Natural rubber latex-based biomaterials for drug delivery and regenerative medicine: Trends and directions.

Natural Rubber Latex (NRL) has shown to be a promising biomaterial for use as a drug delivery system to release various bioactive compounds. It is cost-effective, easy to handle, biocompatible, and exhibits pro-angiogenic and pro-healing properties for both soft and hard tissues. NRL releases compounds following burst and sustained release kinetics, exhibiting first-order release kinetics. Moreover, its pore density can be adjusted for tailored kinetics profiles. In addition, biotechnological applications of NRL in amblyopia, smart mattresses, and neovaginoplasty have demonstrated success. This comprehensive review explores NRL's diverse applications in biotechnology and biomedicine, addressing challenges in translating research into clinical practice. Organized into eight sections, the review emphasizes NRL's potential in wound healing, drug delivery, and metallic nanoparticle synthesis. It also addresses the challenges in enhancing NRL's physical properties and discusses its interactions with the human immune system. Furthermore, examines NRL's potential in creating wearable medical devices and biosensors for neurological disorders. To fully explore NRL's potential in addressing important medical conditions, we emphasize throughout this review the importance of interdisciplinary research and collaboration. In conclusion, this review advances our understanding of NRL's role in biomedical and biotechnological applications, offering insights into its diverse applications and promising opportunities for future development.

Evaluation of the in vitro schistosomicidal, leishmanicidal, and trypanocidal activities of the capsaicin metabolite, Capsicum frutescens, and Capsicum baccatum extracts and of their analysis of the main constituents by HPLC/UV and CG/MS.

Neglected tropical diseases are significant causes of death and temporary or permanent disability for millions living in developing countries. Unfortunately, there is no effective treatment for these diseases. Thus, this work aimed to conduct a chemical analysis using HPLC/UV and GC/MS to identify the major constituents of the hydroalcoholic extracts of Capsicum frutescens and Capsicum baccatum fruits, evaluating these extracts and their constituents' schistosomicidal, leishmanicidal and trypanocidal activities. The results obtained for the extracts of C. frutescens are better when compared to those obtained for C. baccatum, which can be related to the different concentrations of capsaicin (1) present in the extracts. The lysis of trypomastigote forms results for capsaicin (1) led to a significant value of IC50 = 6.23 µM. Thus, the results point to capsaicin (1) as a possible active constituent in these extracts.

Recent advances and perspectives on natural latex serum and its fractions for biomedical applications.

Advances and the discovery of new biomaterials have opened new frontiers in regenerative medicine. These biomaterials play a key role in current medicine by improving the life quality or even saving the lives of millions of people. Since the 2000s, Natural Rubber Latex (NRL) has been employed as wound dressings, mechanical barrier for Guided Bone Regeneration (GBR), matrix for drug delivery, and grafting. NRL is a natural polymer that can stimulate cell proliferation, neoangiogenesis, and extracellular matrix (ECM) formation. Furthermore, it is well established that proteins and other biologically active molecules present in the Natural Latex Serum (NLS) are responsible for the biological properties of NRL. NLS can be obtained from NRL by three main methods, namely (i) Centrifugation (fractionation of NRL in distinct fractions), (ii) Coagulation and sedimentation (coagulating NRL to separate the NLS from rubber particles), and (iii) Alternative extraction process (elution from NRL membrane). In this review, the chemical composition, physicochemical properties, toxicity, and other biological information such as osteogenesis, vasculogenesis, adhesion, proliferation, antimicrobial behavior, and antitumoral activity of NLS, as well as some of its medical instruments and devices are discussed. The progress in NLS applications in the biomedical field, more specifically in cell cultures, alternative animals, regular animals, and clinical trials are also discussed. An overview of the challenges and future directions of the applications of NLS and its derivatives in tissue engineering for hard and soft tissue regeneration is also given.

Metabolic response induced by abiotic elicitors in Anacardium othonianum seedlings.

