Antimicrobial potential of Ricinus communis leaf extracts in different solvents against pathogenic bacterial and fungal strains

ObjectiveTo investigate the in vitro antimicrobial activities of the leaf extract in different solvents viz., methanol, ethanol and water extracts of the selected plant Ricinus communis.MethodsAgar well diffusion method and agar tube dilution method were carried out to perform the antibacterial and antifungal activity of methanol, ethanol and aqueous extracts.ResultsMethanol leaf extracts were found to be more active against Gram positive bacteria (Bacillus subtilis: ATCC 6059 and Staphylococcus aureus: ATCC 6538) as well as Gram negative bacteria (Pseudomonas aeruginosa: ATCC 7221 and Klebsiella pneumoniae) than ethanol and aqueous leaf extracts. Antifungal activity of methanol and aqueous leaf extracts were also carried out against selected fungal strains as Aspergillus fumigatus and Aspergillus flavus. Methanolic as well as aqueous leaf extracts of Ricinus communis were effective in inhibiting the fungal growth.ConclusionsThe efficient antibacterial and antifungal activity of Ricinus communis from the present investigation revealed that the methanol leaf extracts of the selected plant have significant potential to inhibit the growth of pathogenic bacterial and fungal strains than ethanol and aqueous leaf extracts.     

In vitro control of Staphylococcus aureus (NCTC 6571) and Escherichia coli (ATCC 25922) by Ricinus communis L.

Objective

To evaluate antibacterial activity of hot and cold ethanol and methanol leaf extracts of Ricinus communis L (R. communis) against Staphylococcus aureus (S. aureus) (NCTC 6571) and Escherichia coli (E. coli) (ATCC 25922).

Methods

Leaf powder of R. communis L. was extracted with hot (in Soxhlet) and cold ethanol and methanol, separately. The antibacterial activity of the extracts was determined by agar well diffusion and macro broth dilution methods. The extracts were also subjected to phytochemical analysis.

Results

All the four test extracts showed inhibition on both S. aureus and E. coli. Hot and cold ethanol extracts revealed significantly (P<0.05) higher inhibition on S. aureus than methanol extracts, and the hot ethanol extract had the lowest minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values (5 mg/mL and 10 mg/mL, respectively). E. coli was highly inhibited by hot extracts of both ethanol and methanol with the MIC and MBC of 40 mg/mL and 80 mg/mL, respectively. Phytochemical analysis revealed the presence of saponins, cardiac glycosides, tannins, flavonoids and terpenoids in all test extracts.

Conclusions

This study demonstrates that the hot and cold methanol and ethanol extracts are potential sources for control of S. aureus and E. coli. Especially, the hot and cold extracts of ethanol are more inhibitive against S. aureus even at lower concentration. Further study is needed to identify the specific bioactive compounds, their mode of action and their nontoxic nature in vivo condition.     

In vitro antibacterial activity of leaf extracts of Zehneria scabra and Ricinus communis against Escherichia coli and methicillin resistance Staphylococcus aureus

ObjectiveTo evaluate the antibacterial activities of the crude leaves extracts of Zehneria scabra (Z. scabra) and Ricinus communis (R. communis) against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and methicillin resistance S. aureus.MethodsThe crude powdered leaves of Z. scabra and R. communis were extracted successively by organic solvents in increasing polarity [benzene, chloroform:acetone (1:1), 70% alcohol and distilled water]. The antibacterial susceptibility of the crude leaves extracts of were tested against standard strains of E. coli (ATCC 25922) and S. aureus (ATCC 2923) and clinical isolates of E. coli, S. aureus and methicillin resistance S. aureus using agar well diffusion method.ResultsIn Z. scabra and R. communis leaf extracts, the most sensitive standard strain was S. aureus with an inhibition zone of (14.00±1.20) mm and (15.90±2.13) mm, respectively. The minimum inhibitory concentration (MIC) values of Z. scabra extracts against test organisms ranged from 1.95 mg/mL for extract 3 in clinical and standard strains of S. aureus to 250 mg/mL for extract 1 and 4 in clinical and standard strains of E. coli. The MIC values of R. communis extracts against test organisms ranged from 1.95 mg/mL for extract 2 and 3 standard strains of S. aureus to 250 mg/mL for extract 1 in clinical isolate of E. coli. Most of the minimum bactericidal concentration and MIC values of plant extracts were almost similar particularly in R. communis, or minimum bactericidal concentration equal to one dilution factor less than MIC value of the extracts mainly in Z. scabra.ConclusionsThe potency of plant extracts against test organisms were depend on different organic solvents used. Clinical isolate of bacterial pathogens showed less zones of diameter compared to the standard strains. Gram-positive had wide inhibition zones than Gram-negative bacteria. Further studies should be carried out to isolate the pure compounds and standardization of the methods of plant extracts for an in vitro testing.     

