective was the use of Vasaka plant parts in the treatment of above diseases?
Negative effect…
No improvement in the
symptoms…
Little improvement …
Moderate improvement …
Very effective…
Completely recovered…
3. Results
3.1 Review results
Plant description
Vasaka is an evergreen shrub of 4-8 feet in height with many
long opposite branches. Leaves are 3-8 inches in length and
lance-shaped, opposite and estipulate. Stem is herbaceous
above and woody below. Flowers are spikes, small irregular
zygomorphic, bisexual, and hypogenous. The flowers are
either white or purple in colour. It has four seeded fruits with
capsule [10].
Plant classification
Kingdom: Plantae; Order: Lamiales; Family: Acanthaceae;
Genus: Adhatoda; Species: Vasica; Common name:
Adhatoda, Vasaka, Vasa; English Name: Malabar nut; Nepali
Name: Asuro
Ayurveda Properties of Vasaka (Justicia adhatoda L.)
As per the description available in Ayurveda classics,
therapeutic effect of medicinal plants depends upon certain
pharmacodynamics properties. These pharmacodynamics
properties are Rasa, Guna, Veerya, Vipaka, Prabhava etc.
Properties of Vasaka [11]:
Rasa: Tikta, Kasaya
Guna: Rukshya, Laghu
Veerya: Shita
Vipaka: Katu
Doshakarma: Kapha Pitta Samaka, Jwaraghna, Swashahara,
Kasahara, Shlesmahara, Raktastambhaka, Mutrajanan.
Adhatoda vasica commonly known as Vasaka, is found in
many regions of Nepal, India and throughout the world.
Adhatoda leaves, root and flowers have been used extensively
in Ayurvedic medicine for the treatment of Tamak swasa
(Bronchial Asthma), Rajayakshma (Pulmonary tuberculosis),
Jwara (Fever), Atisara (diarrhea), Pravahika (dysentery),

~ 46 ~
Journal of Medicinal Plants Studies http://www.plantsjournal.com
Kustha roga (skin diseases), chhardi (vomiting), Pratisyaya
(Common cold), Pinas (Sinusitis), Mutradaha (Burning
micturition), Hridayarog (Heart disease), etc. [12].
Chemical Composition
The main chemical component found in Adhatoda vasica
Nees is a bitter quinazoline alkaloid called vasicine which is
present in the leaves, roots and flowers. Besides vasicine, the
leaves contain several alkaloids such as Vasicinone,
Vasicinol, Adhatodine, Adhatonine, Adhvasinone, Anisotine
and Hydroxypeganine, betaine, steroids and alkanes [13].
Therapeutic action
One animal study shows that aqueous and methanol extract of
Adhatoda vasica has potent anti-viral agents against herpes
simplex viruses [14]. In another study Chavan et.al has suggest
that aqueous and methanolic extracts of Justicia adhatoda
have strong anti-influenza virus activity that can inhibit viral
attachment and viral replication. It was possibly by blockage
of viral attachment through inhibition of viral HA protein, by
blocking the viral absorption to cells, by synergistically
binding to the free virus particles or by blocking the sialic
acid receptors to prevent virus entry into the cells and by
inhibiting the replication of influenza virus or virus budding
from the infected Madin-Darby Canine Kidney (MDCK) cells
[15].
Vasaka has the antibacterial activity against Gram positive
and Gram-negative bacteria. The extract of Vasaka revealed
higher activity against different clinical pathogens like
Klebsiella pneumonia, Proteus valgaris, Staphylococcus
aureus, Streptococcus Pyogens and Pseudomonas aeroginosa
[16]. One study showed that leaf extract (methanolic) of
Adhatoda Vasica and Vitex negundo was effective against
Salmonella typhi [17].
The study suggested that the methanolic, diethyl ether and
chloroform extracts of leaves of Adhatoda vasica have a
immunomodulatory properties [18]. Another animal study
suggested that Ethyl acetate extract of Adhatoda vasica has
potent hepatoprotective effect against CCl4 - induced liver
damage [19].
The main chemical constituent of Adhatoda vasica, vasicine
showed bronchodilatory activity both in vitro and in vivo
study [20]. Similarly the antitussive activity of Vasaka extract
was evaluated in anaesthetized guinea pigs, rabbits and in
unanaesthetized guinea pigs and it was found that it have a
good antitussive activity [21]. In another experimental study
ethanol extracts of Glycyrrhiza glabra and Adhatoda
vasica shows significant improvement in SO2 gas induced
cough [22].
