Antibacterial and antioxidant activities of Musa sp. leaf extracts against multidrug resistant clinical pathogens causing nosocomial infection

Objective

To investigate different Musa sp. leave extracts of hexane, ethyl acetate and methanol were evaluated for antibacterial activity against multi-drug resistant pathogens causing nosocomial infection by agar well diffusion method and also antioxidant activities.

Methods

The four different Musa species leaves were extracted with hexane, ethyl acetate and methanol. Antibacterial susceptibility test, minimum inhibitory concentration and minimum inhibitory bacterial concentration were determined by agar well diffusion method. Total phenolic content and in vitro antioxidant activity was determined.

Results

All the Musa sp. extracts showed moderate antibacterial activities expect Musa paradisiaca with the inhibition zone ranging from 8.0 to 18.6 mm. Among four species ethyl acetate extracts of Musa paradisiaca showed highest activity against tested pathogens particularly E. coli, P. aeruginosa and Citrobacter sp. The minimum inhibitory concentrations were within the value of 15.63- 250 µg/mL and minimum bactericidal concentrations were ranging from 31.25- 250 µg/mL. Antioxidant activity of Musa acuminate exhibited maximum activity among other three Musa species.

Conclusions

The present study concluded that among the different Musa species, Musa paradisiaca displayed efficient antibacterial activity followed by Musa acuminata against multi-drug resistant nosocomial infection causing pathogens. Further, an extensive study is needed to identify the bioactive compounds, mode of action and toxic effect in vivo of Musa sp.     

Antibacterial activity of various leaf extracts of Merremia emarginata

Objective

To investigate the antibacterial activity and phytochemical screening of the aqueous, methanol and petroleum ether leaf extracts of Merremia emarginata (M. emarginata).

Methods

The antibacterial activity of leaf extracts of M. emarginata were evaluated by agar well diffusion method against four selected bacterial species.

Results

The presence of tannins, flavonoids, amino acids, starch, glycosides and carbohydrates in the different leaf extracts was established. The methanol extract was more effective against Bacillus cereus and Escherichia coli, whereas aqueous extract was more effective against Staphylococcus aureus and Pseudomonas aeruginosa.

Conclusions

: The results in the present study suggest that M. emarginata leaf can be used in treating diseases caused by the tested organisms.     

In vitro antioxidant activities of Solanum surattense leaf extract

Objective

To evaluate the antioxidant activity of alcoholic leaf-extract of Solanum surattense (Solanaceae) (S. surattense).

Methods

Leaf extract were tested for in vitro free radical scavenging assays, such as hydroxyl radical and hydrogen peroxide, inhibition of superoxide anion radical and 2, 2-diphenyl-1-picryl hydrazyl radical (DPPH), total antioxidant activity and reducing ability. Further, total phenolic content of S. surattense was analyzed.

Results

S. surattense extract effectively scavenged free radicals at all different concentrations and showed its potent antioxidant activity. Further, these effects were in a dose dependent manner. Results were compared to standard antioxidants such as butylated hydroxytoluene, ascorbic acid and α-tocopherol.

Conclusions

S. surattense have strong antioxidant potential. Further the study validates the therapeutic benefits of the Indian system of medicine.     

Phytochemical screening and in vitro bioactivities of the extracts of aerial part of Boerhavia diffusa Linn.

Objective

To investigate the bioactivities of crude n-hexane, ethyl acetate and methanol extracts of aerial part of Boerhavia diffusa Linn. (B. diffusa) and its phytochemical analysis.

Methods

The identification of phytoconstituents and assay of antioxidant, thrombolytic, cytotoxic, antimicrobial activities were conducted using specific standard in vitro procedures.

Results

The results showed that the plant extracts were a rich source of phytoconstituents. Methanol extract showed higher antioxidant, thrombolytic activity and less cytotoxic activity than those of n-hexane and ethyl acetate extracts of B. diffusa. Among the bioactivities, antioxidant activity was the most notable compared to the positive control and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of the plant showed remarkable antibacterial activity against tested microorganisms. All the extracts showed significant inhibitory activity against Candida albicuns, at a concentration of 1000 µg/disc.

Conclusions

The present findings suggest that, the plant widely available in Bangladesh, could be a prominent source of medicinally important natural compounds.     

Larvicidal and irritant activities of hexane leaf extracts of Citrus sinensis against dengue vector Aedes aegypti L.

