Anti-inflammatory and antinociceptive activities of Daniellia oliveri (Fabaceace) stem bark extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Daniellia oliveri (Rolfe) Hutch. & Dalziel (Fabaceae) is used for the treatment of inflammatory diseases and pains (chest pain, toothache and lumbago) and rheumatism. AIM OF THE STUDY: The study investigates the anti-inflammatory and antinociceptive properties of D. oliveri and possible mechanism of antiinflammatory action. MATERIALS AND METHODS: Acute toxicity of the extract was evaluated in mice using the limit test. The anti-inflammatory activity was assessed in xylene-induced paw oedema and carrageenan-induced air-pouch models at doses of 50, 100 and 200 mg/kg, p.o. Volume of exudate, total protein, leukocyte counts, myeloperoxidase (MPO) and concentration of cytokines (TNF-α and IL-6) were measured in the exudate of rats in the carrageenan-induced air-pouch model. Other parameters include lipid peroxidation (LPO), nitric oxide (NO) and antioxidant indices (SOD, CAT and GSH). Histopathology of the air pouch tissue was also carried out. The antinociceptive effect was assessed using acetic acid-induced writhing, tail flick and formalin tests. Locomotor activity was done in the open field test. The extract was analysed with HPLC-DAD-UV technique. RESULTS: The extract showed significant anti-inflammatory effect (73.68 and 75.79%, inhibition) in xylene-induced ear oedema test at the dose of 100 and 200 mg/kg, respectively. In carrageenan air pouch model, the extract significantly reduced exudate volume, protein concentration, the migration of leukocytes and MPO production in the exudate. The concentrations of cytokines TNF-α (12.25 ± 1.80 pg/mL) and IL-6 (21.12 pg/mL) in the exudate at the dose of 200 mg/kg were reduced compared to carrageenan alone group (48.15 ± 4.50 pg/mL; 82.62 pg/mL) respectively. The extract showed significant increase in the activities of CAT and SOD and GSH concentration. The histopathological assessment of the pouch lining revealed reduction of immuno-inflammatory cell influx. Nociception was significantly inhibited by the extract in acetic acid-induced writhing model and the second phase of formalin test indicating a peripheral mechanism of action. The open field test showed that D. oliveri did not alter locomotor activity. The acute toxicity study did not cause mortality or signs of toxicity at 2000 mg/kg, p.o. We identified and quantified caffeic acid, p-coumaric acid, ferulic acid, rutin, apigenin-7-glucoside, quercetin and kaempferol in the extract. CONCLUSION: The results of our study showed that the stem bark extract of D. oliveri possesses anti-inflammatory and antinociceptive activities thereby supporting its traditional use in the treatment of some inflammatory and painful disorders.

COVID-19 Pandemic: A Case for Phytomedicines.

Coronavirus disease 2019 (COVID-19) is an infection caused by a newly discovered coronavirus which was identified in Wuhan, China. The race is on globally to repurpose drugs for COVID-19 and develop a safe and effective vaccine against the disease. There is an urgent need to search for effective remedies against COVID-19 from the rich and extensive flora of Africa and the world. A literature search was conducted to obtain information on drugs with the potential for effectiveness in the treatment of COVID-19 based mostly on outcomes of preclinical studies and a few clinical investigations. This was considered important to this perspective as some of the identified mechanisms of action may be related to potential anti-COVID-19 actions of phytomedicines. The findings from the literature search were also used to establish the need for exploration of phytomedicines in the fight against COVID-19. This perspective identifies the need to preserve the rich tradition of herbal medicine in Africa, repositioning it by inculcating all aspects of discovery, development, and chemical evaluation of pharmaceuticals from medicinal plants for effective management of prevalent diseases. The identified mechanisms of action of current drugs under consideration for the treatment of COVID-19 include preventing fusion of SARS-CoV-2 with human cells; decrease acidity in endosomes, cell membrane-derived vesicles for transportation of the virus within the host cell and within which the virus can replicate; and blockade of the production of proinflammatory cytokines. Phytomedicines may possibly elicit either one or a combination of these effects. The case for the exploration of phytomedicines against COVID-19 is strengthened by the emergence of a number of conventional drugs from medicinal plants and the emergence of botanicals with proven efficacy for some medical conditions. Caution against indiscriminate use of medicinal plants in the guise of treating COVID-19 has been highlighted and the need for reliable preclinical and clinical studies.

