Sex-dependent vulnerability for Wistar rats model following intranasal instillation with Klebsiella pneumoniae ATCC 43816 causing lobar pneumonia.

BACKGROUND: Klebsiella pneumoniae has become one of the major threats to public health as it causes nosocomial and community-acquired infections like lobar pneumonia. This infection causes acute inflammation in the lung, characterized by the recruitment of polymorphonuclear cells, generating free radicals, and decreasing the endogenous antioxidant balance system. Many experimental studies have focused on the induction, progression and resolution of infection up to its peak, but these documented processes remain highly random and their sex dependence un-elicited. These fluctuations of physiopathological parameters would impact disease progression depending on the animal's model and bacterial strain used. The present study investigated the sex-dependent vulnerability of Wistar rats to K. pneumoniae ATCC 43816 lobar pneumonia induced by the intranasal instillation method. METHODS: Experimental pneumonia was induced by K. pneumoniae ATCC 43816 in male and female Wistar rats following intranasal instillation. The physiopathogenesis of the disease was studied by bacteriological and histopathological exams, histomorphometric analysis of the blood and/or lung tissue, and body weight loss in infected animals. In addition, the overall severity of lesions was determined by the total score obtained by averaging the individual scores from the same group of animals. RESULTS: The K. pneumoniae ATCC 43816 strain showed inoculation dose-, incubation time of the disease- and sex-dependent- differences in its ability to induce lobar pneumonia. Evaluation of different parameters showed that the disease peaked on day 15 post-inoculation, with more pathogenic effects on female rats. This observed sex-dependence difference in Wistar rats was mainly highlighted by the determined lethal dose 50 (LD50), bacterial load count in whole blood and lung tissues, body weight loss, inflammatory granulomas forming and diffuse alveolar damages. The pathogenicity was confirmed by scoring the severity of pathologic lesions of lung tissues. CONCLUSIONS: The results obtained highlighted the gender-dependency in the physiopathogenesis processes of K. pneumoniae ATCC 43816 induced-lobar pneumonia, in Wistar rats. Female Wistar rats' susceptibility is useful in studying pathology and in preclinical trial investigations of new treatments for infectious pneumonia.

Protective and Ameliorative Effects of Hydroethanolic Extract of Piper nigrum (L.) Stem against Antiretroviral Therapy-Induced Hepatotoxicity and Dyslipidemia in Wistar Rats.

Antiretroviral therapy (ART) has revolutionized the lives of people living with HIV/AIDS by overall improving their quality of life and increasing life expectancy. However, ART-associated hepatotoxicity and metabolic disorders in HIV/AIDS patients are growing concerns to clinicians, especially due to the long-term use of the drugs. This study reported on the phytochemical and pharmacological profile of hydroethanolic extracts of Piper nigrum stem (PNS) and evaluated its protective effect against tenofovir/lamivudine/efavirenz (TLE)-induced hepatotoxicity and dyslipidemia in Wistar rats. Cytotoxic, antioxidant, and anti-inflammatory assays were performed on PNS. Thirty-six rats divided into 6 groups of 6 animals/group were administered: distilled water, 17 mg/kg TLE, 17 mg/kg TLE and 100 mg/kg silymarin, 17 mg/kg TLE, and Piper extract (200 mg/kg, 400 mg/kg, or 800 mg/kg) orally for 28 days. The body weight of animals was recorded every 7 days. On Day 29, the rats were sacrificed, and blood samples were collected for hematological and biochemical tests. Portions of the liver and kidneys were collected for histological evaluation, while liver homogenates were prepared from the rest to measure antioxidant enzymes. PNS possessed in vitro cytotoxic, antioxidant, and anti-inflammatory activities. A significant decrease (p < 0.05) in the body weight of rats treated with PNS was observed. A significant high platelet count (p < 0.05) was observed in the PNS800 mg/kg group. A considerable decrease in alkaline phosphatase and triglycerides was observed in the silymarin and PNS group compared to the TLE-only group. The findings also show a significant increase in catalase and glutathione in the TLE-only group compared to the normal group, while SOD decreased. Histological observations revealed normal hepatic and renal tissues in the silymarin, and PNS-treated groups compared to the normal control, while leucocyte infiltration was observed in the TLE-only group. These results suggest that PNS extract possessed antioxidant activity that alleviated TLE-induced toxicity. Further studies are necessary to understand the pharmacokinetic interactions between ART and PNS.

