The Ultrasound-Assisted Extraction of Polyphenols from Mexican Firecracker (Hamelia patens Jacq.): Evaluation of Bioactivities and Identification of Phytochemicals by HPLC-ESI-MS.

The objective of the present work was to optimize the extraction of phytochemicals from Hamelia patens Jacq. by ultrasound-assisted extraction. Taguchi L9 orthogonal array was used to evaluate the factors solid/liquid ratio (1:8, 1:12, and 1:16), extraction time (10, 20, and 30 min), and ethanol concentration (0, 35, and 70%). Total polyphenols were the response variable. Chromatographic fractionation using Amberlite XAD-16 was carried out and the total polyphenols, flavonoids, and condensed tannins were quantified. The redox potential, the reduction of the 2,2-diphenyl-1-picrylhydrazyl (DPPH), and the lipid oxidation inhibition were determined. Anti-bacterial activity was evaluated. The phytochemicals were identified by liquid chromatography coupled to mass spectrometry. Optimal extraction conditions were a solid/liquid ratio of 1:16, ethanol of 35%, and 10 min of ultrasound-assisted extraction. Maximum polyphenol content in the crude extract was 1689.976 ± 86.430 mg of gallic acid equivalents (GAE)/100 g of dried plant material. The purified fraction showed a total polyphenols content of 3552.84 ± 7.25 mg of GAE, flavonoids 1316.17 ± 0.27 mg of catechin equivalents, and condensed tannins 1694.87 ± 22.21 mg of procyanidin B1 equivalents, all per 100 g of purified fraction. Its redox potential was 553.93 ± 1.22 mV, reducing 63.08 ± 0.42% of DPPH radical and inhibiting 77.78 ± 2.78% of lipid oxidation. The polyphenols demonstrated antibacterial activity against Escherichia coli, Klebsiella pneumonia, and Enterococcus faecalis. The HPLC-ESI-MS analysis revealed the presence of coumarins, hydroxycinnamic acids, and flavonoids.

A Phytochemical and Ethnopharmacological Recapitulation on Hamelia patens.

The world health organization reports that 80% of the population living within the developing countries depends basically on traditional medicine for his or her primary health care. Quite half the entire world's population still depends entirely on plants for medicines, and plants provides the active ingredients to the most traditional medical products. Hamelia patens that belong to the family Rubiaceae, is mainly found in tropical and sub-tropical areas. It is used in folk medicine against a wide range of diseases such as athlete's foot, skin problems, insect sting, psychiatric disorder, rheumatism, headache, asthma, dysentery, menses, ovarian and uterine disorders. Hamelia consists of an important bioactive constituent such as oxindole alkaloids, flavonoids, and phenolic content. Due to the presence of chlorogenic acid and epicatechin constituent in the methanolic extract of Hamelia patens, there is a noticeable anti-hyperglycemic activity as well as it possesses antioxidant activity. Acute and sub-acute toxicity study has been performed on Hamelia patens which shows that it is safe and can be used for humans. Against fungi and bacteria, the ethanol leaf extract of Hamelia has a maximum inhibitory effect. The plant has various therapeutic effects like anti-inflammatory, analgesic, anti-diarrheal, anthelmintic, antidepressant, hepatoprotective, antiurolithiatic, diuretic, wound healing, and many others. In this article, we have discussed chemical constituent, pharmacological activity and traditional use of Hamelia patens.

Phenolic content and antibacterial activity of extracts of Hamelia patens obtained by different extraction methods

Abstract Hamelia patens, is a plant traditionally used to treat a variety of conditions among the Huastec people of Mexico. The objective of this study is to characterize the phenolic content and critically examine the antimicrobial activity of leaf extracts H. patens, obtained by maceration, Soxhlet and percolation, using ethanol as 70% solvent. Phenolic compounds are characterized by liquid chromatography, coupled to a High Resolution Mass Spectrometry, and the antimicrobial activity was studied from the inhibitory effect of each extract for Escherichia coli, Staphylococcus aureus, Salmonella typhi and S. paratyphi, and by the Minimum Bactericidal Concentration, the percentage of activity and the Index of Bacterial Susceptibility of each extract. The phenolic compound identified in different concentrations in the three extracts was epicatechin. The extracts obtained by the three methods had antimicrobial activity, however, there was no significant difference (p < 0.05) between the Minimum Bactericidal Concentration of the extracts obtained by maceration, percolation and Soxhlet. The results of this study contribute to the body of knowledge on the use of extracts in controlling microorganisms with natural antimicrobials.

