Prokaryotic communities of the French Polynesian sponge Dactylospongia metachromia display a site-specific and stable diversity during an aquaculture trial.

Dynamics of microbiomes through time are fundamental regarding survival and resilience of their hosts when facing environmental alterations. As for marine species with commercial applications, such as marine sponges, assessing the temporal change of prokaryotic communities allows us to better consider the adaptation of sponges to aquaculture designs. The present study aims to investigate the factors shaping the microbiome of the sponge Dactylospongia metachromia, in a context of aquaculture development in French Polynesia, Rangiroa, Tuamotu archipelago. A temporal approach targeting explants collected during farming trials revealed a relative high stability of the prokaryotic diversity, meanwhile a complementary biogeographical study confirmed a spatial specificity amongst samples at different longitudinal scales. Results from this additional spatial analysis confirmed that differences in prokaryotic communities might first be explained by environmental changes (mainly temperature and salinity), while no significant effect of the host phylogeny was observed. The core community of D. metachromia is thus characterized by a high spatiotemporal constancy, which is a good prospect for the sustainable exploitation of this species towards drug development. Indeed, a microbiome stability across locations and throughout the farming process, as evidenced by our results, should go against a negative influence of sponge translocation during in situ aquaculture.

Identification of Antioxidant Metabolites from Five Plants (Calophyllum inophyllum, Gardenia taitensis, Curcuma longa, Cordia subcordata, Ficus prolixa) of the Polynesian Pharmacopoeia and Cosmetopoeia for Skin Care.

Oxidative stress contributes to impairment of skin health, the wound healing process, and pathologies such as psoriasis or skin cancer. Five Polynesian medicinal plants, among the most traditionally used for skin care (pimples, wounds, burns, dermatoses) are studied herein for their antioxidant properties: Calophyllum inophyllum, Gardenia taitensis, Curcuma longa, Cordia subcordata, and Ficus prolixa. Plant extracts were submitted to in vitro bioassays related to antioxidant properties and their bioactive constituents were identified by a metabolomic analytical approach. High performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) analysis was performed leading to the characterization of 61 metabolites. Compounds annotated for F. prolixa and C. subcordata extracts were reported for the first time. Antioxidant properties were evaluated by total phenolic content (TPC), free radical scavenging DPPH (1,1-diphenyl-2-picryl-hydrazyl), and Ferric Reducing Antioxidant Power activity (FRAP) assays. F. prolixa extract was the most active one and showed antioxidant intracellular activity on keratinocytes by Anti Oxydant Power 1 assay. Online HPLC-DPPH allowed the identification of phenolic bioactive compounds such as quercetin-O-rhamnoside, rosmarinic acid, chlorogenic acid, procyanidins, epicatechin, 5-O-caffeoylshikimic acid, and curcumin as being responsible for the scavenging properties of these plant extracts. These results highlight the potential of F. prolixa aerial roots as a source of antioxidants for skin care applications.

Traditional medical practices for children in five islands from the Society archipelago (French Polynesia).

BACKGROUND: Traditional Polynesian medicine for children has been poorly documented, and few data are available on their efficacy and safety. In this context, the aim of this study was to identify traditional practices used for treating children and then assess the efficacy and safety of the most cited remedies by reviewing the literature. METHODS: In 2022, a semi-structured survey was carried out on five islands from the Society archipelago (Bora Bora, Huahine, Moorea, Raiatea, and Tahiti). A total of 86 participants were interviewed including 19 experts in herbalism. A thorough literature review was performed on the most cited plant species to gather the relevant ethnobotanical, pharmacological, and clinical data of each remedy. RESULTS: Participants mentioned using 469 remedies to treat 69 health disorders. The most represented health categories were digestive system, skin disorders, infectious diseases, and respiratory system. A total of 67 plant species (representing 731 use-reports) were mentioned and Annona muricata, Gardenia taitensis, and Hibiscus rosa-sinensis were the main plants reported. Regarding the safety of cited remedies, one plant (Microsorum grossum) showed high risk of toxicity, and its use should be avoided in infants and children. CONCLUSION: Our survey confirms the importance of traditional medical practices for children in the Society Islands. A lack of data in children for most cited remedies demonstrate the need for more pharmacological and toxicological research on Polynesian medicinal plants. Finally, the potential risk of toxicity for some cited plant species reported calls for a better information of traditional medicine users and healers.

Antimicrobial Properties of Compounds Isolated from Syzygium malaccense (L.) Merr. and L.M. Perry and Medicinal Plants Used in French Polynesia.

