_:b575917247 "2"^^ . _:b575917097 . . _:b575917246 "2"^^ . _:b575917241 "2"^^ . . _:b39203764 "discussion" . _:b575917240 "2"^^ . _:b575917267 . . _:b39203739 . _:b575917243 "2"^^ . _:b575917106 . _:b575917287 . . _:b39203764 . _:b575917191 . _:b39203766 "Curcumin I is the most active component of turmeric that has been explored for its various biological and medicinal properties [1, >>5<<, 23]. In the present study, we focused upon the antibacterial activity of curcumin I against four genera of bacteria, including those that are Gram-positive (S." . _:b575917242 "2"^^ . _:b575917100 . _:b575917101 . _:b39203760 . _:b575917102 . _:b575917103 . _:b575917253 "2"^^ . . . _:b575917097 . _:b575917098 . _:b575917099 . _:b575917252 "2"^^ . _:b575917255 "2"^^ . . . . _:b39203739 . . _:b575917254 "2"^^ . _:b575917116 . _:b575917117 . _:b575917118 . . _:b575917119 . _:b575917284 . _:b575917249 "2"^^ . _:b575917210 . _:b575917112 . _:b39203747 . _:b575917236 . _:b575917113 . _:b39203734 _:b39203744 . _:b575917114 . _:b39203734 _:b39203745 . _:b575917248 "2"^^ . _:b575917115 . _:b39203734 _:b39203746 . _:b575917108 . . _:b575917109 . _:b39203734 _:b39203740 . _:b575917110 . _:b39203734 _:b39203741 . _:b575917251 "2"^^ . _:b575917111 . . _:b575917104 . _:b39203734 _:b39203742 . _:b39203734 _:b39203743 . _:b575917105 . _:b39203734 _:b39203736 . _:b575917106 . _:b39203734 _:b39203737 . _:b575917250 "2"^^ . _:b575917107 . _:b39203734 _:b39203738 . _:b39203734 _:b39203739 . _:b575917261 "2"^^ . . _:b575917138 . _:b39203734 _:b39203735 . _:b575917260 "2"^^ . . _:b575917263 "2"^^ . . _:b39203739 . _:b575917241 . _:b575917262 "2"^^ . . _:b575917211 . _:b575917257 "2"^^ . . _:b575917256 "2"^^ . _:b39203769 "Besides, it has also been found that curcumin is involved in disordering the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membranes [>>25<<]. All previous studies on curcumin have indicated its membrane altering properties such as thinning and disruption of the membrane at high concentrations using artificial membranes only [26]. However, curcumin induced membrane" . _:b575917259 "2"^^ . _:b575917146 . _:b39203743 . . _:b575917154 . _:b575917258 "2"^^ . _:b575917251 . _:b39203737 "Curcumin is a pleiotropic molecule that interacts with multiple targets involved in inflammatory reaction such as tumor necrosis factor-alpha (TNF\u03B1) and interleukins (ILs) [>>5<<]. Curcumin has also been shown to possess in vitro anti-microbial potential against a wide range of microorganisms including fungi [6] as well as several Gram-positive and Gram-negative bacteria [7\u201317]. Recently, Song et al. [9] showed" . _:b39203772 . _:b575917269 "2"^^ . _:b575917268 "2"^^ . _:b39203777 "Such a strategy could be immensely promising in the current scenario of continuous emergence of resistant microorganisms and antibiotic crisis [>>31<<, 32]. Oxidative stress and inflammation often go together with bacterial infections [33, 34]. Therefore, curcumin I, an established anti-oxidant and anti-inflammatory natural herbal product, with easy availability, high efficacy, and low" . _:b575917271 "2"^^ . . _:b575917270 "2"^^ . . . _:b39203780 . _:b575917265 "2"^^ . _:b575917207 . . _:b575917148 . _:b575917264 "2"^^ . . . _:b575917267 "2"^^ . . _:b575917110 . _:b575917266 "2"^^ . _:b575917277 "2"^^ . _:b39203778 "Such a strategy could be immensely promising in the current scenario of continuous emergence of resistant microorganisms and antibiotic crisis [31, >>32<<]. Oxidative stress and inflammation often go together with bacterial infections [33, 34]. Therefore, curcumin I, an established anti-oxidant and anti-inflammatory natural herbal product, with easy availability, high efficacy, and low" . _:b575917276 "2"^^ . _:b39203762 . _:b575917122 . _:b575917279 "2"^^ . _:b39203755 "The S. aureus cells loaded with calcein were diluted 100-fold (106 