In Vitro Antioxidant, Anti-Inflammatory, and Digestive Enzymes Inhibition Activities of Hydro-Ethanolic Leaf and Bark Extracts of Psychotria densinervia (K. Krause) Verdc.

Psychotria densinervia hydro-ethanolic leaf extract (PHELE) and bark extract (PHEBE) were evaluated for antioxidant, anti-inflammatory, and inhibition of digestive enzymes activities. The antioxidant activity was characterized by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), total phenolic content (TPC), and total flavonoid content (TFC) assays. The anti-inflammatory activity was characterized by protein denaturation and antiproteinase tests, while the inhibition of the enzymes was assessed using α-amylase, α-glucosidase, lipase, and cholesterol esterase activities. PHELE presented low (p < 0.001) IC50 (59.09 ± 5.97 µg/ml) for DPPH compared with ascorbic acid (71.78 ± 6.37 µg/ml) and PHEBE (115.40 ± 1.21 µg/ml). The IC50 of PHELE (262.4 ± 4.46 µg/ml) and PHEBE (354.2 ± 1.97 µg/ml) was higher (p < 0.001) than that of catechin (33.48 ± 2.02 µg/ml) for ABTS. PHELE had high (p < 0.001) FRAP (341.73 ± 21.70 mg CE/g) than PHEBE (150.30 ± 0.32 mg CE/g). PHELE presented (p < 0.001) high TPC (270.05 ± 7.53 mg CE/g) and TFC (23.43 ± 0.032 mg CE/g) than PHEBE (TPC: 138.89 ± 0.91 and TFC: 20.06 ± 0.032 mg CE/g). PHELE showed antiprotein denaturation with IC50 (257.0 ± 7.51 µg/ml) (p < 0.001) and antiproteinase activity (74.37 ± 1.10 µg/ml) lower than PHEBE (316.1 ± 6.02 µg/ml and 177.6 ± 0.50 µg/ml), respectively. Orlistat inhibited lipase (p < 0.001) activity with IC50 (37.11 ± 4.39 µg/ml) lower than PHELE and PHEBE (50.57 ± 2.89 µg/ml and 62.88 ± 1.74 µg/ml, respectively). PHELE inhibited cholesterol esterase with IC50 (34.75 ± 3.87 µg/ml) lower than orlistat (54.61 ± 2.56) and PHEBE (80.14 ± 1.71 µg/ml). PHELE inhibited α-amylase IC50 (6.07 ± 4.05 µg/ml) lower than PHEBE (19.69 ± 6.27 µg/ml) and acarbose (20.01 ± 2.84 µg/ml). Acarbose inhibited α-glucosidase (p < 0.001) activity with IC50 (4.11 ± 3.47 µg/ml) lower than PHELE (24.41 ± 2.84 µg/ml) and PHEBE (38.81 ± 2.46 µg/ml). PHELE presented better antioxidant, anti-inflammatory, and enzyme inhibition activity than PHEBE.

In Vitro Antilipidic and Antithrombotic Activities of Plectranthus glandulosus (Lamiaceae) Leaves Extracts and Fractions.

