Preliminary larvicidal activity
Table 2 display the findings of the preliminary larvicidal activity of the extract of several medicinal herbs. Among the 18 plant extracts, Trigonell foenum, Phyllanthus niruri, Senna auriculata, Mukia maderaspatana, Justicia adhatoda, Andrographis paniculata, Hybanthus enneaspermus, Cardiospermum corundum, Azadirachta indica, Ocimum sanctum, Aloe vera, Solanum nigrum, Syzygium jambolanum, Eclipta allopa, Phylianthus emblica and Andrographis paniculata shows positive effect after 24h and 48h exposure. The MLE-M. maderaspatana had the highest death rate, followed by MLE-T. foenum. Based on the mortality of preliminary activity Mukia maderaspatana, Trigonell foenum, Phyllanthus niruri, Senna auriculata, Justicia adhatoda, Andrographis paniculata, Hybanthus enneaspermus, Cardiospermum corundum and Azadirachta indica were for larvicidal activity.
Table 2
Preliminary larvicidal bioassay of MLE
Sl.No | Sample Name | 24 hours | 48 hours |
1 | Phyllanthus niruri | + | + |
2 | Trigonella foenum graecum | + | + |
3 | Senna auriculata | + | + |
4 | Mukia maderaspatana | + | + |
5 | Justicia adhatoda | + | + |
6 | Andrographis paniculata | + | + |
7 | Hybanthus Enneaspermus | + | + |
8 | Cardiospermum corundum | + | + |
9 | Azadirachta indica | + | + |
10 | Ocimum sanctum | - | - |
11 | Aloe vera | - | - |
12 | Solanum nigrum | - | - |
13 | Syzygium jambolanum | - | - |
14 | Eclipta alloa | - | - |
15 | Phylianthus emblica | - | - |
16 | Andrographis paniculata | - | - |
17 | Hibiscus rosa sinensis | - | - |
18 | Citrus limon | - | - |
The results, larvicidal activity of MLE and ELE-M. maderaspatana tested against Cx. quinquefasciatus, An. stephensis and Ae. aegypti for the duration of 24 h and 48 h were shown in Table 3. The highest mortality 100% and 97% was observed MLE and ELE-M. maderaspatana against An. stephensi at 24h and 48h. Followed by, the mortality 97% and 95% (Ae. aegypti), 95% and 94% (Cx. quinquefasciatus). Table 4 shows the results of testing MLE and ELE-M. maderaspatana larvicidal effectiveness against significant larvae of mosquito vector. MLE-M. maderaspatana was highly effective (LC50/LC90 = 4.46 ppm/9.25 ppm) against the larvae of An. stephensi. Followed by, LC50/LC90 values were Ae. aegypti (11.92 ppm/14.60 ppm) and Cx. quinquefasciatus (47.86 ppm/93.48 ppm) (Fig. 3). The highest mortality (LC50 ppm/LC90 ppm values) was 60.55 ppm/99.51 ppm from the ELE-M. maderaspatana against An. stephensi. Followed by, LC50/LC90 values were Ae. aegypti (141.34 ppm/166.57 ppm) and Cx. quinquefasciatus (181.5 ppm/206.05 ppm) (Fig. 4). A previous work examined the larvicidal efficacy of twelve compounds extracted from the leaf essential oil of two species of Eucalyptus against Ae. aegypti and Ae. albopictus (Cheng et al., 2009). According to Kovendan et al., (2012), an ethanol extract of entire sections of Leucas aspera tested against An. stephensi larvae revealed an LC50 of 9.695, respectively. When tested against Ae. aegypti, An. stephensi, and Cx. quinquefasciatus, Sesamum indicum methanol extract had the highest larvicidal effect (LC50) values of 349.88, 338.27, and 254.85 mg/L (Baranitharan et al. 2015). The larvicidal activity of extracts from Plumbago zeylanica and Cestrum noctumum was investigated against Ae. aegypti (Patil et al. 2011). When evaluated against Ae. aegypti, An. stephensi, and Cx. quinquefasciatus, the LC50 value of the ethyl acetate extract of Commiphora caudata was 97.19, 96.04, and 94.76 mg/L (Baranitharan and Dhanasekaran 2014). To test Pedalium murex methanol extract against Cx. quinquefasciatus and Ae. aegypti, the maximum larvicidal effect (111.66 and 127.08 mg/L) was observed (Gokulakrishnan et al. 2016). Ficus racemosa methanol extract has a lethal impact (LC50) of 64.76 ppm against Ae. aegypti, according to Baranitharan et al. (2016). Linalool from the essential oil of Lavender augustifolia had the largest larval impact, its LC50 values against Ae. aegypti, An. stephensi, and Cx. quinquefasciatus were 36.26, 36.81, and 37.49 ppm (Baranitharan et al. 2021).