CFU/ml), treated with different concentrations of curcumin I (i.e., 25 \u03BCM, 50 \u03BCM & 100 \u03BCM) and gramicidin D, a well known pore forming antimicrobial peptide [>>20<<] for 2h at 37\u00B0C." . _:b575917157 . _:b575917278 "2"^^ . _:b575917273 "2"^^ . . _:b39203773 . _:b575917272 "2"^^ . _:b575917190 . _:b39203774 . _:b39203764 _:b39203765 . _:b575917275 "2"^^ . _:b39203764 _:b39203766 . _:b39203764 _:b39203767 . _:b39203744 "aeruginosa) infection, curcumin was shown to have anti-infective activity through affecting virulence, quorum sensing and biofilm initiation [>>17<<]. Moreover, these mechanisms have not been confirmed in the case of other bacterial genera, hence could not be generalized for all bacteria. Therefore, a detailed study on antibacterial mechanism of curcumin, including a large number of" . _:b575917215 . _:b575917274 "2"^^ . _:b39203764 _:b39203772 . . _:b575917285 "2"^^ . _:b39203764 _:b39203773 . . . _:b39203764 _:b39203774 . _:b39203764 _:b39203775 . _:b39203764 _:b39203768 . _:b39203764 _:b39203769 . _:b575917284 "2"^^ . . _:b39203764 _:b39203770 . . _:b575917196 . _:b39203764 _:b39203771 . _:b575917287 "2"^^ . _:b575917145 . _:b39203760 _:b39203761 . _:b575917286 "2"^^ . _:b39203760 _:b39203762 . _:b575917117 . _:b39203760 _:b39203763 . _:b575917281 "2"^^ . . _:b575917280 "2"^^ . . . _:b575917283 "2"^^ . _:b39203774 "observations are in agreement with previous studies, which showed an 80% decrease in E. coli cell growth on exposure of 100 \u03BCM curcumin [15], 100% inhibition of S. aureus and P. aeruginosa [8], and 80% inhibition in case of E. faecalis [>>8<<] due to the exposure of 200 \u03BCM of curcumin within 4h. The high concentrations required to kill the bacteria in this and other studies may be due to poor solubility of curcumin in aqueous media and the low bioavailability of curcumin [28]." . _:b575917282 "2"^^ . _:b39203758 "Statistical analysis (multiple comparison among data sets) was performed using one-way analysis of variance (ANOVA) using Minitab [>>19<<, 20]. A p value \u2264 0.05 was considered significant." . _:b575917159 . _:b39203735 "It is also commonly used for medicinal purposes, particularly to treat inflammatory conditions [>>1<<]. Over the years, curcumin has been explored for various clinical applications. Previous research has shown that it plays a therapeutic role in many diseases including diabetes, inflammatory disorders and different types of cancers [2\u20134]." . _:b575917252 . . . . _:b575917124 . . . . _:b575917289 "2"^^ . _:b39203751 . . _:b575917179 . _:b39203742 "For instance, studies have demonstrated that the antibacterial activity of curcumin against Bacillus subtilis occurs through the inhibition of bacterial cell proliferation by blocking the assembly dynamics of FtsZ in the Z ring [>>15<<, 16]. In the case of Pseudomonas aeruginosa (P. aeruginosa) infection, curcumin was shown to have anti-infective activity through affecting virulence, quorum sensing and biofilm initiation [17]." . . _:b39203750 . _:b575917288 "2"^^ . . . _:b575917182 . _:b575917256 . _:b39203749 "The killing assay was performed according to the procedure mentioned in our previous publications [19, >>20<<]. Bacterial cells were grown in BHI broth to mid logarithmic phase. Using spectrophotometer, the optical density (OD 600nm) of cells was adjusted to 0.5 (~108 CFU/ml) in 10 mM PBS buffer (pH 7.4)." . _:b39203747 _:b39203752 . . _:b575917140 . _:b39203747 _:b39203753 . _:b575917291 "2"^^ . _:b39203747 _:b39203754 . _:b39203747 _:b39203755 . _:b39203747 _:b39203756 . _:b39203747 _:b39203757 . _:b39203748 . _:b575917290 "2"^^ . _:b39203747 _:b39203758 . . _:b39203747 _:b39203759 . . _:b39203747 _:b39203748 . _:b39203747 _:b39203749 . . _:b39203747 _:b39203750 . . _:b39203747 _:b39203751 . _:b39203741 "aureus) [>>10<<\u201312]. However, very few studies have