OBJECTIVE: The present study investigated the effect of the leaves extracts and fractions of Plectranthus glandulosus on the inhibition of pancreatic lipase, cholesterol esterase, adipocytes lipid uptake, and antithrombotic activity which may be important in atherosclerosis development. METHODS: Aqueous, ethanolic, and hydroethanolic extracts of Plactranthus glandulosus were prepared by maceration. The hydroethanolic extract was fractionated into n-hexane, ethylacetate, and n-butanol fractions and their inhibition of pancreatic lipase, cholesterol esterase, adipocytes lipid uptake, and antithrombotic activities measured. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis was carried out to determine phytochemical constituents present in the extracts. RESULTS: The standard orlistat exhibited a higher inhibitory activity on pancreatic lipase and cholesterol esterase (16.31 µg/mL and 15.75 µg/mL, respectively) compared to ethyl acetate fraction (IC50, 17.70 µg/mL and IC50, 24.8 µg/mL, respectively). Among crude extract, hydroethanolic extract showed a better inhibition against pancreatic lipase (IC50, 21.06 µg/mL) and cholesterol esterase (IC50, 25.14 µg/mL) though not comparable to the effect of orlistat. The best lipid uptake inhibition was observed in the hydroethanolic extract (IC50, 45.42 µg/mL) followed by the ethyl acetate fraction (IC50, 47.77 µg/mL). A better antithrombolytic activity was exhibited by the ethyl acetate fraction at all concentrations (50-800 µ/mL), while hydroethanolic extract exhibited the best activity among crude extract. However, these were not comparable to the standard aspirin. The LC-HRMS analysis revealed the presence of 7-O-methyl luteolin 5-O-ß-D-glucopyranoside, chrysoeriol 5-O-ß-D-glucopyranoside, 5,7-dihydroxy-3,2',4'-trimethoxyflavone, and plectranmicin as major compounds in both hydroethanolic extract and ethyl acetate fraction. CONCLUSION: Thus, our finding supports the traditional use of this plant, which might provide a potential source for future antiatherosclerotic drug discovery.

Endophytic Fungi from Alstonia boonei De Wild and Greenwayodendron suaveolens (Engl. and Diels) Verdc. subsp. Suaveolens Possess Inhibitory Activity against Pneumonia Causing Bacteria.

This study evaluated the antibacterial efficacy of methanolic extracts of isolated endophytic fungi from stem barks and leaves of Alstonia boonei De Wild and Greenwayodendron suaveolens (Engl. and Diels) Verdc. subsp. Suaveolens against Klebsiella pneumoniae ATCC 43816, Haemophilus influenzae ATCC 49247, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 35218, responsible for causing pneumonia. The endophytic fungi were isolated and characterized in the Potato Dextrose Agar (PDA), Sabouraud Dextrose Agar (SDA), and Czapek Dox Agar (CDA) media. The fungi and their methanolic extracts were tested for in vitro antibacterial potential by antagonistic assay for endophytic fungi against bacterial pathogens and microdilution method. The phytochemical screening of extracts was carried out according to the colorimetric and precipitation methods to reveal the presence of secondary metabolites. The results showed that 24 macroscopically and microscopically distinct endophytic fungi were isolated, identified, and stored. These endophytic fungi possessed antibacterial activity against the selected bacterial strains with inhibition zones ranging from 7.00 to 25.00 mm. The endophytic fungi GS15 and AB24 have presented the inhibitions zones of 20.33 mm and 25.00 mm, respectively, and these were better than the ones obtained for Levofloxacin®. The endophytes with inhibition zones greater than 10 mm were used for extraction of their secondary metabolites. The endophytic fungi extracts showed antibacterial activity with the minimum inhibitory concentrations (MICs) ranging from 6.25 × 10-4 to 2 × 10-2 g/L and the minimum bactericidal concentrations (MBCs) ranging from 2.5 × 10-3 to 2 × 10-2 g/L. The endophytic fungi GS15 extract was the most effective extract; it showed bactericidal effects on the tested bacterial strains. The phytochemical screening of the extracts revealed the presence of secondary metabolites classes, responsible for causing the obtained antibacterial activity. Thus, the endophytic fungi methanolic extracts from A. boonei and G. suaveolens have the potential to inhibit the growth of bacteria responsible for nosocomial pneumonia.

Cafeteria Diet-Induced Metabolic and Cardiovascular Changes in Rats: The Role of Piper nigrum Leaf Extract.

