Antiarthritic and Antioxidant Activities of Antrocaryon micraster Seed Extract and Its Fractions.

Rheumatoid arthritis (RA) is an incurable debilitating disease which attacks the joints and impairs quality of life. Antrocaryon micraster is used to treat RA in African traditional medicine. However, its antiarthritic activity has not been pharmacologically studied. This study, therefore, reports the antiarthritic and antioxidant activities of A. micraster seed extract and its fractions. The seed extract (ASE) was produced by Soxhlet extraction and partitioned into petroleum ether (ASEP), ethyl acetate (ASEE), and aqueous (ASEA) fractions. The total polyphenolic content, DPPH antioxidant activity, and in vitro arthritic activity using the protein denaturation assay were evaluated for ASE and its fractions. The arthritic activity of the crude extract (ASE) and its most effective fraction (ASEA), in the in vitro assay, were then evaluated against CFA-induced arthritis in rats. The polyphenolic constituent of ASE was estimated to be 13.00 ± 0.00 mg/100 mg of GAE. ASEA contained the highest quantity of polyphenolic constituents (10.76 ± 0.00 mg/100 mg of GAE) among the fractions of the extract. ASE and ASEA produced profound antioxidant activity (IC50 = 20.17 ± 1.291 and 19.35 ± 0.865, respectively) which were similar to that of ascorbic acid (IC50 = 17.35 ± 0.500) in the DPPH free radical scavenging assay. Furthermore, in vitro antiarthritic activity of ASEA was 13.63 and 5.75 times higher than the antiarthritic activity of the crude extract and diclofenac sodium, respectively. In the CFA-induced arthritis assay, both ASE and ASEA significantly (P < 0.001) inhibited cachexia, paw edema, infiltration of inflammatory cells, pannus formation, and synovium damage. These results indicate that A. micraster seed extract and its fractions possessed significant antiarthritic activity via inhibition of oxidative stress, inflammation, protein denaturation, infiltration of inflammatory cells, and synovium injury due to its constituents such as polyphenols and phytosterols.

Assessment of the phytochemical composition and antimicrobial properties of Tapinanthus bangwensis leaves hosted by the branches of Persea americana.

BACKGROUND: Medicinal plants represent a valuable source for new effective and safe antimicrobial drugs making them an alternative therapy. Existing antimicrobial agents are costly and mostly associated with possible side effects. The aim of the present study therefore, was to assess the antimicrobial property and phytochemical composition of hydroethanolic extract of Tapinanthus bangwensis leaves and its fractions. METHOD: T. bangwensis leaves (harvested from its host plant, Persea americana) was extracted by cold maceration with 70% ethanol and further fractionated with different organic solvents using the solvent partitioning method to obtain the crude extract, petroleum ether, chloroform, ethyl acetate and the resulting aqueous fractions. The phytochemical constituents of the extracts were screened and quantified. Also, the TLC of the extracts were analyzed to serve as a fingerprint. Using the agar diffusion and broth dilution methods, the antimicrobial properties of the extracts were assessed. RESULTS: The study showed that the hydroethanolic (70%) crude extract of T. bangwensis leaves and its fractions contain phenolic compounds, flavonoids, saponins, phytosterols and reducing sugars. The phytoconstituents were well extracted into the ethyl acetate fraction than the other fractions evidenced in the high levels (p < 0.0001) of saponins (66.47 ± 1.72% w/w), phenolic compounds (77.75 ± 1.06 mg/100 mg GAE) and flavonoids (44.34 ± 0.06 mg/100 mg QE) contents. From the antimicrobial studies, all the microorganisms tested exhibited varying degrees of susceptibility to the extracts with MIC values between 0.78 to 12.5 mg/mL. The crude extract of T. bangwensis leaves, its ethyl acetate and chloroform fractions also exhibited lethal antimicrobial activity with MLC between 6.25 to 50 mg/mL. CONCLUSION: The crude extract of T. bangwensis leaves and its fractions demonstrated antimicrobial properties against Escherichia coli, Staphylococcus aureus, Staphylococcus saprophyticus and Candida albicans, thereby representing a potential source of natural antimicrobial agent. Further study is required to identify and isolate antimicrobial compounds from the plant for the development of the natural bioactive antimicrobial agents.

In vitro effects and mechanisms of action of Bidens pilosa in Trypanosoma brucei.

