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The in vivo anti-inflammatory and analgesic activities of the crude ethanol extract and chemical constituents of Clausena anisata roots were investigated. The crude extract, which was devoid of any visible acute toxicity, displayed significant anti-inflammatory effect at the dose of 1000 mg/kg (p.o.) when assessed using the carrageenan-induced oedema model. In the acetic acid-induced writhing and hot plate tests, it produced a very significant ( p < 0.001), dose-dependent analgesic effect, with maximum analgesic activity of 72.1% at 1000 mg/kg (p.o.). Phytochemical analysis of the crude extract resulted in the isolation of four coumarins (anisocoumarin B, osthol, imperatorin and xanthotoxol) and a carbazole alkaloid, heptaphylline. Among the isolated compounds, osthol and anisocoumarin B produced the highest anti-inflammatory activity at 9 mg/kg (p.o.): slightly better than the positive control, indomethacin. Except for xanthotoxol, all the isolated compounds administered at 6 mg/kg (p.o.) produced significant analgesic activity and higher than diclofenac; with heptaphylline being the most potent (48.7%). The analgesic activity of anisocoumarin B (50.4%) was the highest among the isolates tested and the standard, tramadol, in the hot plate test. The nonselective opioid receptor antagonist, naloxone, abolished the analgesic effect of the crude extract and the tested isolates (anisocoumarin B and xanthotoxol) in the hot plate test suggesting an effect via the central opioidergic system. These findings provide the scientific basis for the use of C. anisata roots in traditional medicine as anti-inflammatory and analgesic agents.

Paullinia pinnata L. (Sapindaceae) is an endemic West African plant that is extensively used in traditional medicine to treat various diseases. Previous phytochemical analysis by various groups led to the isolation of several novel lupene-based triterpenene derivatives along with other classes of compounds. As part of our continued phytochemical studies on the roots of this plant, we have now identified yet another novel triterpene, 6α-(3′-methoxy-4′-hydroxybenzoyl)-lup-20(29)-ene-3-one. The identification of the compound through comprehensive spectroscopic studies is discussed.

The fresh leaves of Moringa stenopetala (family, Moringaceae) are commonly eaten as cabbage while dried leaves are used as nutritional supplement and for treating a variety of disease conditions including diabetes. The present investigation into the therapeutic potential of the leaves and seeds of the plant revealed no inhibitory effect against α-glucosidase enzyme up to the concentration of 200 μg/mL but the leaves extract displayed potent DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect (IC50, 59.5 ± 4.1 μg/mL). An activity directed fractionation and isolation procedure resulted in the identification of the major antioxidant compound as rutin and minor active component, neochlorogenic acid. Both the crude extract (0.8–200 μg/mL) and rutin (0.8–200 μM) but not neochlorogenic acid displayed a concentration-dependent protection of human pancreatic β-cells (1.4E7 cells) from oxidant-induced cell death. The identification of these compounds along with their potential role in the nutritional and medicinal significance of the plant is discussed.

Berberis darwinii is native to South America but has been widely distributed in Europe and other continents following its discovery by Charles Darwin. Herewith, the therapeutic potential of stem-bark of the plant for treating Alzheimer's disease was studied using an in vitro acetylcholinesterase inhibition assay. It was found that the methanolic extract of the stem-bark was a potent inhibitor of the enzyme with an IC50 value of 1.23 ± 0.05 μg/mL. An HPLC-based berberine quantification study revealed an astonishing 38% yield of the dried methanolic extract.

Quercetin, kaempferol and to a lesser extent rutin have been reported to have antidiabetic activities when assessed by various assay models including in vitro α-glucosidase inhibition studies. A related structural analogue, kaempferol-3- O-rutinoside (KR) however has not yet been studied for such biological effects. It was found that KR is a potent inhibitor of α-glucosidase in vitro with over 8-times more activity than the reference antidiabetic drug, acarbose. Furthermore, KR displayed a synergistic effect with a less potent flavonoid aglycones, kaempferol and quercetin. The structure-activity profile of these drugs and implications of drug combinations are discussed.

The crude ethanolic extract of leaves, stem-bark and roots of J. flammea were tested for their cytotoxic effect against two mammalian cell lines (HeLa and RAW 264.7) and four bacterial species (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa). When tested at the concentration of 100 μg/mL, the root extract showed the highest cytotoxic activity against mammalian cells followed by the stem-bark extract while the leaves extract did not show significant activity. No antibacterial activity was detected for all extracts when tested up to 500 μg/disc in the disc diffusion assay. The cytotoxic root extract was subjected to fractionation using solvents of ascending polarity: petroleum ether, chloroform, ethylacetate, butanol and water. The water fraction which showed cytotoxic activity was further subjected to routine bioassay-guided fraction to lead to the isolation of sakurasosaponin as the active principle. The recorded IC50 value for sakurasosaponin was 11.3 ± 1.52 and 3.8 ± 0.25 μM (n=3) against HeLa and RAW 264.7 respectively. The identification of sakurasosaponin was based on analysis of spectroscopic data.

Activity-directed fractionation and isolation procedures were used to identify the antioxidant components of Boneset (Eupatorium perfoliatum). Dried powdered leaves were extracted with ethanol and subsequently fractionated into light petroleum, chloroform, ethyl acetate, and n-butanol fractions. The ethyl acetate fraction, which showed the strongest antioxidant activity, reducing power and highest phenolic content, was subjected to Sephadex LH-20 chromatography followed by repetitive preparative TLC to afford protocatechuic acid as the major antioxidant constituent, together with small amounts of other antioxidants (hyperoside, quercetin and rutin). Similar treatment of the n-butanol fraction, the second most potent fraction, yielded predominantly rutin and a trace amount of hyperoside as active constituents. The identity of the compounds was established based on direct comparison of spectral data (UV, IR, 1D- and 2D-NMR and MS) with those of authentic samples and literature values.

Activity-directed fractionation and isolation procedures were used to identify the antioxidant components of Peltiphyllum peltatum. Fresh leaves were extracted with ethanol and subsequently fractionated into light petroleum, chloroform, ethyl acetate, n-butanol, and water fractions. The ethyl acetate fraction, which showed the strongest antioxidant activity, was subjected to Sephadex LH-20 chromatography, followed by repetitive preparative TLC, to afford the major antioxidant principle, quercitrin, together with other antioxidants (isoquercitrin, catechin and gallate) as minor principles. The identities of the isolated compounds were established by spectroscopic methods (1D and 2D NMR and MS) and by direct comparison with authentic samples and literature values. Quercitrin displayed a potent protective effect of DNA from UV generated hydroxyl radical damage.