Plants, food and treatments used by BaKongo tribes in Uíge (northern Angola) to affect the quality and quantity of human breast milk.

BACKGROUND: Angola has one of the highest annual under-five mortality rates in in the world and malnutrition poses a severe problem in the country. This study is the first to focus on the traditional knowledge of plants, foods, and treatments used by the local population in the province of Uíge to affect the quality and quantity of human breast milk, since decades of independence and civil war impeded ethnobotanical studies in this area. METHODS: This study was conducted in eight municipalities in the province of Uíge, Northern Angola in February and March 2018. In 265 semi-structured interviews, 360 informants in 40 rural villages were asked about plants, food, and treatments used to affect the quality and quantity of human breast milk. Additionally, information on child mortality and the duration of breastfeeding were collected. Whenever possible, plant specimens were collected for later identification. To determine the local importance of the collected plants, food, and treatments, the Relative Frequency of Citations was calculated. RESULTS: Most women reported to have no problems with their breast milk production. The duration of breastfeeding meets the recommendations of the World Health Organization (WHO). Across all use categories, 69 plants from 36 plant families, and 21 other foods and treatments could be identified. CONCLUSIONS: The study shows an overview of a variety of plants, foods, and treatments used by mothers as galactagogues, to "clean" or to reduce their breast milk and those which they avoided to use during the lactation period. There is great potential for further research into this traditional knowledge. Also, further analysis of some of the plants could be of interest.

Dihydrochalcone Glucosides from the Subaerial Parts of Thonningia sanguinea and Their in Vitro PTP1B Inhibitory Activities.

Six new and four known dihydrochalcone glucoside derivatives (1-10), the phenylpropanoid coniferin (11), and the lignans (+)-pinoresinol (12) and lariciresinol (13) were isolated from the subaerial plant parts of Thonningia sanguinea in the course of a screening campaign for new antidiabetic lead compounds. The structures of the new substances were elucidated by HRESIMS, NMR, GC-MS, and ECD data evaluation. 2'- O-(3-Galloyl-4,6- O- Sa-hexahydroxydiphenoyl-ß-d-glucopyranosyl)-3-hydroxyphloretin (4), 2'- O-(4,6- O- Sa-hexahydroxydiphenoyl-ß-d-glucopyranosyl)phloretin (5), 2'- O-(3- O-galloyl-4,6- O- Sa-hexahydroxydiphenoyl-ß-d-glucopyranosyl)phloretin (6), and thonningianin B (9) showed moderate protein tyrosine phosphatase-1B inhibition in an enzyme assay (IC50 values ranging from 19 to 25 µM), whereas thonningianin A (10) was identified as a more potent inhibitor (IC50 = 4.4 µM). The observed activity differences could be explained by molecular docking experiments. The activity of 10 could further be confirmed in HEPG2 liver carcinoma cells, where the compound was able to increase the level of phosphorylated insulin receptors in a concentration-dependent manner.

First large-scale ethnobotanical survey in the province of Uíge, northern Angola.

BACKGROUND: Angola suffered a long-lasting military conflict. Therefore, traditional knowledge of plant usage is still an important part of cultural heritage, especially concerning the still very poor health care system in the country. Our study documents for the first time traditional knowledge of plant use of local Bakongo communities in the northern province of Uíge on a large scale with a focus on medicinal plants and puts data in context to different parameters of age, gender and distance to the provincial capital. METHODS: Field work was carried out during nine field trips in 13 municipalities between October 2013 and October 2016. In 62 groups, 162 informants were interviewed. Herbarium specimens were taken for later identification. Database was analysed using Relative Frequency of Citations, Cultural Importance Index, and Informant Consensus Factor. Furthermore, significances of influence of age, gender and distance were calculated. RESULTS: Our study presents 2390 use-reports, listing 358 species in 96 plant families, while just three out of 358 mentioned species are endemic to Angola about one-fifth are neophytes. The larger the distance, the higher the number of use citations of medical plants. Although women represent just a fifth of all citations (22%), their contribution to medicinal plants was proportionally even higher (83%) than those of men (74%). Fifty percent of all plants mentioned in the study were just listed by men, 12% just by women. We made some new discoveries, for example. Gardenia ternifolia seems to be promising for treatment of measles, and Annona stenophylla subsp. cuneata has never been ethnobotanically nor phytochemically investigated. CONCLUSIONS: While the study area is large, no significant influence of the distance in regard to species composition in traditional healer's concepts of the respective village was pointed out. Although several plants were just mentioned by women or men, respectively, no significant restriction to gender-specific illnesses in medical plant use could be found. Merely concerning the age of informants, a slight shift could be detected. Visual representation of the ethnobotanical study in Uíge, northern Angola.

Medicinal plants of northern Angola and their anti-inflammatory properties.

ETHNOPHARMACOLOGICAL RELEVANCE: 32 plants, from which 30 are used in local traditional medicine - identified by interviews with the resident population - in the province of Uíge in northern Angola for the treatment of inflammation related disorders, were screened on different anti-inflammatory parameters. Three extracts were selected for a detailed ethnobotanical, pharmacological and phytochemical investigation based on their in vitro activity. AIM OF THE STUDY: We aimed to assess the in vitro anti-inflammatory activity of these plants and highlight the active principles of the three most promising candidates. MATERIALS AND METHODS: Plant material was collected in northern Angola during eight field trips from 2013 to 2015 based on data documented in 61 interviews with 142 local informants. 36 methanol (MeOH) extracts were prepared and tested at different concentrations (100, 50, 10µg/mL) to evaluate their inhibition on cyclooxygenase (COX)-2 expression and on nitric oxide (NO) release in lipopolysaccharide (LPS)-stimulated J774A.1 macrophages. Five selected extracts were additionally tested at the lower concentrations of 5, 2.5, and 1.25µg/mL and for their potential on inhibition of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) release. The major compounds of three of those five extracts were either identified by HPLC coupled with (tandem) mass spectrometry and comparison with data from literature or isolated from the respective extracts and confirmed by NMR experiments (one and two dimensional). RESULTS: 30 plant species with in total 161 citations were mentioned by the informants to have anti-inflammatory properties. The predominantly used plant part is the leaf (39%), followed by underground organs like roots and rhizomes (25%), bark (18%) as well as fruits and seeds with 15%. With 47%, decoction is the most frequent preparation form. A large number of the MeOH extracts showed promising activities in our preliminary screening for the inhibition of COX-2 expression and NO release. Five extracts with high activities in both assays showed also concentration dependent inhibition at lower concentrations and a decreased release of two additional pro-inflammatory mediators (IL-6 and TNF-α) vs. LPS. Three leaf extracts where chosen for a detailed investigation, which lead to the identification of several constituents: verbascoside and isoverbascoside (Acanthus montanus), geraniin, chebulagic acid and a large flavonoid fraction (Alchornea cordifolia) as well as the four flavonoids astilbin, isovitexin, isoorientin and swertisin (Chaetocarpus africanus). Their implication in the observed biological activity was proved by comparison with published data of these compounds in identical or similar pharmacological models. CONCLUSIONS: The indigenous use of these plants against inflammation related ailments could be - at least partly - verified by our in vitro models for many of the investigated extracts. Acanthus montanus and Alchornea cordifolia particularly stood out with their high activity in all four performed assays, which was in accordance with pharmacological studies of their major constituents in literature. In addition, this study was the first phytochemical investigation of Chaetocarpus africanus and first description of the occurrence of the ellagitannins geraniin and chebulagic acid in Alchornea cordifolia. These results support the traditional use and should encourage further investigations of medicinal plants of northern Angola.