The objective of this study is to isolate and identify the bioactive compounds that possess antibacterial activities from Melastoma malabathricum stem bark acetone extract (MMSBAE) against Streptococcus mutans. M. malabathricum is widely used in the Southeast Asia to treat many ailments. A total of 12 fractions was purified by vacuum liquid chromatography (VLC) and further analysed by TLC-bioautography to determine antibacterial activities. TLC-bioautography showed that fraction 9 possesses antibacterial activities against S. mutans. Identification of fraction 9 had been done by GCMS and revealed 21 compounds. Some of the compound were important as agent pharmaceutical such as α-amyrin, β-sitosterol, hexadecenoic acid, stearic acid and hexacosanoic acid. Crystal violet and glass surface assay were used to determine anti-biofilm and anti-adherence activity, respectively. The concentrations of fraction 9 that produce 50% reduction in anti-biofilm and anti-adherence activities were 5 mg/mL and 2.50 mg/mL, respectively. Scanning electron microscopy (SEM) was performed to visualize the effect of the fraction 9 on biofilm structure of S. mutans. SEM analysis showed lysed biofilm were found on treated cells. These results indicated that this fraction possesses a powerful anti-cariogenic potential against S. mutans.

Background: Streptococcus mutans is the main causative agents of dental caries by developing biofilm and increase adherence activity. Dental caries have becoming more common due to antibiotic resistance towards Streptococcus mutans. Spilanthes acmella is well-known as anti-toothache plant with high medicinal usages. It has been recognized as an important medicinal plant with high demand worldwide. Therefore, the objective of this study is to establish antimicrobial activities, including anti-biofilm and anti-adherence activity of Spilanthes acmella on cariogenic Streptococcus mutans. Methods: Spilanthes acmella leaves extracts were prepared by serial extraction with n-hexane, dichloromethane, acetone and methanol. Antibacterial activities of these extracts were conducted using disc diffusion assay, anti-biofilm and anti-adherence activities methods. Results: The result indicates that n-hexane and methanol leaves extracts are endowed with anti-streptococcus activity. Both methanol and n-hexane extracts inhibit moderately Streptococcus mutans growth as indicated in the disc diffusion assay. Methanol and a n-hexane extracts inhibit the biofilm formation and adherence activity of Streptococcus mutans. Conclusion:This study highlights the potential of Spilanthes acmella leaves extract as a new promising anti Streptococcus mutans agents.

Introduction: Silver nanoparticles has been proven to be an effective agent for antimicrobial efficacy against bacteria, viruses and other eukaryotic microorganisms. Green synthesis is one of the methods that has been developed to synthesize silver nanoparticles in environmentally-friendly conditions. It uses plant extracts as reducing and capping agents. Besides act as reducing and capping agents, bioactives such as phenolic compounds may bind to silver nanoparticles and enhance its medicinal properties. Strobilanthes crispus is a Malaysian native plant. Previous studies had shown that S. crispus contains polyphenols, catechins, alkaloids, caffeine, tannins and vitamins. Therefore, the aim of this study is to determine antibacterial activities of silver nanoparticles-Strobilanthes crispus (AgNP-SC) against clinically important pathogens such as Escherichia coli, Pseudomonas aeruginosa and Streptococcus mutans. Methods: The disc diffusion assay (DDA) was performed to investigate the inhibition zone of AgNps-Sc towards E. coli, P. aeruginosa and S. mutans. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) was used to determine bactericidal/bacteriostatic profile of AgNP- SC against E. coli, P. aeruginosa and S. mutans. Results: AgNP-SC (40mg/mL) shows the greatest inhibition properties (12.67±0.6mm) against S. mutans when compared to Strobilanthes crispus leaves extract (6.0±0.001mm) and blank silver nanoparticles (6.0±0.001mm). MIC values for AgNP-SC against S. mutans and E. coli were at 0.625 mg/mL and 1.25 mg/mL, respectively. Whereas the MIC value of AgNP- SC against P. aeruginosa was at 2.5 mg/mL. MBC values of AgNP-SC against E. coli, P. aeruginosa and S. mutans were at 1.25, 2.5 mg/mL respectively. Results are concentration-dependent, with higher concentration demonstrating better inhibition property. Conclusion: It can be concluded that AgNP-SC possesses bactericidal properties against S. mutans, E. coli and P. aeruginosa.