Applying elicitors in plants growing under natural conditions change the metabolic content of volatile compounds extracted from their tissues. Here, we have investigated how abiotic elicitors influence the volatile composition of the ethyl acetate extract of Anacardium othonianum seedlings propagated in vitro and ex-vitro cultures. Abiotic factors such as salicylic acid, silver nitrate, light quality, and cultivation mode affected the composition of volatile compounds in ethyl acetate extract of A. othonianum leaves seedlings. GC/MS analysis demonstrated that α-tocopherol was the main metabolite in cultures added with chemical elicitors, reaching 22.48 ± 4.06% in the case of 30 µM salicylic acid. Higher concentrations of salicylic acid decreased the amount of α-tocopherol. The addition of AgNO3 had a linear effect on α-tocopherol. Thus, the production of this metabolite indicates that salicylic acid and AgNO3 elicitors positively affect α-tocopherol production at specific concentrations helping to understand how plant culture can be better manipulated.

Hexane Extract from Tradescantia pallida (Rose) D.R. Hunt (Commelinaceae): Its Volatile Constituents and in vitro Antifungal and Cytotoxic Activities

Abstract: Tradescantia pallida (Commelinaceae) has shown promising antibacterial, antioxidant and anticancer activities. This study aimed at extracting hexane from T. pallida (HE-TP) aerial parts to identify and quantify its volatile compounds by GC-MS and GC-FID and at evaluating its antifungal and antiproliferative activities. (E)-4-Methoxycynnamic acid (50.2%), 2,5-di-tert-butyl-1,4-benzoquinone (13.7%) and epijuvabione (10.4%) were the major components identified in HE-TP. HE-TP was incorporated into PDA medium, poured into Petri dishes and transferred to mycelial discs of pathogens. Percentages of inhibition of fungal growth were determined. HE-TP showed remarkable antifungal potential at the dose of 400 µL since it inhibited 100% of Penicillium digitatum and Sclerotinia sclerotiorum growth and 92.6% of Rhizopus stolonifer growth. Besides, HE-TP demonstrated cytotoxic activity against different human tumor cell lines with IC50 values between 231.43 and 428.76 µg/mL. Therefore, results showed that HE-TP has potential against fungi of agronomic interest and tumor cells.

Phenolic Compound Biotransformation by Trametes versicolor ATCC 200801 and Molecular Docking Studies.

The filamentous fungus Trametes versicolor is a rich source of laccase (Tvlac). Laccases catalyze reactions that convert substituted phenol substrates into diverse derivatives through aromatic oxidation. We investigated methyl p-coumarate, methyl ferulate, and methyl caffeate biotransformation by Trametes versicolor ATCC 200801. Despite substrate similarity, the biotransformation reactions varied widely. Only methyl p-coumarate was converted into three derivatives. We isolated and identified the chemical structures of such derivatives by NMR and IR analysis. Hydroxylation, methylation, and hydrolysis were the main reactions resulting from the studied biotransformation. We also analyzed the interactions between Tvlac (PDB ID: 1GYC) and the three phenolic substrates by molecular docking simulations. The substituents in the phenol ring influenced substrate conformation and orientation in the Tvlac site. The biotransformation reaction selectivity correlated with the different binding energies to the Tvlac site. Our results demonstrated that docking studies successfully predict the biotransformation of cinnamic acid analogs by T. versicolor.

Chemical composition and in vitro antibacterial activity of essential oils from Murraya paniculata (L. ) Jack (Rutaceae) ripe and unripe fruits against bacterial genera Mycobacterium and Streptococcus