Evaluation of in-vitro antibacterial activity and anti-inflammatory activity for different extracts of Rauvolfia tetraphylla L. root bark

Objective

To assess the in-vitro antibacterial activity and anti-inflammatory activity of orally administered different extracts (Hydro-alcoholic, methanolic, ethyl acetate and hexane) of Rauvolfia tetraphylla (R. tetraphylla) root bark in Carrageenan induced acute inflammation in rats.

Methods

In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate assay. Hydro-alcoholic extract (70% v/v ethanol) at 200, 400 and 800 mg/kg doses and methanolic, ethyl acetate and hexane extracts at doses 100, 200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 hrs.

Results

All extracts of R. tetraphylla root bark showed good zone of inhibition against tested bacterial strains. In Carrageenan induced inflammation model, hydro-alcoholic and methanolic extract of R. tetraphylla root bark at three different doses produced significant (P<0.001) reduction when compared to vehicle treated control group and hexane, ethyl acetate extracts.

Conclusions

In the present study extracts of R. tetraphylla root bark shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.     

Protective capacity of Artemisia annua as a potent antioxidant remedy against free radical damage

ObjectiveTo evaluate the antioxidant capacity of four leaf-derived solvent extracts of Artemisia annua (A. annua), a medicinal plant widely touted for its vast phyto-therapeutic potential.MethodsA. annua leaves were extracted with four solvents (absolute ethanol, absolute methanol, 70% ethanol and 70% methanol), and extracts obtained studied by five complementary in vitro antioxidant test systems using ascorbic acid (vitamin C) and rutin as standard references.ResultsThe extracts remarkably inhibited lipid peroxidation (79.81%-86.70%), and erythrocyte haemolysis (40.02%-49.91%). Their IC₅₀ values for hydroxyl, nitric oxide and hydrogen peroxide radical scavenging activities ranged from 2.39–3.81 mg/mL (superior to the standards), 107.24–144.49 μg/mL and 28.53–53.20 μg/mL, respectively. 70% alcohol extracts generally showed better antioxidant activity than absolute alcohol extracts.ConclusionsThe results indicate that A. annua leaf extracts have potent antioxidant activities that would have beneficial effect on human health, and aqueous organic solvents are superior to the absolute counterparts in yielding extracts with better antioxidant potential.     

Analgesic,antibacterial and central nervous system depressant activities of Albizia procera leaves

ObjectiveTo ascertain analgesic, antibacterial and central nervous system (CNS) depressant activities of ethyl acetate, dichloromethane and carbon tetrachloride fractions of methanol extract of Albizia procera (A. procera) leaves.MethodsLeaves extracts of A. procera were tested for analgesic activity by acetic acid induced and formalin test method in mice. The in vitro antibacterial activity was performed by agar well diffusion method. CNS depressant activity was evaluated by hole cross and open field tests.ResultsAll the extracts at 200 mg/kg exhibited significant (P<0.01) analgesic activity in acetic acid induced and formalin tests method in mice. Analgesic activity of the ethyl acetate fraction was almost same like as standard drug indomethacin in acetic acid induced method. The CNS depressant activity of the extracts at 500 mg/kg was comparable to the positive control diazepam as determined by hole cross and open field test method. The extracts exhibited moderate antimicrobial activity against all the tested microorganisms (Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Esherichia coli, Shigella soneii, Shigella boydii) at concentration of 0.8 mg/disc. The measured diameter of zone of inhibition for the extracts was within the range of 7 to 12 mm which was less than the standard kanamycin (16-24 mm).ConclusionsIt is concluded that all the extracts possess potential analgesic and CNS depressants activity. This study also showed that different fractions of methanol extract could be potential sources of new antimicrobial agents.     

Antioxidant and antibacterial activity of different parts of Leucas aspera

Objective

To evaluate antioxidant, antimicrobial and cytotoxic activity of different parts (root, flower, leaf and stem) of Leucas aspera (L. aspera) (Labiatae).

