Metabolomic profiling and micropropagation of Salvia africanalutea L. potent against Fusarium verticillioides

Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Salvia africana lutea is one of 26 Sage species indigenous to Southern Africa from a total of 900 worldwide. The genus Salvia belongs to the Lamiaceae family. Labeled a ‘broad spectrum remedy’ S. africana lutea amongst other sage species is medicinally important. Reports are many highlighting its benefits, which include from alleviating coughs and colds to gynaecological complaints. Studies have revealed in vitro antimicrobial, anti-cancer and antioxidant activity. Plant secondary metabolites fundamentally have a strong bearing on the phytochemical activities a plant may possess. Consequently the environment indirectly affects the phytochemical properties as it influences the variation in the plant metabolome via plant-environment interactions. Five S. africana lutea plant populations, within the Western Cape province of South Africa were sampled and chemotypes and bioactivity tested. Four populations were wild growing in protected areas namely; Brackenfell, Koeberg, Silwerstroomstrand and Yzerfontein, while the fifth was a garden growing population from Stellenbosch. Using gas chromatography hyphenated with mass spectrometry (GC-MS), compounds such as monosaccharides, carboxylic acids and fatty acids were detected. Variation of compounds identified with 80% certainty was compared across all populations. Stellenbosch population showed some compounds that were not present in the other four sites. These compounds were namely; propanoic acid, rythronic acid, 2-keto-1-gluconic acid and 1,3-dibromobicyclon, while this population also did not have xylitol that was detected in all the other four populations. To consolidate the GC-MS findings, analysis on the metabolite profiles (utilizing liquid chromatography linked with mass spectrometry (LC-MS) and nuclear magnetic resonance (1H NMR)) was done. Principal component analysis (PCA) was applied to the NMR data. The partial least squaresdiscriminant analysis (PLS-DA) was used to integrate LC-MS and NMR data sets. All statistics were performed with the SIMCA-P+ 12.0 software. By integrating LC-MS and 1H NMR analyses, large chemotype differences leading to samples grouping by site, suggested strong plant-environment interactions as factors influencing metabolite composition. Signals distinguishing the Stellenbosch profile were in the aromatic part of the 1H NMR spectra. Antimicrobial activity was tested against two Fusarium species. Fusarium is a plant pathogenic species that causes large agricultural losses particularly in the maize crop, one of the staple foods in the African continent. Some species also produce mycotoxins in infected crop and lead to a significant increase in the risk factor of cancers when contaminated foods are consumed. Four high-mycotoxin producing strains from two species F. verticillioides (MRC 826 and MRC 8267); F. proliferatum (MRC 7140 and MRC 6809) were utilized in all in vitro antifungal assays in this study. A preliminary assay using dichloromethane: methanol (1:1 v/v) crude plant extracts of the five populations; Stellenbosch, Brackenfell, Koeberg, Silwerstoomstrand and Yzerfontein, from 2009 and 2011. All test samples exhibited good activity as the minimum inhibitory concentrations (MIC) values ranged from 0.031 mg ml-1 to 0.5 mg ml-1, values below the latter are regarded as strong inhibitors. The Stellenbosch extracts were the most active for both 2009 and 2011 collections, with the best activity against F. verticillioides MRC 8267 and MRC 826 at 0.031 mg ml-1. While the least activity, albeit still a strong inhibitor, was observed from the Yzerfontein extracts with an MIC value of 0.5 mg ml-1. Generally comparison between the two years revealed that samples collected in 2011 were more potent than those in 2009, possibly due to prolonged storage that may have resulted in chemical decomposition. As the Stellenbosch population had shown the best activity as well as a relatively different chemical profile, leaves from these plants were then introduced into tissue culture conditions. Leaf explants were placed on solid plant growth regulator (PGR)-free Murashige and Skoog media and that supplemented with hormones in various combinations. (two concentrations of benzyl adenine (BA) utilized individually and in combination with naphthalene