Semi-synthetic derivatives of vasicine from the
herb Adhatoda vasica, have a pH-dependent growth-
inhibitory effect on Mycobacterium tuberculosis [23]. In
another study chemical constituent’s vasicine and vasicinone
have shown significant cardial depressant effect [24].
3.2. Survey results
The survey results show that 73% of the respondents have
used medicinal plants in the treatment of some diseases.
However, only 15% reported that they have used Vasaka plant
parts in treating respiratory related diseases (Table 2).
Table 2: Use of medicinal plants by respondents' characteristics
Respondent characteristics
Overall (n=215)
Medicinal plants
Vasaka plants
Used (n=157)
Not used (n=58)
Used (n=33)
Not used (n=182)
Gender (Male %)
42.3
33.1
67.2
36.4
43.4
Age (Years)
49.7
51.2
45.8
52.5
47.2
Education (Years)
8.1
8.2
7.1
8.4
8.1
Employment status (Employed %)
68.8
69.1
66.5
69.7
68.7
Distance to hospital (Minutes)
63.1
63.4
62.9
67.7
62.3
Survey results show that 42.3% of the sampled respondents
are male. Among the users of medicinal plants, 33.1% are
male and among the non-users of medicinal plants, 67.2% are
male. Similarly, among the Vasaka plant users 36.4% are
male whereas among the non-users of Vasaka plants, 43.4%
are male. The average age of the respondents is 49.7. The age
of medicinal plants users is significantly higher than that of
non-users (P < 0.01). Similarly, the age of Vasaka plants users
is significantly higher than that of non-users (P<0.05). On
average, respondents have attained 8 years of education.
68.8% of the respondents were employed. We do not find
significant difference between the users and non-users of
medicinal plants and Vasaka plants in relation to education
and employment status. On average, it takes 63.1 minutes to
reach the nearest hospital from respondent’s home. There is
no significant difference between users and non-users of
medicinal plants in relation to distance from home to hospital.
However, this distance is significantly (P<0.01) higher in the
case of Vasaka plants users in comparison to non-users. This
result indicates that those who live farther away from hospital
are more likely to use Vasaka plants.
When asked about the effectiveness of Vasaka plant parts in
the treatment of respiratory disorders, 36.4% reported that
they were completely recovered from the diesase by the use of
Vasaka plant parts (Figure 1). Similarly, 30.3% of the
respondents who used Vasaka plants in the treatment of
respiratory diseases stated that the use of plant parts was very
effective in the treatment of the disease. Moreover, 21.2% and
9.1% said the use of the plant parts resulted moderate and
little improvement respectively, in the disease symptoms. A
few respondents (3%) reported that the plant parts was not
effective in the treatment of the diseases. We also asked if the
use of Vasaka plant parts had caused any negative effects on
them, however, none of the respondents reported negative
effects of the use of the plant parts. (Figure 1.)
Fig 1: Respondents’ experience on the effectiveness of Vasaka

~ 47 ~
Journal of Medicinal Plants Studies http://www.plantsjournal.com
4. Discussion
An outbreak of pneumonia in December, 2019 in Wuhan,
China, has now been determined to be caused by a novel
coronavirus. Due to its severe effect in respiratory system it is
named as severe Acute Respiratory Syndrome Coronavirus 2
(SARSCoV-2) [25]. Vasaka is a well-known shrub in Ayurveda
systems of medicine. The classical Ayurvedic medicine
prepared from the Vasaka plant is used in many respiratory
system related disease like Tamak Swasa (Bronchial Asthma),
Pratishaya (Rhinitis), Pinas (Sinusitis), Rajakshma
(Pulmonary tuberculosis), Kasa (Cough) and Swasa
(Breathing disorder) since vedic period. Numerous clinical
trials have shown that Vasaka has been beneficial in the
management of various diseases like pulmonary disease,
inflammatory diseases, cardiovascular diseases, metabolic
diseases, liver diseases, neurological diseases. Vasaka leaves
decoction has a soothing effect on irritation in the throat and it
acts as an expectorant [26].
