Antimicrobial activity of garlic against oral streptococci

Evaluation of Cytotoxicity of Allium sativum (Garlic Extract) against Human Dental Pulp Fibroblasts

Background

Vital pulp therapy procedures in primary dentition focuses on preservation and maintenance of pulp tissue that has been compromised due to caries, trauma, etc. Several pulp dressing materials have been used in primary teeth and some natural materials from the field of traditional medicine have also been introduced as medicaments in vital pulp therapy. The understanding of biologic and cytotoxic properties of newer materials is important for safe clinical usage. The biologic compatibility of these newer materials is imperative to limit or avoid tissue irritation or degeneration.

Aim

To evaluate the cytotoxic effects of Allium sativum on cultured human primary dental pulp fibroblasts.

Materials and methods

Primary pulp fibroblasts were cultured from the pulp tissue obtained from extracted deciduous primary canines and central incisor teeth. The freshly prepared concentrations of 1000, 500, 250, 125, and 62.5 µg/mL A. sativum extract were added to the 96-well plate in triplicates to which culture medium containing fourth passage cell suspension was added previously. Cells without treatment served as control, while cells treated with 5% dimethyl sulfoxide (DMSO) served as toxic control. After the addition of experimental and control agents, cells were incubated for 24 and 48 hours at 37°C in 5% CO2 atmosphere. After the incubation period, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the number of viable cells. Absorbance was read with a microplate reader at 570 nm wavelength and the relative viability of dental pulp fibroblasts at various concentrations was expressed as color intensity of the experimental wells relative to that of control. The percentage of cell viability was also calculated accordingly.

Results

The MTT assay results revealed that A. sativum extract, in all the concentrations tested at both the time intervals maintained a cell viability of greater than 90%. At 24 hours, the mean absorbance value of untreated control wells was recorded as 0.84400 ± 0.00916 with 100% cell viability. Among all the concentrations of garlic extract tested, highest mean absorbance value of 0.83933 ± 0.00550 with 99.44% cell viability was recorded for 62.5 µg/mL concentration. At 48 hours, the mean absorbance value of untreated control wells was recorded as 1.22767 ± 0.01106 with 100% cell viability, and the highest mean absorbance value of 1.22567 ± 0.01006 with 99.83% cell viability was recorded for 62.5 µg/mL concentration. The cell viability did not seem to be affected by the concentration of A. sativum extract at 24 hours. However, at 48 hours, the sensitivity of the cells was observed to be dependent on the concentration of A. sativum with a decrease in the viability of cells noted with the increase in concentration.

Conclusion

A. sativum extract is noncytotoxic in nature and preserves the vitality of cultured human primary dental pulp fibroblasts making it a suitable material for use in vital pulp therapy procedures of primary teeth.

How to cite this article

Devaraju R, Reddy D, Paul ST, et al. Evaluation of Cytotoxicity of Allium sativum (Garlic Extract) against Human Dental Pulp Fibroblasts. Int J Clin Pediatr Dent 2024;17(2):143-148.

The In Vitro Assessment of Antibacterial and Antioxidant Efficacy in Rosa damascena and Hypericum perforatum Extracts against Pathogenic Strains in the Interplay of Dental Caries, Oral Health, and Food Microbiota

The rising demand for novel antibiotic agents prompts an investigation into natural resources, notably plant-derived compounds. In this study, various extracts (aqueous, ethanolic, aqueous-ethanolic, and enzymatic) of Rosa damascena and Hypericum perforatum were systematically evaluated against bacterial strains isolated from dental lesions (n = 6) and food sources (raw milk and broiler carcass, n = 2). Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), antibiofilm activity, and time-kill kinetics were assessed across a range of extract concentrations, revealing a dose-responsive effect. Notably, some extracts exhibited superior antibacterial efficacy compared to standard clinical antibiotics, and the time-kill kinetics demonstrated a rapid elimination of bacterial loads within 24 h. The susceptibility pattern proved strain-specific, contingent upon the extract type, yet all tested pathogens exhibited sensitivity. The identified extracts, rich in phenolic and polyphenolic compounds, as well as other antioxidant properties, contributed to their remarkable antibiotic effects. This comprehensive investigation not only highlights the potential of Rosa damascena and Hypericum perforatum extracts as potent antibacterial agents against diverse bacterial strains including caries pathogens, but also underscores their rapid action and dose-dependent efficacy. The findings suggest a promising avenue for harnessing plant-derived compounds in the development of novel antimicrobial strategies against dental caries and other oral inflammations, bridging the gap between natural resources and antibiotic discovery.