acetic acid (NAA) 4.4 and 8.8, while for NAA 0.27, 2.7 and 5.4.) Namely: 4.4 BA, 8.8 BA, 0.27 NAA: 4.4 BA, 2.7 NAA: 4.4 BA, 5.4 NAA: 4.4 BA, 2.7 NAA: 8.8 BA and 5.4 NAA: 8.8 BA. The PGR combinations did not induce shooting nor rooting, only callus on PGR-free MS media. Antifungal activity of the callus extract was in the same range as the whole plant extracts from which the leaf explants were harvested from, showing no ‘loss’ of activity after introduction to tissue culture conditions. Metabolite profiles using LC-MS, however, did reveal qualitative and quantitative differences, though they appear to not have any bearing on the activity. A bioassay-guided fractionation was then conducted on samples collected from Stellenbosch. This led to the identification of carnosol and carnosic acid being involved in the anti-Fusarium activity of S africana-lutea. A combinational study revealed no synergistic activity of the two compounds against four Fusarium test strains, with fractional inhibitory concentration (FIC) values of 1.5 and 3.0. Antifungal activity of carnosol and carnosic acid was observed to be in the same range (strong inhibitor) as was the callus and whole plant extracts. The study showed variation in population chemotypes and identified two compounds that are involved in S. africana-lutea activity against Fusarium species. It also provided a tissue culture system onto which mass production of the two bioactives may be achieved from, in the development of new fungicides.AFRIKAANSE OPSOMMING: Salvia Africana lutea is een van die 26 Salie spesies wat inheems aan Suid-Afrika is uit ‘n totaal van 900 spesies wêreldwyd. Die genus Salvia hoort tot die Lamiaceae familie. S. africana lutea word geklassifiseer as ‘n “breë spektrum geneesmiddel”, en medisinaal as belangrik geag tussen die ander salie spesies, want volgens verslag word dit gebruik vir die verligting van hoes en verkoues tot selfs ginekologiese ongesteldhede. Definitiewe biologiese aktiwiteit eksperimente het anti-mikrobiese, antikanker en anti-oksidant aktiwiteite aan die lig gebring. Plant sekondêre metaboliete het fundamenteel ‘n baie sterk verband met die fitochemiese aktiwiteite van ‘n plant. Gevolglik affekteer die omgewing indirek die fitochemiese eienskappe, want dit beïnvloed die variasie in die plant metaboloom deur die interaksies van die plant met die omgewing. In vyf streke binne die Wes-Kaap van Suid-Afrika waar S. africana lutea bevolkings voorkom, is steekproewe gedoen en chemotipes en bioaktiwiteit getoets. Vier bevolkings was wild-groeiende bevolkings in beskermde areas, naamlik; Brackenfell, Koeberg, Silwerstroomstrand en Yzerfontein, terwyl die vyfde uit ‘n tuingroeiende bevolking in Stellenbosch geneem is. Deur gas chromatografie gekoppel met massa spektrometrie te gebruik, is primêre samestellings soos monosakkariede, karboksielsure en vetsure gevind. Variasies van samestellings wat met 80% sekerheid geïdentifiseer is, is oorkruis met al die bevolkings vergelyk. Die Stellenbosch bevolking het ‘n paar samestellings geopenbaar wat nie aanwesig was in die ander vier terreine nie. Hierdie samestellings was: propanoësuur, erythroniese suur, 2-keto-1-glukoniese suur en 1,3-dibromobicyclon. Verder het hierdie bevolking geen xylitol gehad nie en dit is in al vier die ander bevolkings gevind. Verdere studies was gedoen met die gebruik van vloeibare chromatografie gekoppel met massa spektrometrie (LC-MS) sowel as kern magnetiese resonansie (1H NMR). Chemiese profiele het hoë variasies getoon, en dus deur te fokus op die aromatiese samestelling streke, het die Stellenbosch terrein duidelik merkbare verskille en punte op die PLS-DA aangetoon. Met die koppeling van NMR data met LC-MS data, is daar gevind dat onderskeidende punte van die NMR PLS-DA wat gegroepeer is met retensie tye die skeiding van die Stellenbosch terrein van ander terreine gedryf het. Dit het onweerlegbaar bewys dat daar variasie binne die vyf bevolkings voorkom en dat Stellenbosch die mees noemenswaardige chemotipe variasie het. Dit blyk uit die anti-mikrobiese eksperimente dat aktiwiteit teen Fusarium heel nuwe belangstelling wek. Fusarium is ‘n plant-patogeniese spesie wat groot landbou verliese veroorsaak veral in die mielie gewasse, een van die stapelvoedsels van die Afrika kontinent. Dit produseer ook mikotoksiene in aangetaste gewasse en hierdie kan lei tot die ontstaan van kankers wanneer besmette voedsel op groot skaal