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The development of rootstocks that are less sensitive to abiotic and biotic stresses can help mitigate the negative effects of climate change on crop productivity, soil health, and water use. Though, the phenomenon of graft incompatibility is a significant limitation to the spread of new rootstock genotypes. Numerous studies have focused on this issue, highlighting the role of certain phenolic molecules as predictive markers of incompatibility. Given the lack of specific research on table grape, , this study proposes a protocol for the extraction of polyphenols from its woody tissues, which is a fundamental prerequisite for further analysis on secondary metabolites involved in graft incompatibility. The proposed eco-friendly method coupled a traditional maceration using solvent with a green technique utilizing an ultrasound-assisted extractor. The following parameters were compared: (1) sample weight (0.1 g, 0.5 g, and 1 g), (2) time of ultrasound-assisted extraction (10 min, 20 min, and 30 min), and (3) solvent volume for maceration (10 mL, 15 mL, and 20 mL). Four phenol classes were considered based on previous works on Vitis spp.: cinnamic acids, flavonols, benzoic acids, and catechins. The characterization of polyphenolic biomarkers was carried out via HPLC. 1 g of plant material, 30 minutes of sonification, and 20 mL of organic solvent was the combination of factors that resulted in the most efficient fingerprint, both quantitatively (267.68 ± 3.91 mg/100 g fresh weight [FW]) and qualitatively, with the four classes analyzed significantly represented. This is the first work to come up with an extraction protocol for phenol compounds in table grape woody tissue based on both ecological and routine techniques.

Morella spathulata (Myricaceae family) is a common plant from Madagascar and is present on the IUCN Red List of threatened species classified at the ’least concern’ level, used by the local population to treat numerous illnesses and pain. Despite its frequent use, comprehensive phytochemical and pharmacological research on the species is limited. This study evaluated the antioxidant, analgesic, and anti-inflammatory properties, as well as the toxicity of methanol extracts from the leaves (MS_L) and bark (MS_B) of M. spathulata. The research involved the analysis of nutritional traits such as sugars, organic acids, vitamin C, polyphenolic content (TPC) and the main phytochemicals by HPLC analysis. Antioxidant capacity was assessed through DPPH and FRAP assays. Analgesic and anti-inflammatory activities were evaluated using acetic acid-induced writhing and carrageenan-induced paw oedema tests in mice. The results showed a high content of phenolic and bioactive components in the leaf and bark extracts, associated with antioxidant, analgesic and anti-inflammatory properties. The interaction of key compounds such as ferulic acid and ellagic acid with proteins involved in pH regulation and immune modulation provides clues to the mechanisms underlying the therapeutic effects. However, conservation efforts are crucial due to habitat loss and illegal logging, and further studies are needed to fully explore the plant’s therapeutic potential.

Background: The aerial parts of Micromeria madagascariensis Baker and M. flagellaris Baker are used by the population of the Vakinankaratra and Itasy regions (Madagascar) to treat breathing difficulty, fever and/or headache, wounds, and sores. Purpose: This work aimed to characterise plant materials from M. madagascariensis and M. flagellaris to report i) chemical composition, ii) antimicrobial properties, and iii) antioxidant capacity of the essential oils extracted from the aerial parts of these species. Materials and methods: The essential oils from M. madagascariensis (MMO) and M. flagellaris (MFO) were obtained by hydrodistillation. Their chemical composition was quantified using gas chromatography coupled with mass spectrometry (GC-MS). MMO and MFO were also tested against 7 microbial strains using the disk diffusion method and their antioxidant capacity was assessed using the DPPH scavenging assay. Results: Hydrodistillation yielded 0.26% MMO and 0.29% MFO (w/w) in relation to the fresh weight. Twenty-seven compounds were identified by GC-MS in MMO extract against 36 in MFO one. The main compounds in MMO were pulegone (24.67%), trans-menthone (24.67%), eucalyptol (8.12%), β-caryophyllene (4.98%), α-guanene (4.47), iso-menthone (3.85%), iso-pulegone (3.34%), azulene (3.28%) and 2-isopropyl-5-methylcyclohexenone (2.82%). The main compounds in the MFO were eudesma-4,11-dien-2-ol (13.88%), δ-guanene (6.62%), pulegone (6.40%), cyperone (5.56%), 4-epi-dehydrobietinol acetate (5.39%), eucalyptol (5.12%), trans-menthone (4.67%), limonene (3.77%) and sabinene (2.29%). Regarding the chemotaxonomy, M. flagellaris was very different from M. madagascariensis and both species also differed from the other Micromeria species, as confirmed by multivariate statistical analysis. Both MMO and MFO exerted activities against a large microbial spectrum; the antimicrobial activity of MMO was higher than MFO one against S. pneumoniae and C. albicans due to the presence of pulegone as the main component. MFO showed an excellent scavenging capacity with an SC50 value of 2.17 ± 0.03 μg/mL. Conclusion: The biological properties of the essential oils extracted from the selected species may explain their therapeutic value showing that Malagasy Micromeria species may be very important as new natural sources of bioactive compounds. This study may promote the effectiveness and quality of Malagasy Micromeria species, contributing to sustainable development and commercial valorisation of traditional preparations based on natural local resources.

