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Croton macrostachyus is an important plant in traditional African medicine, widely utilized to treat a variety of diseases. In Kenya, HIV-infected patients use leaf and root decoctions of the plant as a cure for cough, back pain, bleeding, skin diseases, warts, pneumonia, and wounds. This study aimed to evaluate the anti-HIV activities and cytotoxic effects of extracts and chemical constituents isolated from C. macrostachyus. In our previous study we demonstrated that the hexane, CH 2 Cl 2 , ethyl acetate and methanol soluble fractions of a 1:1 v/v/ CH 2 Cl 2 /MeOH crude extracts of the leaves and stem bark of C. macrostachyus exhibited potent anti-HIV activities against HIV-1 with IC 50 values ranging from 0.02-8.1 μg/mL and cytotoxicity effects against MT-4 cells ranging from IC 50  = 0.58-174 μg/mL. Hence, hexane soluble extract of 1:1 v/v/ CH 2 Cl 2 /MeOH crude extract of the leaves of C. macrostachyus, that was more potent against HIV-1 at IC 50  = 0.02 μg/mL was subjected to column chromatography leading to the isolation of 2-methoxy benzyl benzoate (1), lupenone (2), lupeol acetate (3), betulin (4), lupeol (5), sitosterol (6) and stigmasterol (7). Lupenone (2), lupeol acetate (3) and betulin (4) exhibited anti-HIV-1 inhibition at IC 50  = 4.7 nM, 4.3 and 4.5 μg/mL respectively. The results obtained from this study support the potential of C. macrostachyus, as a source of anti-HIV constituents., (© 2022. The Author(s).)

The dichloromethane/methanol (1:1) extracts of the roots of Pentas longiflora and Pentas lanceolata showed low micromolar (IC(50) = 0.9-3 µg/mL) IN VITRO antiplasmodial activity against chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of PLASMODIUM FALCIPARUM. Chromatographic separation of the extract of PENTAS LONGIFLORA led to the isolation of the pyranonaphthoquinones pentalongin (1) and psychorubrin (2) with IC(50) values below 1 µg/mL and the naphthalene derivative mollugin (3), which showed marginal activity. Similar treatment of Pentas lanceolata led to the isolation of eight anthraquinones ( 4-11, IC(50) = 5-31 µg/mL) of which one is new (5,6-dihydroxydamnacanthol, 11), while three--nordamnacanthal (7), lucidin-ω-methyl ether (9), and damnacanthol (10)--are reported here for the first time from the genus Pentas. The compounds were identified by NMR and mass spectroscopic techniques., (© Georg Thieme Verlag KG Stuttgart · New York.)

The chloroform extract of the stem bark of Erythrina burttii showed antifungal and antibacterial activities using the disk diffusion method. Flavonoids were identified as the active principles. Activities were observed against fungi and Gram(+) bacteria, but the Gram(-) bacteria Escherichia coli was resistant.