verbruik word. Vier hoë-mikotoksien produserende swamlyne van twee spesies, naamlik F. verticillioides (MRC 826 en MRC 8267) en F. proliferatum (MRC 7140 en MRC 6809) is gebruik in alle in vitro anti-swam ondersoeke in hierdie studie. Die eerste analise het dichloromethan: methanol (1:1 v/v) ongesuiwerde plant ekstrakte bevat van die vyf bevolkings: Stellenbosch, Brackenfell, Koeberg, Silwerstroomstrand en Yzerfontein, geneem gedurende 2009 en 2011. Al hierdie toets monsters het goeie aktiwiteit getoon waar die minimum beperkende konsentrasie (MIC) waardes van 0.031 mg ml-1 tot 0.5 mg ml-1 gevarieer het. Waardes laer as laasgenoemde word beskou as sterk inhibeerders. Die Stellenbosch ekstrakte was die mees aktief vir albei jare hierbo genoem, met die beste aktiwiteit teen F. verticillioides MRC 8267 en MCR 826 by 0.031 mg ml-1. Die minste aktiwiteit (hoewel nog ‘n sterk inhibeerder) waargeneem was van die Yzerfontein ekstrakte, met ‘n MIC waarde van 0.5 mg ml-1. Oor die algemeen het ‘n vergelyking tussen die twee jare aangetoon dat die monsters wat in 2011 versamel is veel sterker was dan dié van 2009, moontlik te wyte aan ‘n verlengde bewaringstyd wat moontlik ‘n chemiese dekomposisie ten gevolge gehad het. Omdat die Stellenbosch bevolking die beste aktiwiteit getoon het sowel as ‘n relatief afwykende chemiese profiel, is blare van hierdie plante toe bekendgestel aan weefselkultuur kondisies. Blaar eksplante is op soliede hormoonvrye Murashige en Skoog media geplaas en dit is aangevul met sintetiese auksien Naftaleen asynsuur (NAA) en sitokien Bensiel adenien (BA) individueel en in verskillende kombinasies. Geen wortels of uitloopsels is waargeneem in al die hormoon kombinasies nie maar in die hormoonvrye media het daar egter Kallus in twintig persent van die eksplante voorgekom. Kallus is toe as subkultuur van hormoonvrye MS media gekweek en saamgevoeg en dichloromethan: methanol (1:1v/v) ekstrakte is getoets teen die volgende Fusarium swamlyne MRC 826; MRC 8267; MRC 7140 en MRC 6809. MIC waardes het sterk inhiberende eienskappe getoon met die laagste waarde as 0.025 mg ml-1 teen drie swamlyne: MRC 1740, MRC 8267 en MRC 826, en die hoogste was 0.25 mg ml-1 na 48 uur. Die minimum inhiberende konsentrasie waardes het gestyg na 0.5mg ml-1 na 60 uur, wat ‘n fungistatiese aksie getoon het. Maar van 60 tot 92 uu het waardes egter ‘n swamdodende aksie aangetoon met geen verandering van 0.5mg ml-1 nie. In die identifisering van die bioaktiewe komponente, is die ekstraksie van Stellenbosch se bevolking in dichloromethan: methanol (1:1 v/v) uitgevoer, en met gebruik van vyftig gram van die ekstrak is bioanalise-geleide fraksionering gedoen deur gebruik van ‘n VersaFlash®. Die mees aktiewe fraksie is verder gefraksioneer deur die gebruik van ‘n konvensionele silikajel kolom. Aktiewe fraksies is getoets deur LC-MS te gebruik, en twee verbindings, carnosol en carnosic suur, is geïdentifiseer. Voorbereidende TLC is gebruik om identiteit te bevestig, want fraksies was naas die kommersiele standaarde van die twee verbindings getoets. Sinergistiese aktiwiteit van die twee samestellings is ondersoek deur ‘n antiswam ontleding teen die vier swamlyne uit te voer. Hierdie studie het dus die veronderstelde bestaan van verskillende chemotipes tussen die bevolkings waarvan voorbeelde geneem is, bekend gestel. Veral die Stellenbosch se bevolking het die meeste verskil, heel moontlik omrede die verlengde en hoër versteurings deur die nabyheid van mense. Plant– omgewing interaksies speel ‘n belangrike rol in die metaboloom van plante, wat dan indirek hul eienskappe verander, en in hierdie geval die antiswam aktiwiteit. Die tuingroeiende bevolking was die mees aktief, heel moontlik omrede hierdie aspek. Nietemin was geen bioaktiwiteit verloor waar die mees kragtige bevolking met weefsel kultuur kondisies in aanraking gebring is nie. Dus is dit ideaal vir kommersialisering. Een nuwe belangrike bevinding was die carnosol en carnosic suur wat twee welbekende samestellings is wat meesal geassosieer is met Rosmarinus officinalis en gedokumenteer is vir antioksidant aktiwiteit. Hier dui laasgenoemde samestellings ‘n antiswam aktiwiteit aan teen die getoetste Fusarium swamlyne. Met ‘n gevestigde weefsel kultuur sisteem alreeds in plek, voorsien dit ‘n beginpunt vir die bestudering van hoe hierdie bioaktiewe komponente in massa geproduseer kan word in die ontwikkeling van nuwe swamdodende produkte