Objective This study aims to compare the antimicrobial activity of calcium hydroxide (CaOH) and zinc oxide (ZnO) when incorporated with other solutions such as 2% chlorhexidine (CHX), 2.5% sodium hypochlorite (NaOCl), 1% povidone-iodine (PVP-I), and sterilized distilled water (ddH2O) against Enterococcus faecalis. Materials and Methods The materials were prepared by mixing CaOH and ZnO with other solutions (CHX, PVP-I, NaOCl, and ddH2O) separately. The antibacterial activity of CaOH and ZnO mixtures against E. faecalis was done by using disk diffusion assay (DDA). Twofold serial dilutions of the mixtures were used against E. faecalis to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Biofilm inhibition of E. faecalis had been measured by using crystal violet assay. Statistical Analysis The quantitative data of this study had been analyzed by using two-way analysis of variance with software SPSS version 27. The result is considered as significant if the value of analysis is p-value less than 0.05. Results From the DDA results, the lowest zone of inhibition toward E. faecalis was CaOH-PVP-I (6.00 0.00 mm), while the highest zone of inhibition toward E. faecalis was CaOH-CHX (22.73 0.02 mm). Besides that, ZnO-PVP-I showed the lowest zone of inhibition (16.50 0.06 mm), while ZnO-CHX showed the highest zone of inhibition (18.30 0.08 mm) against E. faecalis. The MIC and MBC values of CaOH-CHX and ZnOCHX were 0.78 and 6.25 mg/mL, respectively. In biofilm assay, CaOH-CHX and ZnOCHX were reduced biofilm formation of E. Faecalis. Conclusion Both CaOH-CHX and ZnO-CHX showed the highest antimicrobial activities toward E. faecalis. CaOH and ZnO alone showed no antimicrobial activities against E. faecalis.

Introduction:Spilanthes acmella, also known as “subang nenek’, has been used traditionally in Malaysia to treat toothache. A previous study has shown Spilanthes acmella leaves extracts (SALE) inhibit Streptococcus mutans growth. Streptococcus mutans is commonly found in the human oral cavity and is the main contributor to tooth de-cay. There is no study on the antibacterial effects of Spilanthes acmella flower extracts (SAFE) against Streptococcus mutans reported to date. Therefore, the objective of this study is to investigate antibacterial properties of SAFE against S. mutans. Methods:S. mutans was subcultured in Muller Hinton (MH) broth and agar. Sequential extractions of S. acmella flowers were conducted using four different solvents with increasing polarity, [n- hexane, dichloromethane (DCM), acetone, methanol (MeoH)] and tested with different concentrations against S. mutans via the disc diffusion assay, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Sodium fluoride (NaF) was used as a positive control while DMSO was used as a negative control. Results: The disc diffusion assay shows SAFE inhibited Streptococcus mutans growth. SAFE-DCM shows the greatest inhibition properties (12.33±2.30 mm) followed by SAFE-n-hexane (11.33±0.57 mm). Meanwhile, SAFE-Meoh and SAFE-acetone show no inhibition zone (6.00±0.001 mm). MIC value for SAFE-DCM and SAFE-n-hexane is 12.5 mg/mL respectively. Whereas, MBC value SAFE-DCM and SAFE-n-hexane is 50.0 mg/mL respectively. Conclusion: It can be concluded SAFE-DCM and SAFE-n-hexane possesses bactericidal properties against Streptococcus mutans.