This study aims to investigate chemical composition of essential oils from Murraya paniculata (L.) Jack (Rutaceae) ripe and unripe fruits and determine their in vitro antibacterial activity. Essential oils were extracted by hydrodistillation from Murraya paniculata (L.) Jack ripe and unripe fruits collected in the Cerrado, in Rio Verde, southwestern Goiás, Brazil. They were analyzed by gas chromatography with flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC-MS). Sesquiterpenes, which represent the most abundant class of compounds in oils, predominated in both ripe and unripe fruits. Major constituents of essential oils extracted from ripe fruits (RF-EO) were (-caryophyllene (21.3%), (-ylangene (13.3%), germacrene-D (10.9%) and (-zingiberene (9.7%) whereas the ones of unripe fruits (UF-EO) were sesquithujene (25.0%), (-zingiberene (18.2%), germacrene-D (13.1%) and (-copaene (12.7%). In vitro antibacterial activity of essential oils was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method in 96-well microplates. Both essential oils under investigation showed moderate anti-streptococcal activity against the following bacteria: Streptococcus mutans, S. mitis, S. sanguinis, S. sobrinus and S. salivarius. MIC values ranged between 100 and 400 µg/mL. Regarding the antimycobacterial activity, essential oils from M. paniculata (L.) Jack unripe and ripe fruits were active against Mycobacterium kansasii (MIC = 250 µg/mL), moderately active against M. tuberculosis (MIC = 500 µg/mL) and inactive against M. avium (MIC = 2000 µg/mL). This study was pioneer in revealing similar chemical profiles of both essential oils extracted from Murraya paniculata (L.) Jack unripe and ripe fruits, besides describing their in vitro anti-streptococcal and antimycobacterial activities.

Essential Oil from Psidium cattleianum Sabine (Myrtaceae) Fresh Leaves: Chemical Characterization and in vitro Antibacterial Activity Against Endodontic Pathogens

Abstract Endodontic infections result from oral pathogenic bacteria which reach and infect dental pulp, as well as surrounding tissues, through cracks, unrepaired caries and failed caries restorations. This study aims to determine the chemical composition of essential oil from Psidium cattleianum leaves (PC-EO) and to assess its antibacterial activity against endodontic bacteria. Antibacterial activity of PC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method on 96-well microplates. Bacteria Porphyromonas gingivalis (MIC = 20 µg/mL), Prevotella nigrescens (MIC = 62.5 µg/mL), Fusobacterium nucleatum (MIC = 12.5 µg/mL), Actinomyces naeslundii (MIC = 50 µg/mL), Bacteroides fragilis (MIC = 12.5 µg/mL), Aggregatibacter actinomycetemcomitans (MIC = 6.25 µg/mL) and Peptostreptococcus anaerobius (MIC = 62.5 µg/mL) were evaluated and compared to chlorhexidine dihydrochloride (CDH), the positive control. PC-EO was obtained by hydrodistillation with the use of a Clevenger-type apparatus whereas its chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Viridiflorol (17.9%), β-caryophyllene (11.8%), 1,8-cineole (10.8%) and β-selinene (8.6%) were the major constituents found in PC-EO, which exhibited high antibacterial activity against all endodontic pathogens under investigation. Therefore, PC-EO, a promising source of bioactive compounds, may provide therapeutic solutions for the field of endodontics.

Brazilian Green Propolis: Chemical Composition of Essential Oil and Their In Vitro Antioxidant, Antibacterial and Antiproliferative Activities

Abstract Propolis is a resinous substance collected and processed by Apis mellifera from parts of plants, buds and exudates. In Minas Gerais (MG) state, Brazil, green propolis is produced from the collection of resinous substance found in shoot apices of Baccharis dracunculifolia. This paper aims to investigate the chemical composition and in vitro antioxidant, anti-Helicobacter pylori, antimycobacterial and antiproliferative activities of essential oil (EO) from Brazilian green propolis (BGP-EO). The oil showed high antibacterial activity against H. pylori (MIC = 6.25 µg/mL), Mycobacterium avium (MIC = 62.5 µg/mL) and M. tuberculosis (MIC = 64 µg/mL). Its antioxidant activity was evaluated in vitro by both DPPH (IC50 = 23.48 µg/mL) and ABTS (IC50 = 32.18 µg/mL) methods. The antiproliferative activity in normal (GM07492A, lung fibroblasts) and tumor cell lines (MCF-7, HeLa and M059J) was analyzed by the XTT assay. BGP-EO showed inhibition of normal cell growth at 68.93 ± 2.56 µg/mL. Antiproliferative activity was observed against human tumor cell lines, whose IC50 values were 56.17, 66.43 and -65.83 µg/mL for MCF-7, HeLa and M059J cells, respectively. Its major constituents, which were determined by GC-FID and GC-MS, were carvacrol (20.7 %), acetophenone (13.5 %), spathulenol (11.0 %), (E)-nerolidol (9.7 %) and β-caryophyllene (6.2 %). These results showed the effectiveness of BGP-EO as a natural product which has promising biological activities.