Experiences on the Use of Complementary and Alternative Medicine in Individuals Diagnosed With COVID-19: A Content Analysis Study

The aim of this study was to examine past experiences related to the use of the complementary and alternative medicine (CAM) during the disease process by individuals diagnosed with COVID-19. Content analysis method was used for data analysis. The study consisted of 21 patients diagnosed with COVID-19, who applied to a family health center. The data were collected using an individual information form and a semistructured interview form consisting of open-ended questions. All interviews were recorded with audio recording and transcribed. Three main themes related to the use of CAM by COVID-19 patients and subthemes associated with these main themes were determined (1) while starting to use CAM; (2) experiences of CAM use; and (3) recommending CAM. During using the CAM methods, most of the participants were affected by their circle, they preferred the use of fruit/fruit juice containing vitamin C, they chose affordable and easily accessible methods, they found the methods they used useful, and recommended these methods to others. The CAM use of patients should be questioned in future studies related to COVID-19 by nurses. Nurses should inform patients with COVID-19 accurately about safety, efficacy, indications, and contraindications for CAM methods.

Effect of aqueous and organic solvent extraction on in-vitro antimicrobial activity of two varieties of fresh ginger (Zingiber officinale) and garlic (Allium sativum)

The current state of antimicrobial resistance to synthetic antimicrobial drugs has led to renewed interest in natural antimicrobial compounds. Antimicrobial activity of extracts of (local and hybrid) ginger and garlic was investigated using the agar well diffusion method against Staphylococcus aureus, Escherichia coli and Candida albicans. Aqueous and organic solvent extracts of both varieties of ginger and garlic exhibited varied and concentration-dependant antimicrobial activity. Inhibition zones at 25 mg/mL varied significantly against the microorganisms, being highest on C. albicans; 18.00 ± 2.00 to 30.67 ± 1.16 mm for acetone extracts and raw juice of hybrid ginger and 19.67 ± 1.16 to 30.33 ± 1.53 mm for methanol and raw extracts of local garlic respectively. Minimum Inhibitory Concentration ranged from 2.5 to 10 mg/mL in garlic extracts. The study concluded that both varieties of ginger and garlic possess antimicrobial substances, though ginger is more potent as antifungal agent.

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Extracts exhibited varied concentration-dependant antimicrobial activity.

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Inhibition was higher for garlic compared to ginger extracts against bacteria.

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Activity of garlic ethanolic extracts compared favourably with garlic raw juices

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Minimum Inhibitory Concentration ranged from 2.5 to 10 mg/mL in garlic extracts

Garlic (Allium sativum L.) Bioactives and Its Role in Alleviating Oral Pathologies

Garlic (Allium sativa L.) is a bulbous flowering plant belongs to the family of Amaryllidaceae and is a predominant horticultural crop originating from central Asia. Garlic and its products are chiefly used for culinary and therapeutic purposes in many countries. Bulbs of raw garlic have been investigated for their role in oral health, which are ascribed to a myriad of biologically active compounds such as alliin, allicin, methiin, S-allylcysteine (SAC), diallyl sulfide (DAS), S-ally-mercapto cysteine (SAMC), diallyl disulphide (DADS), diallyl trisulfide (DATS) and methyl allyl disulphide. A systematic review was conducted following the PRISMA statement. Scopus, PubMed, Clinicaltrials.gov, and Science direct databases were searched between 12 April 2021 to 4 September 2021. A total of 148 studies were included and the qualitative synthesis phytochemical profile of GE, biological activities, therapeutic applications of garlic extract (GE) in oral health care system, and its mechanism of action in curing various oral pathologies have been discussed. Furthermore, the safety of incorporation of GE as food supplements is also critically discussed. To conclude, GE could conceivably make a treatment recourse for patients suffering from diverse oral diseases.