Table 3
Mortality percentage of MLE and ELE-Mukia maderaspatana against mosquito larvae
Extracts | Target species | Duration | NEX | Mean ± SD | Mortality (%) |
MLE | C. quinquefsciatus | 24 hours | 25 | 23.5 ± 0.2 | 94% |
A. stephensi | 25 | 24.3 ± 0.4 | 97% |
A. aegypti | 25 | 23.7 ± 0.2 | 95% |
C. quinquefasciatus | 48 hours | 25 | 23.8 ± 0.3 | 95% |
A. stephensi | 25 | 25.0 ± 0.0 | 100% |
A. aegypti | 25 | 24.2 ± 0.4 | 97% |
ELE | C. quinquefsciatus | 24 hours | 25 | 14.8 ± 4.2 | 59% |
A. stephensi | 25 | 23.2 ± 2.3 | 93% |
A. aegypti | 25 | 25.0 ± 0.0 | 100% |
C. quinquefasciatus | 48 hours | 25 | 20.0 ± 0.6 | 80% |
A. stephensi | 25 | 24.2 ± 1.6 | 97% |
A. aegypti | 25 | 25.0 ± 0.0 | 100% |
Signification at p > 0.05 level, SD- Standard Deviation, NEX- Number of larvae exposed, Mortality (%)- percentage of mortality. |
Table 3
Hydrogen peroxide Activity of Solanumincanum crude extracts
Solvents | Concentrations (µg/ml) | IC50 value (mg/ml) |
50 | 150 | 250 | 500 |
Hexane | 17.11 ± 0.09 | 23.35 ± 0.06 | 27.50 ± 0.02 | 37.35 ± 0.03 | 584.511 |
Chloroform | 19.89 ± 0.06 | 25.76 ± 0.02 | 29.45 ± 0.02 | 41.15 ± 0.02 | 597.87 |
Ethyl acetate | 32.70 ± 0.05 | 37.75 ± 0.05 | 43.45 ± 0.03 | 55.96 ± 0.02 | 367.647 |
Methanol | 38.46 ± 0.03 | 44.60 ± 0.07 | 54.46 ± 0.01 | 65.64 ± 0.01 | 133.641 |
EDTA | 41.42 ± 0.75 | 67.30 ± 0.03 | 75.45 ± 0.50 | 84.50 ± 0.50 | 82.715 |
Table 4
LC50/LC90 values of MLE and ELE-Mukia maderaspatana against mosquito larvae
Extract | Target species | Intercept | Slope | LC50 (ppm) | 95% confidence limit (ppm) | LC90 (ppm) | 95% confidence limit (ppm) | χ² (df = 6) |
| LCL | UCL | | LCL | UCL |
MLE | A. stephensi | 1.75 | 2.38 ± 0.06 | 4.46 | 3.93 | 5.05 | 9.25 | 7.09 | 12.06 | 11.1 (6) |
C. quinquefasciatus | 1.91 | 2.39 ± 0.06 | 47.86 | 42.53 | 53.85 | 93.48 | 72.54 | 120.48 | 16.1 (6) |
A. aegypti | 6.35 | 10.75 ± 0.02 | 11.92 | 11.49 | 12.37 | 14.60 | 13.62 | 15.60 | 1.3 (6) |
ELE | A. stephensi | 3.43 | 9.51 ± 0.03 | 60.55 | 64.06 | 73.35 | 99.51 | 87.22 | 113.53 | 2.7 (6) |
C. quinquefasciatus | 10.10 | 47.57 ± 0.01 | 181.5 | 177.24 | 185.94 | 206.05 | 196.8 | 215.67 | 2.4 (6) |
A. aegypti | 7.79 | 33.58 ± 0.02 | 141.34 | 137.02 | 145.8 | 166.57 | 157.02 | 176.69 | 2.5 (6) |