Antileishmanial activity of Melampodium divaricatum and Casearia sylvestris essential oils on Leishmania amazonensis.

Leishmaniasis is a disease that affects millions of people and it is an important public health problem. The drugs currently used for the treatment of leishmaniasis present undesirable side effects and low efficacy. In this study, we evaluated the in vitro activity of Melampodium divaricatum (MD-EO) and Casearia sylvestris (CS-EO) essential oils (EO) against promastigote and amastigote forms of Leishmania amazonensis. Sesquiterpenes E-caryophyllene (56.0%), germacrene D (12.7%) and bicyclogermacrene (9.2%) were identified as the main components of MD-EO, whereas E-caryophyllene (22.2%), germacrene D (19.6%) and bicyclogermacrene (12.2%) were the main constituents of CS-EO. CS-EO and E-caryophyllene were active against promastigote forms of L. amazonensis (IC50 24.2, 29.8 and 49.9 µg/mL, respectively). However, MD-EO, CS-EO and E-caryophyllene were more active against amastigote forms, with IC50 values of 10.7, 14.0, and 10.7 µg/mL, respectively. E-caryophyllene presented lower cytotoxicity against macrophages J774-A1 (CC50 of 62.1 µg/mL) than the EO. The EOs and E-caryophyllene should be further studied for the development of new antileishmanial drugs.

Acidic and hepatic derivatives of bioactive clerodane diterpenes casearins J and O.

Clerodane diterpenes from Casearia sylvestris are antiulcerogenic and anti-inflammatory. The finding that they may undergo acid degradation or hepatic metabolization led to an investigation of their degradation products. Purified clerodane diterpenes (casearins J and O) were subjected to in vitro assays to simulate their oral administration. Resulting derivatives were identified using chromatographic and spectrometric techniques. Nitric oxide synthesis by LPS-stimulated macrophages was assayed to verify whether structural modifications alter the anti-inflammatory activity of diterpenes. Nine compounds (1-9) were identified after acid degradation remaining 5.05% of casearin J. Besides the remaining casearin O (13.1%), eight compounds (10-17) were identified. The dialdehydes from each casearin were the major constituents. S9 rat liver treatment of casearins J and O generated two compounds identical to some of those produced by acid degradation, which remained 36.8% and 36.5% intact, respectively. Both casearins and its derivatives were not cytotoxicity at concentrations lower than 0.312 µg/mL (0.555 µM for casearin J and 0.516 µM for casearin O) and did not inhibit the nitric oxide production in this concentration. Thus, the structural modifications conducted did not alter the activity of casearins and the anti-inflammatory pathway of diterpenes probably is not involved on nitric oxide modulation.

In vitro and in vivo anti-Helicobacter pylori activity of Casearia sylvestris leaf derivatives.