Antinociceptive activity of Euadenia trifoliolata (Schum. & Thonn.) Oliv. leaves and roots in mice.

The leaves and roots of Euadenia trifoliolata are used in Nigeria traditional medicine for the treatment of ear ache, head ache and inflammation. The aim of the study was to evaluate the antinociceptive activity of ethanolic extract of the leaves (EL) and roots (ER) of E. trifoliolata in mice. Oral toxicity testing was performed using OECD guidelines. Antinociceptive effect was studied in mice using acetic acid-induced writhing, formalin, tail immersion and hot plate tests. Total polyphenolic contents were determined using standard methods. No mortality was recorded 24 h after oral administration of both EL and ER up to 5000 mg/kg. At the dose of 50, 100 and 200 mg/kg, administration of EL and ER resulted in significant reduction in the number of writhes compared to control. The percentage inhibition of writhings was calculated as 35.67%, 46.71% and 67.94% (EL) and 55.41%, 57.32% and 72.61% (ER), respectively. In hot plate test, EL and ER showed statistically significant antinociceptive effect, although low percentage inhibition (<50%) was recorded for ER at all the doses tested. Only EL (100 and 200 mg/kg) significantly (p < 0.001) increased the reaction time in tail immersion test. Both extracts significantly (p < 0.001) reduced the licking time in both phases of formalin test compared to control. The content of total phenolic, flavonoid and proanthocyanidin varies between the two extracts and may be the basis of the observed antinociceptive effect. The results indicate antinociceptive activity for the leaves and roots of E. trifoliolata, with the extract of the leaves showing better activity.

Sub-acute and chronic toxicity profiles of Markhamia tomentosa ethanolic leaf extract in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Markhamia tomentosa (Benth.) K. Schum Ex Engl. (Bignoniaceae) is used in traditional African medicine for the treatment of diarrhoea, oedema, pain and malaria. The leaf extract was reported to show no visible sign of toxicity on acute exposure. This present study investigates the sub-acute and chronic toxicity effects of Markhamia tomentosa in rats. MATERIALS AND METHODS: The animals (n=6/group) were treated daily with the extract at doses of 40, 200 and 1000mg/kg orally for 28 and 90 days. Control rats received distilled water and all animals were weighed at 7 days interval. The haematological, biochemical and histological parameters were determined. RESULTS: The extract showed non-significant changes in body weight gain of treated compared to control rats in both studies. Extract significantly decreased red blood cell (RBC), mean cell haemoglobin concentration and increased mean corpuscular volume (MCV) parameters after the 28 day study. In the 90 day study, a significant increase in white blood cell, RBC, platelets and decrease in MCV and mean cell haemoglobin (MCH) parameters were observed. Biochemical parameters were significantly changed in both studies; triglycerides, total protein, alanine transaminase, aspartate transaminase and albumin showed significant increase while creatinine, blood urea nitrogen and uric acid levels showed significant decrease. Significant increase in liver weight with no treatment-related histological changes was observed in all harvested vital organs. CONCLUSION: Markhamia tomentosa extract elicited non-toxic effect in the liver and kidney function parameters in rats. Thus, the extract is safe when administered orally.

