Review on biologically active natural insecticides from Malaysian tropical plants against Aedes aegypti and Aedes albopictus

4.1 Pyrethroids

According to (Davies et al., 2007), pyrethroids are the well-known neurotoxic insecticides. Pyrethrin is the organic compounds which it can be obtained from a flower species, Chrysanthemum cinerafolis. This type of dried flowers was applied as insecticides to prevent the biting of insects because of its insecticidal abilities in ancient China. The usages of pyrethroids became more general within some countries such as Persia and Europe. In the mid of 19th century, the development and marketing of various pyrethroid related insecticides were done and these insecticidal products were manufactured by using Chrysanthemum flower or pyrethrum. There are two types of pyrethrin compounds which can be extracted from a flower species, Chrysanthemum cinerafolis (Kshirsagar & Phal, 2022). These two pyrethrin compounds are chrysanthemic acid (pyrethrin I) and pyrethric acid (pyrethrin II). The pyrethroids are the substitute compound of insecticidal esters of both pyrethrin that produced naturally. There are 3 natural variation which derived from alcohol moiety of pyrethrin and it give rise to different version of pyrethroids such as jasmolin I, jasmolin II, cinerin I, cinerin II, pyrethrin I and pyrethrin II. Pyrethroids can be categorized into 2 classes which are class I and class II. Allethrin and permethrin are the examples of class I pyrethroids because they consisted of cyclopropane carboxylic ester for the basic structure which required for pyrethroids formations. Class II pyrethroids are slightly different with class I because they contain cyano group which can lead to choreoathetosis and salivation. Cypermethrin and deltamethrin are the examples of class II pyrethroids (Gajendiran & Abraham, 2018).

According to (Soderlund, 2012), it has been reported that several agencies like academic research laboratories, governments and agrochemical industries have conducted plenty of researches and studies to prove the wide ranges of pyrethroid structures. Furthermore, most of the researchers also proved the usages of pyrethroids to different field types such as medical, agriculture and control of pests. However, the stability of natural pyrethroid insecticides can be reduced when it exposed under air and light. This factor became the weakness of natural pyrethroids because the effect of pyrethroid insecticide cannot be fully expressed to control the pest problems and protects the crops. Thus, synthetic insecticides were developed from the original structure of natural pyrethroids can boost up the stability at light and air conditions. Modified pyrethroids also can retain its own functions such as reduction the toxicity towards mammalian and high rate of insecticidal effects. Permethrin and deltamethrin are the two examples of synthetic pyrethroid insecticides. These two synthetic pyrethroids insecticides upgraded the overall functions of natural pyrethroid insecticides such as insecticidal activity and photostability. The pyrethroid insecticides attaches to the open sodium channels and alter the transition of channel gating. This situation can cause the extension of periods for the opening of sodium channels. The insects can have several symptoms such as paralysis, conduction blockage of nerve and even death can be happened due to the action of pyrethroids which alters the sodium channel gating (Soderlund, 2012); (Du, Nomura, Zhorov, & Dong, 2016).

4.2 Dichlorodiphenyltrichloroethane (DDT)

Dichlorodiphenyltrichloroethane (DDT) is a lipid soluble types of organophosphate insecticides and the version of this insecticide is older compared to other versions. The scientific name of DDT is called as 1, 1, 1-Trichloro-2,2-bis(p-chlorophenyl) ethane. India is the major manufacturing country which produces high quantities of DDT insecticides while DDT has been applied by some of the countries like Africa to solve the vector control problems (Du et al., 2016). According to (Harada, Takeda, Kojima, & Tomiyama, 2016), it has been reported that the neurotoxicity properties which can be expressed by DDT insecticides are avoiding the activation of potassium gates and extends the opening periods of sodium ion channels. In addition, some of the neuronal ATPase is aimed by DDT insecticides through nervous system to alter the flow rate of elements like calcium, potassium and sodium. The calcium ions are the main element which can help in neurotransmitter release processes but DDT insecticides can restrict the transfer of calcium ions. These merged actions can enhance the sustainable for nerve depolarization, strengthen the transmitter release and give rise to excitation of central nervous system such as tremors and hyperexcitability.