ESSENTIAL OIL COMPOSITION OF ARTEMISIA VULGARIS GROWN IN EGYPT

Objective: The objective of this research was to evaluate the significance of the plant's origin and to assess the essential oil composition of Artemisia vulgaris grown in Egypt simultaneously evaluating the effect of environmental conditions on essential oil composition.Methods: Seeds were planted and the essential oils extracted, using hydrodistillation, from the plants that grew. The resulting essential oils were examined, using gas chromatography linked to mass spectrometry (GC-MS). Thus also evaluating the essential oil chemotype fingerprint†in A. vulgarisResults:  The study identified: the most abundant compounds being camphor, 3, 5-dimethylcyclohexane, germacrene D, cubebene, yomogi alcohol, artemisia alcohol, caryophyllene, while is lower concentrations thujopsene, muurolene, borneol, terpinen-4-ol, valencene, elemene and humulene. Despite the origins of the seeds, the chemical profile was very similar to those of plants grown in Egypt, thus suggesting essential oil composition was significantly influenced by the environmental conditions.Conclusion: Based on the present study, It is suggested that seed origin may play a less significant part if the seed is planted in an environment different to that of its origin, this study proved that and favors the plant-environment interaction to influence the secondary metabolite composition. This supports that plant metabolite profiles are greatly affected by the environment they are grown in.Â

Biological activities of Heteropyxis natalensis against micro-organisms involved in oral infections

The use of complementary and alternative medicine from plants in South Africa, as in the rest of the world, continues to increase. Heteropyxis natalensis, known as the Lavender tree, is indigenous to South Africa and is traditionally used for oral care. The ethanolic extract, of the leaves and twigs, of H. natalensis was investigated for antimicrobial activity against selected oral microorganisms. Actinomyces israelii was found to be the most sensitive oral microorganism to the extract, with a minimum inhibitory concentration (MIC) of 0.88 mg/ml and an MIC of 2.6 mg/ml against Streptococcus mutans. Five known compounds were identified from the ethanolic extract of H. natalensis. The compounds were identified as aurentiacin A (1), cardamomin (2), 5-hydroxy-7-methoxy-6-methylflavanone (3), quercetin (4) and 3,5,7-trihydroxyflavan (5). The MICs of the compounds 1 and 4 were found to be 0.06 mg/ml and 1 mg/ml, respectively, against A. israelii. The cytotoxicity, acute and sub-acute toxicity in pre-clinical studies were also determined for H. natalensis. The extract showed moderate cytotoxicity (35.56 0.16 mg/ml) on human monocyte cells. The acute and sub-acute toxicity analysis of H. natalensis indicated the NOEL (noobserved- effect level) at 200 mg/kg. Interleukin-8 (IL-8) is a chemokine that stimulates the recruitment of leukocytes. A significant reduction of IL-8 production by macrophage cells was observed when exposed to the extract of H. natalensis. It is possible that H. natalensis can prevent excessive tissue damage in periodontal diseases through its reduction of inflammation. Enzymatic bioanalysis of lactic and acetic acid production from Streptococcus mutans and Lactobacillus paracasei was done. A reduction in the acid production from each bacterium was observed on exposure to the extract of H. natalensis. Consequently, this increased the pH, which could possibly reduce the demineralization of enamel which may help prevent the formation of dental caries. In addition the extract may be considered for preventing periodontal diseases.The National Research Foundation (Grant 90355), NRF innovation doctoral scholarship as well as the Gen Foundation Grant (from National Trust, United Kingdom).http://www.frontiersin.org/Pharmacologyam2018Paraclinical SciencesPlant Production and Soil Scienc