Objective

To assess the larvicidal and irritant activities of the hexane extracts of leaves of Citrus sinensis (C. sinensis) against the early fourth instars and female adults of Aedes aegypti (Ae. aegypti).

Methods

The larvicidal potential of the prepared leaf extract was evaluated against early fourth instar larvae of Ae. aegypti using WHO protocol. The mortality counts were made after 24 h and LC₅₀ and LC₉₀ values were calculated. The efficacy of extract as mosquito irritant was assessed by contact irritancy assays. Extract-impregnated paper was placed on a glass plate over which a perspex funnel with a hole on the top was kept inverted. Single female adult, 3-day old unfed/blood-fed, was released inside the funnel. After 3 min of acclimatization time, the time taken for the first take-off and total number of flights undertaken during 15 min were scored.

Results

The citrus leaf extracts from hexane possessed moderate larvicidal efficiency against dengue vector. The bioassays resulted in an LC₅₀ and LC₉₀ value of 446.84 and 1 370.96 ppm, respectively after 24 h of exposure. However, the extracts were proved to be remarkable irritant against adults Ae. aegypti, more pronounced effects being observed on blood-fed females than unfed females. The extract-impregnated paper was thus proved to be 7–11 times more irritable as compared with the control paper.

Conclusions

The hexane extracts from C. sinensis leaves are proved to be reasonably larvicidal but remarkably irritant against dengue vector. Further studies are needed to identify the possible role of extract as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the extract could help in formulating strategies for mosquito control.     

In vitro analysis on bactericidal screening and antioxidant potentiality of leaf and root extracts of Thottea siliquosa (Lam.) Ding Hou. An ethnobotanical plant

Objective

Natural products of plant origin are potential source of novel antimicrobial and antioxidative agents. Thottea siliquosa (Lam.) Ding Hou. (T. siliquosa). A medicinal herb used by local tribals for treating various ailments. The present study aims at the phytochemical screening, GC-MS analysis, in vitro antibacterial activity and antioxidant potentiality of root and leaf extracts of T. siliquosa.

Methods

Hot continuous Soxhlet extraction, GC-MS analysis, antibacterial analysis by disc diffusion, microdilution assay and antioxidant potentialities by hydroxyl radical and nitric oxide radical scavenging. The data was statistically analyzed.

Results

Phytochemical screening of the ethyl acetate and methanolic extract of leaf and root revealed the presence of phenols, alkaloids, tannins and saponin. The extract revealed a pool of phytochemicals by comparison with authentic standards from spectral library. Both the extracts has shown their broad spectrum of inhibition against the selected bacteria Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia compared with standard antibiotic drug streptomycin. The extracts showed antioxidant activity by scavenging of free radicals such as hydroxyl and nitric oxide. The IC₅₀ values of the ethyl acetate extracts leaf and root and standard in this assay were 167.5±0.67, 99.4±1.2, 192±2.5 µg/mL respectively. Similarly those methanolic extracts of leaf and root were 269.5±0.89 and 289.1±2.66 µg/mL respectively. Similarly, ethyl acetate and methanolic extracts also caused a moderate dose-dependent inhibition of nitric oxide with an IC₅₀ range 65.5±1.55 to 148 ±3.09 µg/mL. The inhibitory activities were found to be dose dependent.

Conclusion

The present study provides evidence that ethyl acetate and methanol extract of leaf and root of T. siliquosa are potential source of natural antioxidants and bactericidal nature. It is essential that research should continue to isolate and purify the bio active components of this natural plant and use in drug discovery and development.     

Phytochemical screening and free radical scavenging activity of Citrullus colocynthis seeds extracts

Objective

To study the phytochemical screening of different extracts from Citrullus colocynthis (C. colocynthis ) seeds extracts and to assess their antioxidant activity on the DPPH free radical scavenging.

Methods

Phytochemical screening, total content of polyphenols and flavonoids of C. colocynthis seeds extracts, including a crude aqueous extract (E1), a defatted aqueous extract (E2), a hydromethanolic extract (HM), an ethyl acetate extract (EA) and a n-butanol extract (n-B) was carried out according to the standard methods and to assess their corresponding effect on the antioxidant activity of this plant.