Methods

Different parts of L. aspera were extracted with 80% (v/v) methanol. The methanol extracts were subjected to antioxidant, antimicrobial and brine shrimp lethality assay.

Results

All the extracts showed moderate to potent antioxidant activity, among which the root extract demonstrated the strongest antioxidant activity with the IC₅₀ value of 6.552 µg/mL. Methanol extract of root possessed antioxidant activity near the range of vitamin E and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of root, flower, leaf and stem showed notable antibacterial activity against tested microorganisms. The root extract showed the highest mean zone of inhibition ranging from 9.0–11.0 mm against tested microorganisms, at a concentration of 100 mg/mL. In the brine shrimp lethality bioassay, it was evident that the methanol root extract did not show significant toxicity. The LC₅₀ value for 12 h and 24 h observation was 2.890 mg/mL and 1.417 mg/mL, respectively.

Conclusions

The present finding suggests that the methanol root extract of L. aspera could be developed as pharmaceutical products.     

Antimicrobial activity against periodontopathogenic bacteria,antioxidant and cytotoxic effects of various extracts from endemic Thermopsis turcica

ObjectiveTo investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan, Vural & Küçüködük against periodontopathogenic bacteria, its antioxidant activity and cytotoxic effect on various cancer cell lines.MethodsIn vitro antimicrobial activities of ethanol, methanol, ethyl acetate (EtAc), n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Antioxidant properties of the extracts were evaluated by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and β-carotene bleaching methods. Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent. Additionally, cytotoxic activity of the extracts on androgen-insensitive prostate cancer, androgen-sensitive prostate cancer, chronic myelogenous leukemia and acute promyelocytic leukemia human cancer cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human gingival fibroblast cells were used as a control.ResultsOur data showed that EtAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemcomitans (MIC: 1.562 mg/mL, MBC: 3.124 mg/mL) and Porphyromonas gingivalis (MIC: 0.781 mg/mL, MBC: 1.562 mg/mL). In antioxidant assays, EtAc extract exhibited also the highest radical scavenging activity [IC₅₀=(30.0±0.3) μg/mL] and the highest inhibition [(74.35±0.30)%] against lineloic acide oxidation. The amount of phenolic content of it was also the highest [(162.5±1.2) μg/mg gallic acid]. In cytotoxic assay, only ethanol [IC₅₀=(80.00±1.21) μg/mL] and EtAc extract [IC₅₀=(70.0±0.9) μg/mL] were toxic on acute promyelocytic leukemia cells at 20-100 μg/mL (P<0.05). However, no toxic effect was observed on human gingival fibroblast cells.ConclusionsAccording to our findings, owing to its antioxidant and cytotoxic potential, EtAc extract might include anticancer agents for acute promyelocytic leukemia.     

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.     

Antibacterial efficacy of the seed extracts of Melia azedarach against some hospital isolated human pathogenic bacterial strains

Objective

To investigate the antibacterial potential of the polar and non-polar extracts of the seeds of Melia azedarach (M. azedarach) L. (Meliaceae) against eighteen hospital isolated human pathogenic bacterial strains.

Methods

Petrol, benzene, ethyl acetate, methanol, and aqueous extracts at five different concentrations (1, 2, 5, 10 and 15 mg/mL) were evaluated. Disk diffusion method was followed to evaluate the antibacterial efficacy.

Results

All extracts of the seeds demonstrated significant antibacterial activity against tested pathogens. Among all extracts, ethyl acetate extract revealed the highest inhibition comparatively. The present study also favored the traditional uses reported earlier.

Conclusions

Results of this study strongly confirm that the seed extracts of M. azedarach could be effective antibiotics, both in controlling gram-positive and gram-negative human pathogenic infections.     

