An Eye-Catching and Comprehensive Review on Leucas zeylanica (Ceylon slitwort’ )

The traditional system of medicine has many plants with medicinal and pharmacological importance. The primary sources of food and medicine are plants and their highly beneficial products for various animals and humans. This article mainly focuses on the complete Leucas zeylanica profile, which is also called Ceylon slitwort, a small, erect, annual, herbaceous, terrestrial or occasionally aromatic, hispid and tufted plant of the family Lamiaceae subfamily Lamioideae. It is widely available in several places in India and Nueva Viscaya’s low altitudes open grasslands and Luzon’s Bataan Provinces and Mindanao and Panay (Davao and Lanao). This article provides a comprehensive review of the complete profile of a vital plant, Leucas zeylanica. Traditional use of Leucas zeylanica in various diseases includes Antibacterial, Anti-fungal, Anti-inflammatory, nociceptive, analgesia, gout, antidiabetic a photoprotective agent in various skin diseases. The isolated components are Alkaloids, Terpenoids, Vitamins, Carbohydrates, Flavonoids, glycosides, saponins, fixed oils, and other miscellaneous compounds. Hence, this review can be a useful reference for researchers who are willing to undertake further investigation about Leucas zeylanica.

Leucas zeylanica, Ethnobotany, Anti-fungal, Anti-diabetic, Larvicidal, Pharmacological activities, Phytoconstituents A The traditional system of medicine has many plants with medicinal and pharmacological importance. The primary sources of food and medicine are plants and their highly bene icial products for various animals and humans. This article mainly focuses on the complete Leucas zeylanica pro ile, which is also called Ceylon slitwort, a small, erect, annual, herbaceous, terrestrial or occasionally aromatic, hispid and tufted plant of the family Lamiaceae subfamily Lamioideae. It is widely available in several places in India and Nueva Viscaya's low altitudes open grasslands and Luzon's Bataan Provinces and Mindanao and Panay (Davao and Lanao). This article provides a comprehensive review of the complete pro ile of a vital plant, Leucas zeylanica . Traditional use of Leucas zeylanica in various diseases includes Antibacterial, Anti-fungal, Anti-in lammatory, nociceptive, analgesia, gout, antidiabetic a photoprotective agent in various skin diseases. The isolated components are Alkaloids, Terpenoids, Vitamins, Carbohydrates, Flavonoids, glycosides, saponins, ixed oils, and other miscellaneous compounds. Hence, this review can be a useful reference for researchers who are willing to undertake further investigation about Leucas zeylanica.

INTRODUCTION
Nature re lects the creative power of God, and plants are an integral part of this nature. Plants have been used for medicinal purposes since prehistoric days. With increasing resistance to antimicrobial agents, scientists are encouraged to look for new antimicrobial agents from plants. They have been found very ef icient in treating many contagious diseases with a minimal side effect (Prabhadevi et al., 2012;Muhammad, 2014). As per the World health organization (WHO), most of the population uses herbal medicine for most diseases by altering the plant species. Natural products like medicinal plants as primary potential sources of innovative therapeutic agents through investigation and research (Malik et al., 2012;Foster et al., 2005) Lamiaceae or Leucas zeylanica, which is also called Ceylon slitwort, is a medicinal herb (Zhang et al., 2016), small, erect, annual, herbaceous, terrestrial or occasionally aromatic, hispid and tufted plant of the family Lamiaceae's subfamily Lamioideae which is distributed in southern regions of China. It is used to treat cold, tooth aches, rheumatic diseases and as a remedy for worms and abdominal pain. Leaves of Leucas zeylanica are vulnerary, stimulant, sedative, diaphoretic, and anthelmintic used in wound healing. Leucas zeylanica's leaves poultice is used for treating vertigo, headaches, and itching (Dutta et al., 2016). After childbirth, the abdomen is rubbed the entire plant, ever, jaundice, and for scorpion and snake bites (Jain et al., 2010;Rajakaruna et al., 2010). Hence, this review can be a useful reference for researchers who are willing to undertake further investigation about Leucas zeylanica.

Common names/vernacular names
The common names of the Leucas zeylanica in different languages have been shown in Table 1 Taxonomical classi ication of Leucas zeylanica The Taxonomical classi ication of Leucas zeylanica (Jain et al., 2010) has been shown in Table 2 Botanical description Leucas zeylanica, which is also called Ceylon slitwort, is a small, erect, annual, herbaceous, terrestrial or occasionally aromatic, hispid, and tufted plant of the family Lamiaceae's sub-family Lamioideae. The plant grows to a height of up to 120 cm. The stem is quadrangular. Sub-sessile leaves are 2.5 to 7.5 cm long, at margins coarsely dentate, hispid, glandular, obtuse, blunt at the tip, and not divided or lobed (Jain et al., 2010).

Microscopic characteristics
Trichomes are long ligni ied and multicellular, upper stomata are anisocytic, Lower stomata are paracytic, starch grains are absent, Vascular tissue like xylem and phloems are present (Hossain et al., 2013).

