Antimicrobial activity and essential oils of Curcuma aeruginosa,Curcuma mangga,and Zingiber cassumunar from Malaysia

Objective:To analyze the chemical composition of the essential oils of Curcuma aeruginosa (C.aeruginosa),Curcuma mangga(C.mangga),and Zingiber cassumunar(Z.cassumunar). and study their antimicrobial activity.Methods:Essential oils obtained by steam distillation were analyzed by gas chromatography-mass speclrometry(GC-MS).The antimicrobial activity of the essential oils was evaluated against four bacteria:Bacillus cereus(H.cereus).Staphylococcus aureus(S.aureus).Escherichia coli(E.coli).and Pseudomonas aeruginosa(P.aeruginosa);and two fungi:Candida albicans(C.albicans) and Cyptococcus neoformans(C.neoformans),using disc-diffusion and broth microdilution methods.Results:Cycloisolongifolene,8.9-dehydro-9- formyl(35.29%) and dihydrocoslunolide(22.51%) were the major compounds in C.aeruginosa oil; whereas caryophyllene oxide(18.71%) and caryophyllene(12.69%) were the major compounds in C.mangga oil:and 2,6.9,9-tetramethyl-2.6.10-cycloundecatrien-1-one(60.77%) andα-caryophyllene(23.92%) were abundant in Z.cassumunar oil.The essential oils displayed varying degrees of antimicrobial activity against all lested microorganisms.C.mangga oil had the highest and most broad-spectrum activity by inhibiting all microorganisms tested,with C.neoformans being the most sensitive microorganism by having the lowest minimum inhibitory concentration(MIC) and minimum fungicidal concentration(MFC) values of 0.1μL/mL. C.aeruginosa oil showed mild antimicrobial activity,whereas Z.cassumunar had very low or weak activity against the tested microorganisms.Conclusions:The preliminary results suggest promising antimicrobial properties of C.mangga and C.aeruginosa,which may be useful for food preservation,pharmaceutical treatment and natural therapies.

Antimicrobial activity of mangrove plant(Lumnitzera littorea)

Objective:To investigate the antimicrobial activities of n-hexane.ethyl acetate and methanol extracts of the leaves of Lumnitzera littorea(L littorea) against six human pathogenic microbes. Methods:The antimicrobial activity was evaluated using disc diffusion and microdilution methods.Results:The antimicrobial activities of the crude extracts were increased with increasing the concentration.It is clear that n-hexane extract was the most effective extract. Additionally.Gram positive Bacillus cereus(B.cereus) appear to be the most sensitive strain while Pseudomonas aeruginosa(P.aeruginosa) and the yeast strains(Candida albicans(C. albicans) and Cryptococcus neoformans(C.neqformans)) appear to be resistance to the tested concentrations since no inhibition zone was observed.The inhibition of microbial growth at concentration as low as 0.04 mg/ml.indicated the potent antimicrobial activity of L littorea extracts.Conclusions:The obtained results are considered sufficient for further study to isolate the compounds responsible for the activity and suggesting the possibility of finding potent antibacterial agents from L littorea extracts.

Apoptosis,antimicrobial and antioxidant activities of phytochemicals from Garcinia malaccensis Hk.f