The literature survey revealed that Vasaka has been widely
studies for its pharmacological activities. It has vasicine,
vasicinone and vasicolone as a major chemical constituents.
These primary alkaloids are well established as a therapeutical
respiratory agents. Previous experimental and clinical trials
demonstrated that Vasaka has antiviral action. It has shown
antiviral action against different viruses indicating that it
could be a therapeutic option for the management of COVID-
19 related symptoms.
The survey results of the study indicate that only 15% of the
sampled respondents used Vasaka plants in the treatment of
respiratory related diseases. Nevertheless, among the
respondents who used the plants, 97% stated that the use of
plant parts was useful in the treatment of diseases.
Interestingly, 36.4% of the sampled respondents reported that
they were completely recovered from the respiratory related
diseases with the use of Vasaka plant parts. The findings of
this study indicate that Vasaka plant parts can be potentially
utilized in the treatment of respiratory related diseases.
However, there are several limitations of this study. First, the
survey was conducted in only one district of Nepal. Second,
we do not know the intensity of the plant parts used in the
treatment. Thus, we recommend, further detail studies on the
potentiality and effectiveness of Vasaka plant parts.
Nevertheless, this study provides an evidence on the
usefulness of Vasaka plant parts in the treatment of
respiratory related diseases.
One of the challenges with medicinal plants is that such plants
can be produced only in specific environmental conditions
and requires intensive care in growing. This is linked with the
high cost of producing associated drugs. Thus, economics of
producing medicinal plants in adequate quantity is a concern.
However, Vasaka plant’s distribution in wide range of
climatic conditions indicates the potentiality of large-scale
production.
5. Conclusion
Due to Vasaka multi-modal therapeutic effects, we
hypothesize that Vasaka could be effective in the prevention
and Management of COVID-19 symptoms. Existing literature
and the findings from the survey-based research indicate the
potentiality of Vasaka plant parts in the management of
COVID-19 symptoms. However, there is no standard
formulation regarding the use of the plant parts, this is
limiting its wider use. In this context, we recommend
translational research in order to provide scientific evidences
for the efficacy and to establish the standard formulation of
Vasaka in the management of COVID-19 systems.
Acknowledgments
Authors are thankful to all the participants for their necessary
support during this work.
Conflicts of interest
There are no any conflicts of interest.
Funding
None.
Reference
1. Chen N. et al. Epidemiological and clinical characteristics
of 99 cases of 2019 novel coronavirus pneumonia in
Wuhan, China: A descriptive study. Lancet. 2020;
395:507-513. 10.1016/S0140–6736(20)30211–7.
2. https://www.who.int/emergencies/diseases/novel-
coronavirus–2019/advice-forpublic/ myth-busters.
3. Lai, Chih-Cheng, et al. "Severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) and corona virus
disease-2019 (COVID-19): the epidemic and the
challenges." International journal of antimicrobial agents,
2020, 105924.
4. Sri Susruta, Susruta Samhita, Sutra Sthana, Verse no.
15/3, Elaborated by Sri Dalhan and Sri Gayadash, Hindi
Commentary by Dr. Kebal Krishna Thakral;
Chaukhambha Orientalia, Varansi, Second Ed, 2016, 157.
5. Sri Susruta, Susruta Samhita, Sutra Sthana, Verse no.
15/41, Elaborated by Sri Dalhan and Sri Gayadash, Hindi
Commentary by Dr. Kebal Krishna Thakral;
Chaukhambha Orientalia, Varansi, Second Ed. 2016;
1:179.
6. Sri Vagbhata, Ashtanga Hridayam Sutra Sthana Verse no.
1/19, 20. Commentary by Dr. Brahmanand Tripathi,
Choukhambha Sanskrit Pratishthan, Delhi, Ed. 2015, 16.
7. Agnivesa, Caraka Samhita, Sutra Sthana, Verse no. 11/43.
Elaborated by Caraka and Drdhabala, Commentary by Sri
Cakrapanidatta, Edited by Vaidya Yadavji Trikamji
Acharya, Prologued by Prof. R.H. Singh; Chaukhamba
Surbharati Prakashana, Varanasi, Ed., 2017, 76.
8. Sri Vagbhata, Ashtanga Hridayam Sutra Sthana Verse no.
1/20. Commentary by Dr. Brahmanand Tripathi,
Choukhambha Sanskrit Pratishthan, Delhi, Ed. 2015, 16.