demonstrated the mechanism of antibacterial activity of curcumin I which seems to differ depending on the strain being studied." . _:b39203753 . . . _:b39203738 . _:b39203758 . . . _:b575917165 . _:b39203757 . . _:b575917289 . _:b575917246 . _:b39203779 . . _:b575917234 . _:b39203764 _:b39203780 . . _:b575917263 . . _:b39203764 _:b39203776 . _:b39203764 _:b39203777 . _:b39203764 _:b39203778 . _:b39203764 _:b39203779 . _:b575917155 . _:b39203756 "SEM was performed as described in our previous report [>>20<<]. In brief, 108 CFU/ml bacterial suspension was incubated with different doses of curcumin I (25 \u03BCM, 50 \u03BCM & 100 \u03BCM) in PBS for 60 min and centrifuged at 4,000 rpm for 10 min." . _:b39203771 . . _:b575917269 . _:b575917152 . . . _:b575917098 . . "PMC0" . . _:b39203773 "These observations are in agreement with previous studies, which showed an 80% decrease in E. coli cell growth on exposure of 100 \u03BCM curcumin [15], 100% inhibition of S. aureus and P. aeruginosa [>>8<<], and 80% inhibition in case of E. faecalis [8] due to the exposure of 200 \u03BCM of curcumin within 4h." . _:b39203752 . . . . . _:b575917266 . _:b39203776 "To deal with this issue, several bio-conjugates and nanoparticles of curcumin have been synthesized by other groups and are under investigation [>>28<<\u201330]." . . _:b575917214 . _:b575917131 . . . . _:b39203767 . . . _:b575917119 . _:b575917270 . _:b575917186 . . _:b39203775 . _:b39203743 "For instance, studies have demonstrated that the antibacterial activity of curcumin against Bacillus subtilis occurs through the inhibition of bacterial cell proliferation by blocking the assembly dynamics of FtsZ in the Z ring [15, >>16<<]. In the case of Pseudomonas aeruginosa (P. aeruginosa) infection, curcumin was shown to have anti-infective activity through affecting virulence, quorum sensing and biofilm initiation [17]." . . . _:b575917201 . . . _:b39203761 "represent the number of S. aureus cells showing PI fluorescence on exposure of 25 \u03BCM, 50 \u03BCM and 100 \u03BCM curcumin I and two positive controls HNP-1 and nisin (well known antimicrobial peptides causing bacterial membrane permeabilization [>>22<<]) after 2h incubation, as quantified from a flow cytometry experiment repeated on three different days." . . . _:b575917281 . . . _:b575917170 . . _:b39203745 . _:b39203770 "All previous studies on curcumin have indicated its membrane altering properties such as thinning and disruption of the membrane at high concentrations using artificial membranes only [>>26<<]. However, curcumin induced membrane permeabilization was never studied exclusively using live bacteria from either Gram-positive or Gram-negative groups, which is the main focus of our study. The level of bacterial infection is directly" . _:b39203762 "Gramicidin D was incorporated as a positive control in this assay, which caused loss of calcein from 94% of cells as a result of membrane pore formation [>>19<<, 20]. Furthermore, the percentage of calcein leakage was quantified from the flow cytometry data repeated on different days (Fig. 5B). The exposure of S. aureus cells to 25 \u03BCM, 50 \u03BCM and 100 \u03BCM curcumin I for 2h led to 65.5 \u00B1 5.2%, 70.3 \u00B1" . . . _:b575917227 . _:b575917101 . . _:b575917166 . _:b575917261 . "10.1371%2Fjournal.pone.0121313" . _:b575917275 . _:b575917100 . . . _:b575917262 . . _:b39203776 . _:b575917108 . _:b575917103 . _:b575917102 . . . _:b575917097 . . _:b575917274 . . . _:b575917099 . _:b575917231 . _:b575917098 . . . _:b575917109 . _:b575917144 . . _:b575917108 . . _:b575917111 . . _:b575917283 . . _:b39203760 "results" . _:b575917110 . _:b575917278 . _:b575917282 . _:b575917105 . . _:b575917111 . _:b575917242 . . _:b575917104 . _:b575917277 . _:b575917218 . _:b575917107 . _:b39203763 "Gramicidin D was incorporated as a positive control in this assay, which