According to (Davies et al., 2007), the characteristic of DDT was discovered by a chemist from Sweden called Paul Muller and he make an important contribution for pest controls. There are several factors to prove DDT can be the suitable insecticides. For example, the production of DDT insecticides can be produced with large or limitless amounts. The production costs of DDT insecticides were relatively low and it also can maintain its toxicity for certain periods. Although, the toxicity is harmful towards insects relatively it is safe to human kind. After the establishment of DDT insecticides, other related types of insecticides which contain chlorinated hydrocarbon were also created and sold. The effect of DDT insecticides can mainly influence on peripheral nervous systems. The exposure of insecticides can cause the neuron to trigger several symptoms which can be happened to insect body such as body quivering, muscle twitching and even appendages and joints tremors. The increase of neurotransmitter release can cause the rising of miniature post synaptic dispersion. These actions can affect the neuromuscular junctions due to depolarization. The depletion of neurotransmitter can lead to inhibition of neurotransmitter joints as the depolarization process keeps on (Perry, Yamamoto, Ishaaya, & Perry, 1998); (Davies et al., 2007).

5.1 Knockdown resistance

Voltage-gated sodium channels are the integrated membrane protein which located at entire cell membrane. The main roles of this sodium channels are launching of neuron activity potentials and distributes them across the body parts. Domain I, domain II, domain III and domain IV are the four similar replicate domains of pore forming α-subunits. The α-subunit are the main components of voltage gated sodium channels. There are six portions of trans- membrane (S1–S6) and linked by certain loops from both intracellular and extracellular. The formation of voltage sensing domain structures is done by S1 to S6 segments. S5 and S6 help to build the central structures of pore. The activation of sodium channels can lead to depolarization of membranes. It can be done by the passing of sodium ions within the cells due to the opening of sodium channels. These actions also can give rise to changes of membrane potential and become depolarized. The stages of action potential can also be increased rapidly by initiation of sodium channels. Fast inactivation is a process which a deactivated component blocks the channel pore after the milliseconds of channel opening. This process can cause the action potentials to be terminated. Sodium channels are the favour sites for most of the insecticides due to its role in alteration of action potentials (Du et al., 2016).

According to (Bass et al., 2007), knockdown resistance (kdr) is a type of common insecticide resistances which it related to the sodium channel of target pests. Basically, the sodium channels of target vectors are the suitable sites for the distributions of synthetic insecticides like DDT and pyrethroids which caused insect mortality. However, the main principle of this insecticide resistance is the para-type sodium channel occurred some certain point mutations within insect body systems. These mutations can reduce the effectiveness of insecticides towards target insects. The alteration of sodium channels can lead to low capacity of insecticides towards insect who developed resistance compared to non– resistance insects. There are related studies showed that pyrethroids and DDT insecticides are the main insecticide type which leads to kdr mutation. Besides that, it also reported that the combination of both DDT and pyrethroids insecticides can give rise to cross resistances and caused insecticide resistances. (Davies et al., 2007); (Kushwah et al., 2015).

5.2 Behaviour resistance

Physiological resistances and behavioural avoidance are the two main common characterizations of insect responses towards insecticides (Chareonviriyaphap et al., 1997); (Chareonviriyaphap et al., 2013). Physiological resistances are a type of insecticide resistance which certain populations of insects manage to live at certain environments and expose themselves towards insecticides which its concentration levels of insecticides normally can lead to mortality of insects (Carrasco et al., 2019; Chareonviriyaphap et al., 2013; Roberts, Andre, & hygiene, 1994). There are still having some possibilities for the combination of more than one physiological resistances. For examples, the detoxification through enhancement of activity for certain enzymes (mediated P450 mono-oxygenase or glutathione S-transferases) and the modification of target site nerve receptors are the mechanisms which can work together for physiological resistances (Ranson et al., 2011). Behavioural avoidance or behavioural resistance is the resistance which insects can avoid the exposure towards insecticides by its own altered behaviour. The insects which had developed behavioural resistances can detect the insecticides within the environments and move to another site. This is due to its properties which have the stimulus for the detection of environmental changes (Gatton et al., 2013); (Panini, Manicardi, Moores, & Mazzoni, 2016). The changes of mosquito behaviour can be categorized into two types: direct contact excitation and non-contact spatial repellence. Direct contact excitation is the ability of some insecticides-threated mosquitoes to escape from areas which covered by insecticides. The mosquito behaviour which can avoid the insecticide-threated areas before they have any contact with insecticides is called non-contact spatial repellence (Roberts, Chareonviriyaphap, Harlan, & Hshieh, 1997); (Chareonviriyaphap et al., 2013); (Amelia-Yap, Chen, Sofian-Azirun, Low, & vectors, 2018).