Vegetal Compounds as Sources of Prophylactic and Therapeutic Agents in Dentistry

Dental pathology remains a global health problem affecting both children and adults. The most important dental diseases are dental caries and periodontal pathologies. The main cause of oral health problems is overpopulation with pathogenic bacteria and for this reason, conventional therapy can often be ineffective due to bacterial resistance or may have unpleasant side effects. For that reason, studies in the field have focused on finding new therapeutic alternatives. Special attention is paid to the plant kingdom, which offers a wide range of plants and active compounds in various pathologies. This review focused on the most used plants in the dental field, especially on active phytocompounds, both in terms of chemical structure and in terms of mechanism of action. It also approached the in vitro study of active compounds and the main types of cell lines used to elucidate the effect and mechanism of action. Thus, medicinal plants and their compounds represent a promising and interesting alternative to conventional therapy.

Allium sativum derived carbon dots as a potential theranostic agent to combat the COVID-19 crisis

Coronavirus disease 2019 (COVID-19) is one of the worst pandemics to have hit the humanity. The manifestations are quite varied, ranging from severe lung infections to being asymptomatic. Hence, there is an urgent need to champion new tools to accelerate the end of this pandemic. Compromised immunity is a primary feature of COVID-19. Allium sativum (AS) is an effective dietary supplement known for its immune-modulatory, antibacterial, anti-inflammatory, anticancer, antifungal, and anti-viral properties. In this paper, it is hypothesized that carbon dots (CDs) derived from AS (AS-CDs) may possess the potential to downregulate the expression of pro-inflammatory cytokines and revert the immunological aberrations to normal in case of COVID-19. CDs have already been explored in the world of nanobiomedicine as a promising theranostic candidates for bioimaging and drug/gene delivery. The antifibrotic and antioxidant effects of AS are elaborated, as demonstrated in several studies. It is found that the most active constituent of AS, allicin has a highly potent antioxidant and reactive oxygen species (ROS) scavenging effect. The antibacterial, antifungal, and anti-viral effects along with their capability of negating inflammatory effects and cytokine storm are discussed. The synthesis of theranostic CDs from AS may provide a novel weapon in the therapeutic armamentarium for the management of COVID-19 infection and, at the same time, could act as a diagnostic agent for COVID-19.

Lactobacillus bulgaricus improves antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus: a randomized control trial

Objectives:Lactobacillus bulgaricus may improve antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus (GDM).

Methods: Black garlic was prepared with or without L. bulgaricus. Volatile and polysaccharides were analyzed by using LC-MS, Fourier Transform infrared (FTIR) and ¹³C nuclear magnetic resonance (NMR). The study design was parallel randomized controlled trial and 226 GDM patients were randomly assigned into BG (black garlic and L. bulgaricus) and CG (black garlic) groups, and allocation ratio was 1:1. The treatment duration was 40 weeks. Fasting blood glucose (FBG) and 1- and 2-h blood glucose (1hBG and 2hBG) after oral glucose tolerance test (OGTT) were detected. Antioxidant function of black garlic was determined by measuring plasma malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC) in GDM patients. The comparison between two groups was made using two independent samples t test.

Results: The intake of nutrients was similar between two groups (P>0.05). L. bulgaricus promoted the transformation of the glucopyranoside to glucofuranoside. L. bulgaricus increased the abilities of black garlic for scavenging hydroxyl radicals, 2,2′-azino-bis (3-ethylbenzenthiazoline-6-sulfonic) acid (ABTS) and DPPH free radicals. L. bulgaricus reduced the levels of FBG, 1hBG and 2hBG, and incidence of perinatal complications (P<0.01). Plasma MDA level in the BG group was lower than in the CG group, whereas the levels of SOD, GSH-PX and T-AOC in the BG group were higher than in the CG group (P<0.01).

Conclusions:L. bulgaricus improves antioxidant capacity of black garlic in the prevention of GDM.

Complementary and alternative medicine use among elderly patients living with chronic diseases in a teaching hospital in Ethiopia

BACKGROUND

The use of complementary and alternative medicine (CAM) among patients with chronic diseases has grown rapidly worldwide. Yet, little has been known about CAM use by elderly patients with chronic diseases in Ethiopia. This study aimed at assessing the prevalence and reasons for CAM utilization among elderly patients living with chronic diseases in Ethiopia.