The aim of this study is to futher investigate and validate the antibacterial effect of Clinacanthus nutans plant extract against periodontal pathogens namely Porphyromonas gingivalis and Aggregatibacter actinomycetamcomitans. Four samples of alcoholic extract of C. nutans leaves were used in different concentrations i.e. 100%, 50%, 10% ethanol and 100% chlorofom and Chlorhexidine 0.2% (CHX) was used as the positive control. The antibacterial activity of C.nutans extract were investigated using disc diffusion agar test for determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In this study, 50% ethanol extract and 100% chlorofom extract were found to have antibacterial activity against P.gingivalis, while only 50% ethanol crude extract was found to have acceptable antibacterial activity against A. actinomycetamcomitans (p < 0.05). The MIC and MBC tests showed that 50% ethanol extract had bacteriostatic activity against both P.gingivalis and A. actinomycetamcomitans while 100% chlorofom extract had bactericidal activity against P. gingivalis. These two findings were also found to be better than the activity of CHX. C. nutans extract was found to have notable antibacterial activity against P. gingivalis and A. actinomycetamcomitans comparable to CHX 0.2%. � 2019 Journal of International Dental and Medical Research.

Curculigo latifolia fruit is used as alternative sweetener while root is used as alternative treatment for diuretic and urinary problems. The antidiabetic and hypolipidemic activities of C. latifolia fruit:root aqueous extract in high fat diet (HFD) and 40 mg streptozotocin (STZ) induced diabetic rats through expression of genes involved in glucose and lipid metabolisms were investigated. Diabetic rats were treated with C. latifolia fruit:root extract for 4 weeks. Plasma glucose, insulin, adiponectin, lipid profiles, alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), urea, and creatinine levels were measured before and after treatments. Regulations of selected genes involved in glucose and lipid metabolisms were determined. Results showed the significant (𝑃 < 0.05) increase in body weight, high density lipoprotein (HDL), insulin, and adiponectin levels and decreased glucose, total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL), urea, creatinine, ALT, and GGT levels in diabetic rats after 4 weeks treatment. Furthermore, C. latifolia fruit:root extract significantly increased the expression of IRS-1, IGF-1, GLUT4, PPAR𝛼, PPAR𝛾, AdipoR1, AdipoR2, leptin, LPL, and lipase genes in adipose and muscle tissues in diabetic rats. These results suggest that C. latifolia fruit:root extract exerts antidiabetic and hypolipidemic effects through altering regulation genes in glucose and lipid metabolisms in diabetic rats

Musa paradisiaca also known as banana possess great medicinal value such as haematopoietic, immunomodulatory, antifungal, anti-diabetic and antioxidant effects. Antioxidant and antiproliferative activities between two different species, banana soft pith (BSP) Awak and Abu were conducted in this study. Briefly, BSP were collected (Baling, Kedah) and extracted by 70% ethanol forming crude extract. The crude extracts were then fractionated by n-hexane, ethyl acetate, butanol and water. All BSP extracts and fractions were subjected to total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazil (DPPH) free radical scavenging assay, ferric reducing antioxidant potential (FRAP) assay and cytotoxic assay screening (MTT). Fraction ethyl acetate from BSP Abu showed the highest cytotoxic activity towards HSC-4 cell lines (26.95 ± 1.80 µg/mL) and the highest TPC (12.25 ± 0.39 mg GAE/g) and FRAP assay (191.03 ± 0.83 mg FeSO4/g) values as compared to other fractions among BSP Abu. However, TPC (13.93 ± 0.28 mg GAE/g) and TFC (441.59 ± 19.31 mg QE/g) values of BSP Awak were found to be higher as compared to BSP Abu.

The antioxidant properties of germinated brown rice (GBR) are likely mediated by multiple bioactives. To test this hypothesis, HepG2 cells pretreated with GBR extracts, rich in acylated steryl glycoside (ASG), gamma amino butyric acid GABA), phenolics or oryzanol, were incubated with hydrogen peroxide (H2O2) and their hydroxyl radical (OH•) scavenging capacities and thiobarbituric acid-reactive substances (TBARS) generation were evaluated. Results showed that GBR-extracts increased OH• scavenging activities in both cell-free medium and posttreatment culture media, suggesting that the extracts were both direct- And indirect-acting against OH•. The levels of TBARS in the culture medium after treatment were also reduced by all the extracts. In addition, H2O2 produced transcriptional changes in p53, JNK, p38 MAPK, AKT, BAX, and CDK4 that were inclined towards apoptosis, while GBR-extracts showed some transcriptional changes (upregulation of BAX and p53) that suggested an inclination for apoptosis although other changes (upregulation of antioxidant genes, AKT, JNK, and p38 MAPK) suggested that GBR-extracts favored survival of the HepG2 cells. Our findings show that GBR bioactive-rich extracts reduce oxidative stress through improvement in antioxidant capacity, partly mediated through transcriptional regulation of antioxidant and prosurvival genes.