LC50 = Lethal Concentration brings out 50% mortality and LC90 = Lethal Concentration brings out 90% mortality. LCL = Lower Confidence Limit; UCL = Upper Confidence Limit; Slope; Chi-square. |
Phytochemical screening of MLE and ELE- M. maderaspatana
Phytochemical screening of MLE and ELE-M. maderaspatana revealed a wide number of bioactive compounds present (Table 5). Bioactive substances found in LE include coumorins, glycosides, cardiac glycosides, terpenoids, alkaloids, saponins, tannins, and flavonoids. Thin layer chromatography in a methanol solvent solution was used to investigate phytochemical screening. Alkaloids, terpenoids, phenolic compounds and glycosides are among the phytochemical group members that contain it in large quantities. The pytochemical group’s presence (flavonoids, saponins, tannins and steroid) and the phytochemical group’s trace amounts (cardiac glycosides and coumorins) come next. The phytochemical group flavonoid was abundantly, alkaloids and saponins is presence in ethanol extract, while tannins, glycosides, and steroids were present in trace amounts. The results of this work are comparable to those of an MPC screening of Coleus aromaticus leaf fractions, which identified a variety of bioactive chemicals including tannins, terpenoids, tri-terpenoids, steroids, saponins, phenol, proteins, alkaloids and glycosides (Baranitharan et al. 2017). According to Yadav and Agarwala (2011), phytochemicals like carbohydrates, tannins, saponins, proteins, phenols, and flavonoids were identified from various solvent extracts of Bryophyllum pinnaaum, Ricinus communis, Ipomea aquatic, Tinospora cordifolia, Terminalia bellerica, Xanthium strumarium and Oldenlandia corymbosa. According to Anindita and Bikramjit (2017), primary phytochemical screening of Rouvolfia serpentine and Moringa olifera revealed the presence of metabolites such as glycosides, alkaloids, phenolic compounds, tannins, steroids, flabinoids, saponins. Aqueous and methanol extracts of some therapeutic plants revealed the presence of steroids, alkaloids, tannins, glycosides, phenols, flavonoids, cards, and terpinoids (Padmapriya et al. 2020). Bischofia javanica and Curcuma domestica showed presence of compounds such as terpenoids, saponins, alkaloids and flavonoids (Aththorick and Berutu 2018).