There are four major phases of resistances which can be categorized from behavioural resistances: qualitative, quantitative, tolerance and exploitation. The first phase of behavioural resistance is called qualitative behavioural resistances whereby mosquitoes prevent any exposure towards insecticides. The mosquitoes can avoid any insecticide exposures by altering their activities times to prevent any clashing with insecticide applied periods. The changing of feeding locations can be done by mosquitoes to reduce the insecticide exposure rates. Quantitative behavioural resistances are the second phase of behavioural resistances whereby mosquitoes may have some reactions to get away from area where insecticide can found easily. Thus, the exposure time towards insecticides also can be reduced (Carrasco et al., 2019). Temperature regulations are also one of the quantitative behavioural resistances for mosquitoes to lower the reactions of insecticides within target sites. (Maliszewska & Tęgowska, 2017); (Carrasco et al., 2019). The third phase of resistances is behavioural tolerance and this resistance is suitable to mosquitoes that cannot escape from exposure or decrease the rate of insecticidal effects. For instances, mosquitoes can alter the production and distribution of their eggs. Besides that, the increases of nutrient qualities of bloods and decrease the usage of energies can be occurred due to this resistance. Reorganization of egg distribution and production also can be caused by this resistance (Cutler, 2013); (Carrasco et al., 2019). Behavioural exploitation is the last phase of resistance which the mosquitoes have physiological resistance and they can utilize these properties to detection the surrounding insecticides.

5.3 Reduce cuticle penetration resistance

The most of the insects synthesized certain amounts of apical extracellular matrix around their body parts such as tracheal, epidermis, epithelial at foregut and hindgut. These extracellular matrixes are usually called as cuticle which only produced at certain periods such as replacement of new cuticle during metamorphosis and moulting process. Embryogenesis is the biological process which can also leads to the formation of insect cuticles (Moussian & biology, 2010). According to (Vincent, Wegst, & development, 2004), the cuticles can provide some basic functions like locomotion, waterproof properties and give stable shapes to insects. Temporarily food reserved sites and obstacles to harmful diseases or parasite are also play as a parts of cuticle functions. It also consisted of several mechanical related functions such as high flexibility, regulation of diffusion and wear resistances. Chitins are the main constituents for the basic structural formations of cuticles. These arranged crystallized chitin nano–fibres embedded within the matrix of protein. There are others relevant substances like lipids, polyphenols and waters also included in cuticle productions.

According to (Strycharz et al., 2013), reduced cuticle penetration resistances are a well-known insecticides resistance mechanism which can be produced within insect body systems. The scattering levels of insecticides within the insect’s hemolymph became low as the penetration rate of insecticides through the cuticle decreased. The slow-going distribution rate of insecticides in hemolymph of insects can also leads to time extension for the detoxification of insecticides. Hence, it can reduce the insecticide accumulation at the targeted regions of insect body system. There are certain relevant studies showed that Ae. albopictus had developed resistances towards pyrethroid insecticides within Kuala Lumpur, Malaysia and these insecticide resistances developments were caused by reduced cuticle penetration resistances. The main factor that gives rise to cuticle penetration resistances was due to the over-expression of relevant cuticular protein genes in Ae. albopictus mosquitoes (Ishak et al., 2016). The modifications of cuticle are the elementary requirement to develop cuticle penetration resistance. The increases of cuticle thickness and the alteration of cuticle constituents are the two major parameters which involved in cuticle modifications. Among these 2 parameters, the cuticle thickness is more correlated with insecticide resistances but there are some studies showed the linkage between the reduction of xenobiotic penetration and constituents of cuticle (Dang, Doggett, Veera Singham, Lee, & vectors, 2017);(Balabanidou, Grigoraki, & Vontas, 2018). These types of insecticide resistance can defend against many different types of insecticides but the rates of resistance towards insecticides are very low. These cuticle penetration resistances can work with other types of insecticide resistance to boost up the resistance effects (Oppenoorth & Welling, 1976); (Scott, 1990); (Strycharz et al., 2013); (Kasai et al., 2014); (Panini et al., 2016).