BACKGROUND: Cafeteria diet is known to induce excessive body fat accumulation (obesity) that could cause metabolic and cardiovascular changes and even death. The increase in prevalence over time and the failure in treatment options make obesity a real public health problem. The present study assessed the preventive effect of the hydro-ethanolic extract of the Piper nigrum leaf on the development of metabolic and cardiovascular changes in cafeteria diet fed Wistar rats. METHODS: Thirty-six male rats were divided into 5 groups of 6 rats each: a normal control group (Nor.), a negative control group (Neg.), two groups administered different doses of extract in mg/kg (E250 and E500), and a group administered atorvastatin 10 mg/kg (Ator., reference drug). The animals were fed with experimental diets (standard and cafeteria) for a period of 5 weeks. Food and water intake were assessed daily, and the body weight assessed weekly. At the end of the feeding, plasma lipid profile and markers of hepatic and renal function were assessed. Furthermore, the relative weights of the adipose tissue and the organs were assessed. The liver, kidneys, and heart homogenates were assessed for markers of oxidative stress while the aorta was histopathologically examined. RESULTS: Cafeteria diet-induced weight gain of 30% and increased triglyceride, total cholesterol, and low-density lipoprotein cholesterol level of more than 50%. Equally, an increase in the relative weight of accumulated adipose tissues of more than 90%, oxidative stress, and alteration in the organ structure were visible in cafeteria diet fed rats (Neg). Treatment with P. nigrum extract significantly prevented weight gain, dyslipidemia, oxidative stress, and alteration in the architecture of the aorta. The effect of P. nigrum extract was comparable to that of the reference drug. CONCLUSION: Piper nigrum leaf may prevent weight gain and possess cardioprotective activity with a strong antioxidant activity.

Costus afer Protects Cardio-, Hepato-, and Reno-Antioxidant Status in Streptozotocin-Intoxicated Wistar Rats.

Medicinal plants are efficient modulators of oxidative stress associated with diabetes mellitus. This study evaluated the cardio-, reno-, and hepato-antioxidant status of hydroethanolic extract of Costus afer on streptozotocin-intoxicated diabetic rats. Experimental animals were daily administered with hydroethanolic extract of C. afer by oral intubation for eight weeks (60 days), after which the levels of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and lipid peroxidation marker (MDA) were evaluated in the heart, liver, and kidney homogenates. Plasma biochemical parameters such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total protein, creatinine, and urea were determined. Meanwhile, parts of the heart, kidneys, and liver were histopathologically examined. Streptozotocin administration induced toxicity in the cardiac, hepatic, and renal tissues by stimulating significant increases (p<0.05) in the levels of CAT and SOD, GSH, and MDA. Similarly, significant increases (P<0.05) in the levels of ALT, AST, urea, and total protein were observed in streptozotocin treated rats, whereas decreases were observed in the levels of ALP, LDH, and creatinine. Following the treatments with C. afer hydroethanolic extract prevented the effect of streptozotocin by maintaining the tissue antioxidant status (CAT, SOD, GSH, and MDA) and the plasma biochemical parameters (AST, ALT, ALP, LDH, creatinine, and urea) towards the normal ranges. The histopathological examination revealed hepatovascular congestion and leucocyte infiltration as well as renovascular congestion, glomerulosclerosis, and tubular clarification in the untreated diabetic control and their absence in the group of animals treated with a high dose of C. afer extract. The findings of the present investigation suggest that C. afer possesses antioxidant activities capable of regulating drug induced tissue damage.

Medicinal Uses and Natural Availability of Three Plant Species in Selected Ecosystems in Cameroon.

In many developing countries traditional medicine constitutes a major part of health care because of its local availability and affordability compared to modern medicine. However, little is known about the specific uses and availability of medicinal plants. In this research an exploratory study was conducted to determine the uses of three medicinal plants in Cameroon, and to examine their relative distribution and abundance in specific habitats. From a questionnaire administered to traditional healers, we and found that three species of medicinal plants including: Alstonia boonei, Picralima nitida and Sarcocephalus latifolius that are commonly used, either singly or in mixtures to treat human diseases such as muscle and joints pains, hyperthermia, hypertension, hepatitis, jaundice and rheumatism. Fresh or dry barks of the tree plants and fresh fruits of Picralima nitida, as well as various ethnopharmacological preparations (decoctions, maceration, infusion and powder) are widely commercialized. Findings from our ecological study revealed that Alstonia boonei was represented by 2, or 1 % of total individuals recorded in 0.5 ha, implying 3 individuals and 6 trees/ha. This tree was well represented and was sometime among the forests. Picralima nitida was represented by 0.6 % of total trees recorded in 0.5 ha, implying 0.70 tree and 1 tree/ha. This tree was poorly represented and was not a dominant species in its habitats. Sarcocephalus latifolius belonged to a group of 72 plants with a recovery < 5% corresponding to Braun- Blanquet scale1. Hence, this plant was not densely represented in the Sudono-Guinean and Sahelian savannahs. It is the most harvested species of the three species that has undergone a strong anthropogenic destruction. Therefore these three plants, and especially Sarcocephalus latifolius, need to be protected through a sustainable management of their habitats in Cameroon.