Antioxidant and antibacterial properties of selected Thai weed extracts

ObjectiveTo analyze antioxidant and antibacterial properties of selected weeds commonly found in Northeast Thailand including Ageratum conyzoides L., Alysicarpus vaginalis L., Commelina bengalensis L., Euphorbia hirta L., Hyptis suaveolens L., Parthenocissus quinquefolia L., and Trianthema portulacastrum L.MethodsFerric reducing antioxidant power and radical scavenging activity of the aqueous and ethanol weed extracts were determined. Phytochemical screening, total phenolic and flavonoid contents were done. Antibacterial activity against Aeromonas hydrophila, Aeromonas caviae, Edwardsiella tarda, Plesiomonas shigelloides, Ralstonia spp., Xanthomonas campestris pv. Vesicatoria, Salmonella spp. and Shigella spp. was performed by disc diffusion assay.ResultsThe results showed that Euphorbia hirta extract had the highest total phenolic contents and was the most effective against most of the test organisms compared to the other weed extracts. Hyptis suaveolens ethanol extract weakly inhibited Ralstonia spp. and Salmonella spp. (10.42% and 9.84% inhibition, respectively). Trianthema portulacastrum ethanol extract had 20.10% inhibition against Shigella spp. Parthenocissus quinquefolia aqueous extract strongly inhibited Aeromonas caviae and Aeromonas hydrophila with 55.90% and 59.68% inhibition, respectively.ConclusionsThese weeds may be serving as a potential source of antibacterial agents.     

Hepatocurative potential of Vitex doniana root bark,stem bark and leaves extracts against CCl4–induced liver damage in rats

ObjectiveTo evaluate the hepatocurative effects of aqueous root bark, stem bark and leaves of Vitex doniana in carbon tetrachloride (CCl₄) induced liver damage and non induced liver damage albino rats.MethodsA total of 60 albino rats (36 induced liver damage and 24 non induced liver damage) were assigned into liver damage and non liver damage groups of 6 rats in a group. The animals in the CCl₄ induced liver damage groups, were induced by intraperitoneal injection with a single dose of CCl₄ (1 mL/kg body weight) as a 1:1(v/v) solution in olive oil and were fasted for 36 h before the subsequent treatment with aqueous root bark, stem bark and leaves extracts of Vitex doniana and vitamin E as standard drug (100 mg/kg body weight per day) for 21 d, while the animals in the non induced groups were only treated with the daily oral administration of these extracts at the same dose. The administration of CCl₄ was done once a week for a period of 3 weeks.ResultsThere was significant (P<0.05) increase in concentration of all liver marker enzymes, alanine aminotransferase, aspartate aminotransferase and alkaline aminotransferase (ALT, AST and ALP) and significant (P<0.05) decrease in albumin in the CCl₄ induced liver damage control when compared to the normal control. The extracts caused a significant (P<0.05) reduction in the serum activities of liver marker enzymes (ALT, AST and ALP) and a significant (P<0.05) increase in albumin of all the induced treated groups. Only stem bark extract and vitamin E significantly (P<0.05) increased total protein. All the extracts significantly (P<0.05) lowered serum creatinine whereas only root bark extract significantly (P<0.05) lowered serum level of urea in the rats with CCl₄ induced liver damage.ConclusionHepatocurative study shows that all the plant parts (root bark, stem bark and leaves) possess significant hepatocurative properties among other therapeutic values justifying their use in folklore medicine.     

Cytotoxicity screening of Melastoma malabathricum extracts on human breast cancer cell lines in vitro

ObjectiveTo screen the cytotoxic activity of Melastoma malabathricum (M. malabathricum) against human breast cancer cell line (MCF-7) in vitro.MethodsA three steps extraction protocol using n-hexane, chloroform and methanol as the solvents systems was carried out on leaves, stems and flowers of M. malabathricum. Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations (100 μg/mL, 50 μg/mL, 25 μg/mL, 12.5 μg/mL and 6.25 μg/mL). The evaluation of cell growth was determined using methylene blue assay.ResultsMethanol extract from the leaves showed significant anticancer activity against MCF-7 cell lines with the IC₅₀ value of 7.14 μg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line with the IC₅₀ value of 33.63 μg/mL and 45.76 μg/mL respectively after 72 h of treatment.ConclusionsThe extracts from leaves and flowers of M. malabathricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC₅₀ at 7.14 μg/mL while the extracts from stems showed less growth inhibition activity.     

Antibacterial activity of leaves extracts of Trifolium alexandrinum Linn. against pathogenic bacteria causing tropical diseases

Objective

To investigate antibacterial potential of Trifolium alexandrinum (T. alexandrinum) Linn. against seven gram positive and eleven gram negative hospital isolated human pathogenic bacterial strains responsible for many tropical diseases.