Results

None of these extracts contained detectable amount of alkaloid, quinone, antraquinone, or reducing sugar. Catechic tannins and flavonoids were abundant in E1, HM and EA, whilst terpenoids were abundantly present in E1 and n-B but only weekly in HM. Coumarins were found in E2, EA and n-B. Polyphenols, expressed as gallic acid equivalent, amounted, per 100 g plant matter, to 329, 1002 and 150 mg in EA, HM an E1 respectively. Flavonoids, expressed as catechin equivalent, amounted, per 100 g plant matter to 620, 241 and 94 mg in EA, HM and E1 respectively. Comparable values were found in n-B and E1, with lower values in E2. Quercetin, myricetin and gallic acid were found in the EA and HM extracts by thin layer chromatography, The antioxidative effect of these extracts yielded, when tested at a concentration of 2 000 µg/mL in a 1,1-diphenyl-2-picrylhydrazyl assay, a reducing percentage of 88.8% with EA, 74.5% with HM and 66.2% with E1, and corresponding IC₅₀ of 350, 580 and 500 µg/mL as compared to 1.1 µg/mL for ascorbic acid.

Conclusions

These qualitative and quantitative analytical data document the presence in C. colocynthis extracts of such chemical compounds as flavonoids responsible for the antioxidant activity, as well as other biological activities of this plant.     

Phytochemical analysis and antioxidants activities of aqueous stem bark extract of Schotia latifolia Jacq

Objective

To evaluate the phytochemical constituents and antioxidant activities of aqueous extract of Schotia latifolia (S. latifolia) bark locally used for the treatment of oxidative stress-induced ailments in South Africa.

Methods

The antioxidant and free radical scavenging activity of aqueous extract of the plant was assessed against 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the ferric reducing agent. Total phenolics, flavonoids, flavonols and proanthocyanidins were also determined to assess their corresponding effect on the antioxidant activity of this plant.

Results

The activities of plant extract against DPPH, ABTS and NO radicals were concentration dependent with IC₅₀ value of 0.06, 0.05 and 0.05 mg/mL, respectively. The reducing power of the extract was greater than that of butylated hydroxyl toluene (BHT) and ascorbic acid which were used as standard drugs in a concentration dependent manner. The total phenolics content of the aqueous bark extract was (193.33±0.03 TE/g), followed by flavonoids (72.70±0.01 QE/g), proanthocyanidins (48.76±0.00 CE/g) and flavonols (47.76±0.21 QE/g). Phytochemical analysis revealed the presence of percentage tannin (11.40±0.02), alkaloid (9.80±0.01), steroids (18.20±0.01), glycosides (29.80±0.01) and saponins (6.80±0.00). The results exhibited a positive linear correlation between these polyphenols and the free radical scavenging activities.

Conclusions

Our findings provide evidence that the crude aqueous extract of S. latifolia is a potential source of natural antioxidants and this justifies its uses in folkloric medicines.     

Pharmacognostic evaluation of leaf and root bark of Holoptelea integrifolia Roxb.

Objective

To evaluate the pharmacognostic characters of an important medicinal plant, Holoptelea integrifolia (H. integrifolia) Roxb.

Methods

The pharmacognostic studies were carried out in terms of organoleptic, microscopic, macroscopic and fluorescence analysis.

Results

The characteristic microscopic features of leaves were observed as trichomes, multicellular trichomes, xylem cells, phloem cells, collenchyma, vascular bundles, spongy parenchyma and palisade cells. The characteristic microscopic features of root bark included cork cambium, primary cortex, phloem fibers, medullary rays, endodermis, pericycle and lignified fibers in the transverse section and longitudinal section. The characteristic microscopy of root bark powder showed the presence of cortex cells, sieve tubes, calcium oxalate crystals and lignified fibers. Macroscopic study showed that leaf shape-oval, apex-acute, base-cordate and leaf margin was entire with glabrous surface, bitter taste and characteristic odour. The morphological features of root bark showed deep fissured, rough and firm surface with rhitydome and the periderm parallel to cambium.

Conclusions

Various pharmacognostic characters observed in this study help in the identification and standardization of H. integrifolia.     

Ovicidal and repellent activities of botanical extracts against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi (Diptera: Culicidae)

Objective

To determine the ovicidal and repellent activities of methanol leaf extract of Ervatamia coronaria (E. coronaria) and Caesalpinia pulcherrima (C. pulcherrima) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).

Methods

The ovicidal activity was determined against three mosquito species at various concentrations ranging from 50-450 ppm under the laboratory conditions. The hatch rates were assessed 48 h after treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm² under the laboratory conditions.