METHODS

An institution-based quantitative cross-sectional survey was conducted among elderly patients with chronic disease attending outpatient ambulatory clinics of University of Gondar referral and teaching hospital (UoGRTH). An interviewer-administered and semi-structured questionnaire were utilized to collect the data.

RESULT

Of the total respondents, 240 (74%) reported the use of CAM, with herbal medicine and spiritual healing being the most commonly utilized CAM modalities (50.4% and 40.8% respectively). Dissatisfaction with conventional therapy (40.8%) and belief in the effectiveness of CAM (30.8%) are the most commonly cited reasons for the use of CAM therapies. Rural residency, higher educational status, higher average monthly income and presence of co-morbidity were positively associated with the use of CAM.

CONCLUSION

This survey revealed a higher rate of CAM use among elderly patients with chronic diseases, along with a very low rate of disclosing their use to their health care providers. Special attention should be given for these patient population due to the potentially harmful interaction of different herbal remedies with the prescribed medications, thereby predisposing the patient to untoward adverse effects and compromised overall health outcome.

Traditional herbal medicine use among people living with HIV/AIDS in Gondar, Ethiopia: Do their health care providers know?

BACKGROUND

People living with HIV/AIDS (PLWHA) are increasingly using herbal remedies due to the chronic nature of the disease, the complexities of treatment modalities and the difficulty in adhering to the therapeutic regimens. Yet, research on herbal medicine use in this patient population is scarce in Ethiopia. The present study aimed at investigating the prevalence and factors associated with the use of traditional herbal medicine among PLWHA in Gondar, Ethiopia.

METHODS

A cross sectional survey was conducted on 360 PLWHA attending the outpatient clinic of University of Gondar referral and teaching hospital from September 1 to 30, 2016. A questionnaire about the socio-demographic, disease characteristics as well as traditional herbal medicine use was filled by the respondents. Descriptive statistics, univariate and multivariate logistic regression analyses were performed to determine prevalence and correlates of herbal medicine use.

RESULTS

Out of 360 respondents, 255 (70.8%) used traditional herbal medicine. The most common herbal preparations used by PLWHA were Ginger (Zingiber officinale) (47%), Garlic (Allium sativum L.) (40.8%) and Moringa (Moringa stenopetala) (31.4%). Majority of herbal medicine users rarely disclose their use of herbal medicines to their health care providers (61.2%). Only lower educational status was found to be strong predictors of herbal medicine use in the multivariate logistic regression.

CONCLUSIONS

The use of herbal medicine among PLWHA is a routine practice and associated with a lower educational status. Patients also rarely disclose their use of herbal medicines to their health care providers. From the stand point of high prevalence and low disclosure rate, health care providers should often consult patients regarding herbal medicine use.

Antimicrobial Activity of Two Garlic Species (Allium Sativum and A. Tuberosum) Against Staphylococci Infection. In Vivo Study in Rats

Purpose: This study observed the effect of garlic extracts and amoxicillin against an induced staphylococcal infection model. MIC and MBC were also obtained for aqueous extracts of Allium sativum (Asa) and Allium tuberosum (Atu) against Staphylococcus aureus penicillin-sensitive (PSSA - ATCC 25923) and MRSA (ATCC 33592).

Methods: Granulation tissues were induced in the back of 205 rats. After 14 days, 0.5 mL of 10⁸ CFU/mL of PSSA or MRSA were injected inside tissues. After 24h, animals were divided: G1 (Control) – 0.5 mL of NaCl 0.9%; G2 – Asa 100 mg/kg or 400mg/kg; G3 – Atu 100 mg/kg or 400 mg/kg; G4 – amoxicillin suspension 50 mg/kg, considering PSSA infection; and G5 (Control) - 0.5 mL of NaCl 0.9%; G6 – Asa 400mg/kg; G7 – amoxicillin 50 mg/kg; and G8 - Asa 400 mg/kg + amoxicillin 50 mg/kg for MRSA. All treatments were administered P.O. every 6h. Animals were killed at 0, 6, 12 and 24h. Samples were spread on salt-mannitol agar. Colonies were counted after 18 h at 37 °C. Atu was not able to inhibit or kill PSSA and MRSA. Considering Asa, MIC and MBC against PSSA were 2 mg/mL and 4 mg/mL, respectively; and 16 mg/mL and 64 mg/mL against MRSA.