Table 5
Phytochemical screening of Mukia maderaspatana leaf extract
S.No. | Phytoconstituents | Reagent used | CLE | BCL | PELC | ELE (50%) | WLE |
1 | Alkaloids | Wagner’s test | + | +++ | +++ | ++ | ++ |
Mayer’s test | ++ | - | +++ | +++ | - |
Picric acid test | ++ | ++ | +++ | +++ | ++ |
2 | Flavonoids test | Alkaline reagent | ++ | + | - | +++ | +++ |
Lead acetate test | ++ | +++ | - | ++ | - |
Ammonia test | ++ | + | - | +++ | +++ |
3 | CHO test | Benedicts reagent | - | - | - | +++ | - |
Fehling’s reagent | +++ | +++ | ++ | +++ | - |
Conc. H2SO4 test | +++ | ++ | - | +++ | - |
4 | Proteins & amino acids | Xanthoproteic test | ++ | + | - | +++ | +++ |
Biuret test | ++ | - | - | +++ | - |
5 | Glycosides test | Modified Bomtrager’s test | + | + | + | +++ | ++ |
Keller killiani test | +++ | +++ | +++ | - | - |
6 | Steroids & terpenoids test | Salkowski’s test | ++ | - | +++ | +++ | - |
Libermann Burchard test | +++ | - | + | - | - |
7 | Inorganic compound test | Sulphate test | +++ | +++ | +++ | - | - |
Carbonate test | - | - | - | - | +++ |
8 | Saponins | Froth test | ++ | +++ | +++ | - | - |
9 | Anthrax Quinones | Bomtrager’s test | - | - | - | - | - |
10 | Tannins & Phenol | FeCl3 test | - | - | - | - | - |
Galatin test | +++ | +++ | +++ | + | + |
11 | Resins | Acetone test | +++ | + | +++ | + | + |
12 | Gum & Mucilage | Ppt by Alcohol | - | +++ | - | - | - |
13 | Fixed oils & fats | Spot test | ++ | - | ++ | - | + |
14 | Lipids | Dichromate | - | +++ | +++ | +++ | - |
15 | Starch | Lugol’s iodine | + | + | - | - | - |
+++: Abundance of the phytochemical group; ++ : presence of the phytochemical group; +: trace of the phytochemical group; - : absence of the phytochemical group. CLE: Chloroform Leaf Extract; BLE: Benzene Leaf Extract; PELE: Petroleum ether Leaf Extract; ELE (50%): 50% Ethanol Leaf Extract; WLE: Water Leaf Extract |
FTIR spectra analysis of MLE- M. maderaspatana
FTIR spectra analysis was identified the functional groups of the MLE-M. maderaspatana; FT-IR spectra clearly exhibited absorption in the different range 2920.69 cm− 1 to 649.60 cm− 1 (Fig. 5). The peak values corresponded to functional groups like alkanes (C-H stretching 2920.69 cm− 1 to 2851.35 cm− 1) medium bonding, alkynes (-C ≡ C- stretching 2251.24 cm− 1) weak bonding, aromatics (C-C stretching (in ring) 1464.73 cm− 1) medium bonding, carbonyl (general) (C = O stretching 1379.01 cm− 1) very weak bonding, 1*, 2* amines (N-H wag 907.64 cm− 1) strong and broad bonding, and alkyl halides (-C ≡ C-H: C-H bend 649.60 cm− 1) medium bonding. The functional groups such as alkanes, alkynes, aromatics, carbonyl (general), 1*, 2* amines and alkyl halides confirmed their presence in MLE-M. maderaspatana. By using FTIR analysis, similar findings were made for Phyla nodiflora-MLE, which contained functional groups such amides, alkanes, 1* amines, aliphatic amines and alkyl halides (Irrusappan et al. 2022). FTIR spectroscopy analysis was found OH stretching and C = O vibration functional groups from Punica granatum-MLE (Jebanesan et al. 2020). Jussiaea repens-ELE, the major component, included the functional groups that were discovered by FTIR analysis, such as 4-piperidineacetic acid, 1-acetyl-5-ethyl-2-[3-(2-hydroxyethyl]-1H-indol-2-yl]-á-methyl-, methyl ester (Krishnappa et al. 2020). Further, Citrus limetta-MLE contained phytocompound of Corynan-17-01, 18, 19-didehydro-10-methoxy-, acelate (ester) (Baranitharan et al. 2020).