A preliminary ethnopharmacological survey, achieved in French Polynesia, led to the collection of the most cited plants among 63 species used to treat "infectious" diseases, with a description of their medicinal uses. Bibliographical investigations and antimicrobial screening permitted the selection of the botanical species Syzygium malaccense (Myrtaceae) for phytochemical analysis. Leaves of Syzygium malaccense were usually used in mixture with rhizomes of Curcuma longa to treat infectious diseases such as cystitis. The methanolic plant extracts were tested in vitro with an agar microdilution method on 33 bacteria strains and 1 yeast to obtain their Minimal Inhibitory Concentration (MIC), and cytotoxicity against HepG2 cells were evaluated. Antimicrobial synergistic effects of methanolic plant extracts from leaves of Syzygium malaccense and rhizomes from Curcuma longa were also evaluated. The bio-guided isolation of leaf extract from Syzygium malaccense led to the identification of seven alkyl-salicylic acids (anacardic acids or ginkgolic acids C15:0, C15:1, C17:0, C17:1, C17:2, C17:3 and C19:1) described for the first time in this species. All compounds were tested against Staphylococcus aureus (18.75 < MIC < 75.0 µg/mL), Streptococcus pyogenes (2.34 < MIC < 18.75 µg/mL) and Pseudomonas aeruginosa (MIC = 150 µg/mL), and their structure−activity relationships were discussed. The methanolic extract and salicylic derivatives from S. malaccense showed an interesting antimicrobial activity against Gram+ bacteria, without toxicity on hepG2 cells at 400 µg/mL. Moreover, these antibacterial compounds have already been studied for their anti-inflammatory activity, which supports the therapeutic interest of S. malaccense against infectious diseases.

Polynesian medicine used to treat diarrhea and ciguatera: An ethnobotanical survey in six islands from French Polynesia.

ETHNOPHARMACOLOGICAL RELEVANCE: In French Polynesia, many pathologies common or endemic to the territory cause diarrhea. This is the case for rotavirus gastroenteritis, salmonella food poisoning, ingestion of water contaminated by bacteria, and ciguatera. To treat these ailments, the population may employ traditional medicine for cultural reasons, geographical isolation, and poor health coverage. Polynesian remedies are often used without medical consultation and there is no data on their benefit-risk balance. A few ethnobotanical studies have been carried out in order to identify the traditional remedies used for various ailments, but few studies have focused on gastrointestinal pathologies. In this context, an ethnobotanical survey was carried out to identify treatments used for diarrhea and ciguatera, inventory the plants used, better understand the local representation of these remedies, and provide efficacy and safety data on these uses. MATERIALS AND METHODS: From February to April 2021, a semi-structured survey was conducted on six islands in French Polynesia, including one island in the Windward Islands archipelago (Tahiti), three islands in the Marquesas archipelago (Hiva Oa, Nuku Hiva, Tahuata), and two islands in the Leeward Islands archipelago (Raiatea, Tahaa). A total of 133 people was interviewed including 34 specialists (of which 29 experts in herbalism). RESULTS: These people mentioned the use of 27 plants for the treatment of diarrhea, and 24 for the treatment of ciguatera. Citrus aurantiifolia, Psidium guajava and Cordyline fruticosa were the three most cited plant species used for treating diarrhea, while Cocos nucifera, Punica granatum and Barringtonia asiatica were the most cited for ciguatera. A large majority of plants are widespread and introduced plants, which is congruent with the history of Polynesian people. While some plants are well known for similar uses (e.g. Psidium guajava for diarrhea, Heliotropium arboreum for ciguatera), others are less well known and may present toxicity risks (e.g. Barringtonia asiatica for ciguatera). CONCLUSION: Traditional Polynesian medicine is an integral part of the local culture so important to be preserved and valued. However, more pharmacological and toxicological studies are still needed to determine the benefit-risk balance of some of these remedies and to allow their official integration into the Polynesian health system.

Feature-Based Molecular Networks Identification of Bioactive Metabolites from Three Plants of the Polynesian Cosmetopoeia Targeting the Dermal Papilla Cells of the Hair Cycle.

