Millettia aboensis ameliorates oxidative stress through synergic interaction of its active compounds.

Background M. aboensis has wide ethnopharmacological applications but very little has been done on the pharmacological basis for these indications. This study evaluated the antioxidant potentials of the leaf extracts of M. aboensis. Methods Total phenolic content of the extract and fractions was carried out using folin-ciocalteu method while in vivo site specific effect determined using carbon tetrachloride (CCl4)-induced liver oxidative damage. Chromatographic separations of the most active fraction led to the isolation of compounds 1 and 2 with their structures elucidated by a combination of 1D and 2D NMR and mass spectrometry. Inhibition of liver microsome lipid peroxidation was used to evaluate the antioxidant activities of these compounds while DPPH test was used to study their interaction. Results Ethyl acetate fraction had the highest phenolic content of 305.2 mgGAE/g with n-hexane fraction having the least (26.1 mgGAE/g). Structural elucidation revealed compound 1 as epicathechin-(2ß→O→7, 4ß→8)-cathechin and compound 2 as epicathechin-(2ß→O→7, 4ß→8)-epicathechin. Compounds 1 & 2 inhibited liver microsome lipid peroxidation with EC50 of 46 and 55 µg/mL respectively. Combination of the compounds produced synergic inhibition of DPPH radical with EC50 of 7 µg/mL against 9 µg/mL produced by ascorbic acid. Conclusion M. aboensis expressed strong antioxidant property which may explain its diverse ethnopharmacological uses.

Dryopteris filix-mas (L.) Schott ethanolic leaf extract and fractions exhibited profound anti-inflammatory activity.

OBJECTIVE: Dryopteris filix-mas (D. filix-mas) (L.) Schott, (Dryopteridaceae) is used in traditional medicine, particularly in the Southern parts of Nigeria for the treatment of inflammation, rheumatoid arthritis, wounds and ulcers. In this study, we evaluated the anti-inflammatory activity of its ethanolic leaf extract and fractions. MATERIALS AND METHODS: The ethanolic leaf extract and fractions were screened for anti-inflammatory properties using egg-albumin-induced paw edema, xylene-induced topical ear edema, formaldehyde-induced arthritis and ulcerogenic models. The ethyl acetate most promising vacuum liquid chromatography fraction (VLC-E7) was purified using size exclusion chromatography technique (Sephadex LH-20) and its structure was elucidated using nuclear magnetic resonance (NMR) and mass spectrometry. Total phenolic and flavonoid contents were also determined. RESULTS: From the study, ethyl acetate and butanol fractions elicited better anti-inflammatory activities in egg-albumin-induced paw edema, formaldehyde-induced arthritis and xylene-induced topical ear edema. The ethanol extract, ethyl acetate and butanol fractions were non-ulcerogenic at 200 and 400 mg/kg. The compound isolated from Sephadex fraction (SPH-E6) was quercetin-3-O-α-L-rhamnopyranoside. CONCLUSION: Results of this study justify the ethnomedicinal use of D. filix-mas leaf for treatment of inflammation and rheumatoid arthritis. We suggest that D. filix-mas could be a prospective anti-inflammatory agent with no gastric irritation side effect, due to its bioactive component, quercetin-3-O-α-L-rhamnopyranoside.

Sub-chronic toxicity evaluation of Dryopteris filix-mas (L. ) schott, leaf extract in albino rats

This study evaluated the acute and sub-chronic toxicities of ethanol leaf extract of Dryopteris filix-mas. Acute toxicity and phytochemical tests on ethanol leaf extract were determined. In sub-chronic toxicity test, animals were treated with 62.5, 125, 250 and 500 mg/kg of extract every day for 90 days. Blood samples were collected via retro-orbital puncture for baseline studies and at 31, 61 and 91st days for determination of hematological, kidney and liver function parameters. Liver and kidneys were harvested for histopathology analyses on 91st day. Also, a 28 day recovery study was carried out to determine reversibility in toxicological effects. Phytochemical screening revealed the presence of tannins, phenols, flavonoids, saponins, steroids, alkaloids, terpenoids, reducing sugar and cardiac glycosides. Acute toxicity test did not show toxicity or death at 5000 mg/kg. There was significant (p<0.005) reduction in white blood cell and lymphocyte counts, significant (p<0.05) increase in some liver and kidney biomarkers as well as alterations in liver and kidney histo-architecture on 91st days in animals that were treated with 250 and 500 mg/kg extract. However, toxicities observed on 91st day were reversible in recovery studies. The leaf extract of Dryopteris filix-mas may be hepatotoxic and nephrotoxic when used for long periods

Advances in acute toxicity testing: strengths, weaknesses and regulatory acceptance.