Gastroprotective and antioxidant potentials of ethanolic stem bark extract of Margaritaria discoidea (Euphorbiaceae) in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Decoctions prepared from the bark of Margaritaria discoidea (Baill.) G. L. Webster (Euphorbiaceae) are used in Nigeria and other parts of West Africa in the treatment of wounds and ulcers. The study was conducted to investigate the gastric ulcer protective effect of ethanolic stem bark extract of M. discoidea in rats. MATERIALS AND METHODS: Antiulcer assays were performed using ethanol, indomethacin and pylorus ligation-induced ulcer models at the dose of 50, 100 and 150 mg/kg, p.o. The antioxidant effect of the extract was evaluated in vitro and by studying its effect on antioxidant enzymes (superoxide dismutase, catalase, and reduced glutathione) and lipid peroxidation in the stomach tissue of rats in ethanol-induced model. Solvent fractions (hexane, dichloromethane, ethyl acetate, butanol and aqueous) from the crude extract were investigated for antiulcerogenic effects in ethanol-induced ulcer model at the dose of 150 mg/kg. GC-MS analysis of the active hexane fraction was also carried out. RESULTS: The extract significantly (P<0.05) reduced gastric lesion in ethanol and indomethacin-induced ulcer models. The extract had significant influence on in vivo antioxidant status in ethanol-induced model. In pylorus ligation-induced model, only the dose of 150 mg/kg showed significant reduction (88.89%, P<0.05) of ulcer lesions. There was no significant reduction in the gastric juice volume and total acidity. The solvent fractions showed ulcer inhibition in varying degrees but significance (P<0.01) was only observed in the hexane fraction. Ethyl esters of palmitic and linoleic acids were found as the major compounds in the GC-MS analysis of the hexane fraction. CONCLUSION: Our results suggest that M. discoidea possesses gastroprotective activity possibly mediated through antioxidant mechanism. The data obtained in this study provide some support to the traditional use of M. discoidea in the treatment of gastric ulcer.

Antiulcer activity of the ethanolic extract and ethyl acetate fraction of the leaves of Markhamia tomentosa in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Markhamia tomentosa (Benth.) K. Schum. Ex Engl. (Bignoniaceae) are used traditionally in the treatment of skin afflictions, sores, ulcers and inflammation. The aim of the study was to investigate the antiulcer activity of the crude ethanolic extract from the leaves of Markhamia tomentosa, determine the active fraction(s) of the extract and identify the chemical constituents in the active fraction by LC-MS. MATERIALS AND METHODS: The antiulcer activity of the crude extract (50, 100 and 150mg/kg, p.o.) was evaluated in ethanol and indomethacin-induced models while the solvent fractions (150mg/kg) were screened using ethanol-induced gastric lesions in rats. Furthermore, anti-ulcer activity of the active fraction (50, 100 and 150mg/kg, p.o.) was performed using indomethacin and pylorus ligation models. Parameters such as gastric volume, pH and acidity were determined in the pylorus ligation model. LC-ESI-MS analysis was used to identify the components in the active fraction. RESULTS: The extract at the dose of 50, 100 and 150mg/kg caused a significant (p<0.05) dose-dependent inhibition of ulcer in the ethanol and indomethacin-induced ulcer models, respectively. The ethyl acetate (EtOAc) fraction showed the most potent antiulcer activity from all the fractions tested. This fraction produced 72% and 92% inhibition of indomethacin and pylorus-induced ulcer at a dose of 150mg/kg respectively. Acteoside, luteolin, luteolin-7-rutinoside, Luteolin-3',7-di-O-glucoside, carnosol, dilapachone, tormentic acid, oxo-pomolic acid and ajugol were detected in the EtOAc fraction. CONCLUSION: Our data provide a rational base for the folkloric use of Markhamia tormentosa in the treatment of ulcers.