Major chemical compound analysis
The twenty-one compounds of MLE-M. maderaspatana were found in their mass spectra, representing 100% of the sample. Table 6 and Fig. 6 display the chemical formula and concentration as percentages (%). The MCC in MLE-M. maderaspatana are Geranylgeraniol (C20H34O and 16.04%) (Fig. 7), Isodecyl diphenyl phosphate (C22H31O4P and 10.98%), 7,9-Di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione (C17H24O and 10.03%), 1-Monoacetin (C5H10O4 and 8.76%), Diphenylamine (C12H11N and 5.11%), Citronellol epoxide (C10H20O2 and 5.00%), Isopropyl Myristate (C17H34O2 and 4.84%), 9-Cedranone (C15H24O and 4.75%), Oleyl alcohol (C18H36O and 3.59%), n-Butyl myristate (C18H36O2 and 3.66%), benzoyl peroxide (C14H10O4 and 3.42%), 2,5-Pyrrolidinedione, 1-butyl- (C8H13NO and 3.27%), 4-tert-Butyl-2,6-diisopropylphenol (C16H26O and 3.27%), Limonen-6-ol, pivalate (C15H24O2 and 2.73%) and 5,5-Dibutylnonane (C17H36 and 2.03%). The present study’s results are comparable to the LE’s GC-MS analysis, which revealed the existence of twenty compounds primarily composed of palmitic acid, neophytadiene, and limonene dioxide (Mamudha and Sunilson, 2021). Continuously, the mass spectral analysis also confirmed these compounds and molecules consist of carbon 8 atoms, hydrogen 15 atoms and oxygen 4 atoms were indicated in different colors (Krishnappa et al. 2020). Medicinal plant, Erythrina variagata LME was found 12-octadecenoic acid, methyl ester and it had predominant toxicity against HVMs (Baranitharan et al. 2019). Petalonema alatum LME was found different major phyto-compounds (MPCs) like 5-thio-D-glucose, 5-allylsulfanyl-l-(4-methoxy-phenyl)-1H-tetrazole, E)-10-heptadecen-8-ynoic acid methyl ester, and Z-11-hexadecenoic acid (Saravanakumar et al. 2016). Twenty compounds, or 100% of the compounds, had their chemical constituents identified in the methanol extract following GC-MS analysis of the LME-Loranthes pentandrus. These investigations were conducted to determine the principal phytocompounds (Krishnappa et al. 2019). Citrus limetta-MPCs was showed six compounds, the main Corynan-17-01, 18, 19-didehydro-10-methoxy-, acelate (ester) (Baranitharan et al. 2020). In the Ageratina adenophora-MLE secondary metabolic study, twenty-one chemicals were found, with 5-isopropyl-2-methylphenol being the predominant one (Dhanasekaran et al. 2022b).
Table 6
Components identified in the MLE-Mukia maderaspatana using GC-MS
MF | Name of Compound | RT (min)* | PA | PA (%) | MW (g/mol) | Height | Height (%) | MI |
C5H10O4 | 1-Monoacetin | 5.492 | 679233 | 8.76 | 134.13 | 69079 | 4.04 | RI-MS |
C9H14O | trans,cis-2,6-Nonadienal acetate | 7.800 | 90339 | 1.16 | 138.21 | 27715 | 1.62 | RI-MS |
C15H24O | 9-Cedranone | 8.094 | 368347 | 4.75 | 220.35 | 77678 | 4.55 | RI-MS |
C9H10O3 | Ethyl 3-hydroxybenzoate | 8.925 | 144043 | 1.86 | 166.17 | 35032 | 2.05 | RI-MS |
C4H4O4 | Fumaric acid | 8.992 | 104537 | 1.35 | 116.07 | 44792 | 2.62 | RI-MS |
C12H22O2 | Vinyl decanoate | 9.414 | 60151 | 0.78 | 198.30 | 13499 | 0.79 | RI-MS |