Denture stomatitis (DS) can affect about 70% of denture wearers causing inflammation of oral mucosa underneath the removable denture mostly seen at the palatal area. Candida albicans is a well-known as the main causative agent associated with denture stomatitis. Studies shown that DS-related biofilm consists of complex structured of microbial communities. Presence of co-existing bacteria in these biofilms may also contribute to the infection. In order to understand the microbial interaction between C. albicans and bacteria, this study focus on the ability of bacteria species which are Streptococcus mutans and Staphylococcus aureus to form biofilm with and without the presence of C. albicans. For this study, two groups were observed which are the single species biofilm and the mixed species biofilm. Biofilm assay was utilized to measure biofilm mass using spectrophotometer. From the observation, single species groups formed a better biofilm when compared to fungal-bacterial biofilm. Even though biofilm assay is unable to determine the number of cell available, both species were present when fungal-bacterial biofilm sample was observed microscopically using Gram stain technique. This experiment showed that both fungal and bacteria species are able to form biofilm together and this finding can be investigated further for better understanding of DS-related biofilm. KEYWORDS Biofilm, Candida albicans, mixed species biofilm

Bilayer/multilayer tablets have been introduced to formulate incompatible components for compound preparations, but they are now more commonly used to tailor drug release. This research aimed to formulate a novel gastro-retentive tablet to deliver a combination of a fixed dose of two drugs to eliminate Helicobacter pylori (H. pylori) in the gastrointestinal tract. The bilayer tablets were prepared by means of the direct compression technique. The controlled-release bilayer tablets were prepared using various hydrophilic swellable polymers (sodium alginate, chitosan, and HPMC-K15M) alone and in combination to investigate the percent of swelling behavior and average drug release. The weight of the controlled-release floating layer was 500 mg, whereas the weight of the floating tablets of pantoprazole was 100 mg. To develop the most-effective formulation, the effects of the experimental components on the floating lag time, the total floating time, T 50%, and the amount of drug release were investigated. The drugs’ and excipients’ compatibilities were evaluated using ATR-FTIR and DSC. Pre-compression and post-compression testing were carried out for the prepared tablets, and they were subjected to in vitro characterization studies. The pantoprazole layer of the prepared tablet demonstrated drug release (95%) in 2 h, whereas clarithromycin demonstrated sustained drug release (83%) for up to 24 h (F7). The present study concluded that the combination of sodium alginate, chitosan, and HPMC polymers (1:1:1) resulted in a gastro-retentive and controlled release drug delivery system of the drug combination. Thus, the formulation of the floating bilayer tablets successfully resulted in a biphasic drug release. Moreover, the formulation (F7) offered the combination of two drugs in a single-tablet formulation containing various polymers (sodium alginate, chitosan, and HPMC polymers) as the best treatment option for local infections such as gastric ulcers.

As pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) are the two major cell types that comprise the immunosuppressive tumor microenvironment of pancreatic cancer, we aimed to investigate the role of conditioned medium derived from PCCs and PSCs co-culture on the viability of lymphocytes. The conditioned medium (CM) collected from PCCs and/or PSCs was used to treat peripheral blood mononuclear cells (PBMCs) to determine CM ability in reducing lymphocytes population. A proteomic analysis has been done on the CM to investigate the differentially expressed protein (DEP) expressed by two PCC lines established from different stages of tumor. Subsequently, we investigated if the reduction of lymphocytes was directly caused by CM or indirectly via CM-induced MDSCs. This was achieved by isolating lymphocyte subtypes and treating them with CM and CM-induced MDSCs. Both PCCs and PSCs were important in suppressing lymphocytes, and the PCCs derived from a metastatic tumor appeared to have a stronger suppressive effect than the PCCs derived from a primary tumor. According to the proteomic profiles of CM, 416 secreted proteins were detected, and 13 DEPs were identified between PANC10.05 and SW1990. However, CM was found unable to reduce lymphocytes viability through a direct pathway. In contrast, CM that contains proteins secreted by PCC and/or PSC appear immunogenic as they increase the viability of lymphocytes subtypes. Lymphocyte subtype treated with CM-induced MDSCs showed reduced viability in T helper 1 (Th1), T helper 2 (Th2), and T regulatory (Treg) cells, but not in CD8+ T cells, and B cells. As a conclusion, the interplay between PCCs and PSCs is important as their co-culture displays a different trend in lymphocytes suppression, hence, their co-culture should be included in future studies to better mimic the tumor microenvironment.