Methods

Non-polar and polar extracts of the leaves of T. alexandrinum i.e., hexane, dichloromethane (DCM), ethyl acetate (EtOAc), methanol (MeOH) and aqueous (AQ) extracts at five different concentrations (1, 2, 5, 10 and 15 mg/mL) were prepared to evaluate their antibacterial value. NCCL standards were strictly followed to perform antimicrobial disc susceptibility test using disc diffusion method.

Results

Polar extracts demonstrated significant antibacterial activity against tested pathogens. EtOAc and MeOH extracts showed maximum antibacterial activity with higher inhibition zone and were found effective against seventeen of the tested pathogens. While AQ plant extract inhibited the growth of sixteen of the test strains. EtOAc and MeOH plant extracts inhibited the growth of all seven gram positive and ten of the gram negative bacterial strains.

Conclusions

The present study strongly confirms the effectiveness of crude leaves extracts against tested human pathogenic bacterial strains causing several tropical diseases. Since Egyptian clover is used as a fodder plant, it could be helpful in controlling various infectious diseases associated with cattle as well.     

Susceptibility of microorganism to selected medicinal plants in Bangladesh

ObjectiveTo analyze in-vitro antimicrobial activities of some ethno-pharmacologically significant medicinal plants (methanol extract) against the pathogenic microorganisms (Escherichia coli, Salmonella spp., Bacillus cereus, Staphylococcus aureus, Aspergillus niger and Candida albicans).MethodsThe disc diffusion method was applied for antibacterial test and the poisoned food technique was applied for antifungal test.ResultsThe methanol extract of Terminalia chebula (bark), Phyllanthus acidus (fruits), Sarcochlamys pulcherrima (leaves) and Abelmoschus esculentus (fruits) had significant in vitro antibacterial activity angainst the entire test samples in comparison to standard drug ciprofloxacin. Most of the plant extracts showed low activity against Gram negative bacteria while potential activity against Gram positive bacteria. The antifungal activities of methanol extracts of these plants and standard drug griseofulvin were determined against two pathogenic fungi, and Polygonum lapathifolium (leaves) and Cinnamomum tamala (leaves) showed maximum activity, while Erioglossum rubiginosum (leaves) showed no antifungal activity.ConclusionsFurther chemical and pharmacological investigations are required to identify and isolate chemical constituents responsible for these potential bioactivities and thus to determine their full spectrum of efficacy.     

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.     

Inhibition of Platelet Aggregation and In Vitro Free Radical Scavenging Activity of Dried Fruiting Bodies of Pleurotus eous

Objective: To evaluate the ethyl acetate, methanol and aqueous extracts of dried fruiting bodies of Pleurotus eous for its anti-platelet activity on human volunteer''s blood. And also to analyze the free radical scavenging property of the extracts of P.eous by using various in vitro models. Methods: Anti-platelet activity of dried fruiting bodies of P.eous was evaluated by in vitro model using blood platelets. Inhibition of platelet aggregation was monitored after pre-incubation of platelets with the crude extracts of mushroom P.eous. Antioxidant activities of extracts of P.eous were evaluated by different in vitro experiments, namely, 1, 1-diphenyl- 2-picryl hydrazyl (DPPH), superoxide, hydroxyl radical and lipid peroxide radical models. Results: Crude extracts of mushroom P.eous inhibited platelet aggregation dose-dependently which was induced by adenosine diphosphate (ADP). At a maximum concentration of 10 mg/mL, methanol extract effected 64.02% inhibition of lipid per-oxidation and 50.12% scavenging effect on superoxide anion radical. Aqueous extract of P.eous have shown 69.43% chelating ability on ferrous ions, 24.27% scavenging effect on hydroxyl radical and 49.57% scavenging effect on DPPH radical at 10 mg/mL. Increasing concentrations of the extract were found to cause progressively decreasing of the intensity of absorbance. Conclusions: Anti-platelet effects could be related in part to the polyphenolic compounds present in the extracts. Antioxidant activity results indicated the free radical scavenging property of the extracts of P.eous which might be due to the high content of phenolic compounds and flavonoids.     

