Garcinia kola: a critical review on chemistry and pharmacology of an important West African medicinal plant.

Garcinia kola Heckel (Clusiaceae) is a tree indigenous to West and Central Africa. All plant parts, but especially the seeds, are of value in local folklore medicine. Garcinia kola is used in treatment of numerous diseases, including gastric disorders, bronchial diseases, fever, malaria and is used to induce a stimulating and aphrodisiac effect. The plant is now attracting considerable interest as a possible source of pharmaceutically important drugs. Several different classes of compounds such as biflavonoids, benzophenones, benzofurans, benzopyran, vitamin E derivatives, xanthones, and phytosterols, have been isolated from G. kola, of which many appears to be found only in this species, such as garcinianin (found in seeds and roots), kolanone (fruit pulp, seeds, roots), gakolanone (stem bark), garcinoic acid, garcinal (both in seeds), garcifuran A and B, and garcipyran (all in roots). They showed a wide range of pharmacological activities (e.g. analgesic, anticancer, antidiabetic, anti-inflammatory, antimalarial, antimicrobial, hepatoprotective and neuroprotective effects), though this has only been confirmed in animal models. Kolaviron is the most studied compound and is perceived by many studies as the active principle of G. kola. However, its research is associated with significant flaws (e.g. too high doses tested, inappropriate positive control). Garcinol has been tested under better conditions and is perhaps showing more promising results and should attract deeper research interest (especially in the area of anticancer, antimicrobial, and neuroprotective activity). Human clinical trials and mechanism-of-action studies must be carried out to verify whether any of the compounds present in G. kola may be used as a lead in the drug development.

The Chemical Composition of Oils and Cakes of Ochna serrulata (Ochnaceae) and Other Underutilized Traditional Oil Trees from Western Zambia.

Currently, the negative effects of unified and intensive agriculture are of growing concern. To mitigate them, the possibilities of using local but nowadays underused crop for food production should be more thoroughly investigated and promoted. The soybean is the major crop cultivated for vegetable oil production in Zambia, while the oil production from local oil-bearing plants is neglected. The chemical composition of oils and cakes of a three traditional oil plant used by descendants of the Lozi people for cooking were investigated. Parinari curatellifolia and Schinziophyton rautanenii oils were chiefly composed of α-eleostearic (28.58-55.96%), linoleic (9.78-40.18%), and oleic acid (15.26-24.07%), whereas Ochna serrulata contained mainly palmitic (35.62-37.31%), oleic (37.31-46.80%), and linoleic acid (10.61-18.66%); the oil yield was high (39-71%). S. rautanenii and O. serrulata oils were rich in γ-tocopherol (3236.18 µg/g, 361.11 µg/g, respectively). The O. serrulata oil also had a very distinctive aroma predominantly composed of p-cymene (52.26%), m-xylene (9.63%), γ-terpinene (9.07%), o-xylene (7.97), and limonene (7.23%). The cakes remaining after oil extraction are a good source of essential minerals, being rich in N, P, S, K, Ca, and Mg. These plants have the potential to be introduced for use in the food, technical, or pharmaceutical industries.

The effect of oregano essential oil on microbial load and sensory attributes of dried meat.

BACKGROUND: Microbial load can be controlled using either synthetic or natural preservatives. Particular interest has been focused on the potential application of plant essential oils as safer additives for meat. However, there is no published research on the use of essential oils during the meat drying process. This study was focused on enhancing the meat drying process by using oregano essential oil (OEO) to inhibit the growth of bacteria and thus obtain a value-added dried meat product. The sensory response from assessors is presented. RESULTS: It was found that the application of OEO in meat was effective in inhibiting Salmonella enteritidis and Escherichia coli. After 6 h of drying at 55 °C, 2 mL (0.038 mL L-1 air) and 1.5 mL (0.028 mL L-1 air) of OEO were considered as the minimal inhibitory concentrations (MICs) against S. enteritidis and E. coli respectively. Samples treated with 0.75 mL of OEO were more attractive for consumption compared with the control; at a higher concentration of OEO, the sensory quality of the food was affected. CONCLUSION: A value-added dried meat product obtained by using OEO to enhance food safety received an acceptable sensory response from consumers. © 2016 Society of Chemical Industry.

Antibacterial activities of plant-derived compounds and essential oils toward Cronobacter sakazakii and Cronobacter malonaticus.