Introduction: This study aimed to characterize silver nanoparticles-kaempferol (AgNP-K) and its antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA). Green synthesis method was used to synthesize AgNP-K under the influence of temperature and different ratios of silver nitrate (AgNO3 and kaempferol). Methods: AgNP-K 1:1 was synthesized with 1 mM kaempferol, whereas AgNP-K 1:2 with 2 mM kaempferol. The characterization of AgNP-K 1:1 and AgNP-K 1:2 was performed using UV–visible spectroscopy (UV–Vis), Zetasizer, transmission electron microscopy (TEM), scanning electron microscopy-dispersive X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The antibacterial activities of five samples (AgNP-K 1:1, AgNP-K 1:2, commercial AgNPs, kaempferol, and vancomycin) at different concentrations (1.25, 2.5, 5, and 10 mg/mL) against MRSA were determined via disc diffusion assay (DDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) assay, and time-kill assay. Results: The presence of a dark brown colour in the solution indicated the formation of AgNP-K. The UV–visible absorption spectrum of the synthesized AgNP-K exhibited a broad peak at 447 nm. TEM, Zetasizer, and SEM-EDX results showed that the morphology and size of AgNP-K were nearly spherical in shape with 16.963 ± 6.0465 nm in size. XRD analysis confirmed that AgNP-K had a crystalline phase structure, while FTIR showed the absence of (-OH) group, indicating that kaempferol was successfully incorporated with silver. In DDA analysis, AgNP-K showed the largest inhibition zone (16.67 ± 1.19 mm) against MRSA as compared to kaempferol and commercial AgNPs. The MIC and MBC values for AgNP-K against MRSA were 1.25 and 2.50 mg/mL, respectively. The time-kill assay results showed that AgNP-K displayed bacteriostatic activity against MRSA. AgNP-K exhibited better antibacterial activity against MRSA when compared to commercial AgNPs or kaempferol alone.

Kenaf (Hibiscus cannabinus) from the family Malvaceae, is a valuable fiber plant native to India and Africa and is currently plantedas the fourth commercial crop in Malaysia. Kenaf seed oil contains alpha-linolenic acid, phytosterol such as𝛽-sitosterol, vitamin E, and other antioxidants with chemopreventive properties. Kenaf seeds oil (KSO) was from supercritical carbon dioxide extraction fluid (SFE) at 9 different permutations of parameters based on range of pressures from 200 to 600 bars and temperature from 40to 80∘C. They were 200/40, 200/60, 200/80, 400/40, 400/60, 400/80, 600/40, 600/60, and 600/80. Extraction from 9 parameters of KSO-SFE was screened for cytotoxicity towards human colorectal cancer cell lines (HT29) and mouse embryonic fibroblast(NIH/3T3) cell lines using MTS assay. KSO-SFE at 600/40 showed the strongest cytotoxicity towards HT29 with IC50of 200𝜇g/mL. The IC50for NIH/3T3 was not detected even at highest concentration employed. Cell cycle analysis showed a significant increase in the accumulation of KSO-SFE-treated cells at sub-G1 phase, indicating the induction of apoptosis by KSO-SFE. Further apoptosis induction was confirmed by Annexin V/PI and AO/PI staining.