The term cosmetopoeia refers to the use of plants in folks' cosmetics. The aerial parts of Bidens pilosa L., the leaves of Calophyllum inophyllum L. and the fruits of Fagraea berteroana A.Gray ex Benth are traditionally used in French Polynesia for hair and skin care. During the hair cycle, dermal papilla cells and their interaction with epithelial cells are essential to promote hair follicle elongation. The aim of our investigations was the identification of metabolites from these three plants and chemical families responsible for their hair growth activity. A bioactivity-based molecular network was produced by mapping the correlation between features obtained from LC-MS/MS data and dermal papilla cell proliferation, using the Pearson correlation coefficient. The analyses pointed out glycosylated flavonols and phenolic acids from B. pilosa and C. inophyllum, along with C-flavonoids, iridoids and secoiridoids from F. berteroana, as potential bioactive molecules involved in the proliferation of hair follicle dermal papilla cells. Our results highlight the metabolites of the plant species potentially involved in the induction of hair follicle growth and support the traditional uses of these plants in hair care.

Hair Growth Activity of Three Plants of the Polynesian Cosmetopoeia and Their Regulatory Effect on Dermal Papilla Cells.

Hair loss is becoming increasingly prevalent as dietary and living habits change. The search for natural products to limit hair loss has led to tapping into traditional cosmetic knowledge. We studied three plants of the Polynesian cosmetopoeia, Bidens pilosa, Calophyllum inophyllum and Fagraea berteroana, to determine their ability to promote hair growth. Their chemical content was characterized by liquid chromatography coupled to mass spectrometry (LC-MS). Their proliferative activity on dermal papilla cells (DPCs) was assessed via MTT assay and molecular targets were evaluated by RT-qPCR analysis of seven factors involved in the modulation of the hair cycle, CCND1, LEF1, DKK1, WNT5A PPARD, TGFΒ1, PPARD and RSPO2. Our results show that our extracts significantly increased proliferation of dermal papilla cells. Furthermore, LC-MS/MS analysis revealed a diversity of molecules, flavonoids, iridoids and organic acids, some known for hair-inducing properties. Finally, specific extracts and fractions of all three plants either upregulated CCND1, LEF1 and PPARD involved in stimulating hair follicle proliferation and/or lowered the gene expression levels of hair growth inhibiting factors, DKK1 and TGFB1. Our findings suggest that extracts from B. pilosa, C. inophyllum and F. berteroana are interesting candidates to stimulate hair growth.

A selection of eleven plants used as traditional Polynesian cosmetics and their development potential as anti-aging ingredients, hair growth promoters and whitening products.

ETHNOPHARMACOLOGICAL RELEVANCE: In French Polynesia, embellishment of the hair and skin is an important cultural and everyday practice. Yet, little research has focused on traditional preparations used for beautification in this region and their potential development as innovative cosmetic ingredients. AIM OF THE STUDY: In this present study we aim to assess and compile the ethnocosmetic potential of plants of French Polynesia to select and further study plants showing the most promise to be developed as anti-aging, anti-blemish and hair care products. MATERIALS AND METHODS: A literature analysis of plants of the IECIC list, present in French Polynesia was conducted. The most interesting plants from a cosmetic development standpoint were selected based on four main criteria, i.e. their traditional use in Polynesian cosmetic-related preparations, their biogeographical status, their phytochemistry of cosmetic interest, and lastly their availability and absence from the UICN list. Furthermore, a preliminary screening of antioxidant and anti-inflammatory activities was also performed on several extracts obtained. RESULTS: Eleven plants were chosen, and a compilation of multidisciplinary data emphasized each selected plant's potentiality. Traditional allegations showed uses ranging from dermatology such as wound healing or anti-inflammatory properties, to hair growth promoting preparations or even skin ligthening ones. Preliminary screenings were useful in narrowing the number of extracts to study. Literature-based data associated to traditional uses depicted how the remaining plants and plant parts could be developed for targeted cosmetic applications. CONCLUSIONS: A prospective approach of plants used traditionally for cosmetic purposes in French Polynesia gave insight on their development potential when paired with the appropriate multidisciplinary data. The eleven plants presented show promise in being developed sustainably as natural anti-aging or hair care products and as skin brightening agents.

Biological Activity of Polynesian Calophyllum inophyllum Oil Extract on Human Skin Cells.

Oil from the nuts of Calophyllum inophyllum, locally called "Tamanu oil" in French Polynesia, was traditionally used for wound healing and to cure various skin problems and ailments. The skin-active effect of "Tamanu oil emulsion" was investigated on human skin cells (keratinocytes and dermal fibroblasts) and showed cell proliferation, glycosaminoglycan and collagen production, and wound healing activity. Transcriptomic analysis of the treated cells revealed gene expression modulation including genes involved in the metabolic process implied in O-glycan biosynthesis, cell adhesion, and cell proliferation. The presence of neoflavonoids as bioactive constituents in Tamanu oil emulsion may contribute to these biological activities. Altogether, consistent data related to targeted histological and cellular functions brought new highlights on the mechanisms involved in these biological processes induced by Tamanu oil effects in skin cells.