Evaluation of the antidiabetic and antioxidant properties of Morinda lucida stem bark extract in streptozotocin intoxicated rats.

The present research evaluated the antidiabetic and antioxidant properties of M. lucida stem bark (50 and 500mg/kg) and glibenclamide (25mg/kg, standard drug) in acute (Oral glucose tolerance test) and sub-acute (Streptozotocin 60mg/kg, i.p. diabetic model) administration. A group of healthy rats constituted the normal control. The sub-acute experiment lasted 28 days during which water, food intake and weight gain were measured and biochemical parameters analyzed in both plasma and erythrocytes at the end of the experiment. The chemical substances present in M. lucida bark extract were determined. In the Oral glucose tolerance test, the reduction of blood glucose level was statistically significant for both M. lucida extracts and glibenclamide. However, in the diabetic rats acute administration of 500mg/kg extract had better blood sugar lowering effect than glibenclamide, which was better than 50mg/kg extract. Streptozotocin diabetic animal model was characterized by a decrease in weight gain, erythrocyte SOD and CAT activities and an increase in water and food consumption, lipid peroxidation, cholesterol, triglycerides, plasma glucose, creatinine and urea concentrations, and transaminases activities. M. lucida extract and glibenclamide significantly prevented the alteration of these parameters, thus indicating a corrective effect on diabetes and its complications. This study justifies the traditional claim and provides a rationale for the use of M. lucida to treat diabetes. Its antioxidant properties may serve to curb oxidative stress and hence prevent the diabetic complications related to oxidative stress. Chemical substances, which may be accountable for the antidiabetic and antioxidant properties of M. lucida were detected in the aqueous extract of M. lucida bark.

New Approach for the Development of Improved Traditional Medicine: Case of a Preparation of an Oral Hypoglycemic Medicine from Laportea ovalifolia (Schumach. & Thonn.) Chew. (Urticaceae).

A majority of Africans rely on traditional medicine as the primary form of health care. Yet most traditional medicine products have a short shelf life, especially for water-based formulations such as macerations, infusions and decoctions. Indeed, many of these water extracts become unfit for human consumption after five to seven days of conservation either because of the degradation or toxicity of active components, and/or the growth of pathogenic organisms. The purpose of this study was to describe and apply a new approach for the development of an improved traditional medicine (ITM) that is cheap, very efficient, not toxic, and easy to produce, and that can be conserved for a longer time without a significant loss of activity. Hence, Laportea ovalifolia was selected from an ethnobotanical prospection in all regions of Cameroon, and was used to prepare an oral hypoglycemic product. This preparation required 9 steps focused on the characterization of the plant species, and the standardization of the ethnopharmacological preparation by a multidisciplinary team of scientists with expertise in botany, ecology, pharmacognosy and pharmacology. Resultantly, four galenic formulations of hypoglycemic medications were produced. A relationship between these four formulations was described as follow: One spoon of oral suspension (10 ml)=one sachet of powder=2 tablets=3 capsules. Hence, our research provides new insight into a drug discovery approach that could alleviate the major problems affecting traditional medicine and enhance its effectiveness in addressing health care in developing and undeveloped countries.

Costus afer Possesses Carbohydrate Hydrolyzing Enzymes Inhibitory Activity and Antioxidant Capacity In Vitro.