C12H11N | Diphenylamine | 10.685 | 396688 | 5.11 | 169.22 | 77731 | 4.55 | RI-MS |
C8H13NO | 2,5-Pyrrolidinedione, 1-butyl- | 10.859 | 253549 | 3.27 | 99.09 | 31147 | 1.82 | RI-MS |
C14H10O4 | benzoyl peroxide | 11.207 | 265578 | 3.42 | 242.23 | 60392 | 3.53 | RI-MS |
C17H36 | 5,5-Dibutylnonane | 13.586 | 157468 | 2.03 | 240.5 | 46894 | 2.74 | RI-MS |
C16H26O | 4-tert-Butyl-2,6-diisopropylphenol | 13.586 | 253746 | 3.27 | 234.38 | 54830 | 3.21 | RI-MS |
C3H4O4 | Malonic acid, | 14.436 | 134554 | 1.73 | 104.06 | 33332 | 1.95 | RI-MS |
C17H34O2 | Isopropyl Myristate | 14.841 | 375430 | 4.84 | 270.45 | 118132 | 6.91 | RI-MS |
C8H8O2 | Phenylacetic acid | 15.417 | 27440 | 0.35 | 136.15 | 10647 | 0.62 | RI-MS |
C17H24O | 7,9-Di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione | 17.273 | 777931 | 10.03 | 276.37 | 197927 | 11.58 | RI-MS |
C15H24O2 | Limonen-6-ol, pivalate | 19.879 | 211486 | 2.73 | 236.35 | 56425 | 3.30 | RI-MS |
C19H38O2 | Isopropyl Palmitate | 19.996 | 138718 | 1.79 | 298.5 | 37811 | 2.21 | RI-MS |
C18H38N2O | Stearic acid hydrazide $$ Stearic hydrazide $$ | 22.736 | 115686 | 1.49 | 298.5 | 28717 | 1.68 | RI-MS |
C18H26O | 2-Ethylhexyl trans-4-methoxycinnamate | 23.810 | 135157 | 1.74 | 290.39 | 29767 | 1.74 | RI-MS |
C18H36O2 | n-Butyl myristate | 24.351 | 284249 | 3.66 | 284.5 | 64298 | 3.76 | RI-MS |
C6H10O2 | Caprolactone oxime | 27.258 | 16884 | 0.22 | 114.14 | 8693 | 0.51 | RI-MS |
C10H20O2 | Citronellol epoxide | 28.999 | 387834 | 5.00 | 172.26 | 71828 | 4.20 | RI-MS |
C22H31O4P | Isodecyl diphenyl phosphate | 30.782 | 851567 | 10.98 | 390.5 | 201014 | 11.77 | RI-MS |
C18H36O | Oleyl alcohol | 32.552 | 278499 | 3.59 | 268.47 | 52912 | 3.10 | RI-MS |
C17H23N5O | 3,5-Ethanol Quinolin-10-ol | 41.908 | 2738 | 0.04 | 313.4 | 4227 | 0.25 | RI-MS |
C20H34O | Geranylgeraniol | 43.620 | 1244158 | 16.04 | 290.48 | 254014 | 14.87 | RI-MS |
| | | 7756010 | 100.00 | | 1708533 | 100.00 | RI-MS |
MF = Molecular formula, *RT = Retention time (min), PA = Peak area, MW = molecular weight, MI = Mode of identification |
Nuclear Magnetic Resonance (NMR) analysis
The MLE-M. maderaspatana underwent NMR spectral analysis, and the spectral peaks that emerged are displayed (Figs. 8 & 9). The observed peaks were examined, their potential structures were postulated and verified using the available information, and they were contrasted with the NIST chemical library. The band that was observed at 907.64 cm− 1 is a result of the N-H wag stretching vibration, which is a strong and wide bonding. The spectrum unequivocally shows that MLE-M. maderaspatana was used to extract the geranylgeraniol molecule. Subsequently, components were detected in the isodecyl diphenyl phosphate compound, exhibiting almost 80% similarity. In a similar vein, Blumea mollis-LAE was subjected to 1H and 13C NMR spectral analysis, the results of which clearly revealed the molecule Atalantin (Elumalai et al. 2020). The signals found in the phenol, 2-methyl-5-(1-methylethyl) molecule from Punica granatum 1H NMR (400 MHz, CDCl3) spectrum (Jabanesan et al. 2020).