Phenolic content and antibacterial activity of extracts of Hamelia patens obtained by different extraction methods.

Hamelia patens, is a plant traditionally used to treat a variety of conditions among the Huastec people of Mexico. The objective of this study is to characterize the phenolic content and critically examine the antimicrobial activity of leaf extracts H. patens, obtained by maceration, Soxhlet and percolation, using ethanol as 70% solvent. Phenolic compounds are characterized by liquid chromatography, coupled to a High Resolution Mass Spectrometry, and the antimicrobial activity was studied from the inhibitory effect of each extract for Escherichia coli, Staphylococcus aureus, Salmonella typhi and S. paratyphi, and by the Minimum Bactericidal Concentration, the percentage of activity and the Index of Bacterial Susceptibility of each extract. The phenolic compound identified in different concentrations in the three extracts was epicatechin. The extracts obtained by the three methods had antimicrobial activity, however, there was no significant difference (p<0.05) between the Minimum Bactericidal Concentration of the extracts obtained by maceration, percolation and Soxhlet. The results of this study contribute to the body of knowledge on the use of extracts in controlling microorganisms with natural antimicrobials.

Antioxidant and hepatoprotective activity of Hamelia patens extracts.

Hamelia patens is widely used in the traditional medicine of Mexico and Central America for the treatment of illnesses associated with inflammatory processes. In this study, antioxidant and hepatoprotective activity were assayed on the methanolic crude (ME), hexane (HE), ethyl acetate (AE), and butanol (BE) extracts of H. patens. The total phenolic content (TPC) as mg of gallic acid equivalents per g of dry extract was determined by Folin-Ciocalteu's method (ME=141.58±11.99, HE=33.96±1.13, AE=375.18±13.09, BE=132.08±3.62), and antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical-scavenging method (EC(50) ME=77.87±5.67, HE=236.64±26.32, AE=45.87±2.24, BE=50.97±0.85µg/mL). Hepatoprotective activity was evaluated through AST activity on HepG2 cells subjected to damage with CCl(4) (ME=62.5±3.41, HE=72.25±2.87, AE=63.50±4.20, BE=43.74±4.03). BE showed the greater hepatoprotective activity and a good antioxidant capacity, while HE did not show hepatoprotective or antioxidant activity. Cytotoxicity was evaluated on Vero cells cultures; none showed significant toxicity.

Anti-inflammatory, free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents.

Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications. Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds. Materials and methods Four extracts were obtained by maceration and liquid-liquid extraction: HEX, DCM-EtOAc, MeOH-EtOAc and MeOH-Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6 h (50, 200 and 500 mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4 h (0.5 and 1 mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis. Results We found that the oral administration of the HEX extract at 500 and 200 mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3 h, respectively. The MeOH-EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM-EtOAc extract (76%), ß-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH-EtOAc, MeOH-Aq and DCM-EtOAc extracts showed good DPPH scavenging activity (IC50 values of 18.6, 93.9 and 158.2 µg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC50 value of 26.07 µg/mL), followed by the MeOH-EtOAc extract (an IC50 value of 30.18 µg/mL), ß-sitosterol/stigmasterol (IC50 34.6 µg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC50 value of 114.6 µg/mL), which were isolated for the first time from Hamelia patens. Discussion and conclusion Hamelia patens possesses anti-inflammatory, antioxidant and α-glucosidase inhibitory activities, which support its traditional use. These effects can be attributed to the identified compounds.

Bioconjugated gold nanoparticles accelerate the growth of new blood vessels through redox signaling.

We have designed and developed novel pro-angiogenic bio-synthesized gold nanoconjugates (b-Au-HP) that make new blood vessels, as observed by several in vitro and in vivo assays, suggesting their future potential applications in alternative treatment strategies for wound healing, cardiovascular diseases (CVD) and ischemic diseases using a nanomedicine approach.

Intercropping with shrub species that display a 'steady-state' flowering phenology as a strategy for biodiversity conservation in tropical agroecosystems.