Objective:To study the chemical constituents of stembark of Garcinia malaccenm（G.malaccenm） together with apoptotic.antimicrobial and antioxidant activities.Methods:Purification and structure elucidation were carried out by chromatographic and spectroscopic techniques, respectively.MTT and trypan blue exclusion methods were performed to study the cytotoxic activity.Antibacterial activity was conducted by dise diffusion and microdilulion methods, whereas antioxidant activities were done by ferric thiocyanate method and DPPH radical scavenging.Results:The phylochemical study led lo the isolation ofα,β-mangostin and cycloarl-24-en-3β-ol.α-Mangostin exhibited cytotoxic activity against HSC-3 cells with an IC50 of 0.33μM.β- andα-mangostin showed activity against K562 cells with IC50 of 0.40μM and 0.48μM,respectively,α-Mangostin was active against Gram-positive bacteria, Staphylococcus aureus（S.aureus） and Bacilus anthracis（B.anthmcis） with inhibition zone and MIC value of（19 mm;0.02S mg/mL） and（20 mm;0.013 mg/mL）,respectively.In antioxidant assay,α-mangostin exhibited activity as an inhibitor of lipid peroxidation.Conclusions:G.malaccenm presenceα- andβ-mangostin and cycloart-24-en-3β-ol.β-Mangostin was found very active against H.SC-3 cells and KS62.The results suggest that mangoslins derivatives have the potential to inhibit the growth of cancer cells by inducing apoptosis.In addition,α-andβ-mangostin was found inhibit the growth of Cram-positive pathogenic bacteria and also showed the activity as an inhibitor of lipid peroxidation.

In vitro antimicrobial activity of mangrove plant Sonneratia alba

Objective:To investigate the antimicrobial property of mangrove plantSonneratia alba(S. alba).Methods:The antimicrobial activity was evaluated using disc diffusion and microdilution methods against six microorganisms. Soxhlet apparatus was used for extraction with a series of solvents,n-hexane, ethyl acetate and methanol in sequence of increasing polarity.Results:Methanol extract appeared to be the most effective extract whilen-hexane extract showed no activity. The antimicrobial activities were observed against the gram positive bacteria Staphylococcus aureus(S. aureus) and Bacillus cereus(B. cereus), the gram negative Escherichia coli(E. coli) and the yeast Cryptococcus neoformans. Pseudomonas aeruginosa and Candida albicans appeared to be not sensitive to the concentrations tested since no inhibition zone was observed.E. coli(17.5 mm) appeared to be the most sensitive strain followed by S. aureus(12.5 mm)and B. cereus(12.5 mm).Conclusions:From this study, it can be concluded that S. alba exhibit santim icrobial activities against certain microorganisms.

Polyphenol content and antioxidant capacity in organically and conventionally grown vegetables

Objective:To evaluate the polyphenol content and antioxidant capacity of ethanol extracts of some organically and conventionally grown leafy vegetables.Methods:The ethanol extracts of kailan(Brassica alboglabra),bayam(Amaranthus spp.)and sawi(Brassica parachinensis)were tested for total phenolic content(TPC),total flavonoid content(TFC),and total anthocyanin content(TAC)and the antioxidant capacity of the extracts measured using 2,2-diphenyl-1-picrylhydrazyl assay.Results:In TPC test,sawi extract showed the highest phenolic content while bayam contained the least phenolic content for both organically and conventionally grown types.In TFC test,organically grown sawi extract showed the highest flavonoid content,while organically grown kailan extract showed the least flavonoid content among all types of vegetables.The flavonoid content of the conventionally grown types of vegetable extracts was the highest in kalian and the least in sawi.For 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity,the activity increased with the increasing concentration of each extract.All conventionally grown vegetable extracts showed higher antioxidant activity compared to their organically grown counterparts.Extracts of conventionally grown sawi showed the highest percentage inhibition followed by conventionally grown kailan and organically grown sawi.There were no correlation between TPC,TFC,TAC and IC_(25)of both organically and conventionally grown vegetables.However,there was a correlation between TAC and IC_(25)of conventionally grown vegetable extracts.The results showed relatively similar polyphenol content between organically and conventionally grown vegetable extracts.However,the conventionally grown vegetables extracts generally have higher antioxidant activity compared to the organically grown extracts.Conclusions:These results suggested that the different types of agricultural practice had a significant contribution to the polyphenol content and antioxidant activity in the vegetables.