ETHNOPHARMACOLOGICAL RELEVANCE: The number of bacterial strains that are resistant to multiple conventional antimicrobial agents is increasing. In this context, natural products have been widely used as a strategy to treat diseases caused by bacteria. Infections by Helicobacter pylori have attracted attention because they are directly related to severe gastric medical conditions. Casearia sylvestris Swartz, popularly known as guaçatonga, is largely employed to treat gastric disorders in Brazilian folk medicine. This plant species has aroused much interest mainly because it displays anti-inflammatory activity and can act as an antiulcer agent. AIM OF THE STUDY: To evaluate the in vitro and in vivo anti-H. pylori action of C. sylvestris leaf derivatives incorporated or not in a nanostructured drug delivery system. MATERIALS AND METHODS: The essential oil (obtained by hydrodistillation) and ethanolic extract (obtained by maceration) were obtained from C. sylvestris leaves. The ethanolic extract was submitted to fractionation through solid phase extraction and column chromatography, to yield the ethanolic fractions. Hydrolyzed casearin J was achieved by submitting isolated casearin J to acid hydrolysis. The derivatives were chemically characterized by nuclear magnetic resonance (NMR), gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS) analyses. A nanostructured lipid system was used as drug delivery system. To assess the in vitro antibacterial activity of C. sylvestris leaf essential oil, ethanolic extract, and derivatives, microdilution, biofilm, and time-kill assays were performed against H. pylori ATCC 43504. Finally, the in vivo action was investigated by employing male Wistar rats experimentally infected with H. pylori. RESULTS: Many C. sylvestris leaf derivatives presented significant in vitro activity against H. pylori. Among the derivatives, fraction 2 (F2) was the most effective. In vivo tests showed that both the ethanolic extract and F2 decreased the ulcerative lesion size, but only the ethanolic extract eradicated H. pylori from the gastric lesions. Incorporation of plant derivatives in nanostructured lipid system blunted the in vitro action, as demonstrated by the microdilution assay. However, this incorporation improved the ethanolic extract activity against biofilms. CONCLUSION: C. sylvestris leaf derivatives are effective against H. pylori both in vitro and in vivo. According to phytochemical analyses, these derivatives are rich in terpenoids, which could be related to the anti-H. pylori action. Synergism could also underlie C. sylvestris efficacy judging from the fact that the sub-fractions and isolated compounds had lower activity than the extract. Incorporation in a nanostructured lipid system did not improve the activity of the compounds in our in vivo protocol.

Chemical variability between different organs of the medicinal plant Casearia sylvestris

The phytochemical profile of essential oils and extracts from Casearia sylvestris leaves, flowers and fruits have been investigated here. Leaf and flower extracts were prepared by sonication and analyzed by thin-layer chromatography and high-performance liquid chromatography. The phenolic content was determined by ultraviolet spectrophotometry. Leaves, flowers, and fruits essential oils were extracted by hydrodistillation. The highest extracts yields were 20.3 % (leaves) and 23.4 % (flowers) with ethanol 70 %. Essential oil extraction yields were 0.3 % (leaves) and 0.1 % (flowers and fruits). Bicyclogermacrene was the major component in all essential oil. Thin-layer chromatography suggests a chemical profile similar for leaves and flowers. The leaves and flowers phenolic content were similar (14.0 and 15.0 %, respectively). Chromatography analyses indicated the predominance of casearin clerodane diterpenes in leaves (λmax 232-235), whereas in flowers, diterpenes with a different standard diene in side-chain C13(16) and C14 (λmax 223-229). The different phytochemical profile of C. sylvestris flowers as compared to the leaves could be explored by the search for new bioactive components. This is the first report on the fruit and flower C. sylvestris essential oil composition. These data could be used as quality control of herbal medicine derived from C. sylvestris leaves.(AU)

Differentiation between 3,4- and 4,15-Epoxyeudesmanolides by Electrospray Ionization Tandem Mass Spectrometry.

We investigated the fragmentation of the eudesmanolide-type sesquiterpene lactones 1α-(4-hydroxymethacryloyloxy)-3α,4α-epoxy-8α-hydroxyeudesm-11(13)-6α,12-olide (1) and 1α-(2,3-epoxyangeloyloxy)-4α,15-epoxy-8α-hydroxyeudesm-11(13)-6α,12-olide (2) by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The elimination of the different ester substituent at C(1) directly from protonated 1 and 2 (A) led to the formation of two regioisomer product ions B (A - RCO2H). Further fragmentation of B resulted from consecutive eliminations of H2O and CO molecules. However, we identified four product ions that allowed for the differentiation between 3,4- and 4,15-epoxyeudesmanolides. The formation of these diagnostic ions was associated with the C(3)-O bond of compound 1, which propitiates the participation of the lone pair of the oxygen epoxide in the formation of B through a Grob-Wharton-type fragmentation, then resulting in an alternative fragmentation pathway. These data can be useful for the fast differentiation between epoxyeudesmanolide regioisomers directly from Dimerostemma extracts by liquid chromatography-tandem mass spectrometry (LC-MS/MS), as an alternative to NMR, or even for quantitation studies of these compounds using multiple reaction monitoring (MRM) scan.