Geographical distribution
In Luzon's Bataan and Nueva Viscaya Provinces at low altitudes in open grasslands and Panay and Mindanao (Lanao and Davao) -also found in tropical Asia to Malaya.

Physicochemical Characteristics
These parameters such as loss on drying, Moisture content, Acid soluble ash, Water-soluble ash, and Total ash (TA) were described in Table 3 Morphology Morphological characters such as color, shape, size, odor, taste (Dubey et al., 2004;Gaikwad et al., 2003) were described in Table 4 Preliminary phytochemical screening of the extract Hydroalcoholic extract of Leucas zeylanica's was subjected to preliminary phytochemical screening using different methods, and the results were shown in Table 5, (Chase and Pratt, 1949;Pandey et al., 1984;Geethika and Kumar, 2017)

Quantitative Microscopy
The Quantitative Microscopical characteristics like Trichomes, upper and lower stomata, starch grains and vascular tissue of Leucas zeylanica (Radhika et al., 2017) was carried out and the results were shown in Table 6.

Ethnobotanical signi icance
The blended leaves of Leucas species are used for chronic skin diseases, diseases of eyes and nose, for treating wounds, against sores like scabies and psoriasis. They are also used to decoction against roundworm infestation, mainly for children, and against malaria. A decoction of the whole plant is used for chronic stomach problems, including Indigestion. Roots and leaves are used to treat skin diseases and used as a poultice for wounds, sores, and itches.
Operates as an aromatic, stomachic, carminative. Useful in chronic dyspepsia, Acute as well as anorexia, and latulence. Leaves and lower extracts can be used in treating jaundice (Valsaraj et al., 1997).

CNS Depressant Activity
Leucas zeylanica has an excellent medicinal herb and has a wide variety of CNS activities. Ethanolic extract Leucas zeylanica CNS depressant activity was evaluated by using a hole cross test at different doses. The ethanolic extract of L. zeylanica has presented a critical CNS depressant action by lowering the movement of mice mostly at 60 and 120 minutes in a dose-dependent manner (Mian et al., 2017).   Water-soluble ash 5 3 Acid soluble ash 10 4 Moisture content 16 5 Loss on drying 69.9

Analgesic activity
Ethanolic extract of Leucas zeylanica was investigated for analgesic activity by using the writhing model induced by acetic acid and paw licking and biting method induced by formalin in mice. L. zeylanica's ethanolic extract showed a substantial decrease in both models in a dose based manner (84%) in paw licking and biting when compared with control and standard, and it is due to the pres-ence of phytoconstituents like gums, tannins, and saponins (Khan et al., 2010).

Antibacterial activity
A new Triterpenoid glucoside, namely leuctriterpencoside and other two compounds from Leucas zeylanica, was extracted using the comprehensive spectroscopic techniques. The isolated compounds were tested beside several phytopathogenic bacteria Bacillus subtilis, Micrococcus luteus, Saphy- Gums and Mucilage -  (Chen et al., 2020).

Antidiabetic activity
Antidiabetic potential activity of aqueous leaves extracts of Leucas zeylanica was tested in diabetic rats induced with alloxan, and for blood, glucose 1 lowering effect was evaluated. Leucas zeylanica extract at 50mg/kg dose has signi icantly reduced the level of fasting blood glucose. Moreover, extracttreated animals were not simulated with the levels of serum insulin. Changes in liver glycogen levels and body weight were reviewed, and the aqueous extract has shown signi icant results (Dutta et al., 2016).

In lammation and gout
Lipophilic extracts of the Leucas zeylanica were tested for key enzymes, inhibition in gout and in lammation. Xanthine Oxidase (XO), microsomal prostaglandin E2 synthase (mPGES)-1 and 5-lipoxygenase (5-LO) inhibition by L. zeylanica's in various extracts was examined for determining the anti-gout and anti-in lammatory activities, respectively. In isolated human mPGES-1and5-LO and stimulated humanneutrophilseffectivelyinhibited5-LO activity by L. zeylanica's dichloromethane extract. XO, mPGES-1, and5-LO's potent inhibition and justi ies L. zeylanica ethnopharmacological ben-e its as anti-gout and anti-in lammatory remedy due to the presence of bioactive constituents (Napagoda et al., 2018).

Anti-fungal activity
Ethanolic extracts of the Leucas zeylanica (seeds, leaves, and stems) were investigated for anti-fungal activity in various microorganisms species like Aspergillus, Penicillium, Trichoderma, Mucor, and Rhizopus by using the agar streaking method at the incubation period of 24-48 h. Leucas zeylanica has shown vigorous anti-fungal activity against Mucor species due to tannins, lavonoids, triterpenoids, and cardiac glycosides (Manoranjan et al., 2018;Babu et al., 2016).

Anti-in lammatory activity
A new Abietane Diterpenoid, namely leucasinoside, was isolated from aerial parts of the Leucas zeylanica, characterized by various spectroscopic methods like 1H and 13 C NMR. The isolated compounds were investigated for Anti-in lammatory activity (Zhang et al., 2016) in lipopolysaccharide (LPO) induced nitric oxide model. The compounds isolated were tested on LPS-induced NO production and have shown moderate inhibitory activities with IC 50 values ranging from 12.6 to 18.8 µM.