Diabetes mellitus is a metabolic disorder of glucose metabolism which correlates with postprandial hyperglycemia and oxidative stress. Control of blood glucose level is imperative in the management of diabetes. The present study tested the hypothesis that Costus afer, an antihyperglycemic medicinal plant, possesses inhibitory activity against carbohydrate hydrolyzing enzymes. Hexane, ethyl acetate, methanol, and water extracts were prepared from the leaf, stem, and rhizome of C. afer and subjected to phytochemical screening, assayed for α-amylase and α-glucosidase inhibitory activities and antioxidant capacity (determined by total phenolic and total flavonoids contents, ferric reducing antioxidant power (FRAP), and DPPH radical scavenging activity). All extracts inhibited α-amylase and α-glucosidase activities. Ethyl acetate rhizome and methanol leaf extracts exhibited the best inhibitory activity against α-amylase and α-glucosidase (IC50: 0.10 and 5.99 mg/mL), respectively. Kinetic analysis revealed two modes of enzyme inhibition (competitive and mixed). All extracts showed antioxidant capacity, with hexane extracts exhibiting the best activity. DPPH assay revealed that methanol leaf, rhizome, and ethyl acetate stem extracts (IC50 < 5 mg/mL) were the best antioxidants. The presence of bioactive compounds such as flavonoids, alkaloids, phenols, and tannins may account for the antioxidant capacity and carbohydrate hydrolyzing enzyme inhibitory activity of C. afer.

Pharmacological evidence for the folk use of Nefang: antipyretic, anti-inflammatory and antinociceptive activities of its constituent plants.

BACKGROUND: Nefang is a polyherbal anti-malarial composed of Mangifera indica ( MiB and MiL; bark and leaf), Psidium guajava ( Pg ), Carica papaya ( Cp ), Cymbopogon citratus ( Cc ), Citrus sinensis ( Cs ) and Ocimum gratissimum ( Og ) (leaves). Previous studies have demonstrated its in vitro and in vivo antiplasmodial activities, antioxidant properties and safety profile. This study aimed at evaluating the antipyretic, anti-inflammatory and antinociceptive activities of the constituent plants of Nefang which are relevant to the symptomatic treatment of malaria fever. METHODS: Antipyretic activities were determined by the D-Amphetamine induced pyrexia and Brewer's Yeast induced hyperpyrexia methods. Anti-inflammatory activities were investigated using the carrageenan-induced rat paw edema method. Antinociceptive activities were determined by mechanical nociception in the tail pressure and thermal nociception in the radiant heat tail flick and hot plate methods. Data was analysed using the one way ANOVA followed by Neuman-Keuls multiple comparison test. RESULTS: Best percentage inhibition of induced pyrexia (amphetamine/brewer's yeast; p < 0.05) was exhibited by Cc (95/97) followed by Og (85/94), MiL (90/89), MiB (88/84) and Cs (82/89). Cc and Og exhibited comparable activities to paracetamol (100/95). Anti-inflammatory studies revealed paw edema inhibition (%) as follows (p < 0.05): Indomethacin (47), MiL (40), Cp (30), MiB (28) and Og (22), suggesting best activity by MiL. Antinociceptive studies revealed significant (p < 0.01) pain inhibition (%) as follows: Paracetamol (97), Og (113), MiL (108), Pg (84) and MiB (88). Og and MiL exhibited the best activities. CONCLUSION: The results obtained suggest that the constituent plants possess biologically active compounds with antipyretic, anti-inflammatory and antinociceptive activities. These activities are essential in the symptomatic treatment of malaria fever, thereby justifying the folk use of Nefang. This would be useful in its subsequent development for clinical application.

Anti-malarial activity of a polyherbal product (Nefang) during early and established Plasmodium infection in rodent models.