Antinociceptive and anti-inflammatory activities of ethanolic extract of Alafia barteri

This study analyzes the antinociceptive and anti-inflammatory properties of ethanolic leaf extract of Alafia barteri Oliv., Apocynaceae, based on its medicinal use in the treatment of toothaches, inflammation and fevers. The antinociceptive effect was assessed in mice using acetic acid-induced writhing, tail clip, tail immersion and formalin assays. Anti-inflammatory activity was evaluated on carrageenan-induced paw oedema in rats, and xylene-induced ear oedema in mice. In acetic acid-induced writhing test, the extract at different doses (50, 100 and 200 mg/kg, p.o.) significantly (p < 0.05) and dose-dependently reduced pain by 35.04, 56.49 and 84.25%, respectively. The extract also significantly inhibited both the early and late phases of formalin-induced nociception in mice. In the tail immersion test, the extract caused a significant inhibition of pain (34.43% inhibition, after 90 min) at a dose of 200 mg/kg, while the effect of the extract in the tail clip test was only significant at the 100 mg/kg dose. A. barteri caused a significant inhibition of paw oedema development in the carrageenan and xylene-induced oedema tests. There was no mortality recorded following treatment with the extract (5 g/kg, p.o.). The results support the traditional use of A. barteri in the treatment of various diseases associated with pain and inflammation.

Dose and time-dependent sub-chronic toxicity study of hydroethanolic leaf extract of Flabellaria paniculata Cav. (Malpighiaceae) in rodents.

Flabellaria paniculata Cav. (Malpighiaceae) is a climbing shrub, the preparations of which are used in the treatment of wounds and ulcers in Nigeria and Ghana. This study investigated the sub-chronic toxicity profile of the hydroethanolic leaf extract of F. paniculata (HLE-FP). HLE-FP was administered p.o. (20, 100, and 500 mg/kg) for 30 and 60 days to different groups of rats. Control animals received 10 ml/kg distilled water. In the group of animals for reversibility study, HLE-FP administration ceased on the 60th day and animals were monitored for a further 15 days. Results showed that oral treatment with HLE-FP for 30 days caused significant (p < 0.05) reductions in weight gain pattern compared to control. These changes were sustained with 60 days treatment. However, no significant (p > 0.05) differences in relative organ weights between control and treatment groups were observed. HLE-FP-treated rats showed significant (p < 0.05) increases in Hb, PCV and RBC on day 30 and significant (p < 0.05) increases in MCV and MCH indices on day 60 compared to control. There were significant (p < 0.05) elevations in serum K(+), urea and creatinine compared to control. The liver function tests showed slight but non-significant alterations in relevant parameters when compared to control. Biochemical findings were supported by histopathological observations of vital organs including the kidney and liver. Toxicities observed in respect of kidney function were irreversible at 15 days of stoppage of treatment. In the acute toxicity study, HLE-FP given p.o. caused no lethality at 5000 mg/kg but behavioral manifestations like restlessness, generalized body tremor, feed, and water refusal were observed. The i.p. LD50 was estimated to be 2951.2 mg/kg. Findings in this study showed that HLE-FP is relatively non-toxic on acute exposure and generally safe on sub-chronic administration, but could be deleterious on the kidneys on prolonged oral exposure at a high dose. Thus, caution should be exercised with its long-term usage.

Hypoglycemic and antioxidant activities of the hydroethanolic leaf extract of Byrsocarpus coccineus Schumach. & Thonn. (Connaraceae).

AIM: Diabetes Mellitus is associated with significant morbidity and mortality worldwide. The need for enhanced efficacy and safety, and cheaper and more readily available new drugs has increased the search for new antidiabetic drugs from plants. This study was conducted to investigate the antidiabetic activity of the hydroethanolic leaf extract of B. coccineus in rats. METHODS: The effect of B. coccineus extract (100-800 mg · kg(-1), p.o.) on blood glucose levels in normal and glucose loaded rats, and alloxan-induced diabetic rats was determined. After 10 days of treatment, blood samples were collected from rats for lipid and insulin profiling. Animals were thereafter sacrificed and the kidneys, heart, and liver were harvested for antioxidant indices assay. RESULTS: In normal rats, B. coccineus did not cause significant reduction in blood glucose. At the dose of 800 mg · kg(-1), significant increase in blood glucose level was not observed 30 min. after glucose load. B. coccineus administered acutely did not generally produce significant reduction in blood glucose level in diabetic rats. Administered subacutely, the extract significantly reduced blood glucose level in diabetic rats from the 3(rd) day with peak effect observed at the dose of 800 mg · kg(-1) on the 10(th) day. The extract generally preserved in vivo antioxidant levels in the kidneys, heart, and liver, increased the level of high density lipoprotein and insulin, and reduced the level of triglycerides and low density lipoprotein compared to diabetic control. CONCLUSION: The findings in this study suggest that the hydroethanolic leaf extract Byrsocarpus coccineus possesses antidiabetic activity possibly mediated through inhibition of intestinal glucose absorption, in vivo antioxidant activity, and enhancement of regeneration of beta cells of the pancreas and insulin secretion.