Results

The crude extract of E. coronaria exerted zero hatchability (100% mortality) at 250, 200 and 150 ppm for Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The crude extract of C. pulcherrima exerted zero hatchability (100% mortality) at 375, 300 and 225 ppm for Cx. quinquefasciatus, Ae. aegypti and An. Stephensi, respectively. The methanol extract of E. coronaria found to be more repellenct than C. pulcherrima extract. A higher concentration of 5.0 mg/cm² provided 100% protection up to 150, 180 and 210 min against Cx. quinquefasciatus, Ae. aegypti and An. stephensi, respectively. The results clearly showed that repellent activity was dose dependent.

Conclusions

From the results it can be concluded the crude extracts of E. coronaria and C. pulcherrima are an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.     

Analgesic,anti-inflammatory and anti-diarrheal activities of ethanolic leaf extract of Typhonium trilobatum L. Schott

Objective

To explore the efficacy of ethanolic leaf extract of Typhonium trilobatum L. Schott in treating diarrhea, pain and inflammation using experimental models.

Methods

In the present study, acetic acid-induced writhing, xylene-induced ear edema and castor oil-induced diarrheal model were used to evaluate the analgesic, anti-inflammatory and anti-diarrheal activities, respectively. Acute toxicity test was carried out to fix the safe doses of the plant extract.

Results

The plant extract demonstrated a significant inhibition of writhing (P<0.01) compared with the control group in acetic acid-induced writhing test in mice. The extract also significantly inhibited the xylene induced ear edema formation (P<0.05). In anti-diarrheal test, the extract significantly decreased the frequency of defecation and increased the mean latent period (P<0.01) in castor oil-induced diarrheal model mice at the doses of 250 and 500 mg/kg body weight.

Conclusions

These results suggest that the extract possesses significant analgesic, anti-inflammatory and anti-diarrheal activities that support to the ethnopharmacological uses of this plant.     

Evaluation of anti-inflammatory potential of leaf extracts of Skimmia anquetilia

Objective

To evaluate anti-inflammatory potential of leaf extract of Skimmia anquetilia by in-vitro and in-vivo anti-inflammatory models.

Methods

Acute toxicity study was carried out to determine the toxicity level of different extract using acute toxic class method as described in Organization of Economic Co-operation and Development Guidelines No.423. Carrageenan (1% w/w) was administered and inflammation was induced in rat paw. The leaf extracts of Skimmia anquetilia were evaluated for anti-inflammatory activity by in-vitro human red blood cell (HRBC) membrane stabilization method and in-vivo carrangeenan-induced rat paw edema method.

Results

The in-vitro membrane stabilizing test showed petroleum ether (PE), chloroform (CE), ethyl acetate (EE), methanol (ME) and aqueous extracts (AE) showed 49.44%, 59.39%, 60.15%, 68.40% and 52.18 % protection, respectively as compared to control groups. The in-vivo results of CE, EE and ME showed 58.20%, 60.17% and 67.53% inhibition of inflammation after 6h administration of test drugs in albino rats. The potency of the leaf extracts of Skimmia anquetilia were compared with standard diclofenac (10 mg/kg) which showed 74.18% protection in in-vitro HRBC membrane stabilization test and 71.64% inhibition in in-vivo carrangeenan-induced rat paw edema model. The ME showed a dose dependent significant (P< 0.01) anti-inflammatory activity in human red blood cell membrane stabilization test and reduction of edema in carrageenan induced rat paw edema.

Conclusions

The present investigation has confirmed the anti-inflammatory activity of Skimmia anquetilia due to presence of bioactive phytoconstitutes for the first time and provide the pharmacological evidence in favor of traditional claim of Skimmia anquetilia as an anti- inflammatory agent.     

Antidiabetic and hypolipidemic activities of ethanolic leaf extract and fractions of Melanthera scandens

Objective

To evaluate the antidiabetic and hypolipidemic activities of ethanolic leaf extract and fraction of Melanthera scandens (M. scandens) in alloxan-induced diabetic rats.

Methods

M. scandens leaf extract/fractions (37–111 mg/kg) were administered to alloxan-induced diabetic rats for 14 days and blood glucose levels (BGL) of the diabetic rats were monitored at intervals of 7 hours for acute study and 14 days for prolonged study. Lipid profiles of the treated diabetic rats were determined after the period of treatment.