Direct and indirect antimicrobial effects of α-mangostin on pathogenic microorganisms

Objective:To test direct and indirect antimicrobial properties of α-mangostin towards a number of bacteria and fungi.Methods:Activity of α-mangostin paired with an antibiotic was studied by calculating its fractional inhibitory concentration(FIC).Results:The experiment was carried out using broth microdilution and checkerboards methods.tetracycline showed no interaction with the combination withα-mangostin where the FIC indexes were between the range of 0.5<FIC_(index)>4.Activity of doxycycline on Pseudomonas aeruginosa fell into other set of range,FIC_(index)≥4 which is an antagonism.The activity of all four bacteria towards ampicillin,penicillin G,streptomycin and Conclusions:The FIC index is far away in the range.The coupled antibiotic andα-mangostin is considered synergy in action if it lies in FIC_(index)≤0.5 and it was found that the isolated compound,α-mangostin revealed very low synergistic antimicrobial effects when coupled with antibiotics.

Antioxidant and antimicrobial activities of Shorea kunstleri

Objective:To evaluate antioxidant and antimicrobial activities of stembark of Shorea kunstleri(S.kunstleri)together with analysis of phytochemical and total phenolic contents.Methods:Extraction was conducted with different solvent polarity of n-hexane,dichloromethane(DCM)and methanol by using Soxhlet extraction.Total phenolic content was determined using Folin-Ciocalteu method.Free radical scavenging activity and inhibition of lipid peroxidation were evaluated with DPPH radical scavenging and ferric thiocyanate assays,respectively.Antimicrobial activities were performed using disc diffusion method,minimum inhibition concentration(MIC),minimum bactericidal concentration(MBC),and minimum fungicidal concentration.Results:S.kunstleri stembark extracts revealed presence of steroids,terpenoids,saponins,flavonoids,and phenolic compounds.Methanol extract exhibited the highest total phenolic content and free radical scavenging activity resulting in phenolic content of(8.340±0.003)g GAE/100 g of extract and(95.90±1.07)%DPPH inhibition(IC_(50)value of 18.6μg/mL),respectively.Ferric thiocyanate assay of n-hexane,DCM,and methanol extracts indicated lipid peroxidation inhibitory activity of(74.20±0.35)%,(74.00±0.10)%,and(72.80±0.27)%,respectively.In antimicrobial and antifungal tests,methanol extract showed inhibition against Staphylococcus aureus(S.aureus),Candida albicans,and Candida tropicalis with inhibition zones of 10-12,18-22,and 18-19 mm,respectively.The MIC test of methanol extract showed highest inhibition against Candida albicans and S.aureus(0.04 and 0.08 mg/mL,respectively)while DCM extract exhibited the highest activity towards Candida tropicalis(MIC value of 0.63 mg/mL).Taken together,MBC test of methanol extract strongly demonstrated bactericidal effect against S.aureus with MBC value of 0.08 mg/mL.Conclusions:The study demonstrated that stembark extracts of S.kunstleri possessed antioxidant and antimicrobial properties.

Antioxidant,antimicrobial and total phenolic contents of Calophyllum symingtonianum

Objective:To determine the total phenolic content,antioxidant and antimicrobial activities of the extracts from Calophyllum symingtonianum.Methods:The extracts were tested for their antioxidant activity by the DPPH radical scavenging assay and the β-carotene bleaching assay,while the antimicrobial activity was determined by disc diffusion method.Results:All the tested extracts showed antioxidant and antimicrobial properties.The extracts showed moderate antimicrobial activity against Staphylococcus aureus with zone of inhibition values of 10,11 and 12 mm for n-hexane,dichloromethane and methanol extracts respectively at 30μg/disc.N-hexane showed low antimicrobial activity against Pseudomonas aeruginosa(5 mm)at 30μg/disc.The total phenolic test showed that methanol has high phenolic content(162.25 mg GAE/g of extract)compared to the other extracts.Conclusions:The ability of the extracts to inhibit microbial growth at a concentration of 30μg/disc indicated the its potent antimicrobial activity.