Background and aim: African trypanosomiasis poses serious health and economic concerns to humans and livestock in several sub-Saharan African countries. The aim of the present study was to identify the antitrypanosomal compounds from B. pilosa (whole plant) through a bioactivity-guided isolation and investigate the in vitro effects and mechanisms of action against Trypanosoma brucei (T. brucei). Experimental procedure: Crude extracts and fractions were prepared from air-dried pulverized plant material of B. pilosa using the modified Kupchan method of solvent partitioning. The antitrypanosomal activities of the fractions were determined through cell viability analysis. Effects of fractions on cell death and cell cycle of T. brucei were determined using flow cytometry, while fluorescence microscopy was used to investigate alterations in cell morphology and distribution. Results and conclusion: The solvent partitioning dichloromethane (BPFD) and methanol (BPFM) fractions of B. pilosa exhibited significant activities against T. brucei with respective half-maximal inhibitory concentrations (IC50s) of 3.29 µg/ml and 5.86 µg/ml and resulted in the formation of clumpy subpopulation of T. brucei cells. Butyl (compound 1) and propyl (compound 2) esters of tryptophan were identified as the major antitrypanosomal compounds of B. pilosa. Compounds 1 and 2 exhibited significant antitrypanosomal effects with respective IC50 values of 0.66 and 1.46 µg/ml. At the IC50 values, both compounds significantly inhibited the cell cycle of T. brucei at the G0-G1 phase while causing an increase in G2-M phase. The results suggest that tryptophan esters may possess useful chemotherapeutic properties for the control of African trypanosomiasis.

Antrocaryon micraster (A. Chev. And Guillaumin) stem bark extract demonstrated anti-malaria action and normalized hematological indices in Plasmodium berghei infested mice in the Rane's test.

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria is caused by infection with some species of Plasmodium parasite which leads to adverse alterations in physical and hematological features of infected persons and ultimately results in death. Antrocaryon micraster is used to treat malaria in Ghanaian traditional medicine. However, there is no scientific validation of its anti-malaria properties. The plant does not also have any chemical fingerprint or standardization parameters. AIM OF THE STUDY: This study sought to evaluate the anti-malaria activity of standardized A. micraster stem bark extract (AMSBE) and its effect on mean survival time (MST) and body weight reduction of Plasmodiumberghei infested mice. And to study the effect of treatment of AMSBE on hematological indices of the P. berghei infested mice in order to partly elucidate its anti-malarial mechanism of action. MATERIALS AND METHODS: Malaria was induced in female ICR mice by infecting them with 0.2 mL of blood (i.p.) containing 1.0 × 107P. berghei-infested RBCs from a donor mouse and leaving them without treatment for 3 days. AMSBE or Lonart (standard control) was then orally administered at 50, 200 and 400 mg/kg or 10 mg/kg once daily for 4 consecutive days. The untreated control received sterile water. Malaria parasitemia reduction, anti-malarial activity, mean change in body weight and MST of the parasitized mice were evaluated. Furthermore, changes in white blood cells (WBCs), red blood cells (RBCs), platelets count, hemoglobin (HGB), hematocrit (HCT) and mean corpuscular volume (MCV) were also determined in the healthy animals before infection as baseline and on days 3, 5 and 8 after infection by employing complete blood count. Standardization of AMSBE was achieved by quantification of its constituents and chemical fingerprint analysis using UHPLC-MS. RESULTS: Administration of AMSBE, standardized to 41.51% saponins and 234.960 ± 0.026 mg/g of GAE phenolics, produced significant (P < 0.05) reduction of parasitemia development, maximum anti-malaria activity of 46.01% (comparable to 32.53% produced by Lonart) and significantly (P < 0.05) increased body weight and MST of P. berghei infected mice compared to the untreated control. Moreover, there were significant (P > 0.05) elevation in WBCs, RBCs, HGB, HCT and platelets in the parasitized-AMSBE (especially at 400 mg/kg p.o.) treated mice compared to their baseline values. Whereas, the non-treated parasitized control recorded significant reduction (P < 0.05) in all the above-mentioned parameters compared to its baseline values. The UHPLC-MS fingerprint of AMSBE revealed four compounds with their retention times, percentage composition in their chromatograms and m/z of the molecular ions and fragments in the spectra. CONCLUSIONS: These results show that A. micraster stem bark possessed significant anti-malaria effect and also has the ability to abolish body weight loss, leucopenia, anemia and thrombocytopenia in P. berghei infected mice leading to prolonged life span. The UHPLC-MS fingerprint developed for AMSBE can be used for rapid authentication and standardization of A. micraster specimens and herbal preparations produced from its hydroethanolic stem bark extract to ensure consistent biological activity. The results justify A. micraster's use as anti-malaria agent.