caused loss of calcein from 94% of cells as a result of membrane pore formation [19, >>20<<]. Furthermore, the percentage of calcein leakage was quantified from the flow cytometry data repeated on different days (Fig. 5B). The exposure of S. aureus cells to 25 \u03BCM, 50 \u03BCM and 100 \u03BCM curcumin I for 2h led to 65.5 \u00B1 5.2%, 70.3 \u00B1" . _:b575917106 . . _:b39203771 "The level of bacterial infection is directly related to the level of inoculum size of the bacterium and infections with high densities of bacteria are resistant to antibiotics [>>27<<]. Therefore, in order to critically evaluate the antibacterial efficacy of curcumin I, the killing assay was performed using both low (104 CFU/ml) and high (106 CFU/ml) cell densities of S. aureus and E. coli. Moreover, all of the" . . . _:b575917117 . . . _:b39203751 "The fluorescence emission can be detected by both spectrofluorimeter [>>19<<] and flow cytometer [21] equipped with an appropriate filter." . _:b575917171 . _:b575917116 . . _:b575917128 . _:b575917119 . _:b575917118 . _:b575917151 . _:b575917113 . _:b575917101 . . _:b575917112 . _:b575917115 . _:b575917114 . _:b39203765 . . _:b575917264 . _:b575917125 . _:b575917124 . . _:b575917127 . _:b575917137 . _:b575917225 . . _:b575917126 . _:b575917121 . . . _:b575917120 . . _:b575917123 . _:b575917204 . _:b39203775 "The high concentrations required to kill the bacteria in this and other studies may be due to poor solubility of curcumin in aqueous media and the low bioavailability of curcumin [>>28<<]. To deal with this issue, several bio-conjugates and nanoparticles of curcumin have been synthesized by other groups and are under investigation [28\u201330]." . . _:b575917122 . _:b575917133 . _:b575917164 . _:b39203753 "The permeabilization of bacterial membrane due to curcumin I exposure was measured via calcein leakage by flow cytometry, as described in our previous reports [>>19<<, 20]. Calcein-AM (Calcein-Acetoxy Methyl Ester) is a membrane-permeating, non-fluorescent derivative of calcein whose excitation and emission wavelengths are 490 nm and 517 nm, respectively." . _:b575917132 . _:b575917199 . . _:b575917135 . _:b575917291 . . . _:b575917134 . . _:b575917129 . _:b575917202 . _:b39203739 . _:b39203746 . _:b575917128 . . _:b575917131 . _:b575917226 . _:b575917130 . _:b575917228 . _:b575917141 . _:b39203739 "Curcumin has also been shown to possess in vitro anti-microbial potential against a wide range of microorganisms including fungi [6] as well as several Gram-positive and Gram-negative bacteria [>>7<<\u201317]. Recently, Song et al. [9] showed that curcumin suppresses adherence of Streptococcus mutants to human tooth surfaces and extra-cellular matrix protein. Research has further highlighted that curcumin possesses a synergistic effect" . . _:b575917102 . _:b575917140 . . _:b575917143 . _:b39203767 "Curcumin I is the most active component of turmeric that has been explored for its various biological and medicinal properties [1, 5, >>23<<]. In the present study, we focused upon the antibacterial activity of curcumin I against four genera of bacteria, including those that are Gram-positive (S." . _:b575917142 . . _:b575917134 . _:b575917137 . _:b575917276 . _:b575917126 . _:b575917224 . _:b575917216 . _:b575917136 . _:b575917238 . . _:b575917139 . _:b575917168 . _:b575917138 . _:b39203739 . _:b575917233 . _:b575917143 . _:b575917149 . _:b575917115 . . _:b575917148 . _:b575917280 . _:b575917271 . _:b575917248 . _:b39203745 "Curcumin I showed no toxic effect on human health even when taken at doses as high as 8 g day\u22121 [>>18<<, 2]. Considering these factors, in the present study, we investigated the detailed antibacterial activity of curcumin I (the major component of commercial curcumin) against two Gram-positive bacteria, namely, S. aureus and Enterococcus" . _:b575917151 . _:b39203740 . . . _:b575917150 . _:b39203754 "The permeabilization of bacterial membrane due to curcumin I exposure was measured via calcein leakage by flow cytometry, as described in our previous reports [19, >>20<<]. Calcein-AM (Calcein-Acetoxy Methyl Ester) is a membrane-permeating, non-fluorescent derivative of calcein whose excitation and emission wavelengths are 490 nm and 517 nm, respectively." . _:b575917265 . _:b575917145 . _:b575917113 . _:b575917133 . _:b39203752 "The fluorescence emission can be detected by both spectrofluorimeter [19] and flow cytometer [>>21<<] equipped with an appropriate filter." . _:b575917103 . _:b575917144 . . . . _:b575917147 . _:b575917102 "7"^^ . . _:b39203779 "Oxidative stress and inflammation often go together with bacterial infections [>>33<<, 34]. Therefore, curcumin I, an established anti-oxidant and anti-inflammatory natural herbal product, with easy availability, high efficacy, and low cytotoxicity, could be an ideal candidate to use in combination therapies against" . . _:b575917146 . _:b575917268 . _:b575917239 . _:b575917103 "7"^^ . . . _:b575917157 . _:b575917100 "8"^^ . _:b575917178 . _:b575917156 . _:b39203735 . _:b575917101 "7"^^ . _:b575917099 "10"^^ . _:b575917159 . . _:b575917139 . . _:b39203736 . _:b575917158 . . _:b575917098 "13"^^ . _:b575917220 . _:b575917153 . _:b575917097 "13"^^ . _:b575917221 . _:b575917152 . _:b575917155 . _:b39203739 . _:b575917222 . _:b575917198 . _:b575917109 "4"^^ . . _:b575917212 . . _:b575917154 . _:b575917108 "5"^^ . _:b575917165 . _:b575917111 "4"^^ . _:b575917164 . _:b575917110 "4"^^ . . _:b575917167 . _:b575917161 . _:b575917166 . _:b575917158 . _:b575917104 "6"^^ . _:b575917176 . _:b575917161 . _:b575917107 "5"^^ . _:b575917105 "6"^^ . _:b575917160 . _:b575917205 . . _:b575917106 "5"^^ . _:b575917163 . _:b575917117 "4"^^ . . . _:b575917162 . . _:b575917116 "4"^^ . _:b575917119 "3"^^ . _:b575917173 . _:b575917162 . _:b575917172 . _:b575917118 "4"^^ . _:b575917156 . _:b575917100 . . _:b575917175 . _:b575917113 "4"^^ . _:b575917153 . _:b39203746 "Curcumin I showed no toxic effect on human health even when taken at doses as high as 8 g day\u22121 [18, >>2<<]. Considering these factors, in the present study, we investigated the detailed antibacterial activity of curcumin I (the major component of commercial curcumin) against two Gram-positive bacteria, namely, S. aureus and Enterococcus" . . _:b575917174 . _:b575917112 "4"^^ . . _:b575917169 . _:b575917115 "4"^^ . _:b575917135 . . . _:b575917105 . _:b39203776 . _:b575917168 . _:b575917114 "4"^^ . _:b575917171 . _:b575917223 . _:b575917125 "3"^^ . _:b575917170 . _:b575917124 "3"^^ . _:b575917130 . _:b575917181 . _:b575917127 "3"^^ . _:b575917147 . _:b575917126 "3"^^ . _:b575917180 . . . _:b575917121 "3"^^ . _:b575917183 . _:b575917118 . . _:b575917120 "3"^^ . _:b575917182 . . _:b575917116 . _:b575917177 . _:b575917123 "3"^^ . _:b575917122 "3"^^ . _:b575917176 . _:b575917272 . _:b575917133 "3"^^ . _:b575917179 . . _:b575917132 "3"^^ . _:b575917178 . _:b39203765 "Curcumin I is the most active component of turmeric that has been explored for its various biological and medicinal properties [>>1<<, 5, 23]. In the present study, we focused upon the antibacterial activity of curcumin I against four genera of bacteria, including those that are Gram-positive (S." . _:b575917104 . _:b575917195 . _:b575917135 "3"^^ . _:b575917189 . _:b575917183 . _:b575917200 . _:b575917206 . . _:b575917188 . _:b575917134 "3"^^ . . _:b39203739 . _:b575917129 "3"^^ . _:b575917191 . _:b575917128 "3"^^ . _:b575917190 . . _:b575917240 . _:b575917131 "3"^^ . _:b575917258 . _:b575917185 . _:b575917255 . _:b575917112 . _:b575917130 "3"^^ . _:b575917184 . _:b575917141 "3"^^ . _:b575917187 . _:b575917187 . _:b575917208 . _:b575917140 "3"^^ . _:b575917186 . _:b575917143 "3"^^ . _:b575917197 . _:b575917129 . _:b575917188 . _:b575917142 "3"^^ . _:b575917196 . _:b39203769 . . _:b575917199 . _:b575917177 . _:b575917137 "3"^^ . . _:b575917136 "3"^^ . _:b575917286 . _:b575917198 . _:b39203734 "introduction" . _:b39203766 . _:b575917139 "3"^^ . _:b575917193 . . _:b39203734 . _:b575917138 "3"^^ . _:b575917192 . _:b39203735 . _:b575917149 "3"^^ . _:b575917195 . _:b575917259 . _:b575917273 . _:b39203748 "The killing assay was performed according to the procedure mentioned in our previous publications [>>19<<, 20]. Bacterial cells were grown in BHI broth to mid logarithmic phase. Using spectrophotometer, the optical density (OD 600nm) of cells was adjusted to 0.5 (~108 CFU/ml) in 10 mM PBS buffer (pH 7.4)." . _:b575917148 "3"^^ . _:b575917194 . _:b575917151 "3"^^ . _:b575917205 . _:b575917245 . . _:b575917204 . _:b575917150 "3"^^ . . _:b575917136 . _:b575917145 "3"^^ . _:b575917207 . _:b39203740 . _:b575917144 "3"^^ . _:b575917206 . _:b39203741 . _:b39203780 "Oxidative stress and inflammation often go together with bacterial infections [33, >>34<<]. Therefore, curcumin I, an established anti-oxidant and anti-inflammatory natural herbal product, with easy availability, high efficacy, and low cytotoxicity, could be an ideal candidate to use in combination therapies against bacterial" . _:b575917147 "3"^^ . _:b575917201 . _:b575917172 . . . _:b39203742 . _:b575917232 . _:b575917146 "3"^^ . _:b575917200 . _:b39203743 . _:b575917157 "2"^^ . . _:b575917181 . _:b575917203 . _:b39203736 . _:b575917156 "2"^^ . _:b575917202 . _:b39203768 "Being an amphipathic and lipophilic molecule, curcumin inserts into liposome bilayers and enhances their permeability [>>24<<]. Besides, it has also been found that curcumin is involved in disordering the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membranes [25]. All previous studies on curcumin have indicated its membrane altering properties such as" . . _:b39203737 . _:b575917159 "2"^^ . _:b575917213 . _:b39203738 . _:b575917158 "2"^^ . . _:b575917212 . _:b39203739 . . _:b575917215 . _:b575917153 "3"^^ . . _:b39203770 . _:b39203748 . _:b575917152 "3"^^ . _:b575917250 . _:b575917214 . . . _:b39203749 . . _:b575917155 "2"^^ . . _:b575917209 . _:b39203747 "materials and methods" . _:b39203750 . _:b39203737 . . _:b575917208 . _:b575917154 "3"^^ . . _:b39203751 . _:b575917165 "2"^^ . _:b575917114 . _:b575917211 . _:b575917173 . _:b39203744 . _:b575917164 "2"^^ . _:b575917210 . . _:b39203745 . _:b575917121 . _:b575917167 "2"^^ . _:b575917189 . _:b575917221 . _:b39203746 . _:b575917166 "2"^^ . _:b575917220 . _:b39203736 "Previous research has shown that it plays a therapeutic role in many diseases including diabetes, inflammatory disorders and different types of cancers [>>2<<\u20134]. Curcumin is a pleiotropic molecule that interacts with multiple targets involved in inflammatory reaction such as tumor necrosis factor-alpha (TNF\u03B1) and interleukins (ILs) [5]. Curcumin has also been shown to possess in vitro" . . _:b39203747 . _:b575917213 . _:b575917161 "2"^^ . . . _:b575917223 . _:b39203756 . . _:b575917160 "2"^^ . _:b575917141 . _:b575917222 . _:b575917290 . _:b39203757 . _:b575917163 "2"^^ . _:b575917217 . _:b39203758 . . _:b575917162 "2"^^ . _:b575917150 . _:b575917216 . . _:b39203759 . _:b575917173 "2"^^ . . _:b575917219 . _:b39203752 . _:b575917172 "2"^^ . _:b575917218 . _:b575917132 . _:b39203753 . _:b575917175 "2"^^ . _:b575917229 . _:b39203754 . _:b575917109 . _:b575917174 "2"^^ . _:b575917107 . _:b575917228 . _:b39203755 . _:b575917169 "2"^^ . _:b39203738 "Curcumin has also been shown to possess in vitro anti-microbial potential against a wide range of microorganisms including fungi [>>6<<] as well as several Gram-positive and Gram-negative bacteria [7\u201317]." . _:b575917231 . _:b575917184 . _:b39203740 "Recently, Song et al. [>>9<<] showed that curcumin suppresses