Results: No effect was observed in vivo for control, Asa 100 mg/kg and Atu 100 mg/kg, while amoxicillin, Atu 400 mg/kg and Asa 400 mg/kg decreased PSSA counts in all-time points. No effect of any group against MRSA was observed at any time.

Conclusion: Thus, A. sativum and A. tuberosum were able to reduce PSSA infection, but not MRSA infection.

Pattern of Traditional Medicine Utilization among HIV/AIDS Patients on Antiretroviral Therapy at a University Hospital in Northwestern Ethiopia: A Cross-Sectional Study

The objective of this study was to assess traditional, complementary, and alternative medicine (TCAM) utilization pattern among HIV/AIDS patients on antiretroviral therapy at University of Gondar Comprehensive Specialized Hospital. Materials and Methods. Data on sociodemographic profile and clinical and TCAM utilization were collected using a structured, pretested questionnaire from April 01 to May 28, 2014, through interviews with patients. Data on CD4 count, HIV stage, and ART regimen were collected from patient records. Analysis was conducted descriptively using SPSS version 20. Results. Of the 300 participants, 43.7% reported using TCAM, with the largest proportion of them from religious institutions (churches/mosques) (41.22%), followed by home prepared (32.82%) and traditional healers (16.03%). The leading forms of TCAM used were spiritual and herbal therapies constituting 56.49% and 36.64% of the patients, respectively. The most frequently used herbal products included Nigella sativa (22.92%) and Moringa oleifera (20.83%). Most of the patients (73.30%) using TCAM reported improvement in their conditions. Conclusions. TCAM utilization among HIV/AIDS patients on ART was common and different sources and types were used alongside ART, with improvement reported by most. Further research is needed to identify CAM therapies which may be used as adjunct treatments among these patients.

The Health Potential of Fruits and Vegetables Phytochemicals: Notable Examples

Fruit and vegetables are essential components of a healthy diet. The World Health Organization (WHO) recommends an intake of five to eight portions (400-600 g) daily of fruits and vegetables to reduce risk of cardiovascular disease, cancer, poor cognitive performance, and other diet-related diseases, as well as for the prevention of micronutrient deficiencies. Much of their potential for disease prevention is thought to be provided by phytochemicals, among which the preventive activity of antioxidants is most well documented. Since numerous meta-studies published indicate variable and often contradictory results about the impact of isolated phytochemicals on health, their consumption as supplements must be carried out with care, because doses may exceed the recommended nutritional intake. Nonetheless, there is a general consensus that whole fruit and vegetable intake is more important in providing health benefits than that of only one of their constituent, because of additive and synergistic effects. This review describes the most recent literature regarding the health benefits of some selected fruits and vegetables. Importantly, since some phytochemicals regulate the same genes and pathways targeted by drugs, diets rich in fruits and vegetables in combination with medical therapies are being considered as novel approaches to treatment. Therefore, phytochemicals in fruits and vegetable might be a promising tool for the prevention and/or amelioration of a wide range of diseases.

Inhibitory Effects of Spices on Biogenic Amine Accumulation during Fish Sauce Fermentation

The presence of high levels of biogenic amines is detrimental to the quality and safety of fish sauce. This study investigated the effects of ethanol extracts of spices, including garlic, ginger, cinnamon, and star anise extracts, in reducing the accumulation of biogenic amines during fish sauce fermentation. The concentrations of biogenic amines, which include histamine, putrescine, tyramine, and spermidine, all increased during fish sauce fermentation. When compared with the samples without spices, the garlic and star anise extracts significantly reduced these increases. The greatest inhibitory effect was observed for the garlic ethanolic extracts. When compared with controls, the histamine, putrescine, tyramine, and spermidine contents and the overall biogenic amine levels of the garlic extract-treated samples were reduced by 30.49%, 17.65%, 26.03%, 37.20%, and 27.17%, respectively. The garlic, cinnamon, and star anise extracts showed significant inhibitory effects on aerobic bacteria counts. Furthermore, the garlic and star anise extracts showed antimicrobial activity against amine producers. These findings may be helpful for enhancing the safety of fish sauce.