Background: Acquired immunodeficiency syndrome (AIDS) is a clinical syndrome resulting from infection with human immunodeficiency virus (HIV), which causes profound immunosuppression. Anti-HIV drugs that are currently available are chemically synthesized and are frequently limited by side effects, the emergence of drug resistance, affordability, and availability, with over 5 million people in the world lacking access to treatment. As a result, to discover new anti-HIV agents, we investigated the effects of Kenyan C. dichogamus extracts on the laboratory-adapted strain HIV-1IIIB in human T-lymphocytic MT-4 cells. Methods: Four soluble fractions of 1:1 v/v CH2Cl2:MeOH extract of the twigs of C. dichogamus Pax were tested for their replication inhibition activity against the laboratory-adapted strain HIV-1IIIB in the human T-lymphocytic MT-4 cell line. The plant extracts were further evaluated for their cytotoxicity in MT-4 cells using the MTT assay. Results: The cytotoxicity CC50 values of the methanol and methylene chloride soluble fractions of C. dichogamus were found to be between 19.58 ± 0.79 and 167 ± 0.8 µg/ml, respectively. The hexane, methylene chloride, and methanol soluble fractions of the 1:1 v/v CH2Cl2:MeOH extract of the twigs of C. dichogamus showed inhibition of the HIV-1IIIB laboratory-adapted strain in a virus-infected cell culture antiviral assay. The methanol soluble fraction of the 1:1 v/v CH2Cl2:MeOH extract of the twigs of C. dichogamus showed significant anti-HIV activity by inhibiting more than 90% of viral-induced cytopathic effects with an IC50 value of 0.06 ± 0.01 µg/ml, giving an SI of 318.5. Conclusion: Based on our findings, the methanol soluble fraction of the 1:1 v/v CH2Cl2:MeOH extract of the twigs of C. dichogamus has shown potential efficacy in inhibiting viral replication and could be considered a promising candidate for further studies. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of Tephrosia vogelii seedpods led to the isolation of twelve compounds: vogelisoflavone A (1), vogelisoflavone B (2), isopongaflavone (3), onogenin, luteolin, 4′,7-dihydroxy-3′-methoxyflavanone, trans - p -hydroxycinnamic acid, tephrosin, 2-methoxygliricidol, dehydrorotenone, 6a,12a-dehydro-α-toxicarol and pinoresinol. Compounds 1 and 2 are reported as new natural products. Isopongaflavone (3) was structurally modified using hydrazine to pyrazoisopongaflavone (4). These compounds were characterized based on their NMR and HRESIMS data. Further, four compounds (1–4) were evaluated for their anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs). Treatment of the LPS-stimulated PBMCs with the compounds at a concentration of 100 μM suppressed the secretion of interleukin IL-1β interferon-gamma (IFN-γ), granulocyte macrophage-colony stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-α). Unlabelled Image • Twelve compounds were isolated from Tephrosia vogelii seedpods. • Two new isoflavones vogelisoflavone A (1) and vogelisoflavone B (2) are reported as new compounds. • Isopongaflavone was modified using hydrazine to pyrazoisopongaflavone. • The compounds exhibited anti-inflammatory effects. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Medicinal plants play a major role in many communities across the world, in the treatment and prevention of disease and the promotion of general health. The aim of the study was to escalate documentation from an earlier study of medicinal plants, traditionally used to combat malaria by the Ameru community of Imenti Forest area and Gatunga in Eastern Region of Kenya, and validate their ethnopharmacological claims by evaluating their antiplasmodial efficacies. Materials and methods The study was carried out in Meru County at Imenti Forest Game Reserve and in Tharaka Nithi County at Gatunga. Traditional health practitioners (THP) were interviewed with a standard questionnaire to obtain information on medicinal plants traditionally used for management of malaria. Group interviews were also held among THPs and members of the community. The antiplasmodial activities of the crude extracts against chloroquine sensitive (D6) and resistant (W2) Plasmodium falciparum were determined using the semi-automated micro-dilution technique that measures the ability of the extracts to inhibit the incorporation of (G-3H) hypoxanthine into the malaria parasite. Results Ninety nine (99) species in eighty one (81) genera and forty five (45) families were documented and evaluated for in vitro antiplasmodial activity. Compositae, Fabaceae, Meliceae, Rubiaceae, Rutaceae and Verbenaceae had the highest number of species mentioned in treatment of malaria in Meru/Tharaka Nithi study area. Twenty four (24.2%) species showed antiplasmodial efficacy of IC 50 ≤5 µg/ml and were considered to have potential for isolation of antimalarial compounds. Eight plant (8) species with moderate antiplasmodial activity namely; Cordia africana , Commiphora africana , Elaeodendron buchananii , Gomphocarpus semilunatus, Tarena graveolens , Plectranthus igniarius , Acacia senegal and Ziziphus abyssinica were documented from this region for the first time for the treatment of malaria. The antiplasmodial activity of MeOH root bark extract of Maytenus obtusifolia was very promising (IC 50 <1.9 µg/ml) and this is the first report on traditional use of M. obtusifolia for treatment of malaria and antimalarial activity. Conclusions The results seem to indicate that ethnopharmacological inquiry used in search for new herbal remedies as predictive and could be used as the basis for search of new active principles. Eight plant (8) species are documented from this region for the first time for the treatment of malaria. This is the first report on traditional use of M. obtusifolia for treatment of malaria and evaluation of its antiplasmodial activity. [ABSTRACT FROM AUTHOR]