6.1 Larvicidal activities in Malaysia

(Shivakumar, Srinivasan, Natarajan, & Research, 2013) reported that plants are the resources which can help to overcome the vector problems because they have some bioactive constituents which are harmless to environments. The bioactive constituents of plants consisted of several unique modes of action which can be applied against targeted pests or insects. Traditionally, human communities overcame the problems related to insects or pests by using plant-based products for many centuries. Normally, most of the plants can synthesize several compounds called secondary metabolites and these compounds plays important roles in defence mechanism to fight against insects. These secondary metabolites also contain various types of bioactive chemical which can be applied for others functions. For instances, there are several applications like insecticides, repellents, growth inhibitors, moulting hormones, antifeedants, oviposition deterrents, attractants, juvenile hormone mimics and anti-moulting hormones. Besides that, plant-based pesticides are low toxicity, low rate of resistance developments are the properties of plant-based pesticides due to its high biodegradable rate and its new structures. It has been reported that nine essential oils and seventeen methanol extracts derived from several plants within Malaysia were determined for their larvicidal activity against Ae. aegypti. Most of the plants which found in Malaysia showed effective results which they give high mortality rates to larvae of Ae. aegypti. Malaysia cinnamon species, Cinnamomum microphyllum (Ridl) and Cinnamomum impressicostatum (Kosterm), pear mangosteen, Garcinia griffithii (T. Anders), turmeric, Curcuma domestica (Valeton) and button mangosteen, Garcinia praniana (King) are the few main examples which have significant mortality rates towards Ae. aegypti. (Jantan, Ping, Visuvalingam, & Ahmad, 2003). Azolla pinnata, commonly known as mosquito weed and it can be found around Malaysia. There were some current researches showed that it can yield high effectiveness of larvicidal activities to both Ae. aegypti and Ae. albopictus mosquito species (Ravi et al., 2018).

6.2 Areca catechu (L.)

Areca catechu is a type of palm tree which can be broadly cultivated and noticeable at various countries within Asia like Thailand, India, Malaysia, Taiwan and other relevant countries. Areca catechu plant is commonly known as betel nut tree or betel palm. The height of 20 m is the maximum height for an A. catechu plant grows. The general diameters of its trunks are located within the ranges which approximately between 20 m and 30 cm. The leaves of A. catechu plant have its own features which called as pinnate shapes and it can be used to differentiate with others plants. The normal length of A. catechu leaves can be 1.5 m to 2.0 m (Jaiswal, Kumar, Singh, & Singh, 2011). According to (Binoj, Raj, Sreenivasan, & Thusnavis, 2016), the flowers of A. catechu plant are typically grown in cluster forms and each spathe of flower can produce about 30 to 50 nuts. Areca catechu nuts usually have their own diameters which can grow up to the ranges of 5 cm to 10 cm. The external parts of nut shells were covered by certain amount of fibres which approximately 2.5 g to 2.75 g. Raw, ripe and mature are the 3 main maturity stages of an A. catechu nut. These stages can be determined easily by its colours and features. The nut and husk of a raw A. catechu nut are soft and the nuts are in green colour. The yellow A. catechu nut and juicy husk showed its ripe conditions. A fully matured nut has brownish colour appearance with shaggy fibres (Yusriah, Sapuan, Zainudin, & Mariatti, 2014).