BACKGROUND: The emerging resistance of Plasmodium species to currently available anti-malarials remains a public health concern, hence the need for new effective, safe and affordable drugs. Natural products remain a reliable source of drugs. Nefang is a polyherbal anti-malarial of the Cameroonian folklore medicine with demonstrated in vitro antiplasmodial and antioxidant activities. It is composed of Mangifera indica (bark and leaf), Psidium guajava, Carica papaya, Cymbopogon citratus, Citrus sinensis, Ocimum gratissimum (leaves). This study aimed at investigating the suppressive, prophylactic and curative activities of Nefang in Plasmodium infected rodent models. METHODS: Systemic acute oral toxicity of Nefang aqueous and ethanol extracts was assessed in mice up to a dose of 5,000 mgkg(-1) body weight. BALB/c mice and Wistar rats were inoculated with Plasmodium chabaudi chabaudi and Plasmodium berghei, respectively, and treated with Nefang, the Mangifera indica bark/Psidium guajava combination and a Psidium guajava leaf aqueous extracts (75, 150, 300 and 600 mgkg(-1) bwt). Their schizonticidal activity was then evaluated using the Peter's 4-day suppressive test). The prophylactic and curative (Rane's Test) activity of Nefang was also evaluated by determining the parasitaemia, survival time, body weight and temperature in pre-treated rodents. RESULTS: Acute oral toxicity of the extract did not cause any observed adverse effects. Percent suppressions of parasitaemia at 600 mgkg(-1) bwt were as follows (P. berghei/P. chabaudi): Nefang - 82.9/86.3, Mangifera indica bark/Psidium guajava leaf combination extract - 79.5/81.2 and Psidium guajava leaf - 58.9/67.4. Nefang exhibited a prophylactic activity of 79.5% and its chemotherapeutic effects ranged from 61.2 - 86.1% with maximum effect observed at the highest experimental dose. CONCLUSION: These results indicate that Nefang has excellent in vivo anti-malarial activities against P. berghei and P. chabaudi, upholding earlier in vitro antiplasmodial activities against multi-drug resistant P. falciparum parasites as well as its traditional use. Hence, Nefang represents a promising source of new anti-malarial agents.

In vitro antiplasmodial activities and synergistic combinations of differential solvent extracts of the polyherbal product, Nefang.

Nefang, a polyherbal product composed of Mangifera indica (bark and leaf), Psidium guajava, Carica papaya, Cymbopogon citratus, Citrus sinensis, and Ocimum gratissimum (leaves), is a potential therapy against P. falciparum malaria. In vitro antiplasmodial activities of its constituent solvent extracts were analyzed on CQ-sensitive (3D7) and multidrug resistant (Dd2) P. falciparum strains. The interactions involving the differential solvent extracts were further analyzed using a variable potency ratio drug combination approach. Effective concentration 50 (EC50) values were determined by nonlinear regression curve-fitting of the dose-response data and used in calculating the fractional inhibitory concentration 50 (FIC50) and combination indices (CI) for each pair. The derived EC50 values (3D7/Dd2, µ g/mL) are Nefang-96.96/55.08, MiB-65.33/34.58, MiL-82.56/40.04, Pg-47.02/25.79, Cp-1188/317.5, Cc-723.3/141, Cs-184.4/105.1, and Og-778.5/118.9. Synergism was obtained with MiB/Pg (CI = 0.351), MiL/Pg (0.358), MiB/Cs (0.366), MiL/Cs (0.482), Pg/Cs (0.483), and Cs/Og (0.414) when analyzed at equipotency ratios. Cytotoxicity testing of Nefang and the solvent extracts on two human cell lines (Hep G2 and U2OS) revealed no significant toxicity relative to their antiplasmodial activities (SI > 20). Taken together, our data confirm the antimalarial activities of Nefang and its constituent plant extracts and identified extract pairs with promising synergistic interactions for exploitation towards a rational phytotherapeutic and evidence-based antimalarial drug discovery.

Evaluation of the antidiarrheal and antioxidant properties of Justicia hypocrateriformis.

CONTENT: Justicia hypocrateriformis Vahl (Acanthaceae) is used as an herbal remedy for diarrhea in Cameroon folk medicine. OBJECTIVE: This study evaluates the antidiarrheal and antioxidant properties of the aqueous extract of J. hypocrateriformis (JH). MATERIALS AND METHODS: Preliminary phytochemical screening and an acute toxicity testing of the extract were carried out. The antidiarrheal activity of JH extract (100, 250, and 500 mg/kg) was assessed at curative and preventive levels in castor oil-induced diarrhea in mice. The antioxidant activity was measured by ferric reducing antioxidant power (FRAP), total phenolic content, and radical scavenging activity. RESULTS: A high lethal dose (LD50) of 14.35 g/kg obtained in acute toxicity implies the extract is not toxic. Phytochemical screening revealed the presence of phenols, tannins, flavonoids, saponins, anthraquinones, and anthocyanins. JH showed a significant protection against castor oil-induced diarrhea as evidenced by a decrease in the number of defecation and wet stool. JH (100-500 mg/kg, p.o.) produced a non-significant dose-dependent decrease in castor oil-induced intestinal transit in the preventive study. In the curative and in healthy mice study, the decrease was only significant at 500 mg/kg. JH possessed a radical scavenging activity with an IC50 of 9.93 mg/ml compared to 4.90 mg/ml for catechin. JH FRAP of 2703.77 ± 0 mg/g (catechin equiv) and phenolic concentration of 14 169.99 ± 612.39 mg/g (catechin equiv) were also obtained. CONCLUSION: Justicia hypocrateriformis extract possesses antidiarrheal activity supported by its antioxidant potential and phytochemical constituents.