Kenaf (Hibiscus cannabinus) from the family of Malvaceae is a valuable fibre plant native to India and Africa. Kenafis composed of various active components including tannins, saponins, polyphenolics, alkaloids, essential oils andsteroids. It has been used to treat bruises, bilious conditions, fever and puerperium. Nevertheless, the anti-cancer properties of kenaf seed oil have not yet been investigated. In this study, kenaf seed oils obtained by Sonication,Soxhlet and supercritical carbon dioxide fluid extraction (SFE) with 9 different combinations of pressure (bars) and temperature (◦C) (200/40, 200/60, 200/80, 400/40, 400/60, 400/80, 600/40, 600/60 and 600/80) were investigated for the cytotoxicities. All the oils were cytotoxic towards ovarian cancer (CaOV3) and colon cancer (HT29) cell lines in a dose dependent manner as detected by using the MTT assay and trypan blue dye exclusion method. Oil from Sonication was the most cytotoxic towards CaOV3 cell line. Treated cells exhibited characteristics of apoptosis such as chromatin condensation and nuclear fragmentation. In conclusion, kenaf seed oils from the three extractions were cytotoxic towards CaOV3 cell line in a dose-dependent manner possibly via the induction of apoptosis. In considering the safety of the product, SFE technology is a better alternative extraction method that is suitable in kenaf seed oil extraction

This study aims to characterize and determine the antibacterial activities of synthesized Strobilanthescrispus-mediated AgNPs (SC-AgNPs) against Streptococcus mutans, Escherichia coli and Pseudomonas aer-uginosa. S. crispus water extract acts as a reducing and capping agent in the synthesis of AgNPs. Thesynthesized AgNPs were characterized by using UV-Vis spectrophotometer, dynamic light scattering(DLS), field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and Fouriertransform infra-red (FTIR). FESEM images showed a rough surface with a spherical shape. The averagesize distribution of 75.25 nm with a polydispersity index (PDI) of 0.373. XRD analysis matched the face-centred cubic structure of silver. FTIR analysis revealed a shifted peak from 1404.99 to 1345.00 cm−1.MIC and MBC values of SC-AgNPs were 1.25 mg/mL and 2.5 mg/mL against E. coli, P. aeruginosa andS. mutans, respectively. Time-kill assay showed that SC-AgNPs significantly reduced bacterial growth ascompared to non-treated bacteria. Morphologies of bacteria treated with SC-AgNPs were shrunk, lysed,irregular and smaller as compared to control. SC-AgNPs significantly disrupted the gene expression ofeae A, gtf B and Pel A (p < 0.05). This study indicated that the synthesized SC-AgNPs were stable withenhanced antibacterial activities.

Methicillin-resistant Staphylococcus aureus (MRSA), a multidrug resistant strain, is known to cause a threat to public health due to its limited therapeutic treatment. Kaempferol (K) is a natural flavonoid that shows antibacterial activities toward MRSA, but its effectiveness is limited due to its low water solubility. However, poorly aqueous soluble drugs displayed better solubility through nano formulation. Hence, kaempferols were incorporated with silver nanoparticles (AgNPs) to enhance their solubility and antibacterial activity. Previous study showed that AgNPs incorporated with kaempferol (AgNPs-K) exhibited antibacterial activity against MRSA. However, the knowledge regarding the mechanism of action AgNPs-K against MRSA is still limited. The objective of the study is to unravel the inhibition mechanism of silver nanoparticles-kaempferol (AgNPs-K) on treated MRSA. The scanning electron microscopy (SEM) result showed significant difference in morphology between treated and non-treated MRSA which suggest the effectiveness of the AgNPs-K. Non-treated MRSA has an oval shape while MRSA treated with AgNPs-K showed a disrupted cell wall with contents leakage. The transcriptomic profile analysis by Next Generation Sequencing (NGS) showed that various genes and pathways related to biofilm, virulent activity and glycolysis pathway are differently expressed, with 581 genes were downregulated and 641 were upregulated. The affected genes of icab, clfa and eno which involved in biofilm, clumping factor A (virulent) and glycolysis pathway were validated by RT-PCR technique. The results were consistent with the NGS outcome. In conclusion, AgNPs-K possesses antibacterial activity against MRSA and its mechanism of action are reflected in the gene expression of biofilm pathway, virulent and glycolysis activity. Therefore, AgNPs-K can be suggested as a potential alternative to combat MRSA infection.