Investigation Of The Antinociceptive And Anti-Inflammatory Properties Of Heteromorpha Arborescens (Apiaceae)

Heteromorpha arborescens belongs to the family Apiaceae. It is commonly known as the parsley tree. One of its uses in the Eastern Cape Province of South Africa is for the treatment of abdominal pains. The therapeutic effects of the methanolic and aqueous root extracts of H. arborescens were investigated at two dose levels respectively on experimental models of pain and inflammation in rodents. The antinociceptive activity was evaluated using the hot-plate, abdominal constriction and formalin tests. The anti-inflammatory properties of these extracts were assessed using albumin and carrageenan as phlogistic agents. Both extracts produced significant (P<0.05, P<0.01) inhibition of thermal nociception induced by a hot plate. On chemical nociception induced by intraperitoneal acetic acid and subplantar formalin injection, both extracts significantly (P<0.05, P<0.01) decreased the number of writhing episodes and the licking time in a dose dependent manner. Treatment with the extracts at the same doses produced a significant (P<0.05, P<0.01) pain inhibition of the carrageenan induced inflammatory pain. Similarly, both extracts produced a significant (P<0.05, P<0.01) reduction of edema induced by albumin and carrageenan. These results suggest that both extracts of H. arborescens may act by inhibition of the mediators of inflammation. These findings seem to justify the use of the plant in traditional medicine in the management of pain and inflammation related diseases

Biological Activities of Heteropyxis natalensis Against Micro-Organisms Involved in Oral Infections

The use of complementary and alternative medicine from plants in South Africa, as in the rest of the world, continues to increase. Heteropyxis natalensis, known as the Lavender tree, is indigenous to South Africa and is traditionally used for oral care. The ethanolic extract, of the leaves and twigs, of H. natalensis was investigated for antimicrobial activity against selected oral microorganisms. Actinomyces israelii was found to be the most sensitive oral microorganism to the extract, with a minimum inhibitory concentration (MIC) of 0.88 mg/ml and an MIC of 2.6 mg/ml against Streptococcus mutans. Five known compounds were identified from the ethanolic extract of H. natalensis. The compounds were identified as aurentiacin A (1), cardamomin (2), 5-hydroxy-7-methoxy-6-methylflavanone (3), quercetin (4) and 3,5,7-trihydroxyflavan (5). The MICs of the compounds 1 and 4 were found to be 0.06 mg/ml and 1 mg/ml, respectively, against A. israelii. The cytotoxicity, acute and sub-acute toxicity in pre-clinical studies were also determined for H. natalensis. The extract showed moderate cytotoxicity (35.56 ± 0.16 μg/ml) on human monocyte cells. The acute and sub-acute toxicity analysis of H. natalensis indicated the NOEL (no-observed-effect level) at 200 mg/kg. Interleukin-8 (IL-8) is a chemokine that stimulates the recruitment of leukocytes. A significant reduction of IL-8 production by macrophage cells was observed when exposed to the extract of H. natalensis. It is possible that H. natalensis can prevent excessive tissue damage in periodontal diseases through its reduction of inflammation. Enzymatic bioanalysis of lactic and acetic acid production from Streptococcus mutans and Lactobacillus paracasei was done. A reduction in the acid production from each bacterium was observed on exposure to the extract of H. natalensis. Consequently, this increased the pH, which could possibly reduce the demineralization of enamel which may help prevent the formation of dental caries. In addition the extract may be considered for preventing periodontal diseases