Effect of Flabellaria paniculata Cav. extracts on gastric ulcer in rats.

BACKGROUND: The leaves and root of Flabellaria paniculata (Malpighiaceae) are frequently used in the treatment of wounds and ulcers in Nigerian folk medicine. The purpose of this study was to compare the effect of ethanolic extracts from the leaves (FPL) and root (FPR) of F. paniculata on gastric ulcers in rats. METHODS: The effect of FPL and FPR (100, 200 and 400 mg/kg) was evaluated in ethanol and indomethacin gastric ulcer models. Control groups for FPL and FPR were orally treated with 3% Tween 20 and distilled water respectively. FPL was further investigated in pylorus ligation model. Misoprostol and cimetidine were used as reference. RESULTS: FPL significantly (P < 0.05) reduced gastric lesions by 82.22% and 67.32% in ethanol and indomethacin induced ulcer models at 100 mg/kg respectively while FPR (100, 200 and 400 mg/kg) did not exert significant effect in the two models. In pylorus ligation model, FPL exerted a significant preventive antiulcer effect as indicated by reduction in gastric volume at 200 and 400 mg/kg doses. Only 400 mg/kg of the extract exerted a significant reduction in ulcer index when compared with the control group. The oral route LD50 of FPL was estimated to be 4570 mg/kg while that of FPR was 2754 mg/kg. The LD50 in intraperitoneal injection was estimated to be 1202.26 and 1380.38 mg/kg for FPL and FPR respectively. The phytochemical investigation showed that both extracts possess triterpenoids and saponin, while the presence of flavonoid was detected only in FPL. CONCLUSIONS: The results of this study indicated that FPL and not FPR is effective against experimentally induced gastric ulcers. The presence of varied phytochemical constituents probably influenced the pharmacological differences between the two extracts.

Anti-inflammatory and analgesic activities of the aqueous extracts of Margaritaria discoidea (Euphorbiaceae) stem bark in experimental animal models

Margaritaria discoidea is a medicinal plant used for the treatment of various body pains in Central, Eastern and Southern Africa. The aqueous extract of its stem bark was investigated for its anti-inflammatory and analgesic activities in animal models. The extract at 50, 100 and 200mg/kg body weight reduced significantly the formation of oedema induced by carrageenan and histamine. In the acetic acid-induced writhing model, the extract had a good analgesic effect characterized by a reduction in the number of writhes when compared to the control. Similarly, the extract caused dose-dependent decrease of licking time and licking frequency in rats injected with 2.5% formalin. These results were also comparable to those of indomethacin, the reference drug used in this study. Acute toxicity test showed that the plant may be safe for pharmacological uses. This study has provided some justification for the folkloric use of the plant in several communities for conditions such as stomachache, pain and inflammations. Rev. Biol. Trop. 57 (4): 1193-1200. Epub 2009 December 01.