Objectives: The objectives of the study were to determine antibacterial, anti-adherence, and antibiofilm ctivities of Melastoma malabathricum stem bark acetone extract (MMSBAE) subfraction against Streptococcus mutans. Methods: Fraction 9 (F9) from MMSBAE was subfractionated by thin-layer chromatography (TLC) and analyzed for antibacterial activity against S. mutans by TLC-bioautography. Subfraction 12 (SF12) was isolated from F9 followed by determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Results: MIC and MBC values were 10 mg/mL and 160 mg/mL, indicating bacteriostatic property of SF12. Time-kill assay analysis confirmed bacteriostatic property of SF12 against S. mutans. Crystal violet staining and glass surface assays were used to determine anti-adherence and antibiofilm activities. Concentrations produced 50% reduction in anti-adherence and antibiofilm activities were 40 mg/mL and 20 mg/mL, respectively. Scanning electron microscopy was performed to visualize the effect of SF12 on S. mutans biofilm structure. SF12 was found to lyse biofilm formation on treated bacteria indicating powerful anticariogenic potential against S. mutans. Analysis by quantitative real-time polymerase chain reaction revealed SF12 at MIC value downregulated biofilm formation genes such as gbpA, brpA, gtfC, and comDE. Conclusion: SF12 showed bacteriostatic activities against S. mutans by inhibiting adherence and biofilm activities.

The aim of this study was to isolate lactic acid bacteria (LAB) from fermented food, to determine its antibacterial activity, and to identify the LAB in order to select candidate probiotic strains for preventing caries. The probiotic strains were isolated from eight fermented food which are tapai ubi, tapai pulut, rebung, tauchu, kimchi, incalok, tempeh and tempoyak, taucu. Ten-fold serial dilutions of the fermented food samples were made in sterile peptone water before plating on de Man Rogosa and Sharpe (MRS) agar. The pure cultures were then randomly picked and biochemically identified. Then, the antibacterial activity of LAB against Streptococcus mutans was assessed by using the disk diffusion method. A total of 120 LAB were isolated from eight different fermented foods. The morphologies of the isolates were circular, convex, dull opaque white or translucent white. Gram staining identification showed that the isolates were Gram-positive rods. Of the 120 LAB isolates, five strains displayed moderate to strong antibacterial activity against S. mutans with the inhibition zones ranging from 7- 12 mm. The antibacterial activity demonstrated from LAB isolated from fermented foods suggests that the isolates from fermented foods possess antibacterial properties against a pathogen which responsible for causing dental caries. These strains are currently investigated in depth to assess whether they can be fully characterized as probiotics.

Kenaf (Hibiscus cannabinus) a plant of the family Malvaceae, is a valuable fiber plant native to India and Africa. Kenaf seeds contain alpha-linolenic acid, phytosterol such as β-sitosterol, vitamin E and other antioxidants with chemopreventive properties. In the present study we examined the hypothesis that kenaf seed ‘supercritical fluid extract’ (SFE) extract could suppress the early colon carcinogenesis in vivo by virtue of its bioactive compounds. To accomplish this goal, 60 male rats were randomly assigned to 5 groups which were (1) negative control group [not induced with azoxymethane (AOM)]; (2) positive control group (induced with AOM but received no treatment); (3) group treated with 500 mg/kg kenaf seed SFE extract; (4) group treated with 1000 mg/kg kenaf seed SFE extract; (5) group treated with 1500 mg/kg kenaf seed SFE extract. At 7 weeks of age, all rats except the negative control group received 15 mg/kg of AOM injection subcutaneously once a week for 2 weeks. Rats were euthanized at 13 weeks of the experiment. Number of ACF (mean ± SD) ranged from 84.4 ± 4.43 to 179.5 ± 12.78 in group 2, 3, 4, 5. ACF reductions compared with the untreated group were 45.3, 51.4 and 53.1% in rats fed with 500, 1000 and 1500 mg/kg body weight, respectively. There were no significant differences in weight gain among groups. Our finding indicates that kenaf seed SFE extract reduced AOM-induced ACF in Sprague–Dawley male rats.