Cronobacter sakazakii and C. malonaticus are opportunistic pathogens that cause infections in children and immunocompromised adults. In the present study, the antibacterial activity of 19 plant-derived compounds, 5 essential oils, and an extract of propolis were assessed against C. sakazakii and C. malonaticus. The effects of most of these antimicrobials have not been reported previously. Both strains were susceptible to thymol, carvacrol, thymoquinone, p-cymene, linalool, camphor, citral, eugenol, and trans-cinnamaldehyde as well as cinnamon, lemongrass, oregano, clove, and laurel essential oils; their minimum inhibitory concentrations varied between 0.1 and 2.0 mg/mL. As an alternative treatment method, vapors of the volatiles were tested as an indirect treatment. Vapors of trans-cinnamaldehyde, eugenol, oregano, and cinnamon essential oils inhibited both tested strains, while vapors of linalool were only active against C. sakazakii. To our knowledge, this study is the first time that the inhibitory activity of the vapors of these compounds and essential oils has been reported against Cronobacter spp.

Effects of genotype, sex, and feed restriction on the biochemical composition of chicken preen gland secretions and their implications for commercial poultry production.

Preen gland secretions spread on the feathers contain various chemical compounds dominated by fatty acids (FAs) and volatile organic compounds (VOCs). These chemicals may significantly affect plumage condition, microbial and ectoparasitic load on feathers, and chemical communication of birds. However, how chemical composition of preen secretions varies in commercially produced chickens with respect to their genotype, sex, and feeding regime remain largely unknown, as well as the welfare implications for farmed poultry. We found that while polyunsaturated fatty acids in chicken preen secretions differed significantly with genotype (P << 0.001), saturated fatty acids and monounsaturated fatty acids varied with genotype-dependent preen gland volume (P < 0.01). Chickens of meat-type fast-growing Ross 308 genotype had reduced preen gland volume and lower proportions of all FA categories in their preen secretions compared with dual-purpose slow-growing ISA Dual chickens. A total of 34 FAs and 77 VOCs with tens of unique FAs were detected in preen secretions of both genotypes. While differences in the relative proportion of 6 of the 10 most dominant VOCs in chicken preen gland secretions were related to genotype (P < 0.001), only 1 of the 10 most dominant VOCs showed a sex effect (P < 0.01), and only 2 of the 10 most dominant VOCs showed a genotype-dependent effect of feed restriction (P < 0.05). Feed restriction had no effect on the relative proportion of any of the FAs in chicken preen gland secretions. Moreover, we found that meat-type Ross 308 preen secretions were dominated by VOCs, which are proven attractants for poultry red mite and may also increase infestation with other ectoparasites and negatively influence overall odor-mediated intraspecific communication and welfare. This study shows that no feeding management, but long-term genetic selection in commercial breeding may be the main cause of the differences in the biochemistry and function of chicken preen secretions. This might have negative consequences for chemosignaling, antiparasitic, and antimicrobial potential of preen secretions and can lead to increased susceptibility to ectoparasites, plumage care disorders, and can affect the overall condition, welfare, and productivity of commercially bred chickens. Selection-induced preen gland impairments must therefore be considered and compensated by proper management of the chicken farm and increased care about animal well-being.

The preen gland is the largest sebaceous gland in birds, which produces a secretion that is spread on the feathers during comfort behavior. The secretion of the preen gland contains various chemical compounds that are responsible for mechanical, antimicrobial, and antiparasitic protection of the plumage and probably also for chemical communication between birds. However, there are only a limited number of studies on the composition and function of preen secretions in wild birds and only limited evidence in poultry. In this study, we compared the chemical composition of preen secretions in fast-growing meat-type and slow-growing dual-purpose chickens and evaluated the effect of sex, body condition, and feeding regime on preen secretion composition. Fast-growing meat-type chickens had smaller preen glands and lower proportions of all analyzed compounds in preen secretions compared to slow-growing dual-purpose chickens. In addition, compounds that are proven attractants for a poultry-threatening ectoparasite, poultry red mite, were predominant in the secretions of meat-type chickens. This study is the first to show that genetically distinct breeds of chickens can differ significantly in the biochemistry of preen secretions, which can influence susceptibility to ectoparasites, plumage care disorders, and can affect the overall condition, well-being, and productivity of commercially raised chickens.

The chemical composition of ethanolic extracts from six genotypes of medical cannabis (Cannabis sativa L.) and their selective cytotoxic activity.