The CH 2 Cl 2 /MeOH (1:1) extract of the stems of Tephrosia uniflora yielded the new β-hydroxydihydrochalcone (S)-elatadihydrochalcone-2'-methyl ether (1) along with the three known compounds elongatin (2), (S)-elatadihydrochalcone (3), and tephrosin (4). The structures were elucidated by NMR spectroscopic and mass spectrometric data analyses. Elongatin (2) showed moderate antibacterial activity (EC 50 of 25.3 μM and EC 90 of 32.8 μM) against the Gram-positive bacterium Bacilus subtilis , and comparable toxicity against the MCF-7 human breast cancer cell line (EC 50 of 41.3 μM). Based on the comparison of literature and predicted NMR data with that obtained experimentally, we propose the revision of the structures of three β-hydroxydihydrochalcones to flavanones. [Display omitted] [ABSTRACT FROM AUTHOR]

Five known compounds (1 – 5) were isolated from the extract of Mundulea sericea leaves. Similar investigation of the roots of this plant afforded an additional three known compounds (6–8). The structures were elucidated using NMR spectroscopic and mass spectrometric analyses. The absolute configuration of 1 was established using ECD spectroscopy. In an antiplasmodial activity assay, compound 1 showed good activity with an IC 50 of 2.0 μM against chloroquine-resistant W2, and 6.6 μM against the chloroquine-sensitive 3D7 strains of Plasmodium falciparum. Some of the compounds were also tested for antileishmanial activity. Dehydrolupinifolinol (2) and sericetin (5) were active against drug-sensitive Leishmania donovani (MHOM/IN/83/AG83) with IC 50 values of 9.0 and 5.0 μM, respectively. In a cytotoxicity assay, lupinifolin (3) showed significant activity on BEAS-2B (IC 50 4.9 μM) and HePG2 (IC 50 10.8 μM) human cell lines. All the other compounds showed low cytotoxicity (IC 50 > 30 μM) against human lung adenocarcinoma cells (A549), human liver cancer cells (HepG2), lung/bronchus cells (epithelial virus transformed) (BEAS-2B) and immortal human hepatocytes (LO2) Unlabelled Image [ABSTRACT FROM AUTHOR]

Four new steroidal sapogenins, dracaenogenins C F (1 – 4), a new conjugated chalcone-stilbene, 3′′-methoxycochinchinenene H (5) together with eight known compounds namely, (25 S)-spirosta-1,4-dien-3-one (6), trans -resveratrol (7), 4,4′-dihydroxy-3′-methoxychalcone (8), N - trans -coumaroyltyramine (9), N - trans - p -coumaroyloctopamine (10), N - trans -feruloyloctopamine (11), 7-hydroxy-1-(4-hydroxy-3-methoxyphenyl)- N 2 , N 3 - bis (4-hydroxyphenethyl)-6-methoxy-1,2-dihydronaphthalene-2,3-dicarboxamide (12) and grossamide (13) were isolated from the stems of Dracaena usambarensis Engl. from Kenya. It is important to note that compounds 12 and 13 are being reported from this genus for the first time. Structural elucidation of the isolated compounds was done using spectroscopic (NMR, UV, IR, optical rotation) and spectrometric (HRESIMS) techniques. The absolute and relative configurations of the isolated compounds were determined by employing single crystal X-ray crystallography analysis, NOESY correlations and coupling constants. The anti-inflammatory potencies of the isolated compounds were evaluated by measuring the levels of four cytokines (IL-1β, IL-2, GM-CSF and TNF-α) in the supernatant media of human peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS). At the tested concentration of 100 μM, the new conjugated chalcone-stilbene 5 , the dihydrochalcone, 8 and the lignanamide, 13 were substantially more potent than the standard drug, ibuprofen, inhibiting the release of all the cytokines, IL-1β , IL-2, GM-CSF and TNF-α from 0.06–58.04% compared to LPS control. These compounds should therefore be considered for development into anti-inflammatory drug candidates. Compound 7 significantly decreased the release of GM-CSF (6.11% of LPS control) and TNF-α (18.35% of LPS control). The cytokine TNF-α was sensitive to all the tested compounds 1 - 13. Unlabelled Image • Thirteen secondary metabolites isolated from the stem bark of Dracaena usambarensis. • Four new steroidal sapogenins, 1 - 4 and a new conjugated chalcone-stilbene, 5. • The relative configuration of 1 was confirmed with X-ray analysis. • Inhibitory activity of 5 , 8 and 13 , was higher than ibuprofen against all cytokines. [ABSTRACT FROM AUTHOR]