Antioxidants are important supplements for the human body for their roles in human life for the maintenance of homeostasis. Tapia fruits (Uapaca bojeri) are used by the riverain population of the Tapia forests in Madagascar as complementary foods. This study aims to quantify the main antioxidants in the U. bojeri fruits to verify their contribution to the enhancement of their anti-inflammatory and antihyperglycemic effects. Standard phytochemical screening was used for qualitative analysis, while spectrophotometric (TPC, TAC, and TFC) and chromatographic analyses (HPLC) were used to quantify several phytochemicals in U. bojeri fruits. The antioxidant activity was evaluated using DPPH and FRAP assays. The writhing test was used for the analgesic effects, the carrageenan-induced paw edema was used for the anti-inflammatory activity, and OGTT was used to test the anti-hyperglycemia property of the MEUB in mice. Several phytocompounds were detected and quantified in the fruits, including succinic acid (67.73%) as the main quantified compound. Fruits exerted a good antioxidant capacity and showed analgesic, anti-inflammatory, and antihyperglycemic activities in mice. Isolation of the bioactive compounds should be carried out to confirm these pharmacological properties and develop health-promoting food products or medicinal applications derived from this species.

Traditional medicine plays an important role in the Malagasy health system. In Madagascar, medicinal plants are the main remedies for several diseases, especially chronic diseases. Scientific studies are performed to valorize the use of Imperata cylindrica (Ic), Uapaca bojeri (Ub), Vaccinium secondiflorum (Vs), and Ravenala madagascariensis (Rm). Ic and Ub are used to treat some inflammatory-related diseases, Vs has an anti-diabetic value, and Rm is known as an antihypertensive. Phytochemical and pharmacological studies were carried out using standard scientific models to justify their properties. Firstly, the antioxidant, analgesic, anti-inflammatory, and/or vasorelaxant activities of their crude methanol extracts (ME) were evaluated according to ethnomedicinal information. The ME of Ic, Ub, and Vs showed potent antioxidant activities on DPPH and FRAP methods. These species are rich in phenolics, flavonoids, and organic acids, known for their antioxidant activities. They also possess significant analgesic and anti-inflammatory activities, respectively, assessed on the pain model caused by acetic acid (1%) and on inflammatory edema induced by carrageenan in mice. Sitostenone was isolated as an analgesic and anti-inflammatory compound from Ic. Ub and Vs ME significantly reduced the glycemia level after 30 min of glucose loading in mice compared to glibenclamide. Androsta-1,4-dien-3,16-dione was isolated as the vasorelaxant molecule from Rm, responsible for its antihypertensive activity. These results showed that there are some scientific reasons that can justify the therapeutic properties of these plants. It is very important to investigate the local use of biodiversity to identify new bioactive compounds, to support biodiversity conservation and sustainable development projects in Madagascar.

In recent years, research has focused on phenolic compounds and their putative role as markers of graft incompatibility. Thus far, no studies have been conducted on the role of phenolic compounds in chestnut (Castanea spp.). The present study investigated the content of phenolic compounds in different combinations of Castanea spp. cultivars and rootstocks. Analyses were performed on the inner and outer tissues of chestnut grafts at two phenological sampling stages. The separation, identification and quantification of the phenolic markers via HPLC were preceded by an ultrasonic green extraction. Two chromatographic methods were tested for a total of 15 phenol compounds. Flavonol compounds were not detected, while cinnamic acids were found in low concentrations. The amount of gallic acid turned out to be higher at the graft union of the incompatible combination (20.11 ± 1.47 mg/100 gFW vs. 8.94 ± 1.08 mg/100 gFW). The same pattern was observed for catechin (15.79 ± 1.83 mg/100 gFW vs. 9.63 ± 1.98 mg/100 gFW). Differences in tannin concentrations seemed to be species-specific, and were apparently not related to graft incompatibility. The present work underlines the potential application of certain phenol compounds for the early prediction of graft incompatibility in Castanea spp.

Uapaca bojeri is an endemic Malagasy plant used by the local population. This work aimed to evaluate antioxidant, anti-inflammatory, and antidiabetic activities of the methanol extracts of U. bojeri leaves and stems and to report their total phenolic content and the bioactive compound content by HPLC methods. Antioxidant capacity was determined by DPPH and ferric reducing antioxidant power (FRAP) assays. An in vivo carrageenan-induced paw oedema and acetic acid-induced writhing test in mice were used for anti-inflammatory activity evaluation. An oral glucose tolerance test was performed in mice to evaluate antidiabetic activity. The total bioactive compound content of leaves was higher than that of stems. Stem methanol extract inhibited the free radical DPPH more than the leaf methanol extract. Leaf methanol extract inhibited, in a dose-dependent manner, the carrageenan-induced paw oedema more than the stem extract, but their inhibition of the pain symptoms caused an acetic acid-induced decrease similar to the number of writhes in the dose-dependent case. The leaf and stem methanol extracts significantly reduced blood glucose levels after 30 min of glucose loading in mice compared to the control group blood glucose reduction. The presence of several bioactive compounds in U. bojeri contributed to the different biological activities, but isolation and identification of these bioactive molecules are necessary to confirm these pharmacological properties.