Efficacy of garlic extract and chlorhexidine mouthwash in reduction of oral salivary microorganisms, an in vitro study

Objectives:

To assess and compare the antimicrobial effect of garlic extract and chlorhexidine (CHX) mouthwash solution against oral salivary microorganisms.

Materials and Methods:

Thirty six salivary samples were obtained in dry plastic vials. Collected saliva samples were centrifuged. Each vial was mixed completely on a shaker after which 1 ml of saliva was added to 9 ml of ethanol by a sterile pipette and mixed. A volume of 1 ml of garlic hydro-alcoholic extract and 1 ml of mouthwash was added to 1 ml each case specimen and was transferred to culture medium of Trypticase Soy Agar. Agar plates were incubated at 37°C for 48 h to allow for microbial growth. Microbial colonies were counted by independent interpreter to evaluate the result.

Statistical Analysis:

Data obtained were analyzed using one-way ANOVA test. P < 0.001 was considered statistically significant.

Result:

Result of the study shows that mean colony count of salivary microbial population was (1984 ± 400) 1127 in saline group (negative control), (50 ± 4) 27 in (0.12%) CHX group (positive control), (700 ± 200) 469 in garlic extract (5%) group (case control).

Conclusion:

Mouthwash containing garlic extract can be used as an alternative to CHX mouthwash.

Camellia sinensis (Tea): Implications and role in preventing dental decay

Tea is one of the most commonly consumed beverages with bioactive compounds like polyphenols-flavonoids-catechins, which are thought to be responsible for the health benefits that have traditionally been attributed to the tea. These compounds have multi-dimensional effects such as antibacterial action, inhibitory action on the bacterial and salivary amylase and inhibition of acid production. This article outlines the possible role of these compounds coupled with the presence of high fluoride content in tea to exhibit an anticariogenic effect.

Effect of garlic powder on the growth of commensal bacteria from the gastrointestinal tract

Garlic (Allium sativum) is considered one of the best disease-preventive foods. We evaluated in vitro the effect of a commercial garlic powder (GP), at concentrations of 0.1% and 1% (w/v), upon the viability of representative gut bacteria. In pure culture studies, Lactobacillus casei DSMZ 20011 was essentially found to be resistant to GP whereas a rapid killing effect of between 1 and 3 log CFU/ml reduction in cell numbers was observed with Bacteroides ovatus, Bifidobacterium longum DSMZ 20090 and Clostridium nexile A2-232. After 6h incubation, bacterial numbers increased steadily and once the strains became resistant they retained their resistant phenotype upon sub-culturing. A colonic model was also used to evaluate the effect of GP on a mixed bacterial population representing the microbiota of the distal colon. Lactic acid bacteria were found to be more resistant to GP compared to the clostridial members of the gut microbiota. While for most bacteria the antimicrobial effect was transient, the lactobacilli showed a degree of resistance to garlic, indicating that its consumption may favour the growth of these beneficial bacterial species in the gut. Garlic intake has the potential to temporarily modulate the gut microbiota.

Food components with anticaries activity

Caries is the most common oral infectious disease in the world. Its development is influenced also by diet components that interfere with pathogen mutans group Streptococci (MGS) activity. A very active research to identify functional foods and their components that are generally recognised as safe has been ongoing, with the aim of developing alternative approaches, to the use of synthetic chlorhexidine, and at the reduction or prevention of caries. Until now convincing evidence exists only for green tea as a functional food for oral health, partly owing to its high content of catechins, especially epigallocatechin-gallate. A number of other foods showed potential anticaries activity. Some other foods able to act against MGS growth and/or their virulence factors in in vitro tests are: apple, red grape seeds, red wine (proanthocyanidins), nutmeg (macelignan), ajowan caraway (nafthalen-derivative), coffee (trigonelline, nicotinic and chlorogenic acids, melanoidins), barley coffee (melanoidins), chicory and mushroom (quinic acid). In vivo anticaries activity has been shown by cranberry (procyanidins), glycyrrhiza root (glycyrrhizol-A), myrtus ethanolic extract, garlic aqueous extract, cocoa extracts (procyanidins), and propolis (apigenin, tt-farnesol).