In Vitro Metabolism of Artepillin C by Rat and Human Liver Microsomes.

Artepillin C, a natural product present in the Brazilian green propolis, has several biological properties. Among these properties, the antitumor action of this product is noteworthy and makes it a promising drug candidate for the treatment of several types of cancer. This paper describes the in vitro metabolism of Artepillin C in rat and human liver microsomes. The rat model suggested a sigmoidal profile for the metabolism, adapted to the Hill's kinetic model. The enzymatic kinetic parameters were as follows: maximal velocity = 0.757 ± 0.021 µmol/mg protein/min, Hill coefficient = 10.90 ± 2.80, and substrate concentration at which half-maximal velocity of a Hill enzyme is achieved = 33.35 ± 0.55 µM. Based on these results, the calculated in vitro intrinsic clearance for Artepillin C was 16.63 ± 1.52 µL/min/mg protein. The in vitro metabolism assay conducted on the human model did not fit any enzymatic kinetic model. Two novel metabolites were formed in both mammal microsomal models and their chemical structures were elucidated for the first time. The main human cytochrome P450 isoforms involved in Artepillin C metabolism had been identified, and the results suggest a majority contribution of CYP2E1 and CYP2C9 in the formation of the two metabolites.

Antifungal activity of plant-derived essential oils on Candida tropicalis planktonic and biofilms cells.

Dental prosthesis supports Candida species growth and may predispose the oral cavity to lesions. C. tropicalis has emerged as a colonizer of prosthesis and has shown resistance to clinically used antifungal agents, which has increased the search for new antifungals. This work describes the effectiveness of fifteen essential oils (EOs) against C. tropicalis The EOs were obtained by hydrodistillation and were chemically characterized by gas chromatography-mass spectrometry. The antifungal activities of the EOs were evaluated by the microdilution method and showed that Pelargonium graveolens (Geraniaceae) (PG-EO) was the most effective oil. Geraniol and linalool were the major constituents of PG-EO. The 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay showed that all the clinical C. tropicalis strains formed viable biofilms. Scanning electron microscopy examination of the biofilms revealed a complex architecture with basal layer of yeast cells and an upper layer of filamentous cells. Treatments with PG-EO, linalool, and geraniol significantly reduced the number of viable biofilm cells and inhibited biofilm formation after exposure for 48 h. PG-EO, geraniol, and linalool were not toxic to normal human lung fibroblasts (GM07492A) at the concentrations they were active against C. tropicalis Together, our results indicated that C. tropicalis is susceptible to treatment with PG-EO, geraniol, and linalool, which could become options to prevent or treat this infection.

Antimicrobial activity of the essential oil of Tetradenia riparia (Hochst.) Codd. (Lamiaceae) against cariogenic bacteria.

In Brazilian folk medicine, Tetradenia riparia (Hochst.) Codd. (Lamiaceae) is used to treat toothaches and dental abscesses and diseases induced by worms, bacteria, or fungi. This paper aims to investigate the chemical composition and the antibacterial effects of the essential oil obtained from Tetradenia riparia leaves (TR-EO) grown in Southeastern Brazil against a representative panel of oral pathogens. We evaluated the antibacterial activity of TR-EO in terms of the minimal inhibitory concentration (MIC). We identified aromadendrene oxide (14.0%), (E,E)-farnesol (13.6%), dronabinol (12.5%), and fenchone (6.2%) as the major constituents of TR-EO. TR-EO displayed MIC values between 31.2 and 500 µg/mL, with the lowest MIC value being obtained against Streptococcus mitis (31.2 µg/mL), S. mutans (62.5 µg/mL), S. sobrinus (31.2 µg/mL), and Lactobacillus casei (62.5 µg/mL). In time-kill experiments, TR-EO demonstrated bactericidal activity against S. mutans within the first 12 h, resulting in a curve profile similar to that of chlorhexidine. These results revealed that the essential oil of Tetradenia riparia displays promising activity against most of the selected cariogenic bacteria, including Streptococcus mutans.