UV-protective effects of phytoecdysteroids from Microsorum grossum extracts on human dermal fibroblasts.

Microsorum grossum (Polypodiaceae), locally called metuapua'a, is one of the most frequently used fern species in Polynesian traditional medicine. Fronds or rhizomes of this species are common ingredients of popular medicine recipes to cure various ailments. M. grossum frond and rhizome extracts contain, as their main bioactive components, phytoecdysteroids such as 20-hydroxyecdysone, known to have many interesting biological activities and considered to be adaptogenic compounds [1]. The skin-active effect of M. grossum extract was investigated in two ways on human dermal fibroblasts: a transcriptomic study with c-DNA array for gene expression modulation and a Stress Induced Premature Senescence (SIPS) test. The total extract of M. grossum up-regulates Heme Oxygenase 1 (HO1), an enzyme which protects cells from oxidative stress and which is responsible for skin photoimmunoprotection. The present paper also reports that premature senescence of human skin induced by repeated UV irradiations can be prevented by an ecdysteroid fraction of M. grossum. Our data indicate that extracts of M. grossum could protect skin against oxidative stresses and suggest that they could be used as innovative active cosmetic ingredients.

Isolation and biological activity of compounds from Garcinia preussii.

CONTEXT: Plants of the genus Garcinia (Clusiaceae) are traditionally used to relieve stomachaches, toothaches, and as a chew stick. OBJECTIVE: In order to determine which compounds were responsible for these activities, a phytochemical investigation of the fruits and leaves of Garcinia preussii Engl. was pursued. MATERIALS AND METHODS: Plants were extracted by solvents of various polarities. Compounds isolation was then carried out using chromatography methods (medium- and high-pressure liquid chromatography, open column and thin-layer chromatography). The isolated compounds were identified and characterized by using 1D and 2D NMR spectroscopies. The antioxidant activity was evaluated using DPPH(•), ABTS(•-), ALP, and ORAC assays. The antimicrobial activity was assayed against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis by determining the minimum inhibitory concentration (MIC) value. The cytotoxic activity of most of the isolated compounds was evaluated on a small panel of human cancer cell lines (DU145, HeLa, HT-29, and A431) using the XTT method. RESULTS: The phytochemical investigation of G. preussii led to the isolation of eight known compounds, six benzophenones and two flavonoids. These compounds were tested for their biological activities. 1, 2, 3, 4, 7 and 8 demonstrated a high free radical scavenging activity with ER50 ranging from 0.1 to 0.7. The antimicrobial activity was shown only against Gram-positive bacteria for 1, 4, and 5. A moderate cytotoxic activity with IC50 ranging from 7 to 50 µM was observed, except for 6 which was not active. CONCLUSION: These results appear to support some of the properties reported for Garcinia species.

HPLC profiling with at-line microdilution assay for the early identification of anti-fungal compounds in plants from French Polynesia.

INTRODUCTION: The search for anti-fungal compounds has maintained a scientific interest notably due to existing difficulties in the treatment of mycoses and their increasing occurrence in hospitals. OBJECTIVE: Development of a simple method to rapidly identify anti-fungal compounds in crude plant extracts based on a HPLC microfractionation approach combined with an at-line anti-Candida assay. METHODS: The scale of the semi-preparative HPLC microfractionation was adapted to fit the sensitivity of the Candida albicans anti-fungal in a 96-well microdilution assay. This format is also compatible for MS and NMR dereplication of the active compounds. RESULTS: Based on the screening of 12 crude extracts of plants from French Polynesia, three plants, which displayed various levels of anti-fungal activities, were selected to assess the efficiency of the HPLC anti-fungal profiling and the scale necessary for microfractionation. The same anti-Candida assay was performed on the HPLC microfractions collected using a generic profiling method. Analysis of active microfractions by MS and NMR issued from the most active extract enabled an efficient dereplication of the compounds responsible for the anti-fungal activity. CONCLUSION: A generic HPLC anti-fungal profiling method was developed which revealed that only 50 mg of crude extract were sufficient for a rapid identification of compound(s) responsible for the anti-Candida activity. This approach was illustrated by the study of Alphitonia zizyphoides, a plant traditionally used to treat dermatomycoses.

E- and Z-isomers of new phytoecdysteroid conjugates from French Polynesian Microsorum membranifolium (Polypodiaceae) fronds.