Safety assessment of chemicals, pharmaceuticals, food and food ingredients, cosmetics, industrial products is very crucial prior to their approval for human uses. Since the commencement of toxicity testing (about 500 years ago, since 1520), significant advances have been made with respect to the 3Rs (reduction, refinement and replacement) alternative approaches. This review is focused on the update in acute systemic toxicity testing of chemicals. Merits and demerits of these advances were also highlighted. Traditional LD50 test methods are being suspended while new methods are developed and endorsed by the regulatory body. Based on the refinement and reduction approaches, the regulatory body has approved fixed dose procedure (FDP), acute toxic class (ATC) method and up and down procedure (UDP) which involves few numbers of animals. In terms of replacement approach, the regulatory body approved 3T3 neutral red uptake (NRU), the normal human keratinocyte (NHK), and the 3T3 neutral red uptake (NRU) phototoxicity test for acute phototoxicity. However, other promising replacement alternatives such as organ on chip seeded with human cells for acute systemic toxicity and 3T3 neutral red uptake (NRU) cytotoxicity test for identifying substances not requiring classification, as well as the in silico approaches are yet to receive regulatory approval. With this backdrop, a collaborative effort is required from the academia, industries, regulatory agencies, government and scientific organizations to ensure speedily regulatory approval of the prospective alternatives highlighted.

Upregulation of CD4+ T-Lymphocytes by Isomeric Mixture of Quercetin-3-O-Rutinoside and Quercetin-3-O-Robinobioside Isolated from Millettia aboensis.

BACKGROUND: Millettia aboensis (Hook. F.) Baker (Fabaceae) is popular in ethnomedicine for its acclaimed efficacy in a number of disease conditions. This study evaluated the immunomodulatory effect of the leaf extract as a possible mechanism of its ethnomedicinal uses. METHODS: Humoral and cellular immune responses of Balb/c mice to tetanus toxoid and cyclophosphamide, respectively, were used to monitor immunomodulatory activities of the ethanol leaf extract and fractions of M. aboensis at 200, 300 and 400 mg/kg. Active (butanol) fraction of the extract was subjected to chromatographic purifications to isolate the active compound and the structure elucidated by a combination of 1D and 2D NMR and mass spectrometry. Stimulation of specific T-lymphocytes using intracellular cytokine staining technique was used to evaluate immune-enhancing activity of the isolated compound. RESULTS: The extract and fractions evoked increase in both humoral and cellular immunity. At 400 mg/kg of butanol fraction, the normalized mean secondary production of IgG1 and IgG2a antibodies were 9.0 and 7.7, respectively. Serum cytokine production by butanol fraction following secondary challenge with tetanus toxoid showed that IL-12, IL-17A and IFN-γ were expressed by 48.14, 41.37 and 38.22%, respectively. Structural elucidation of the active compound revealed presence of isomeric mixtures of quercetin-3-O-rutinoside and quercetin-3-O-robinobioside (Compound 1a/b). Compound 1a/b exhibited in vitro upregulation of specific CD4+ T-lymphocytes that were largely IFNγ releasing with up to 43.7% stimulation at 6.25 µg/mL compared to the baseline effect in DMSO vehicle control group. CONCLUSION: M. aboensis expressed strong immune-enhancing properties, which may explain its ethnopharmacological use in disease management.

In vitro and in vivo antioxidant potentials of Alchornea floribunda leaf extract, fractions and isolated bioactive compounds.

OBJECTIVE: Alchornea floribunda leaves are widely used in ethnomedicine for the management of immuno-inflammatory disorders. We investigated the in vivo and in vitro antioxidant activity of the leaf extract, fractions and isolated compounds of A. floribunda. MATERIALS AND METHODS: The ethyl acetate fraction of the methanol leaf extract was subjected to several chromatographic separations to isolate compounds 1-4. The structures of the isolated compounds were elucidated by a combination of 1D and 2D NMR and mass spectrometry. Oxidative stress was induced with carbon tetrachloride (CCl4). Further analysis on the isolated phenolic compounds were done using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and hydrogen peroxide scavenging activity tests. RESULTS: The ethyl acetate fraction at 200 mg/kg produced significant (p<0.05) elevations of catalase enzyme activity and a significant (p<0.05) reduction in serum malondialdehyde. The chemical investigation of the ethyl acetate fraction led to the isolation of three flavans, (-) cathechin (1), (-) epicathechin (2), (+) epicathechin (3) and a flavanone, 2R, 3R dihydroquercitin (4). In hydrogen peroxide scavenging assay, (-) epicathechin exhibited an EC50 value of 8 µg/ml, similar to the standard ascorbic acid (EC50 = 8 µg/ml). (-) epicathechin showed scavenging of DPPH radical with EC50 value of 19 µg/ml while in the FRAP assay, it had EC50 value of 46 µg/ml which was lower than that of the standard, ascobic acid (EC50 = 66 µg/ml). CONCLUSION: The medicinal uses of A. floribunda may be due to the antioxidant activities of its phenolic compounds.

Wound-healing Activity of the Aqueous Leaf Extract and Fractions of Ficus exasperata (Moraceae) and its Safety Evaluation on Albino Rats.