Fusarium inhibition by wild populations of the medicinal plant Salvia africana-lutea L. linked to metabolomic profiling

Background: Salvia africana-lutea L., an important medicinal sage used in the Western Cape (South Africa), can be termed a ‘broad-spectrum remedy’ suggesting the presence of a multiplicity of bioactive metabolites. This study aimed at assessing wild S. africana-lutea populations for chemotypic variation and anti-Fusarium properties. Methods: Samples were collected from four wild growing population sites (Yzerfontein, Silwerstroomstrand, Koeberg and Brackenfell) and one garden growing location in Stellenbosch. Their antifungal activities against Fusarium verticillioides (strains: MRC 826 and MRC 8267) and F. proliferatum (strains: MRC 6908 and MRC 7140) that are aggressive mycotoxigenic phytopathogens were compared using an in vitro microdilution assay. To correlate antifungal activity to chemical profiles, three techniques viz. Gas chromatography-mass spectrometry (GC-MS); Liquid chromatography-mass spectrometry (LC-MS) and 1 H Nuclear Magnetic Resonance (NMR) were employed. Principal Component Analysis (PCA) was applied to the NMR data. The partial least squares-discriminant analysis (PLS-DA) was used to integrate LC-MS and NMR data sets. All statistics were performed with the SIMCA-P + 12.0 software. Results: The dichloromethane:methanol (1:1; v/v) extracts of the plant species collected from Stellenbosch demonstrated the strongest inhibition of F. verticillioides and F. proliferatum with minimum inhibitory concentration (MIC) values of 0.031 mg ml-1 and 0.063 mg ml-1 respectively. GC-MS showed four compounds which were unique to the Stellenbosch extracts. By integrating LC-MS and 1 H NMR analyses, large chemotype differences leading to samples grouping by site when a multivariate analysis was performed, suggested strong plant-environment interactions as factors influencing metabolite composition. Signals distinguishing the Stellenbosch profile were in the aromatic part of the 1 H NMR spectra. Conclusions: This study shows the potential of chemotypes of Salvia africana-lutea in controlling fungal growth and consequently mycotoxin production. Products for use in the agricultural sector may be developed from such chemotypes

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<p>The use of complementary and alternative medicine from plants in South Africa, as in the rest of the world, continues to increase. Heteropyxis natalensis, known as the Lavender tree, is indigenous to South Africa and is traditionally used for oral care. The ethanolic extract, of the leaves and twigs, of H. natalensis was investigated for antimicrobial activity against selected oral microorganisms. Actinomyces israelii was found to be the most sensitive oral microorganism to the extract, with a minimum inhibitory concentration (MIC) of 0.88 mg/ml and an MIC of 2.6 mg/ml against Streptococcus mutans. Five known compounds were identified from the ethanolic extract of H. natalensis. The compounds were identified as aurentiacin A (1), cardamomin (2), 5-hydroxy-7-methoxy-6-methylflavanone (3), quercetin (4) and 3,5,7-trihydroxyflavan (5). The MICs of the compounds 1 and 4 were found to be 0.06 mg/ml and 1 mg/ml, respectively, against A. israelii. The cytotoxicity, acute and sub-acute toxicity in pre-clinical studies were also determined for H. natalensis. The extract showed moderate cytotoxicity (35.56 ± 0.16 μg/ml) on human monocyte cells. The acute and sub-acute toxicity analysis of H. natalensis indicated the NOEL (no-observed-effect level) at 200 mg/kg. Interleukin-8 (IL-8) is a chemokine that stimulates the recruitment of leukocytes. A significant reduction of IL-8 production by macrophage cells was observed when exposed to the extract of H. natalensis. It is possible that H. natalensis can prevent excessive tissue damage in periodontal diseases through its reduction of inflammation. Enzymatic bioanalysis of lactic and acetic acid production from Streptococcus mutans and Lactobacillus paracasei was done. A reduction in the acid production from each bacterium was observed on exposure to the extract of H. natalensis. Consequently, this increased the pH, which could possibly reduce the demineralization of enamel which may help prevent the formation of dental caries. In addition the extract may be considered for preventing periodontal diseases.</p