Phytochemical investigation of the fronds of Microsorum membranifolium resulted in the isolation of a new phytoecdysteroid, E-2-deoxy-20-hydroxyecdysone 3-[4-(1-ß-D-glucopyranosyl)]-caffeate (1), together with two known phytoecdysteroids, E-2-deoxy-20-hydroxyecdysone 3-[4-(1-ß-D-glucopyranosyl)]-ferulate (2), E-2-deoxyecdysone 3-[4-(1-ß-D-glucopyranosyl)]-ferulate (3). Their respective Z-isomers 4-6 were also observed and identified for the first time. The new structures were elucidated on the basis of extensive spectroscopic data analysis (1D, 2D-NMR and HR-MS techniques).

Antimalarial activity of extract and norbergenin derivatives from the stem bark of Diospyros sanza-minika A. Chevalier (Ebenaceae).

The methanol extract from the stem bark of Diospyros sanza-minika as well as five norbergenin derivatives isolated from this crude extract were evaluated for their in vitro activity against Plasmodium falciparum K1 and cytotoxicity on MRC-5 cells. 4-O-(3'-methylgalloyl)norbergenin was found to be the most potent compound (IC(50) 0.6 µg/mL; CC(50) 24.7 µg/mL), followed by 4-O-galloylnorbergenin (IC(50) 3.9 µg/mL; CC(50) > 64 µg/mL) and 11-O-p-hydroxy-benzoyl-norbergenin (IC(50) 4.9 µg/mL; CC(50) > 64 µg/mL). Norbergenin and 4-O-syringoylnorbergenin were inactive (IC(50) > 32 µg/mL; CC(50) > 64 µg/mL). The antimalarial activity of the pure constituents and of the methanol extract from the stem bark of Diospyros sanza-minika is reported for the first time. The results provide interesting baseline information for the potential use of the crude extract well as some of the isolated compounds in the search for novel antimalarial compounds.

Detection by UPLC/ESI-TOF-MS of alkaloids in three Lycopodiaceae species from French Polynesia and their anticholinesterase activity.

Three Lycopodiaceae species from French Polynesia, Lycopodium venustulum C. Gaudichaud, Lycopodiella cernua (C. Linnaeus) R. E. Pichi Sermolli and Lycopodium henryanum E. D. Brown were investigated for their alkaloidal composition by UHPLC/ESI-TOF-MS. Ten alkaloids were identified, with lycopodine and lycodoline being the main constituents in the three species. The acetylcholinesterase-inhibitory activities of the three species are probably due to the occurrence of huperzine A, huperzine B, huperzine E, huperzinine and lycopodine.

Isolation of a new class of ecdysteroid conjugates (glucosyl-ferulates) using a combination of liquid chromatographic methods.

The Polynesian medicinal fern Microsorum membranifolium contains very large amounts of ecdysteroids, including ecdysone, 20-hydroxyecdysone, 2-deoxy-20-hydroxyecdysone, and 2-deoxyecdysone. It also contains large amounts of unusual ecdysteroids which have been unambiguously identified by mass spectrometry and nuclear magnetic resonance. A new class of ecdysteroid conjugates (3-glucosyl-ferulates of 2-deoxyecdysone and 2-deoxy-20-hydroxyecdysone) is isolated, together with a new glycoside (2-deoxyecdysone 25-rhamnoside). The simultaneous presence of a sugar and an aromatic moiety results in a very particular chromatographic behavior of these conjugates. They behave like flavonoids and polyphenols when using the classical purification on polyamide, aimed at removing the latter from crude plant extracts, and would therefore be lost. They elute as non-polar ecdysteroids on reversed-phase high-performance liquid chromatography (RP-HPLC), whereas their behavior on normal-phase (NP) HPLC is strongly dependent on the mobile phase composition. Our data highlight the importance of selectivity in the choice of HPLC methods used for ecdysteroid separations.

Ecdysteroids from the medicinal fern Microsorum scolopendria (Burm. f.).

Fronds of the fern Microsorum scolopendria are widely used in traditional medicine in the Society Islands. They were investigated for the presence of ecdysteroids, which might be responsible for at least some of their medicinal properties. M. scolopendria represents an excellent source of ecdysone (0.16% of dry weight) and 20-hydroxyecdysone (0.20%), and also contains significant amounts (0.01-0.02%) of makisterones A and C, inokosterone and amarasterone A, together with lower amounts of poststerone and of a compound tentatively identified as 24,28-diepi-cyasterone. During this study, three new minor phytoecdysteroids, namely 20-deoxymakisterone A, a 25(?)-epimer of amarasterone A and 25-deoxyecdysone 22-glucoside were also isolated by a combination of normal- and reversed-phase HPLC and subsequently identified by NMR.