Antioxidant and antimicrobial properties of Litsea elliptica Blume and Litsea resinosa Blume (Lauraceae)

ObjectiveTo investigate antioxidant and antimicrobial activities of two plant species, Litsea elliptica (L. elliptica) and Litsea resinosa (L. resinosa).MethodsIn vitro method -2,2-diphenyl-1-picrylhydrazyl radical scavenging assay was conducted for antioxidant activity determination while antimicrobial assay consisted of agar well diffusion assay and mycelial radial growth assay.ResultsMethanol extracts of root and stem of L. elliptica and L. resinosa exhibited the highest antioxidant activity with EC₅₀ of 23.99, 41.69, 11.22 and 35.48 mg/L respectively. All methanol extracts of L. resinosa as well as root extracts from L. elliptica showed significant scavenging activity. Hexane extract from stem of L. resinosa presented the largest inhibition zone in Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli while chloroform extract from inner bark of L. resinosa showed major inhibition towards Gram-positive bacteria Bacillus subtilis. Essential oils from the root of both species showed significant antifungal activities which are 80.11% and 66.85% respectively.ConclusionsOverall, methanol extracts from root and stem of both species showed antioxidant activity comparable to standard butylated hydroxytoluene. Extracts from L. resinosa demonstrated stronger antimicrobial properties compared to that from L. elliptica.     

Antidiabetic and antihyperlipidaemic activity of ethanol extract of Melastoma malabathricum Linn. leaf in alloxan induced diabetic rats

ObjectiveTo evaluate the antidiabetic and antihyperlipidaemic effect of ethanol extract of Melastoma malabathricum (M. malabathricum) Linn. leaf in alloxan induced diabetic rats.MethodsDiabetes was induced in albino rats by administration of alloxan monohydrate (150 mg/kg i.p). the ethanol extracts of M. malabathricum at a dose of 150 and 300 mg/kg of body weight were administrated at a single dose per day to diabetes induced rats for a period of 14 d. The effect of ethanol extract of M. malabathricum leaf extract on blood glucose, plasma insulin, creatinine, glycosylated haemoglobin, urea serum lipid profile [total cholesterol, triglycerides, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol, high density lipoprotein-cholesterol and phospholipid, serum protein, albumin, globulin, serum enzymes (serum glutamate pyruvate transaminases), serum glutamate oxaloacetate transaminases, and alkaline phosphatase] were measured in the diabetic rats.ResultsIn the acute toxicity study, ethanol extract of M. malabathricum leaf was non-toxic at 2 000 mg/kg in rats. The increased body weight, decreased blood glucose, glycosylated haemoglobin and other biochemical parameters level were observed in diabetic rats treated with both doses of ethanol extract of M. malabathricum leaf compared to diabetic control rats. In diabetic rats, ethanol extract of M. malabathricum leaf administration, altered lipid profiles were reversed to near normal than diabetic control rats.ConclusionsEthanol extract of M. malabathricum leaf possesses significant antidiabetic and antihyperlipidaemic activity in diabetic rats.     

Antioxidant,antimicrobial, cytotoxic and analgesic activities of ethanolic extract of Mentha arvensis L.

ObjectiveTo investigate potential antioxidant, antimicrobial, cytotoxic and analgesic activities of ethanolic extract of Mentha arvensis L. in different in vivo and in vitro experimental models.MethodsIn vitro DPPH radical scavenging assay was used to evaluate the antioxidant activity of the plant extract. In vivo analgesic activity was carried out by acetic acid-induced writhing test in Swiss albino mice. All studies in mice were undertaken at the doses of 250 and 500 mg/kg body weight. Antibacterial activity was studied by disk diffusion assay against some Gram-positive and Gram-negative bacterial strains. Brine shrimp lethality assay was used to investigate cytotoxicity effects of the plant extract.ResultsThe extract showed free radical scavenging activity in the DPPH assay (IC₅₀∼41 μg/mL) compared to the standard antioxidant ascorbic acid (IC₅₀∼19 μg/mL). The extract also produced prominent antimicrobial activity against Salmonella typhi, Salmonella paratyphi, Shigella boydii, Streptococcus pyogenes and Streptococcus aureus compared to standard drug kanamycin at the dose of 30 μg/disc. The extract exhibited lethality against the brine shrimp nauplii with the LC₅₀ values of 40 μg/mL, and also 90% mortality (LC₉₀) value was found to be 160 μg/mL. In analgesic test, the extract demonstrated statistically significant (P<0.01) analgesic effect in acetic acid induced writhing in white albino mice at both dose levels.ConclusionsThese results suggest that the ethanolic extract of Mentha arvensis L. has potential antioxidant, antibacterial, cytotoxic and analgesic activities that support the ethnopharmacological uses of this plant.