Image_2.tif

<p>The use of complementary and alternative medicine from plants in South Africa, as in the rest of the world, continues to increase. Heteropyxis natalensis, known as the Lavender tree, is indigenous to South Africa and is traditionally used for oral care. The ethanolic extract, of the leaves and twigs, of H. natalensis was investigated for antimicrobial activity against selected oral microorganisms. Actinomyces israelii was found to be the most sensitive oral microorganism to the extract, with a minimum inhibitory concentration (MIC) of 0.88 mg/ml and an MIC of 2.6 mg/ml against Streptococcus mutans. Five known compounds were identified from the ethanolic extract of H. natalensis. The compounds were identified as aurentiacin A (1), cardamomin (2), 5-hydroxy-7-methoxy-6-methylflavanone (3), quercetin (4) and 3,5,7-trihydroxyflavan (5). The MICs of the compounds 1 and 4 were found to be 0.06 mg/ml and 1 mg/ml, respectively, against A. israelii. The cytotoxicity, acute and sub-acute toxicity in pre-clinical studies were also determined for H. natalensis. The extract showed moderate cytotoxicity (35.56 ± 0.16 μg/ml) on human monocyte cells. The acute and sub-acute toxicity analysis of H. natalensis indicated the NOEL (no-observed-effect level) at 200 mg/kg. Interleukin-8 (IL-8) is a chemokine that stimulates the recruitment of leukocytes. A significant reduction of IL-8 production by macrophage cells was observed when exposed to the extract of H. natalensis. It is possible that H. natalensis can prevent excessive tissue damage in periodontal diseases through its reduction of inflammation. Enzymatic bioanalysis of lactic and acetic acid production from Streptococcus mutans and Lactobacillus paracasei was done. A reduction in the acid production from each bacterium was observed on exposure to the extract of H. natalensis. Consequently, this increased the pH, which could possibly reduce the demineralization of enamel which may help prevent the formation of dental caries. In addition the extract may be considered for preventing periodontal diseases.</p

Image_1.tif

<p>The use of complementary and alternative medicine from plants in South Africa, as in the rest of the world, continues to increase. Heteropyxis natalensis, known as the Lavender tree, is indigenous to South Africa and is traditionally used for oral care. The ethanolic extract, of the leaves and twigs, of H. natalensis was investigated for antimicrobial activity against selected oral microorganisms. Actinomyces israelii was found to be the most sensitive oral microorganism to the extract, with a minimum inhibitory concentration (MIC) of 0.88 mg/ml and an MIC of 2.6 mg/ml against Streptococcus mutans. Five known compounds were identified from the ethanolic extract of H. natalensis. The compounds were identified as aurentiacin A (1), cardamomin (2), 5-hydroxy-7-methoxy-6-methylflavanone (3), quercetin (4) and 3,5,7-trihydroxyflavan (5). The MICs of the compounds 1 and 4 were found to be 0.06 mg/ml and 1 mg/ml, respectively, against A. israelii. The cytotoxicity, acute and sub-acute toxicity in pre-clinical studies were also determined for H. natalensis. The extract showed moderate cytotoxicity (35.56 ± 0.16 μg/ml) on human monocyte cells. The acute and sub-acute toxicity analysis of H. natalensis indicated the NOEL (no-observed-effect level) at 200 mg/kg. Interleukin-8 (IL-8) is a chemokine that stimulates the recruitment of leukocytes. A significant reduction of IL-8 production by macrophage cells was observed when exposed to the extract of H. natalensis. It is possible that H. natalensis can prevent excessive tissue damage in periodontal diseases through its reduction of inflammation. Enzymatic bioanalysis of lactic and acetic acid production from Streptococcus mutans and Lactobacillus paracasei was done. A reduction in the acid production from each bacterium was observed on exposure to the extract of H. natalensis. Consequently, this increased the pH, which could possibly reduce the demineralization of enamel which may help prevent the formation of dental caries. In addition the extract may be considered for preventing periodontal diseases.</p