Predation efficiency of G. affinis
Following a 24-hour period of treatment with modest dosages of MLE-M. maderaspatana, the predation efficiency of G. affinis was observed against III instar larvae of An. stephensi (93.12%), Cx. quinquefasciatus (82.82%), Ae. aegypti (87.90%). Followed by, ELE-M. maderaspatana tested against An. stephensi (90.34%), Cx. quinquefasciatus (78.66%) and Ae. aegypti (85.66%) (Table 7). For the eight days following treatment (i.e., post treatment observation period), no discernible toxicity effects were seen in one G. affinis exposed to the contaminated aquatic environment caused by MLE and ELE-M. maderaspatana. Subramaniam et al. (2015) found that in environments contaminated with Mimusops elengi extract, G. affinis had a predation efficiency of 86.2% against III instar larvae of An. stephensi and 81.7% against Ae. albopictus. Chobu et al. (2015) found that G. affinis outcompetes Carassius auratus, a goldfish from to the Cyprinidae family, as a predator of An. gambiae III instar larvae. A well-known biocontrol agent that is particularly effective in preventing mosquito larvae from developing is the mosquito fish (Griffin and Knight 2012)
Table 7
Predation efficiency of the G. affinia fish against III instar larvae of mosquito larvae
Extracts | Target species | Predated larvae (n) | Predation (%) | Predation efficacy per day |
Day 1 | Day 2 | Day 3 | Day 4 | Day 5 |
MLE | A. stephensi | 183.4 ± 3.71cd | 188.6 ± 4.21d | 185.6 ± 4.03d | 186.4 ± 3.57d | 187.2 ± 3.63d | 93.12 | 186.24 |
C. quinquefsciatus | 160.4 ± 2.70ab | 166.2 ± 3.27b | 167.4 ± 4.15b | 164.6 ± 4.44b | 169.6 ± 4.61bc | 82.82 | 165.64 |
A. aegypti | 171.8 ± 3.78bc | 174.6 ± 4.27c | 178.4 ± 3.71cd | 175.4 ± 2.50c | 178.8 ± 4.32cd | 87.90 | 175.80 |
ELE | A. stephensi | 179.6 ± 4.44cd | 176.8 ± 3.83c | 180.4 ± 3.64cd | 182.2 ± 4.49cd | 184.4 ± 4.15d | 90.34 | 180.68 |
C. quinquefsciatus | 152.4 ± 4.27a | 157.8 ± 2.94ab | 155.4 ± 3.84a | 159.8 ± 4.08ab | 161.2 ± 3.49ab | 78.66 | 157.32 |
A. aegypti | 165.4 ± 3.04b | 169.4 ± 3.36bc | 171.4 ± 3.71bc | 173.6 ± 4.66bc | 176.8 ± 4.86c | 85.66 | 171.32 |
Predation rate are mean ± SD of five replications (i.e. 1 G. affinis adult vs 200 mosquito larvae pre replication). No mortality in control (i.e. clean water without G. affinis). Within each column, means followed by the same letter are not significantly different (P < 0.05) |
Antioxidant assay
The hexane extract exhibited the highest amount of DPPH radical scavenging activity, with an EC50 value of 411.485 mg/ml, higher than that of the crude extracts from M. maderaspatana (154.028 mg/ml), ethyl acetate (104.21 mg/ml), and methanol (64.721 mg/ml). Conversely, the ascorbic acid extract (20.221 mg/ml) showed the lowest value of activity. Hexane, chloroform, ethyl acetate, methanol, and ascorbic acid were the solvents whose scavenging action was reduced by the ascorbic acid, according to the results (Table 8 and Fig. 10). The extracts with the highest IC50 values in the ABTS+ radical scavenging assay were hexane (261.872mg/ml), followed by chloroform (198.495mg/ml), ethyl acetate (138.833mg/ml), methanol (63.541mg/ml), and ascorbic acid (46.935ml/ml), in that order. The findings demonstrate how different solvents scavenging activities reduced ascorbic acid in the following order: hexane, chloroform, ethyl acetate, methanol, and ascorbic acid (Table 9 and Fig. 11).