9. Agnivesa, Caraka Samhita, Viman Sthana, Verse no. 3/11-
18. Elaborated by Caraka and Drdhabala, Commentary by
Sri Cakrapanidatta, Edited by Vaidya Yadavji Trikamji
Acharya, Prologued by Prof. R.H. Singh; Chaukhamba
Surbharati Prakashana, Varanasi, Ed. 2017, 241-242.
10. Sharma PV, Dravyaguna Vijnana, Chaukhambha Bharati
Academy, Varanasi, India; edition. 2019, 2:242.
11. Sharma PV, Dravyaguna Vijnana, Chaukhambha Bharati
Academy, Varanasi, India; edition. 2019; 2:241.
12. Sharma PV, Dravyaguna Vijnana, Chaukhambha Bharati
Academy, Varanasi, India; edition. 2019; 2:241.
13. Lahiri PK, Prahdan SN. Pharmacological investigation of
Vasicinol- an alkaloid from Adhatoda vasicaNees. Indian
J Exp. Biol. 1964; 2:219-23.
14. Chavan, Rahul, et al. "Antiviral activity of Indian
medicinal plant Justicia Adhatoda against herpes simplex
virus: an in-vitro study." Int J Pharm Bio Sci 4.4, 2013.
15. Chavan, Rahul, and Abhay Chowdhary. "In vitro
inhibitory activity of Justicia adhatoda extracts against
influenza virus infection and hemagglutination." Int. J.
Pharm. Sci. Rev. Res 25.2, 2014, 231-236.

~ 48 ~
Journal of Medicinal Plants Studies http://www.plantsjournal.com
16. Sheeba B Josephin, Selva Mohan T. "Antimicrobial
activity of Adhatoda vasica against clinical
pathogens." Asian J Plant Sci Res 2.2, 2012, 83-88.
17. Kumar Manoj et al. "Anti-typhoid activity of Adhatoda
vasica and Vitex negundo." Persian Gulf crop
protection 2.3, 2013, 64-75.
18. Vinothapooshan G, Sundar K. "Immunomodulatory
activity of various extracts of Adhatoda vasica Linn. in
experimental rats." Afr J Pharm Pharmacol 5.3, 2011, 306-
310.
19. Ahmad R, Raja V, Sharma M. Hepatoprotective Activity
of Ethyl Acetate Extract of Adhatoda Vasicain Swiss
Albino Rats. Int J Cur Res Rev. 2013; 5:16-21.
20. Lahiri PK, Pradhan SN. "Pharmacological Investigation of
Vasicinol-Alkaloid From Adhatoda Vasica Nees." Indian
Journal of Experimental Biology 2.4, 1964, 219.
21. Dhuley Jayant N. "Antitussive effect of Adhatoda vasica
extract on mechanical or chemical stimulation-induced
coughing in animals." Journal of
Ethnopharmacology 67.3, 1999, 361-365.
22. Jahan, Yasmeen, Siddiqui HH. "Study of antitussive
potential of Glycyrrhiza glabra and Adhatoda vasica using
a cough model induced by sulphur dioxide gas in
mice." International journal of Pharmaceutical Sciences
and research 3.6, 2012, 1668.
23. Grange John M, Noel JC Snell. "Activity of bromhexine
and ambroxol, semi-synthetic derivatives of vasicine from
the Indian shrub Adhatoda vasica, against Mycobacterium
tuberculosis in vitro." Journal of ethnopharmacology 50.1,
1996, 49-53.
24. Roy, Dipankar Chandra, Md Shark, and Hossain Md
Faruquee. "A Brief Review On Phytochemistry and
Pharmacological Properties of Adhatoda vasica." Journal
of Tropical Medicinal Plants 14, 2013.
25. Daga, Mradul Kumar, et al. "From SARS-CoV to
Coronavirus Disease 2019 (COVID-19)-A Brief
Review." Journal of Advanced Research in Medicine (E-
ISSN: 2349-7181 & P-ISSN: 2394-7047) 6.4, 2019, 1-9.
26. Gangwar, Atul Kumar, Ashoke K Ghosh. "Medicinal uses
and pharmacological activity of Adhatoda
vasica." International journal of herbal medicine 2.1,
2014, 88-91.