Ficus exasperata have been reported to have wide applications in the treatment of many human diseases. However, its traditional use in the treatment of wounds has not been validated by any scientific study. Also, its safety in the management of chronic disease conditions requires attention. We evaluated the wound-healing activity of the aqueous extract and fractions of F. exasperata, as well as its safety after subchronic oral administration. Similar percentage of wound contraction was observed with 5% w/w extract ointment application and administration of cicatrin powder (standard) on the 4(th) day, while better contraction than the standard was recorded with higher concentrations of the extract ointment. Of all the fractions tested, significant (P < 0.05) contraction was only noticed in chloroform fraction, though lower than that of the aqueous extract. The extract also showed concentration-dependent inhibition of all the tested microbial isolates. Extract administered up to 5000 mg/kg (single dose administration) did not cause any mortality after 24 h. Mortality was, however, recorded at 4000 mg/kg within the first 20 days of subchronic administration of the extract. Significant (P < 0.05) increases in alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), and in particular, alkaline phosphatase (ALP) were observed at different doses and time periods. Pathological and histological changes were noticed in the liver and kidney on the 91(st) day of the study with 4000 mg/kg of the extract. Except for the significant (P < 0.05) reduction in WBC on the 91(st) day, no other significant (P < 0.05) changes were observed in other hematological parameters. The aqueous extract demonstrated better wound-healing activity than its fractions; however, the extract may not be safe at higher doses for subchronic oral administration, as may be the case in the management of chronic disease conditions.

beta-Amyrin and alpha-amyrin acetate isolated from the stem bark of Alstonia boonei display profound anti-inflammatory activity.

CONTEXT: Alstonia boonei De Wild (Apocyanaceae) is used in ethnomedicine for the management of malaria, ulcer, rhematic pain, toothache, and inflammatory disorders. OBJECTIVE: To investigate the anti-inflammatory potential of ß-amyrin and α-amyrin acetate isolated from the stem bark of Alstonia boonei using animal models. MATERIALS AND METHODS: Chromatographic purification of the crude methanol extract led to the isolation and structure elucidation of ß-amyrin and α-amyrin acetate. Their anti-inflammatory activities were evaluated in rodents using egg albumen-induced paw edema and xylene-induced ear edema models. The gastric ulcerogenic, in vivo leucocyte migration, and RBC membrane stabilization tests were also investigated. RESULTS: α-Amyrin acetate at 100 mg/kg showed significant (p < 0.05) inhibition of egg albumen-induced paw edema with % inhibition of 40 at the 5th hour. Oral administration up to 100 mg/kg did not produce significant (p > 0.01) irritation of the gastric mucosa while significant (p < 0.01) ulceration was recorded for indomethacin at 40 mg/kg compared with the negative control. At 100 µg/mL, both ß-amyrin and α-amyrin acetate inhibited heat-induced hemolysis to as much 47.2 and 61.5%, respectively, while diclofenac sodium (100 µg/mL) evoked only 40.5% inhibition. Both compounds at 100 µg/ear produced significant (p < 0.01) inhibition of ear edema in mice by 39.4 and 55.5%, respectively. Also at 100 mg/kg (p.o.) α-amyrin acetate evoked 60.3% reduction in total leucocyte count and significant (p < 0.05) suppression (47.9%) of neutrophil infiltration. DISCUSSION AND CONCLUSION: This study generally provided evidence of profound anti-inflammatory activity of ß-amyrin and α-amyrin acetate isolated from the Alstonia boonei stem bark.

Evaluation of Antioxidant, Immunomodulatory Activities, and Safety of Ethanol Extract and Fractions of Gongronema latifolium Fruit.

Gongronema latifolium fruit has wide application in ethnomedicine, especially in maintaining healthy living and general body healing. We therefore investigated the antioxidant, immunomodulatory activities, and safety of its ethanol extract and fractions. The in vitro antioxidant activities of the extract and fractions were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) test while in vivo activities were determined using carbon tetrachloride (CCL4) induced oxidative stress. Cell and humoral mediated immune responses were also evaluated together with toxicity studies. The extract, ethyl acetate, and methanol fractions showed inhibition of DPPH radical with IC50s 120, 90, and 60 µg/mL, respectively. Methanol fraction at 200 mg/kg produced significant (P < 0.05) inhibition of lipid peroxidation (MDA conc. 1.2 µmol/L) compared to control (2.8 µmol/L). Both ethyl acetate and methanol fractions at 200 mg/kg produced significant (P < 0.05) phagocytic index of 0.021 and 0.025, respectively, compared with control (0.01). Significant (P < 0.05) elevations of white blood cells, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were noticed on the 91st day at higher doses. Generally, this study justified the traditional use of G. latifolium fruit for general body healing and maintenance of healthy living. Long term administration is safe on the haematological and biochemical systems especially at lower doses and its toxicity at higher doses is reversible.