Ellagitannin, Phenols, and Flavonoids as Antibacterials from Acalypha arvensis (Euphorbiaceae).

There is a significant need to gain access to new and better antibacterial agents. Acalypha arvensis, a plant from the Euphorbiaceae family, has been used in traditional medicine for centuries to treat infectious diseases. This manuscript reports the isolation, characterization, and antibacterial screening of 8 natural products extracted from maceration of aerial parts of Acalypha arvensis. Specifically, three extracts were assessed (n-hexane, ethyl acetate, and ethanol), in which antibacterial activity was evaluated against diverse bacterial strains. The ethanolic extract showed the best activity against methicillin-sensitive and methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa strains, which supports the medicinal properties attributed to this plant. The chromatographic fractions AaR4 and AaR5 were the most bioactive, in which the ellagitannin natural product known as corilagin (1) was identified for the first time in this plant. Therefore, it can be said that this is the main chemical responsible for the observed antibacterial activity. However, we also identified chlorogenic acid (2), rutin (3), quercetin-3-O-glucoside (4), caffeic acid (5), among others (6-8). Hence, this plant can be considered to be a good alternative to treat health-related issues caused by various bacteria.

Anti-arthritic and anti-inflammatory effects of Baccharis conferta Kunth in a kaolin/carrageenan-induced monoarthritis model.

ETHNOPHARMACOLOGICAL RELEVANCE: Popularly known as "escoba" (broom) or "escobilla china" (Chinese brush), Baccharis conferta Kunth (Asteraceae), is a plant widely used in Mexican folk medicine for alleviating muscular and rheumatic pain. A recent study described that dichloromethane extract as well as fractions and isolated compounds, possess anti-inflammatory activity in TPA-induced acute edema. AIM OF THE STUDY: Based on the popular medicinal uses of B. conferta as well as previous studies on its anti-inflammatory activity, the aim of this research was to evaluate the anti-arthritic and anti-inflammatory effects of dichloromethane extract, fractions, and compounds from B. conferta in a monoarthritis model induced with kaolin/carrageenan (K/C). MATERIALS AND METHODS: Aerial parts of B. conferta were collected, dried, and macerated with dichloromethane. The dichloromethane extract (BcD) was separated by open column chromatography to obtain the BcD2 fraction where the diterpene kingidiol (KIN) was isolated and from the BcD3 fraction the flavonoid cirsimaritin (CIR), which are the most active compounds in the TPA model. In addition, the flavonoids acacetin, pectolinaringenin and 6-methoxykaempferide were identified and isolated from the BcD2 fraction. The content of the main compounds was estimated in BcD, BcD2 and BcD3. The anti-arthritic and anti-inflammatory effects of B. conferta were investigated by evaluating ankle joint inflammation, hyperalgesia using the hot plate test, and pro- and anti-inflammatory cytokine levels in the synovial capsule as well as histological changes in ankle joint tissue in a monoarthritis model induced with K/C in Balb/c mice. RESULTS: Oral administration of BcD2 fraction (25 mg/kg) and KIN (10 mg/kg) reduced the ankle thickness induced by K/C and decreased the levels of TNF-α, IL-1ß, IL-6 and IL-17, while BcD2 increased IL-10. In addition, BcD2 and KIN showed significant edema attenuation of the synovial membrane and decreased inflammatory infiltration and cartilage erosion compared to the VEH group. Finally, BcD (50 mg/kg), KIN (10 mg/kg) and CIR (5 mg/kg) decreased hyperalgesia. CONCLUSIONS: B. conferta constitutes a therapeutic or preventive candidate for osteoarthritis, because of decreased articular inflammation and pain accompanied with the modulation of cytokine concentrations, which confirms the anti-arthritic and anti-inflammatory activities of B. conferta and support its popular use.

Antidiabetic Activity of Xoconostle Fruit from Opuntia matudae Scheivar in Mice.