adherence of Streptococcus mutants to human tooth surfaces and extra-cellular matrix protein." . . _:b575917168 "2"^^ . _:b575917167 . . _:b39203764 . _:b575917230 . _:b575917235 . . _:b575917197 . _:b39203765 . _:b575917171 "2"^^ . _:b575917225 . _:b39203750 "A final inoculum of 106 and 104 CFU/ml was exposed to various concentrations of curcumin I (25 \u03BCM, 50 \u03BCM & 100 \u03BCM) in the presence of PBS [>>19<<]. At the chosen time points (30 min, 60 min & 120 min), aliquots were taken, placed on BHI agar plate in triplicates and incubated overnight at 37\u00B0C. Next day, the bacterial colonies were counted and bacterial survival was expressed as" . . _:b39203777 . _:b575917260 . _:b575917160 . _:b39203766 . . _:b575917170 "2"^^ . . _:b575917224 . _:b575917174 . _:b39203767 . . _:b575917181 "2"^^ . _:b575917227 . _:b39203760 . _:b575917180 "2"^^ . . _:b575917226 . _:b39203761 . _:b575917183 "2"^^ . _:b575917237 . . _:b39203768 . _:b39203762 . _:b575917182 "2"^^ . _:b575917217 . _:b575917236 . . _:b39203763 . _:b575917177 "2"^^ . _:b575917239 . . _:b39203772 . _:b575917176 "2"^^ . _:b575917238 . _:b39203773 . _:b575917179 "2"^^ . _:b575917285 . _:b575917233 . _:b39203774 . _:b575917178 "2"^^ . _:b575917288 . _:b575917232 . _:b39203775 . _:b575917189 "2"^^ . _:b575917235 . . _:b39203768 . _:b575917188 "2"^^ . . _:b575917234 . _:b575917185 . _:b39203769 . _:b575917191 "2"^^ . _:b575917245 . . _:b39203770 . _:b575917190 "2"^^ . _:b575917244 . _:b39203771 . _:b575917185 "2"^^ . _:b575917279 . _:b575917247 . _:b39203780 . . _:b575917184 "2"^^ . _:b575917246 . . _:b575917187 "2"^^ . _:b575917241 . _:b575917186 "2"^^ . _:b575917260 . _:b575917240 . _:b575917261 . _:b575917262 . _:b575917263 . _:b575917197 "2"^^ . _:b575917256 . _:b575917243 . _:b575917257 . _:b575917258 . _:b39203776 . _:b575917259 . _:b575917196 "2"^^ . _:b575917252 . _:b575917242 . _:b575917253 . _:b575917254 . _:b39203777 . _:b575917255 . _:b575917257 . _:b575917199 "2"^^ . _:b575917248 . _:b575917253 . _:b575917249 . _:b575917250 . _:b39203778 . _:b575917251 . _:b575917198 "2"^^ . _:b575917276 . _:b575917252 . _:b575917277 . _:b575917278 . _:b39203779 . _:b575917149 . _:b575917193 "2"^^ . . _:b575917279 . _:b575917272 . _:b575917255 . _:b575917273 . _:b575917274 . _:b575917275 . _:b575917203 . _:b575917192 "2"^^ . _:b575917268 . _:b575917254 . _:b575917127 . _:b575917269 . _:b575917270 . _:b39203757 "Bacterial Viability Assay Kit for microscopy [L7007, from Invitrogen, this is a mixture of stains: SYTO 9 (for live cells) and PI (for dead cells) in two different ratios] according to the protocol as suggested by the manufacturer [>>19<<]. Briefly, 3 \u03BCl of the mixture was added to the bacterial cells previously treated with different concentrations of curcumin I (25 \u03BCM, 50 \u03BCM & 100 \u03BCM) for 2h, and untreated cells were kept as control." . . _:b575917195 "2"^^ . _:b575917271 . _:b575917264 . _:b575917249 . _:b575917265 . _:b39203759 "Statistical analysis (multiple comparison among data sets) was performed using one-way analysis of variance (ANOVA) using Minitab [19, >>20<<]. A p value \u2264 0.05 was considered significant." . _:b575917266 . . _:b575917194 "2"^^ . _:b575917267 . _:b575917248 . _:b575917205 "2"^^ . _:b575917288 . _:b575917251 . _:b575917289 . _:b575917123 . _:b575917290 . _:b575917291 . _:b575917204 "2"^^ . _:b575917284 . _:b575917250 . . _:b575917285 . _:b575917286 . _:b575917287 . _:b575917207 "2"^^ . . _:b575917261 . . _:b575917280 . _:b575917281 . _:b575917282 . _:b575917283 . _:b39203744 . _:b575917206 "2"^^ . . _:b575917260 . . _:b575917175 . . _:b575917201 "2"^^ . _:b575917263 . _:b575917099 . _:b39203778 . _:b575917200 "2"^^ . . _:b39203761 . _:b575917262 . . _:b575917120 . . _:b575917203 "2"^^ . _:b575917257 . _:b575917202 "2"^^ . _:b575917196 . _:b575917256 . _:b575917197 . _:b575917198 . . _:b39203776 . _:b575917213 "2"^^ . _:b575917199 . _:b575917192 . _:b575917259 . _:b575917193 . _:b575917194 . _:b575917195 . _:b575917212 "2"^^ . _:b575917188 . _:b39203736 . _:b575917258 . . _:b575917189 . . _:b575917190 . _:b575917191 . _:b575917215 "2"^^ . _:b575917184 . _:b575917269 . _:b575917169 . _:b575917185 . _:b575917186 . _:b575917180 . _:b575917187 . _:b575917214 "2"^^ . _:b575917212 . _:b575917268 . _:b575917213 . _:b575917214 . _:b575917215 . _:b575917209 "2"^^ . _:b575917208 . _:b575917271 . . _:b575917209 . _:b575917210 . _:b575917211 . _:b575917208 "2"^^ . _:b575917204 . _:b575917270 . _:b575917205 . _:b575917206 . _:b575917207 . _:b575917229 . _:b575917211 "2"^^ . _:b575917200 . _:b575917265 . _:b575917201 . _:b575917202 . _:b575917244 . _:b575917203 . _:b575917210 "2"^^ . _:b575917228 . _:b575917264 . _:b575917229 . _:b575917230 . _:b575917230 . _:b575917253 . _:b575917231 . _:b575917221 "2"^^ . _:b575917224 . _:b575917267 . _:b575917225 . _:b575917226 . . _:b575917227 . _:b575917220 "2"^^ . _:b575917220 . _:b575917266 . _:b575917221 . _:b575917222 . . _:b575917223 "2"^^ . _:b575917223 . _:b575917216 . _:b575917277 . _:b575917247 . _:b575917217 . _:b575917218 . _:b575917243 . _:b575917219 . _:b575917222 "2"^^ . _:b575917244 . _:b575917276 . _:b575917245 . _:b575917246 . _:b575917247 . _:b575917217 "2"^^ . . _:b39203763 . _:b575917279 . _:b575917240 . _:b575917241 . _:b575917242 . _:b575917243 . _:b575917216 "2"^^ . _:b575917236 . _:b39203756 . _:b575917278 . _:b575917237 . _:b575917238 . _:b575917239 . _:b575917219 "2"^^ . _:b575917232 . _:b575917273 . _:b575917194 . _:b575917233 . _:b575917234 . _:b575917235 . _:b575917218 "2"^^ . . _:b575917272 . . _:b575917132 . _:b575917133 . _:b575917134 . _:b575917135 . _:b39203772 "These observations are in agreement with previous studies, which showed an 80% decrease in E. coli cell growth on exposure of 100 \u03BCM curcumin [>>15<<], 100% inhibition of S. aureus and P. aeruginosa [8], and 80% inhibition in case of E. faecalis [8] due to the exposure of 200 \u03BCM of curcumin within 4h." . _:b575917229 "2"^^ . _:b575917128 . _:b39203759 . _:b39203741 . _:b575917275 . _:b575917129 . _:b575917130 . _:b575917131 . _:b575917228 "2"^^ . _:b575917124 . _:b575917274 . _:b575917125 . _:b575917237 . _:b575917126 . _:b575917127 . _:b575917231 "2"^^ . _:b575917120 . _:b39203739 . _:b575917285 . _:b575917121 . _:b575917122 . _:b575917123 . _:b575917230 "2"^^ . _:b575917148 . _:b39203754 . _:b575917284 . _:b575917149 . _:b575917150 . _:b575917151 . _:b575917225 "2"^^ . _:b575917144 . _:b39203755 . _:b575917287 . _:b575917145 . _:b575917146 . _:b575917147 . _:b575917224 "2"^^ . _:b575917140 . _:b575917286 . _:b575917141 . _:b575917142 . _:b575917143 . _:b575917227 "2"^^ . _:b575917136 . _:b39203749 . _:b575917281 . _:b575917137 . _:b575917138 . _:b575917249 . _:b575917139 . _:b575917226 "2"^^ . _:b575917164 . _:b575917280 . _:b575917192 . _:b575917165 . _:b575917166 . _:b575917167 . _:b575917237 "2"^^ . _:b575917160 . _:b575917283 . . _:b575917163 . _:b575917161 . _:b575917162 . . _:b575917236 "2"^^ . _:b575917163 . . _:b575917282 . . _:b575917156 . _:b575917157 . _:b575917254 . _:b575917209 . _:b575917158 . _:b39203742 . _:b575917159 . _:b575917239 "2"^^ . . . _:b575917152 . _:b575917142 . _:b575917153 . _:b575917154 . _:b575917155 . _:b575917238 "2"^^ . _:b575917180 . _:b575917181 . _:b575917182 . _:b575917183 . _:b575917233 "2"^^ . _:b575917176 . _:b575917177 . _:b575917178 . _:b39203739 . _:b575917193 . . _:b575917232 "2"^^ . _:b575917179 . _:b575917172 . _:b575917173 . _:b575917174 . _:b575917125 . _:b575917235 "2"^^ . _:b575917175 . _:b575917168 . _:b575917289 . _:b575917169 . _:b575917170 . _:b575917171 . _:b575917234 "2"^^ . . _:b575917288 . . _:b39203734 . . _:b575917219 . _:b575917245 "2"^^ . . _:b575917291 . _:b575917244 "2"^^ . _:b575917290 . .