Garlic in health and disease

The present article reviews the historical and popular uses of garlic, its antioxidant, haematological, antimicrobial, hepatoprotective and antineoplastic properties and its potential toxicity (from sulfoxide). Garlic has been suggested to affect several cardiovascular risk factors. It has also been shown that garlic and its organic allyl sulfur components are effective inhibitors of the cancer process. Since garlic and its constituents can suppress carcinogen formation, bioactivation and tumour proliferation, it is imperative that biomarkers be established to identify which individuals might benefit most. Garlic powder, aged garlic and garlic oil have demonstrated antiplatelet and anticoagulant effects by interfering with cyclo-oxygenase-mediated thromboxane synthesis. Garlic has also been found to have synergistic effects against Helicobacter pylori with a proton pump inhibitor. The active compound allicin may affect atherosclerosis not only by acting as an antioxidant, but also by other mechanisms, such as lipoprotein modification and inhibition of LDL uptake and degradation by macrophages. Freshly prepared garlic homogenate protects against isoniazid+rifampicin-induced liver injury in experimental animal models. Several mechanisms are likely to account for this protection.

Traditional Medicinal Plant Extracts and Natural Products with Activity against Oral Bacteria: Potential Application in the Prevention and Treatment of Oral Diseases

Oral diseases are major health problems with dental caries and periodontal diseases among the most important preventable global infectious diseases. Oral health influences the general quality of life and poor oral health is linked to chronic conditions and systemic diseases. The association between oral diseases and the oral microbiota is well established. Of the more than 750 species of bacteria that inhabit the oral cavity, a number are implicated in oral diseases. The development of dental caries involves acidogenic and aciduric Gram-positive bacteria (mutans streptococci, lactobacilli and actinomycetes). Periodontal diseases have been linked to anaerobic Gram-negative bacteria (Porphyromonas gingivalis, Actinobacillus, Prevotella and Fusobacterium). Given the incidence of oral disease, increased resistance by bacteria to antibiotics, adverse affects of some antibacterial agents currently used in dentistry and financial considerations in developing countries, there is a need for alternative prevention and treatment options that are safe, effective and economical. While several agents are commercially available, these chemicals can alter oral microbiota and have undesirable side-effects such as vomiting, diarrhea and tooth staining. Hence, the search for alternative products continues and natural phytochemicals isolated from plants used as traditional medicines are considered as good alternatives. In this review, plant extracts or phytochemicals that inhibit the growth of oral pathogens, reduce the development of biofilms and dental plaque, influence the adhesion of bacteria to surfaces and reduce the symptoms of oral diseases will be discussed further. Clinical studies that have investigated the safety and efficacy of such plant-derived medicines will also be described.

Variation in total polyphenolics contents of aerial parts of Potentilla species and their anticariogenic activity

The aerial parts of selected Potentilla species (P. anserina, P. argentea, P. erecta, P. fruticosa, P. grandiflora, P. nepalensis, P. norvegica, P. pensylvanica, P. crantzii and P. thuringiaca) were investigated in order to determine their contents of polyphenolic compounds. The results showed that P. fruticosa has relatively high concentrations of tannins (167.3 ± 2.0 mg/g dw), proanthocyanidins (4.6 ± 0.2 mg/g dw) and phenolic acids (16.4 ± 0.8 mg/g dw), as well as flavonoids (7.0 ± 1.1 mg/g dw), calculated as quercetin. Furthermore, we investigated the in vitro inhibitory effects of aqueous extracts from these species against cariogenic Streptococcus spp. strains. It was found that the tested samples moderately inhibit the growth of oral streptococci. However, all the preparations exhibited inhibitory effects on water-insoluble α-(1→3)-, α-(1→6)-linked glucan (mutan) and artificial dental plaque formation. The extract from P. fruticosa showed the highest anti-biofilm activities, with minimum mutan and biofilm inhibition concentrations of 6.25–25 and 50–100 µg/mL, respectively. The results indicate that the studied Potentilla species could be a potential plant material for extracting biologically active compounds, and could become a useful supplement for pharmaceutical products as a new anticariogenic agent in a wide range of oral care products.