In Mexico, Cactaceae plants are widely used in folk medicine for the treatment of diabetes. The genus Opuntia spp. Opuntia matudae Sheinvar prickly pears are known as xoconostle and are used in Mexican cuisine for their acidic flavor. Currently there are few reports of pharmacological properties of this plant, which include antioxidant and antimicrobial activities. This study focuses on the chemical characterization of the methanolic (OmMe) and aqueous (OmAq) extracts and the evaluation of the antidiabetic activity of O. matudae fruits in two biological models. For the in vivo model, streptozotocin (STZ)-induced diabetic mice were used, and for the in vitro model, liver sections isolated from healthy mice were used. The OmAq (100 mg/kg, oral pathway [p.o.]) extract decreased postprandial glucose peak at 0.5 h after glucose uptake by 43.1%, similarly, OmMe (100 mg/kg, p.o.) extract reduced postprandial glucose peak at 0.5 h by 34.1% in healthy mice. The effect of the two extracts and the fraction of the mixture of unidentified betalains (OmB) of O. matudae evaluated in the isolated mouse liver slice model showed a concentration-dependent decrease in hepatic glucose output (HGO) with and without insulin administration with the OmMe extract. The OmAq extract, however, showed concentration-dependent increases of HGO with and without insulin, and the OmB fraction generally exhibited an insulin mimetic effect. Moreover, both OmAq and OmMe extracts were tested in mice with STZ-induced diabetes (160 mg/kg, intraperitoneal route), using a semichronic daily administration (2-28 days after diabetes onset) of OmAq extract was able to reduce blood glucose by 34.3%, meanwhile OmMe extract reduced blood glucose by 22.9%, 28 days after diabetes onset. We identified five compounds (1-5) in the two extracts, consisting of two phenolic acids (1, 2), three flavanols (3-5), as well as two unidentified betalains. Therefore, we conclude that the aqueous extract of the xoconostle fruit where betalains are present may be useful for the treatment of diabetes mellitus.

Angiotensin-converting enzyme inhibitors from Salvia elegans Vahl.

Phytochemical research of the acetate and methanol extracts of the aerial parts (flowers, leaves and stems) of Salvia elegans allowed to obtain seventeen known compounds (1-17): three of them (4, 5, 14), had already been described for this species, while the others (1-3, 6-13, 15-17) are described for the first time for S. elegans. All isolated compounds were characterized using spectroscopic techniques and mass spectrometry and were evaluated in the Angiotensin I-converting enzyme (ACE) inhibition model, where the phenolic compounds (13, 14 and 15) had the same inhibitory effect as lisinopril at 0.02 mg/mL. The terpenes showed a moderate inhibitory capacity at a concentration of 0.2 mg/mL.

Antibacterial activity of Morinda citrifolia Linneo seeds against Methicillin-Resistant Staphylococcus spp.

In traditional medicine, Morinda citrifolia (Noni) is used to treat various ailments, including skin and respiratory-tract infections. In this work, a bio-directed study (seed extracts) with five bacteria was carried out against four clinical isolates of Methicillin-Resistant Staphylococcus (MRS) and Staphylococcus aureus ATCC 29213 strain to find molecules capable of inhibiting them. Three organic extracts were obtained by maceration of the noni seeds with ascending polarity solvents (n-hexane, dichloromethane and methanol) that were evaluated as antibacterial in the model of bioautography and broth microdilution techniques. The results showed that the methanolic extract was the most active against all bacteria (MIC = 16 mg/mL). The chromatographic fractionation performed on this extract allowed obtaining six fractions (EMF1-EMF6), of which F1, F2 and F5 exhibited activity against some of the bacteria. EMF1 fraction reached an MIC of 25 µg/mL against S. haemolyticus twice as much as the positive control, in which the chemical content is mainly composed of a mixture of γ-butyrolactones (1-2) and esterified fatty acids (3-9); chemical characterization of the nine compounds was carried out based on gas chromatography coupled to masses. EMF2 fraction, presented an MIC of 200 µg/mL against S. aureus 0198 and S. haemolyticus 562B, where a coumarin known as scopoletin (10) was isolated and active against S. aureus 0198 (MIC = 100 µg/mL). EMF5 fraction demonstrated an MIC of 200 µg/mL against S. aureus 0198, S. haemolyticus 562B and S. epidermidis 1042, in which a neolignan known as americanin A (11) was identified, showing activity against S. haemolyticus 562B and S. epidermidis 1042 (MIC = 100 µg/mL). The chemical characterization of isolated compounds 10 and 11 was performed by the analysis of 1H and 13C NMR. Therefore, the methanolic extract, identified and isolated compounds showed important antibacterial activity against the MRS, validating its use in traditional medicine.