Antimicrobial Activity of the Essential Oil of Plectranthus neochilus against Cariogenic Bacteria.

This work used the broth microdilution method to investigate the antimicrobial activity of the essential oil obtained from the leaves of Plectranthus neochilus (PN-EO) against a representative panel of oral pathogens. We assessed the antimicrobial activity of this oil in terms of the minimum inhibitory concentration (MIC). PN-EO displayed moderate activity against Enterococcus faecalis (MIC = 250 µg/mL) and Streptococcus salivarus (MIC = 250 µg/mL), significant activity against Streptococcus sobrinus (MIC = 62.5 µg/mL), Streptococcus sanguinis (MIC = 62.5 µg/mL), Streptococcus mitis (MIC = 31.25 µg/mL), and Lactobacillus casei (MIC = 31.25 µg/mL), and interesting activity against Streptococcus mutans (MIC = 3.9 µg/mL). GC-FID and GC-MS helped to identify thirty-one compounds in PN-EO; α-pinene (1, 14.1%), ß-pinene (2, 7.1%), trans-caryophyllene (3, 29.8%), and caryophyllene oxide (4, 12.8%) were the major chemical constituents of this essential oil. When tested alone, compounds 1, 2, 3, and 4 were inactive (MIC > 4000 µg/mL) against all the microorganisms. These results suggested that the essential oil extracted from the leaves of Plectranthus neochilus displays promising activity against most of the evaluated cariogenic bacteria, especially S. mutans.

Antimicrobial activity of the essential oil of Tetradenia riparia (Hochst.) Codd. (Lamiaceae) against cariogenic bacteria

In Brazilian folk medicine, Tetradenia riparia (Hochst.) Codd. (Lamiaceae) is used to treat toothaches and dental abscesses and diseases induced by worms, bacteria, or fungi. This paper aims to investigate the chemical composition and the antibacterial effects of the essential oil obtained from Tetradenia riparia leaves (TR-EO) grown in Southeastern Brazil against a representative panel of oral pathogens. We evaluated the antibacterial activity of TR-EO in terms of the minimal inhibitory concentration (MIC). We identified aromadendrene oxide (14.0%), (E,E)-farnesol (13.6%), dronabinol (12.5%), and fenchone (6.2%) as the major constituents of TR-EO. TR-EO displayed MIC values between 31.2 and 500 μg/mL, with the lowest MIC value being obtained against Streptococcus mitis (31.2 μg/mL), S. mutans (62.5 μg/mL), S. sobrinus (31.2 μg/mL), and Lactobacillus casei (62.5 μg/mL). In time-kill experiments, TR-EO demonstrated bactericidal activity against S. mutans within the first 12 h, resulting in a curve profile similar to that of chlorhexidine. These results revealed that the essential oil of Tetradenia riparia displays promising activity against most of the selected cariogenic bacteria, including Streptococcus mutans.

Anthelmintic activity of crude extract and essential oil of Tanacetum vulgare (Asteraceae) against adult worms of Schistosoma mansoni.

Schistosomiasis, a parasitic disease caused by trematode flatworms of the genus Schistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel. Tanacetum vulgare (Asteraceae) is used in folk medicine as a vermifuge. This study aimed to investigate the in vitro schistosomicidal activity of the crude extract (TV) and the essential oil (TV-EO) from the aerial parts of T. vulgare. TV-EO was obtained by hydrodistillation and analyzed by GC/MS, which allowed the identification of ß-thujone (84.13%) as the major constituent. TV and TV-EO, at 200 µg/mL, decreased motor activity and caused 100% mortality of all adult worms. At 100 and 50 µg/mL, only TV caused death of all adult worms, while TV-EO was inactive. TV (200 µg/mL) was also able to reduce viability and decrease production of developed eggs. Confocal laser scanning microscopy showed morphological alterations in the tegument of the S. mansoni surface after incubation with TV (50 and 100 µg/mL). Quantitative analysis on the schistosomes tegument showed that TV caused changes in the numbers of tubercles of S. mansoni male worms in a dose-dependent manner. The findings suggest that T. vulgare is a potential source of schistosomicidal compounds.