Results

Treatment of alloxan-induced diabetic rats with the extract/fractions caused a significant (P<0.001) reduction in fasting bloodglucose levels (BGL) of the diabetic rats both in acute study and prolonged treatment (2 weeks). The activities of the extract and fractions were more than that of the reference drug, glibenclamide. The extract/fractions exerted a significant reduction in the levels of serum total cholesterol, triglycerides, LDL and VLDL of extract with increases in HDL levels of the diabetic rats.

Conclusions

These results suggest that the leaf extract/fractions of M. scandens possesses antidiabetic effect on alloxan induced diabetic rats and this justifies its use in ethno medicine and can be exploited in the management of diabetes.     

Phytochemical investigation and in vitro antioxidant activity of an indigenous medicinal plant Alpinia nigra B.L. Burtt

Objective

To investigate antioxidant potential of methanol extract of Alpinia nigra leaves.

Methods

The study was done by using various in vitro methods such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), nitric oxide and hydrogen peroxide radical scavenging assays. Phytochemical constituents, total phenolic content and total flavonoid content of the extract at different concentrations (10-500 µg/mL) were determined.

Results

Alpinia nigra leaves showed high free radical scavenging activity as evidenced by the low IC₅₀ values in DPPH (64.51 µg/mL), in ABTS (28.32 µg/mL), in nitric oxide (80.02 µg/mL) and in H₂O₂ (77.45 µg/mL) scavenging assays. Furthermore the TPC and TFC of the extract were found to be 69.25 mg gallic acid equivalent per gram of extract and 78.84 mg quercetin equivalent per gram of extract respectively.

Conclusions

The results of present comprehensive analysis demonstrated that Alpinia nigra leaves possess high phenolic, flavonoid contents and potential antioxidant activity, and could be used as a viable source of natural antioxidants and might be exploited for functional foods and neutraceutical applications.     

Antioxidant activities of Indigofera cassioides Rottl. Ex. DC. using various in vitro assay models

Objective

To evaluate the antioxidant potential of methanolic leaf extract of Indigofera cassioides (MEIC) using various in vitro antioxidant assay systems.

Methods

Antioxidant and free radical scavenging activity of MEIC was assayed by using different in vitro models like ABTS, DPPH, nitric oxide, superoxide, hydrogen peroxide and hydroxyl radical. Reductive ability of the extract was tested by the complex formation with potassium ferricyanide. Further total phenol and flavonoid contents of the crude extract were also determined. Rutin and ascorbic acid were used as standards.

Results

MEIC exhibited potent and concentration dependent free radical scavenging activity in all the tested models. Reductive ability was also found to increase with increase in MEIC concentration. Total phenol and flavonoid content determination showed that the extract is rich in phenols and flavonoids.

Conclusions

All the results of the in vitro antioxidant assays reveal potent antioxidant and free radical scavenging activity of the leaves of Indigofera cassioides, equivalent to that of standard ascorbic acid and rutin. This potent antioxidant activity may be attributed to its high phenolic and flavonoid contents.     

Assessment of antidiabetic activity and acute toxicity of leaf extracts from Physalis peruviana L. in guinea-pig

Objective

To verify the antidiabetic activity of leaf extracts from Physalis peruviana L. popularly used in the Eastern part of the Democratic Republic of the Congo and to point out the possible toxicity.

Method

Aqueous decoctions prepared from dried leaves powder were administrated to guinea pigs at the dose range of 100 mg/kg to 3.2 g/kg of body weight. The hypoglycemic activity was evaluated by glucose tolerance test, loading animals with glucose 4 g/kg and measuring blood glucose concentrations at various times. The effect was compared to the control and glibenclamide as antidiabetic reference drug. Acute toxicity was evaluated by recording mortality rate, changes on blood biomarkers and damage caused to vital organs.

Results

At a dose of 100 mg/kg, the aqueous extract induced a significant reduction of peak concentration at 30 min after glucose loading as compared with control or reference (P<0.05). At doses greater than 400 mg, some alterations on blood, kidney and liver markers were observed. Upper 800 mg/kg, mortality was observed with LD₅₀ estimated at about 1 280 mg/kg. At the autopsy, vital organs were in haemorrhage and swelling state.

Conclusion

The crude aqueous extracts from the leaves of Physalis peruviana L. present hypoglycemic activity in animal model, but at high doses the plant may cause severe intoxication.     

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta,Sargassaceae) collected from Gulf of Mannar

Objective

To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp. [Turbinaria conoides (T. conoides) and Turbinaria ornata (T. ornata) collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.