Antitrypanosomal Effects of Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler Extracts on African Trypanosomes.

African trypanosomiasis is a disease caused by the parasitic protozoa of the Trypanosoma genus. Despite several efforts at chemotherapeutic interventions, the disease poses serious health and economic concerns to humans and livestock of many sub-Saharan African countries. Zanthoxylum zanthoxyloides (Lam.) Zepern. & Timler (Z. zanthoxyloides LZT) is a plant species of important phytochemical and pharmacological relevance in the subtropical zones of the African continent. However, the mechanisms of its antitrypanosomal effects in African trypanosomes remain to be elucidated. The aim of the study was to determine the in vitro effects and mechanisms of action of Z. zanthoxyloides LZT (root) fractions against Trypanosoma brucei. T. brucei (GUTat 3.1 strain), L. donovani (D10 strain), P. falciparum (3D 7 strain), Jurkat cells, and Chang liver cells were cultivated in vitro to the log phase in their respective media at 37°C. Crude extracts and fractions were prepared from air-dried pulverized plant material of Z. zanthoxyloides LZT (root) using the modified Kupchan method of solvent partitioning. Half-maximal inhibitory concentrations (IC50) were determined through the alamar blue cell viability assay. Effects of fractions on cell death and cell cycle of T. brucei were determined using flow cytometry. Fluorescence microscopy was used to investigate the effects of fractions on the morphology and distribution of T. brucei. Antitrypanosomal compounds of fractions were characterized using high-performance liquid chromatography (HPLC) and attenuated total reflectance infrared (ATR-IR) spectroscopy. Methanol, butanol, and dichloromethane fractions were selectively active against T. brucei with respective IC50 values of 3.89, 4.02, and 5.70 µg/ml. Moreover, methanol, butanol, and dichloromethane fractions significantly induced apoptosis-like cell death with remarkable alteration in the cell cycle of T. brucei. Furthermore, dichloromethane and methanol fractions altered the morphology, induced aggregation, and altered the ratio of nuclei to kinetoplasts in the parasite. The HPLC chromatograms and ATR-IR spectra of the active fractions suggested the presence of aromatic hydrocarbons with hydroxyl, carbonyl, amine, or amide functional groups. The results suggest that Z. zanthoxyloides LZT have potential chemotherapeutic effects on African trypanosomes with implications for novel therapeutic interventions in African trypanosomiasis.

Establishment of a quantitative and qualitative analysis and isolation method for tetracyclic iridoids from Morinda lucida Bentham leaves.

A new high performance liquid chromatography (HPLC) method has been established for quantitative and qualitative analysis of three tetracyclic iridoids: ML-2-3 (1), molucidin (2), and ML-F52 (3), which are responsible for anti-trypanosomal and anti-leishmanial activities of Morinda lucida Bentham leaves. Separation of 1-3 from dried 80% aqueous (aq.) ethanol extract was achieved on a reversed-phase cholester column packed with cholesteryl-bonded silica using an acetonitrile-0.1% aq. formic acid mobile phase system. Ultraviolet-visible (UV-VIS) spectroscopy was employed for detection of compounds, and their contents were determined by measuring absorbance at 254 nm. Depending on the above system, several factors potentially affecting the concentration of tetracyclic iridoids were evaluated resulting in several variation on plant organs, seasonality, variation between individual trees, and branch positions within the trees. Moreover, we developed a simple, quick, and effective method for tetracyclic iridoid isolation from M. lucida leaves that consisted of extraction by sonication into 80% aq. ethanol, basic hydrolysis, acid neutralization, liquid-liquid extraction into an organic solvent, and reverse phase open column chromatography. Employing this method, we have succeeded to obtain 1 as a colorless crystal yielding of 0.23%, which was 28 times higher than that of previous isolation method. Setting up methodology in this paper may be important for future in vitro and in vivo studies of tetracyclic iridoids and moreover for their applications in new drug design and development.