(Amudhan et al., 2012), reported that there are several main compounds of phytochemicals which incorporated within an A. catechu nut such as polyphenol, alkaloids, fatty acids and others related mineral constituents. The isolation of phytochemicals constituents from A. catechu nut differs based on the nut maturity stages (Sumalatha, Ishwara Bhat, & Environment, 2019). Flavonoids such as catechin, epicatechin and leucocyanidin are the major constituents of polyphenols in an A. catechu nut. The fatty acid of A. catechu nut can be categorized into major and minor compounds. The few examples of major fatty acid within the nuts are myristic acid, lauric acid, linoleic acid, oleic acid, hexadecanoic acid and palmitic acid. Stearic acid and decanoic acid are the compounds which play as minor fatty acid groups in the nuts. A. catechu nut also consisted different types of oligomeric procyanidins. The major alkaloids which can be found in A. catechu nut are guvacine, guvacoline, arecaidine and arecoline (Amudhan et al., 2012). Several types of minerals such as calcium, iron, phosphorus and vitamins also can be extracted from A. catechu nuts (Sumalatha et al., 2019).

The betel nut can be processed by various ways such as dried, baked, roasted, cured and boiled. Betel quid is a type of quid which included several components such as betel leaves, tobacco leaves, quench lime mushes and betel nuts. The proper methods to consume betel quid are combine these components and chew it. The staining of teeth and tongue can be happened for the peoples who chew betel quid. The practices of chewing betel quid are mostly occurred within South Asia and even at certain rural areas in India (Hossain, Anwar, Akhtar, & Numan, 2015). Areca catechu nut was used for treatment purposes to certain diseases such as hypoglycemic, regulation of blood pressure and anti-diabetic due to its pharmacological functions (Patil, Rakesh, Dhabale, & Burade, 2009). According to (Dhanraj, Veerakumari, & Ashwini, 2018), it has been reported that A. catechu nut extracts also possessed some anthelmintic activities which it can eradicate Cotylophoron cotylophorum parasites in livestock with high efficiency. The rate of antioxidant activities of A. catechu nut extracts can be enhanced by using extraction techniques with methanol or methanol–water (Hannan, Karan, & Chatterjee, 2012). The dried A. catechu nut is commonly used in these extractions (Fig. 2). Nevertheless, A. catechu has shown very effective response against larvae with just a minimal concentration of 200 mg/l (Bharathithasan et al., 2022).

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Fig. 2

Dried Areca catechu nut (Murugakoothan et al., 2014).

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6.3 Azolla pinnata

Azolla pinnata is a type of free-floating aquatic fern plants which can be found in most of the tropical and subtropical in the world, especially at stagnant water areas or mild freshwater ecosystem (Shamna, Peethambaran, Jalaludeen, Leo, & Muhammad, 2013); Fig. 3). This type of plant species belongs to the family called Azollaceae (E. V. Kumar, Avinash, Bakshi, Kiran, & Narender, 2019). There are several common names for A. pinnata such as mosquito fern, water fern, mosquito weeds and water velvet. Basically, the fern frond of A. pinnata is the main body parts of plants. Polygonal or triangular are the common shape of A. pinnata fern fron d. The stems are the essential part of A. pinnata fern frond and they grow at the surfaces of aquatic habitats. The adventitious roots and alternate leaves also grow by the side of stems at regular intervals. These fronds usually float individually or mats forms at the water surfaces (Israa et al., 2012) (Wilson et al., 2020). The formation of thick mats can also avoid the egg laying processes by adult mosquito which can decrease the rate of mosquito larvae development (AhbiRami et al., 2014); (Ravi et al., 2018).

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Fig. 3

Fresh Azolla pinnata plants (Husna Zulkrnin et al., 2018).