Animal species in the Neotropics have evolved under a lower spatiotemporal patchiness of food resources compared to the other tropical regions. Although plant species with a steady-state flowering/fruiting phenology are rare, they provide predictable food resources and therefore may play a pivotal role in animal community structure and diversity. I experimentally planted a supplemental patch of a shrub species with a steady-state flowering/fruiting phenology, Hamelia patens Jacq., into coffee agroforests to evaluate the contribution of this unique phenology to the structure and diversity of the flower-visiting community. After accounting for the higher abundance of captured animals in the coffee agroforests with the supplemental floral resources, species richness was 21% higher overall in the flower-visiting community in these agroforests compared to control agroforests. Coffee agroforests with the steady-state supplemental floral patch also had 31% more butterfly species, 29% more hummingbird species, 65% more wasps and 85% more bees than control coffee agroforests. The experimental treatment, together with elevation, explained 57% of the variation in community structure of the flower-visiting community. The identification of plant species that can support a high number of animal species, including important ecosystem service providers, is becoming increasingly important for restoration and conservation applications. Throughout the Neotropics plant species with a steady-state flowering/fruiting phenology can be found in all aseasonal forests and thus could be widely tested and suitable species used throughout the tropics to manage for biodiversity and potentially ecosystem services involving beneficial arthropods.

A new monoterpenoid oxindole alkaloid from Hamelia patens micropropagated plantlets.

Chemical studies on Hamelia patens (Rubiaceae) micropropagated plantlets allowed production of a new monoterpenoid oxindole alkaloid, named (-)-hameline (7), together with eight known alkaloids, tetrahydroalstonine (1), aricine (2), pteropodine (3), isopteropodine (4), uncarine F (5), speciophylline (6), palmirine (8), and rumberine (9). The structure of the new alkaloid was assigned on the basis of 1D and 2D NMR spectroscopy, mass spectrometry, and molecular modeling.

Methanol extracts of Hamelia patens containing oxindole alkaloids relax KCl-induced contraction in rat myometrium.

Hamelia patens JAQC. (Rubiaceae) is a medicinal bush widely distributed in tropical areas of the American continent. It is used in Mexican Traditional Medicine for the treatment of menstrual disorders, therefore suggesting that its chemical constituents may have some effect on myometrium contractility. Physiological effects might differ due to quantitative variations in the content of alkaloids arising from its wide geographical distribution. To test this hypothesis, the content of oxindole alkaloids in methanol extracts of five different samples collected in Mexico was quantified by GC-MS. Each extract was assayed on contractility of estrogen-primed rat myometrium. Variations in the content of alkaloids were observed among the different samples. All samples relaxed in a concentration-dependent manner the high KCl-induced contraction in rat myometrium. Those which lack rumberine and/or maruquine displayed a higher relaxant effect than samples containing them, suggesting that these alkaloids might counteract the effects of isopteropodine. However, in contrast with verapamil, Hamelia patens metanol extracts are poor relaxants.

Double incision wound healing bioassay using Hamelia patens from El Salvador.

Hamelia patens Jacq. (Rubiaceae) has received little attention in the laboratory for its wound healing ability even though it is commonly used as a treatment for wounds throughout Central America. A double incision wound healing bioassay was carried out with a crude extract of Hamelia patens collected from El Salvador. Animals were divided into three groups. Group I (n = 14) had the left incision treated with 5% (w/w) Hamelia patens and the contralateral side with petroleum jelly (PJ). Group II (n = 14) had the left incision treated with 10% (w/w) ointment and the contralateral side with petroleum jelly. Group III (n = 10) had the left incision treated with petroleum jelly and the contralateral side left untreated. Breaking strength of the incisions was measured on day 7 and day 12. For Groups I and II, there was no significant difference between treatment and control incisions at day 7. On day 12, there was a significant difference between the treated and control incisions for Groups I and II. There was no significant difference between petroleum jelly and untreated incisions for Group III on day 7 and day 12. Hamelia patens does increase breaking strength of wounds significantly more than the control group. Further wound healing studies of this plant are warranted.

Screening of anti-bacterial activity of medicinal plants from Belize (Central America).

Twenty-one extracts from seven herbal drugs, Aristolochia trilobata (Aristolochiaceae) leaves and bark, Bursera simaruba (Burseraceae) bark, Guazuma ulmifolia (Sterculiaceae) bark, Hamelia patens (Rubiaceae) leaves and Syngonium podophyllum (Araceae) leaves and bark, used in traditional medicine of Belize (Central America) as deep and superficial wound healers, were evaluated for their anti-bacterial properties. Activity was tested against standard strains of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212. Almost all the extracts were able to inhibit the growth of one or more of the bacterial strains, except that of Enterococcus faecalis. For the first time an anti-microbial activity is reported for Aristolochia trilobata as well as for Syngonium podophyllum. The hexane extracts of Aristolochia trilobata leaves and bark were the most active extracts against Staphylococcus aureus (MIC=0.31 and 0.625mg/ml, respectively).