Antioxidant and anti-atherogenic activities of three Piper species on atherogenic diet fed hamsters.

Atherogenic diet is known to induce high plasma lipid concentration, oxidative stress and early atherosclerosis. Antioxidants have potentials to counter the effect of atherogenic diet. The present research aims at evaluating the antioxidant and anti-atherosclerotic activities of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) on atherogenic diet fed hamsters. Hamsters divided into 8 groups: normal control, atherosclerotic control and six test groups. The normal animals fed normal rodent chow, the atherosclerotic control animals fed the same rodent chow supplemented with 0.2% cholesterol and 10% coconut oil (high cholesterol diet). The 6 test groups' animals fed same diet as the atherosclerotic control group but with additional supplementation of 2 graded doses (1 and 0.25 mg/kg body weight, o.p.) of plant extracts for 12 weeks. The atherogenic diet induced a collapse of the erythrocyte antioxidant defense system (significant decrease in superoxide dismutase, catalase and glutathione peroxidase activities). Atherogenic diet also induced an increase in plasma total cholesterol, triglyceride, thiobarbituric acid reactive substances (TBARS), oxidation of low density lipoprotein cholesterol (LDL) and accumulation of foam cells in the aorta a hall mark for atherosclerosis. Administration of the Piper species prevented the collapse of the antioxidant system and the increase of plasma parameters maintaining them towards normality. The Piper species also prevented LDL oxidation by increasing the time (lag time) for its oxidation. The results suggest that these Piper species have significant antioxidant and anti-atherogenic effect against atherogenic diet intoxication.

Piper species protect cardiac, hepatic and renal antioxidant status of atherogenic diet fed hamsters.

Pre-clinical and clinical studies points to the use of antioxidants as an effective measure to reduce the progression of oxidative stress related disorders. The present study evaluate the effect of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) for the protection of cardiac, hepatic and renal antioxidant status of atherogenic diet fed hamsters. Hamsters were classified into eight groups: a normal control, atherogenic control and six other experimental groups (fed atherogenic diet supplemented with different doses of P. nigrum, P. guineense and P. umbellatum (1 and 0.25 g/kg) for 12 weeks. At the end of the feeding period the heart, liver and kidney from each group were analyzed for lipid profile and antioxidant enzymes activities. Atherogenic diet induced a significant (P<0.001) increase in the lipid profile across the board and equally significantly altered the antioxidant enzyme activities. Supplementation with Piper species significantly inhibited the alteration effect of atherogenic diet on the lipid profile and antioxidant enzymes activities. The Piper extracts may possess an antioxidant protective role against atherogenic diet induced oxidative stress in cardiac, hepatic and renal tissues.

Antioxidant capacity of some plant foods and beverages consumed in the Eastern Region of Nigeria.

Today plant foods and beverages are receiving more scientific attention because of their potential to curb the effect of free radicals in the human system. The present study reports on the antioxidant potentials of some plants foods and beverages consumed in the Eastern Region of Nigeria. The study made use of the ferric reducing antioxidant power, phenolic and the flavonoid contents assays to assess the quality of the antioxidant potentials of the plant foods and beverages. Of the different classes of foods analyzed the following showed high antioxidant potentials: coffee for beverages, star apple for fruits, thyme for vegetable and spices, and raices for alcoholic beverages. Generally the vegetables and spices registered the highest antioxidant properties. The results obtained in this study could help consumers' choice based on the antioxidant capacity of the samples analyzed.