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According to (Pabby et al., 2003) and (Abd Kadir et al., 2018), Anabaena azollae is a type of cyanobacteria which have symbiotic relationships with A. pinnata. This cyanobacterium typically hosts by them at the space which located at the leaf centre. The main role of A. azollae cyanobacteria includes productions of high level of nitrogen within A. pinnata plant tissues by absorbing nitrogen gas (N₂) from atmosphere. This makes A. pinnata become a suitable plant which can be used as green manure by various countries (Abd Kadir et al., 2018). It has been reported that A. pinnata contained 21–23 % of high crude protein level which cosidered as a good protein resource. There are various vitamins (Vitamin B-12 and A) and minerals (potassium, calcium, iron, magnesium) have been discovered within A. pinnata. Azolla pinnata also has been utilized as feed supplements for different livestock such as chicks, goats and cattle. The feeding of A. pinnata as feed supplements to livestock led to positive results such as increase of egg laying rates, milk and meat productions (Mathur, Sharma, & Choudhary, 2013); (G. Kumar & Chander, 2017). There are studies reported the high effectiveness of A. pinnata in wastewater treatments and removals of several metals such as cadmium, copper, lead and manganese (Akinbile et al., 2019). There are studies related to A. pinnata showed that the plant extracts caused high mortality rates against 2 main Aedes mosquito larvae species (Ae. aegypti and Ae. albopictus). According to Ravi et al. (2018), the methanol solvent extracts of A. pinnata using soxhlet extraction were analyzed by GC–MS analysis. The GC–MS chromatogram displayed 44 peaks which showed that 44 phytochemical compounds were presented within A. pinnata extracts. The mass spectra consisted of 44 phytochemical compounds were compared with mass spectra within NIST 08 library but there were only 35 compounds were characterized and identified in Table 2. These studies proved the A. pinnata contained potent larvicidal activities against Aedes mosquito larvae (Ravi et al., 2018).

6.4 Lantana camara

The Lantana is the plant genus which is belonging to family called Verbenaceae. Genus of Lantana is indigenous from America, especially from the tropical and subtropical regions. There are also certain taxa which are native to tropical Africa and other Asia countries. The genus Lantana contains one species from Ethiopia and six species from South America as reported by Linnaeus in 1753. This genus also included about 150 species of shrubs or herbs. The cultivated flower species of genus Lantana can be found around 50 countries (Munir, 1996); (Negi et al., 2019). Lantana camara is the one of the plant species derived from genus Lantana and it commonly known as red sage. Lantana camara plant is mostly used as an ornamental plant for gardening purposes (Munir, 1996); (Shah, Alharby, & Hakeem, 2020).

The wide of the L. camara leaves are within 3 cm to 6 cm and the ranges of its length are about 3 cm to 8 cm. The shape of L. camara leaves consisted of several characteristics such as wrinkled leaves surfaces, acute, ovate and both sides of leaves contain scabrid. The maximum width of L. camara plant can reach up to 2.5 m and its height can grow up to the range of 1 m to 3 m. L. camara plant consisted some rough hairs which coated their stems and leaves. The flower of L. camara plant is small and appeared as cluster forms. Orange is the most common colour of L. camara flower (Fig. 4). The alteration of flower colour may occur from white to red in different shades and it depends on their ages. The strong scents of L. camara plant are similar to blackcurrants (Verma & Therapeutics, 2018). Callosobruchus chinensis (L.) is the harmful pest which can penetrate and destroy the entire grain kernel. This type of pests can spoil the grains which can lead to loss of total grain productions (S. J. J. o. E. Singh & Studies, 2017). It has been reported that L. camara plant can give high effectiveness of antiovipositional and insecticidal activities towards C. chinensis (L.) (Saxena, Dixit, & Harshan, 1992); (Shah et al., 2020). The pharmacological studies about L. camara also have been proved that it has the powerful anti-inflammatory and antinociceptive properties (Silva et al., 2015). Some studies also showed that L. camara plant extracts give strong larvicidal effects to Ae. aegypti, Anopheles stephensi and Culex quinquefasciatus larvae (Hemalatha et al., 2015).

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Fig. 4

Lantana camara plant (Dubey & Padhy, 2013).