Table 8
DPPH activity M. maderaspatana crude extracts
Solvents | Concentrations (µg/ml) | IC50 value (mg/ml) |
50 | 150 | 250 | 500 |
Hexane | 29.54 ± 0.13 | 39.20 ± 0.14 | 52.18 ± 0.98 | 71.20 ± 0.50 | 411.485 |
Chloroform | 38.64 ± 0.19 | 48.70 ± 0.50 | 61.31 ± 0.28 | 78.68 ± 0.76 | 154.028 |
Ethyl acetate | 45.35 ± 0.50 | 52.60 ± 0.33 | 65.38 ± 0.78 | 84.12 ± 0.28 | 104.21 |
Methanol | 49.20 ± 0.20 | 58.78 ± 0.78 | 73.88 ± 0.76 | 94.30 ± 0.50 | 64.721 |
Ascorbic acid | 54.17 ± 0.12 | 67.16 ± 0.32 | 78.70 ± 0.05 | 98.28 ± 0.78 | 20.221 |
Table 9
ABTS+ activity of M. maderaspatana crude extracts
Solvents | Concentrations (µg/ml) | IC50 value (mg/ml) |
50 | 150 | 250 | 500 |
Hexane | 26.06 ± 0.44 | 37.74 ± 0.48 | 48.20 ± 0.50 | 59.21 ± 0.70 | 261.872 |
Chloroform | 38.50 ± 0.50 | 43.16 ± 0.27 | 57.27 ± 0.35 | 72.61 ± 0.21 | 198.495 |
Ethyl acetate | 41.01 ± 0.28 | 48.76 ± 0.68 | 64.00 ± 0.50 | 79.65 ± 0.55 | 138.833 |
Methanol | 46.18 ± 0.01 | 65.57 ± 0.02 | 75.02 ± 0.32 | 89.32 ± 0.93 | 63.541 |
Ascorbic acid | 49.18 ± 0.12 | 66.57 ± 0.35 | 75.02 ± 0.32 | 95.12 ± 0.29 | 46.935 |
Using the same quantities, EDTA (82.715mg/ml) was shown to have a lower EC50 value in the H2O2 scavenging assay than chloroform extracts (597.87mg/ml), hexane (584.511mg/ml), ethyl acetate (367.647mg/ml) methanol (133.641mg/ml). The findings show that, in the order of chloroform > hexane > ethyl acetate > methanol > EDTA, the values on the H2O2 radical scavenging activity of the various solvents of M. maderaspatana decrease relative to that of EDTA (Table 10 and Fig. 12). According to Baruah et al. (2023), the LC50 values for different antioxidant activities varied from 27.94 to 114.15 µg/ml for DPPH, 15.05 to 707.74 µg/ml for ABTS, and 40.23 to 338.91 µg/ml for TBARS. In the DPPH, FRAP, and ABTS tests, Ocimum basilicum shown a stronger antioxidant activity than Ocimum americanum (Mahendran and Vimolmangkang 2023). They found that conventional antioxidants had greater activity than essential oils (Horvathova et al. 2014; Hazrati et al. 2020). Additionally, an examination of antioxidants revealed that the leaf oil and inflorescence oil had effective concentrations (EC50) of 22.76 µg/ml and 26.18 µg/ml, respectively, which translates to 17.57 µg/ml of ascorbic acid (John et al. 2022).