Cannabis (Cannabis sativa L.) for medical purposes has been legalized again in many countries in recent years. Currently, only two major cannabinoids (Δ9-THC and CBD) are considered in the legislation and medication, which is not sufficient in case of dried plant material or resulting extract. Other substances (mainly terpenes/terpenoids), or their specific combinations, could influence the resulting therapeutic effect for specific oncology diagnosis and specific patients. Six different genotypes (Conspiracy Kush, Jilly Bean, Jack Cleaner 2, Jack Skellington, Nordle and Nurse Jackie) were cultivated indoor at the Czech University of Life Sciences Prague. Ethanol extracts taken from the inflorescences were assayed for their content of main cannabinoids and terpenes/terpenoids. The extracts were used for in vitro cytotoxicity studies on hepatocarcinoma human cell lines Hep-G2 and colorectal carcinoma human cell lines Caco-2 and Ht-29. Healthy lung fibroblast MRC-5 and healthy intestinal cells FHs 74 Int were used to compare selectivity of cytotoxicity. The average content of Δ9-THC in extracts was 59.1 ± 2.43%, and of CBD 1.84 ± 0.17%. The content of main cannabinoids in the Nurse Jackie genotype extract was significantly greater than that of the other genotypes. Overall, more than 60 different terpenes/terpenoids were identified in the extracts. The major terpenes/terpenoids detected in most genotypes were limonene, linalool, α-terpineol, ß-caryophyllene, trans-α-bergamotene, α-humulene, ß-caryophyllene oxide, guaiol, γ-eudesmol, ß-eudesmol and α-bisabolol. Differences in the terpene composition of individual genotypes were caused by minor terpenoids, such as ß-ocimene, isopulegol acetate, ß-elemene, ß-selinene and spathulenol. All extracts were highly cytotoxic to Ht-29 colorectal carcinoma cells and showed positive selectivity compared to healthy FHs 74 Int colon cells. The Jack Cleaner 2 extract was cytotoxic to all cell lines tested at the lowest concentrations (8.48 ± 2.4-16.14 ± 0,07 µg/mL), but was positively selective only for colorectal cancer cells, especially Ht-29 and to a lesser extent for Caco-2. Similarly, the Nordle extract showed positive selectivity for Ht-29 and Caco-2 only. Jilly Bean was unique in this study, in that its extract functioned on all cell lines at the highest concentrations (20.13 ± 3.05-49.88 ± 1.5 µg/mL), whilst also being highly positively selective in all carcinoma lines (Ht-29, Caco-2 and Hep-G2 hepatocarcinoma) compared to healthy cell lines (FHs 74 Int and MRC-5). The results suggest that Δ9-THC and CBD are responsible for the in vitro cytotoxicity of the extracts, but observed differences in selectivity reveal their synergies with other substances. According to chemical analysis, higher concentrations of myrcene, ß-elemene, ß-selinene and α-bisabolol oxide found in the Jilly Bean genotype may positively affect the selectivity of cytotoxic activity. It is therefore vital that similar studies are performed on other cell lines, in order to be able to recommend these cannabis genotypes for preclinical and clinical studies, which are still lacking.

In vitro antagonistic inhibitory effects of palm seed crude oils and their main constituent, lauric acid, with oxacillin in Staphylococcus aureus.

Infections caused by Staphylococcus aureus are a serious global threat, and with the emergence of antibiotic resistance, even more difficult to treat. One of the possible complications in antistaphylococcal therapy represents negative interactions of antibiotics with food. In this study, the in vitro interaction between oxacillin and crude palm seed oil from Astrocaryum vulgare, Cocos nucifera, and Elaeis guineensis against nine strains of S. aureus was determined using the checkerboard method. Lauric acid was identified as a major constituent of all tested oils by gas chromatography. The results showed strong concentration dependent antagonistic interactions between palm oils and oxacillin with values of fractional inhibitory concentrations indices ranging from 4.02 to 8.56 at concentrations equal or higher than 1024 µg/mL of the tested oils. Similarly, lauric acid in combination with oxacillin produced antagonistic action with fractional inhibitory concentration indices ranging from 4.01 to 4.28 at 1024 µg/mL. These findings suggest that interference between oxacillin and palm oils and their constituents can negatively affect the treatment of staphylococcal infections in humans and other animals.