Anti-oxidant activity
The Methanolic extract of Leucas zeylanica was tested for antioxidant activity using H 2 O 2 -induced oxidative stress on isolated frog heart. In Leucas zey-lanica's methanolic extract presence, the examination of cardiac arrest was for 38 th min, that is, for the longer time heart was protected, which speciies antioxidant activities, and then a comparison is made with the standard ascorbic acid. The antioxidant was due to cardiac glycosides, triterpenoids, lavonoids, and tannins (Swetha, 2019).
For mosquito larvicidal activity, the essential oil from Leucas zeylanicaaerial parts was investigated against Aedesalbopictus and Aedesaegypti. A good larvicidal activity was shown by Leucas zeylanica essential oil against ae. aegypti and ae. albopictus with median lethal concentration-LC50 (24 hours) values of 44 and 67µg/mL, respectively. It has been concluded that for dengue virus vectors control, an environmentally benign and inexpensive agent is represented by L. zeylanica essential oil (Hung et al., 2019).

Hydrogen peroxide-induced oxidative stress on hepatic tissue of rats
The extract of Leucas zeylanica was tested for antioxidant activity by using H 2 O 2 -induced oxidative stress on hepatic tissue. Hepatic tissue was exposed to Fenton's reagent and ethanol for inducing oxidative stress. Effect of oxidative stress on the liver was examined by liver enzyme determination like lipid peroxide (LPO) levels, alkaline phosphatase (ALP) activity, aspartate aminotransferase (AST) activity, and alanine aminotransferase (ALT). L. zeylanica antioxidant activity was examined by assessing the lipid peroxide (LPO) hepatic levels inhibition abilities as an oxidative stress indicator. Presence of lavonoids and polyphenols protects against H 2 O 2 and ethanol on hepatic tissue (Hossain et al., 2013;Medina and Moreno-Otero, 2005) by L. zeylanica.

Antibacterial activity
The Leucas zeylanica leaves' methanol extract was discovered to exhibit potent inhibitory activity against Bacillus subtilis and Staphylococcus aureus.
Remarkably, these plant leaves are used to acquire volatile oil that exhibits high sensitivity for Candida albicans, S. aureus, in luenza, Haemophilus, and Pseudomonas aeruginosa, but no sensitivity against A. Niger, Tricoderma vibriae, Neisseria gonorrhea, Proteus. Vulgaris and Bacillus subtilis (Das et al., 2012).

Elimination of E.coli and S.aureus Corbicula luminea ("Etak") tissue
Leucas zeylanica methanolic extract can eliminate the E.coli and S.aureus and Corbicula luminea ("Etak") tissue. Extraction of bacterial genomic DNA was performed and con irmed the presence of E.coli, S.aureus Corbicula in etaksalai. Antibacterial properties of Leucas zeylanica leaves extract was identiied by using disc diffusion method and found that methanolic extract of Leucas zeylanica inhibits the E.coli and S.aureus in the optimum concentration found to be one of the ingredients for the preparation of etak salai to avoid gastrointestinal infection in consumers (Abdullah et al., 2019;Saritha et al., 2015).

Leucas zeylanica as an Acid-Base indicator
Apart from the various pharmacological activities, Leucas zeylanica has also played a vital role in analysis and endpoint determination. Flowers of Leucas zeylanica plant were recognized in producing color changes with pH values variation. A simple maceration method was used for extracting pigments by utilizing a solvent as Luke warm water. Color change in the extract was observed by inserting it into varying pH standard buffer solutions. Thus, the study has realized that Leucas zeylanica lower pigment can be ef iciently utilized as an alternative to present indicators and factors such as precise and accurate results, good performance, and simple preparation (Abbas et al., 2018;Bhagat et al., 2008).

The photoprotective potential of Leucas zeylanica
Aqueous extracts of the Leucas zeylanica have involved evaluating photoprotective activity and have a medicinal/ traditional importance in treating the various skin diseases and improving skin complexation. Determination of UV iltering potential of Leucas zeylanica extract, UV absorption was measured, and the sun protection factor (SPF) was calculated according to the Mansur equation, and the antioxidant activity was evaluated by DPPH and ABTS assays. The results of the study suggest that the presence of secondary metabolites with antioxidant property could be responsible for the high UV absorbance (Napagoda et al., 2016;Duthie et al., 1999;Reuter et al., 1999).

CONCLUSION
Several parts of Leucas zeylanica have been reported as various traditional healers for treating various ailments of mankind. These contain antibacterial, antifungal, antiin lammatory, nociceptive, analgesia, gout, antidiabetic, and as a photoprotec-tive agent in various skin diseases. This review mainly focused on phytochemical and pharmacological studies, which are explained the phytoconstituents and therapeutic potential of Leucas zeylanica and all the pharmacological activities are due to the presence of phytoconstituents like saponins, lavonoids, steroids, tannins, and phenolic compounds.