Margaritaria discoidea es una planta medicinal usada para el tratamiento de varios dolores corporales en la parte sur, central y oriental de África. Se investigaron las propiedades analgésicas y antiinflamatorias de la extracción acuosa de la corteza de su tallo en modelos animales. Los extractos de 50, 100 y 200mg/kg de peso corporal redujeron significativamente la formación del edema inducido por la carragenina y la histamina. En el modelo de contracción abdominal inducida por ácido acético, el extracto mostró un buen efecto analgésico caracterizado por la reducción en el número de contracciones en comparación con el grupo control. El extracto causó una disminución dependiente de la dosis del tiempo y la frecuencia de lamido en las ratas inyectadas con formalina al 2.5%, lo cual evidencia su efecto analgésico. Estos resultados fueron comparables con los de la indometacina, la droga de referencia usada en este estudio. La prueba de toxicidad aguda mostró que la planta podría ser segura para usos farmacológicos. Este estudio proporciona justificación para el uso folclórico de esta plata en varias comunidades, con el objetivo de tratar padecimientos tales como dolor de estómago, dolor e inflamaciones.

Phenolic contents, antioxidant and antibacterial activities of Hymenocardia acida.

This study investigates the antioxidant and antibacterial activities of aqueous and methanolic extracts from Hymenocardia acida Tul. (Hymenocardiaceae). The inhibition values of the extracts and quercetin were found to be very close, with no significant differences at a concentration of 0.05 mg mL(-1) in their ability to inhibit 1,1-diphenyl-2-picrylhydrazyl (DPPH). Total proanthocyanidins for both water and methanol extracts were 20.2 +/- 0.01 and 30.6 +/- 0.51 mg g(-1) (catechin equivalent) while the total phenol contents were 20.0 +/- 0.52 and 35.6 +/- 1.42 mg mL(-1) (tannic acid equivalent), respectively. Positive correlations R(2) = 0.85, R(2) = 0.94, R(2) = 0.97 for DPPH, reducing power and 2'-azino-bis(3-ethylbenzo thiazoline)6-sulphonic acid (ABTS). Linear regression analysis also produced a high correlation coefficient with total proanthocyanidins (DPPH, R(2) = 0.69; ABTS, R(2) = 0.94). H. acida extracts showed low antibacterial activity (minimum inhibitory concentration (MIC) value >or=5.0 mg mL(-1)) against gram negative bacteria but significantly (MIC value

Anti-inflammatory and analgesic activities of the aqueous extracts of Margaritaria discoidea (Euphorbiaceae) stem bark in experimental animal models.

Margaritaria discoidea is a medicinal plant used for the treatment of various body pains in Central, Eastern and Southern Africa. The aqueous extract of its stem bark was investigated for its anti-inflammatory and analgesic activities in animal models. The extract at 50, 100 and 200mg/kg body weight reduced significantly the formation of oedema induced by carrageenan and histamine. In the acetic acid-induced writhing model, the extract had a good analgesic effect characterized by a reduction in the number of writhes when compared to the control. Similarly, the extract caused dose-dependent decrease of licking time and licking frequency in rats injected with 2.5% formalin. These results were also comparable to those of indomethacin, the reference drug used in this study. Acute toxicity test showed that the plant may be safe for pharmacological uses. This study has provided some justification for the folkloric use of the plant in several communities for conditions such as stomachache, pain and inflammations.

Anti-inflammatory and analgesic activities of the aqueous extract of Acacia karroo stem bark in experimental animals.

The aqueous extract of the stem bark of Acacia karroo Hayne was investigated for its anti-inflammatory and analgesic activities in animal models. The extract at 100 and 200 mg/kg reduced significantly the formation of oedema induced by carrageenan and histamine. In the acetic acid-induced writhing model, the extract showed a good analgesic effect characterized by a significant reduction in the number of writhes with two doses (100 and 200 mg/kg) used when compared to the untreated control group. In the tail immersion test, the extract at the doses used (100 and 200 mg/kg) increased reaction time to pain after 30 min. of oral administration of the extract. Indomethacin at 10 mg/kg served as reference drug in all these tests. The results gave a scientific basis to the traditional uses of Acacia karroo mainly for wound poultices, eye treatments and cold remedies.