Secreted Enzyme-Responsive System for Controlled Antifungal Agent Release.

Essential oil components (EOCs) such as eugenol play a significant role in plant antimicrobial defense. Due to the volatility and general reactivity of these molecules, plants have evolved smart systems for their storage and release, which are key prerequisites for their efficient use. In this study, biomimetic systems for the controlled release of eugenol, inspired by natural plant defense mechanisms, were prepared and their antifungal activity is described. Delivery and antifungal studies of mesoporous silica nanoparticles (MSN) loaded with eugenol and capped with different saccharide gates-starch, maltodextrin, maltose and glucose-against fungus Aspergillus niger-were performed. The maltodextrin- and maltose-capped systems show very low eugenol release in the absence of the fungus Aspergillus niger but high cargo delivery in its presence. The anchored saccharides are degraded by exogenous enzymes, resulting in eugenol release and efficient inhibition of fungal growth.

Screening of medicinal plants traditionally used in Peruvian Amazon for in vitro antioxidant and anticancer potential.

Plants mentioned in this study have numerous records in traditional Peruvian medicine being used in treatment of cancer and other diseases likely to be associated with oxidative stress. Amongst the eight plant species tested, only Dysphania ambrosioides exhibited combinatory antioxidant and anti-proliferative effect on a broad spectrum of cancer cells (DPPH and ORAC values = 80.6 and 687.3 µg TE/mg extract, respectively; IC50 against Caco-2, HT-29 and Hep-G2 = 129.2, 69.9 and 130.6, respectively). Alkaloids and phenolic compounds might significantly contribute to anticancer/antioxidant activity of this plant. The results justify the traditional medicinal use of this plant. Our findings further suggest that D. ambrosioides might serve as a prospective material for further development of novel plant-based antioxidant and/or anti-proliferative agents. Detailed analysis of chemical composition together with toxicology assessments and in vivo antioxidant/anti-proliferative activity of this plant should be carried out in order to verify its potential practical use.

The Effect of the Application of Thyme Essential Oil on Microbial Load During Meat Drying.

Meat is a high protein meal that is used in the preparation of jerky, a popular food snack, where preservation and safety are important. To assure food safety and to extend the shelf life of meat and meat products, the use of either synthetic or natural preservatives have been applied to control and eliminate foodborne bacteria. A growing interest in the application of natural food additives for meat has increased. Microorganisms, such as Escherichia coli, contaminate meat and meat products, causing foodborne illnesses. Therefore, it is necessary to improve the meat conservation process. However, the use of essential oils when the meat is being dried has not been deeply studied. In this regard, there is an opportunity to increase the value of dried meat and reduce the risk of foodborne illnesses by applying essential oils during the drying process. In this protocol, we present a novel method of applying thyme essential oil (TEO) during meat drying, specifically in vapor form directly in a drying chamber. For evaluation, we use Minimal Inhibitory Concentration (MIC) to detect the number of harmful bacteria in the treated samples compared to raw samples. The preliminary results show that this method is a viable and alternative option to synthetic preservatives and that it significantly reduces microbial load in dried meat.

Polycyclic aromatic hydrocarbons in Cambodian smoked fish.

More than 85% of the population in Cambodia is strongly dependent on agriculture, of which freshwater aquaculture is one of the most important sources of food production. The smoked fish represents an important source of nutrients for Cambodian population; however, it can also lead to excessive intake of polycyclic aromatic hydrocarbons (PAHs). A field survey was conducted among selected smoked fish producers near to Tonle Sap river in Kampong Chhnang province, Cambodia. The study revealed that maximal limits for benzo[a]pyrene and the sum of four PAHs given by EC 1881/2006 were exceeded 2-50 times. Such burden can lead to increased risk of development of carcinogenic diseases.

In Vitro Digestibility of Aluminum from Hibiscus sabdariffa Hot Watery Infusion and Its Concentration in Urine of Healthy Individuals.