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6.5 Mukia maderaspatana

Mukia maderaspatana is a plant that belongs to Cucurbitaceae family (A. J. A. J. o. C. Petrus, 2012). Normally, this type of plant can be found in some abandoned fields or unwanted areas. It distributed nearly all over India but it also found in other countries such as Africa, New Zealand, Taiwan, Malaysia, China and Australia (Petrus et al., 2011). (A. J. A. J. o. C. Petrus, 2012), reported that the growing patterns of M. maderaspatana are usually climbing or prostrate. This type of plant contains some tendrils, scattering with certain amount of stiff hairs and mostly branched. The colour of M. maderaspatana flowers are pale yellow and their flower size are small. The M. maderaspatana flowers have categorized into two parts: male and female. Both of flowers are slightly different in appearances. Female flowers usually joint directly to base without peduncle and borne singly while male flowers are attached with a short peduncle.

The length and width of M. maderaspatana plants are generally within the range of 3 cm to 11 cm. Their characteristics of leaves included dark green colour, acute apices, irregularly serrated edge and consist of 3 to 5 lobes per leaf. The length of hairy petioles can reach about 0.6 cm to 2.5 cm. The pale green is the fruit colour of M. maderaspatana plants and reddish colour are the maturation stages of fruits (A. J. A. J. o. C. Petrus, 2012) Fig. 5). It has been reported that the M. maderaspatana plants contain several types of polyphenols which consist of strong antioxidant properties such as saponarin, carotenoids, vitamin E, vitamin C. These polyphenols can against the oxidative stresses and reduce the development of chronic diseases (Petrus et al., 2011). Mukia maderaspatana plant also contains larvicidal properties towards larvae of Ae. aegypti and gave efficient mortality results (Ramamurthy & Krishnaveni, 2014). Some studies also reported that M. maderaspatana plants consisted of high antimicrobial activity against causative agent of tuberculosis, Mycobacterium tuberculosis. Mukia maderaspatana extracts showed the lowest minimum inhibitory concentration against M. tuberculosis compared with others experimental plants (Nirmal et al., 2020).

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Fig. 5

Mukia maderaspatana plant (Petrus et al., 2011).

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6.6 Leucas aspera

Leucas aspera is a type of herbaceous plants which belongs to family called Lamiaceae (Labiatae). Normally, the distribution of these plants includes some temperate or tropical regions of Asia countries. It can be found at various areas such as roadsides, uncultivated land, farmhouse and crop fields located at high land (Prajapati, Patel, Modi, & Shah, 2010); (Srinivasan et al., 2011); (Islam, Ohno, Suenaga, & Kato-Noguchi, 2014). According to (Saritha, Rajesh, Manjulatha, Setty, & Yenugu, 2015) and (E. V. Kumar et al., 2019), the lance head-liked shape, tiny petiole and coated pubescents are the main characteristics of L. aspera leaves (Fig. 6). The height of L. aspera plants can grow within the ranges of 15 cm to 60 cm. The stems and branches are upright, thick and quadrangular shapes. The L. aspera fruits look like a brown colour nut which have diameter of 2.5 mm. The flowers of L. aspera are white in colour and it also comprised with terminal forms of whorls and tiny sessile.

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Fig. 6

Leucas aspera plants (Suganya, Karthi, & Shivakumar, 2014).

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It has been reported that L. aspera plant extracts consisted of antimicrobial activities towards microorganisms such as Escherichia coli. The small pores formation on bacterial membrane is due to the antimicrobial actions of small molecules and protein content within L. aspera plant extracts. These formations of small pores caused the cellular contents leaked out from its membrane (Saritha et al., 2015). The antioxidant properties of L. aspera plant extracts also have been proved by some studies. The root parts of L. aspera plant showed the potent antioxidant activities compared to others plant parts and its activities almost reached the level of vitamin E. Thus, it can become the new potential antioxidant resources (Santhanam Selvaraj, Ponraj, Rameshkumar, & et al., 2021) The larvicidal activities of L. aspera plant extracts against Ae. aegypti, A. stephensi and Cx. quinquefasciatus has been proved by some studies. The results also showed mortality rate on the larvae of these mosquito species (Elumalai et al., 2017).