Methods

The antioxidant activity was evaluated using different in vitro systems, viz., 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2′-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt (ABTS), H₂O₂/HO radical scavenging, Fe²⁺ ion chelating ability, and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts, and the results were expressed as mg of gallic acid equivalents (GE)/g of the seaweed extracts. Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.

Results

Ethyl acetate (EtOAc) fraction of T. conoides registered significantly higher phenolic content (105.97 mg GE/g) than that of T. ornata (69.63 mg GE/g). Significantly higher antioxidant potential as determined by DPPH (64.14%) radical scavenging activity was registered in EtOAc fraction of T. ornata. A higher ABTS^•+ radical scavenging (IC₅₀ 3.16 µg/mL), Fe²⁺ chelating (IC₅₀ 0.46 mg/mL), H₂O₂ scavenging (IC₅₀ 4.25 mg/mL), lipid peroxidation inhibitory (TBARS, IC₅₀ 0.21 mg/mL), and reducing abilities (IC₅₀ 52.67 mg/mL) (P<0.05) were realized in EtOAc fraction of T. ornata than other fractions.

Conclusions

This study indicated the potential use of T. conoides and T. ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption, and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.     

Antioxidant potential of phenolic extracts of Mimusops elengi

Objective

To evaluate the antioxidant potential of the phenolic extracts of Mimusops elengi (M. elengi) L. (Sapotaceae).

Methods

The extract of stem bark and seeds of M. elengi were prepared in methanol and acetone:water (7:3). The acetone: water was further partitioned with ethyl acetate and n-butanol. Antioxidant activity of the extracts and partitioned fractions of M. elengi was evaluated in terms of radical scavenging potential (DPPH), inhibition of lipid peroxidation [ferric thiocyanate (FTC)], and total antioxidant activity (phosphomolybdate method). Total phenolics content were calculated using Folin-Ciocalteu reagent.

Results

The stem bark extract partitioned with ethyl acetate exhibited highest amount of total phenols (98.0 mg GAE/g dry weight), among all other extracts, with 92.0% DPPH radical scavenging activity at concentration of 0.5 mg/mL, while methanol extract (stem bark) had maximum inhibition of lipid peroxidation (62.0%) and total antioxidant activity (771.0 mg/g GAE/g). A positive correlation occurred between total phenols and radical scavenging activity (R² = 0.922 9) and total antioxidant activity (R² = 0.945 1).

Conclusions

Our study suggested that antioxidant activity of stembark extract of M. elengi is due the presence of phenolic compounds. Furthermore, the bark extract is a valuable source of natural antioxidants.     

Acaricidal activity of different extracts from Syzygium cumini L. Skeels (Pomposia) against Tetranychus urticae Koch

Objective

To investigate the acaricidal activity of different extracts from Syzygium cumini (S. cumini) (Pomposia) againsst Tetranychus urticae Koch (T. urticae) and the biochemical changes in antioxidants enzymes.

Methods

Six extracts of S. cumini (Pomposia) at concentrations of 75, 150 and 300µg/mL were used to control T. urticae (Koch).

Results

The ethanol extract showed the most efficient acaricidal activity agent against T. urticae (98.5%) followed by hexane extract (94.0%), ether and ethyl acetate extract (90.0%). The LC₅₀ values of the promising extract were 85.0, 101.0, 102.0 and 98.0µg/mL, respectively. The activities of enzymes including ascorbate peroxidase (APX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in susceptible mites were increased. The activities of all antioxidant enzymes reach the maximum value in mites at LC₅₀ with ethanol and ethyl acetate extracts, respectively.

Conclusions

The extract of S. cumini has acaricidal acivity against T. urticae, and the ethanol extract is the most efficient.     

Repellent properties of Cardiospermum halicacabum Linn. (Family: Sapindaceae) plant leaf extracts against three important vector mosquitoes

Objective

To determine repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Cardiospermum halicacabum (C. halicacabum) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).

Methods

Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of three mosquito species and were assayed in the laboratory condition by using the protocol of WHO 2005; The plant leaf crude extracts of C. halicacabum was applied at 1.0, 2.5, and 5.0 mg/cm² separately in the exposed area of the fore arm. Only ethanol served as control.

Results

In this observation, the plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity was dependent on the strength of the plant extracts. The tested plant crude extracts had exerted promising repellent against all the three mosquitoes.

Conclusions

From the results it can be concluded the crude extract of C. halicacabum was potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.