Increased ingestion of aluminum (Al) can lead to its accumulation in the human body, especially in people with kidney problems. Al is also associated with several nervous diseases and its negative influence on embryo development during pregnancy has been proven in animal models. Hibiscus sabdariffa L. petals are widely used alone or in fruit tea formulas, which are recommended for drinking during pregnancy instead of tea. Its petals can contain similar and even higher amounts of Al as tea, which is a known Al accumulator. Our research investigated whether the regular intake of H. sabdariffa infusion leads to increased burden of Al. Sixteen days of ingestion of H. sabdariffa infusion (c Al = 0.5 mg.L-1) led to increased but unbalanced levels (15-86 µg L-1) of Al in urine compared to a period when the infusion was not ingested. The highest amounts of Al excreted were observed every third day during the ingestion. Mild health problems, such as nausea and dizziness (which could be related to plant properties) were reported by more sensitive volunteers.Our results suggest that the tea infusion from H. sabdariffa petals increases body burden of Al and, therefore, sensitive individuals as pregnant women and people with kidney problems should be cautious with excessive consumption of hibiscus infusion or fruit teas containing this plant. However, further study including more individuals is needed to fully confirm our preliminary results.

Antimicrobial activity of extracts and isoquinoline alkaloids of selected papaveraceae plants.

Alkaloidal extracts of seven selected plants of the family Papaveraceae were studied with respect to their activity against six strains of pathogenic bacteria and their alkaloidal fingerprint. Twenty-four alkaloids were determined by GC/MS, and twenty of them identified from their mass spectra, retention times and retention indexes. In the antibacterial assay, three Gram-positive (Enterorococcus faecalis, Staphylococcus aureus and S. hyicus), and three Gram-negative (Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa) strains were used. The most promising antimicrobial activity was shown by the alkaloidal extract of Macleaya cordata with MIC values of 16 µg/mL for Staphylococcus aureus, 32 µg/mL for Enterococcus faecalis and 64 µg/mL for Staphylococcus hyicus and Escherichia coli. All the tested pure isoquinoline alkaloids were considered inactive within the tested concentrations.

Aluminium and other elements in selected herbal tea plant species and their infusions.

The determination of Al, B, Cu, Fe, Mn, Ni, P, Zn and Ca, K, Mg by inductively coupled plasma optical emission spectrometry (ICP-OES) and flame atomic absorption spectroscopy (FAAS), respectively, in digests and infusions of Hibiscus sabdariffa (petals), Rosa canina (receptacles), Ginkgo biloba (leaves), Cymbopogon citratus (leaves), Aloe vera (leaves) and Panax ginseng (roots) was carried out in this study. Particular attention has been given to Al and heavy metals for the identification of possible raw material contaminants, their transformation into the infusion and for predicting their eventual role in the human diet during daily consumption. Additionally, Ion Chromatography (IC) speciation of Al in the leachates was carried out. In dry herbs, hibiscus and ginkgo appeared to contain the greatest contents of Al, Fe, K, Mn, Ni, Zn and B, Mg, P, respectively. A. vera contained the highest amount of Ca and highest values of Cu and P were observed in ginseng. In infusions, the topmost concentrations of Al, B, Cu, Fe, P, K, Mn, Ni, Zn were detected in those prepared from hibiscus petals, Ca from aloe leaves and Mg from leaves of ginkgo. According to a possible daily consumption exceeding 1 L, hibiscus decoction was identified as potentially dietetically significant in the content of certain elements. It seems to be possibly one of the top contributors of B from food (up to 5.5±0.2 mg/L). The Mg contained in the infusion (up to 106±5 mg/L) may be a contributor in the attenuation of blood pressure. A high amount of accessible Mn (up to 17.4±1.1 mg/L) can probably have an adverse effect in humans. The total Al allowance (up to 1.2±0.1 mg/L) suggests that no more than 1 L of the hibiscus infusion should be consumed per day by sensitive individuals including pregnant women and should be completely excluded from the diet of children under 6 months of age and children with chronic renal failure.

The effect of beverage preparation method on aluminium content in coffee infusions.

Seven types of coffee were prepared by four methods. Three of them - simple coffee infusion, preparation in ibrick and moka pot - are very often used to prepare coffee at home. The fourth one - a single-cup filter is typical for Vietnam. Cookware used for each method was made from glass, aluminium, stainless steel and two types of alloys. Amounts of Al leaching to coffee infusions were determined. On average, the highest amount of Al was in coffee infusions brewed in aluminium single-cup filter, and the lowest in infusions prepared by simple extraction. Other brewing methods in combination with different tool materials resulted in similar Al content. The type of brewing method significantly influences the Al content in final infusion. Aluminium content varies in infusions in relation to the method of choice, especially when using single-cup filter. Despite the fact that coffee is considered to be a poor source of Al for humans, in some cases, Al content in infusions can even reach the values reported for tea infusions.