Inhibition of pancreatic lipase, α-glucosidase, α-amylase,and hypolipidemic effects of the total flavonoids from Nelumbo nucifera leaves

Ethnopharmacological relevance

Nelumbo nucifera Gaertn. leaves have been used as medicinal herbs in the past 1300 years, specifically utilized to cure hyperlipidemia, hyperglycemia, and obesity. It has been recorded in the most famous medicinal book in China for more than 400 years. The present study aims to identify the potential therapeutic activities of the flavonoids isolated from Nelumbo nucifera leaves.

Materials and methods

Nelumbo nucifera leaf flavonoids (NLF) were tested for the inhibition of lipase, α-glucosidase, and α-amylase activities in vitro. A single dose of NLF was administered by oral gavage in mice for acute toxicity. Wistar rats with high-fat diet-induced hyperlipidemia and two other animal models were used to evaluate the hypolipidemic effects of NLF.

Results

Our in vitro biochemistry tests revealed that the NLF showed high inhibitory activity against porcine pancreatic lipase, α-amylase, and α-glucosidase with IC₅₀ values of 0.38±0.022, 2.20±0.18, and 1.86±0.018 mg/mL, respectively. Furthermore, the NLF significantly lowered the lipid components, such as the total cholesterol, triglycerides, low-density lipoprotein cholesterol, and malondialdehyde, in various established in vivo systems and raised the high-density lipoprotein cholesterol. Moreover, the NLF alleviated high-fat diet-induced lipid accumulation in the liver.

Conclusions

The results demonstrate that NLFs can effectively ameliorate hyperlipidemia and inhibit the key enzymes related to type 2 diabetes mellitus. Our findings may provide new pharmacological basis for the treatment of hyperlipidemia, hyperglycemia, and obesity using NLFs.     

Acute and subchronic oral toxicity studies of Nelumbo nucifera stamens extract in rats

Ethnopharmacological relevance

Since the use of Nelumbo nucifera stamens in herbal medicines as well as in cosmetic products are highly prevalent in Thailand and increasing worldwide, acute and subchronic toxicity studies to confirm the safe use of Nelumbo nucifera stamens are warranted.

Aim of the study

Acute and subchronic oral toxicity studies of Nelumbo nucifera stamens extract in rats were performed in the present study in order to evaluate its safety.

Materials and methods

In acute toxicity study, Nelumbo nucifera stamens extract was administered by oral gavage to Sprague-Dawley rats (5 males and 5 females) at a dose of 5000 mg/kg. In subchronic toxicity study, the extract at doses of 50, 100, and 200 mg/kg/day were given orally to groups of rats (6 rats/dose/sex) for 90 consecutive days.

Results

The extract at a dose of 5000 mg/kg produced no treatment-related signs of toxicity or mortality in any of the animals tested during 14 days of the study. In the repeated dose 90-day oral toxicity study, there was no significant difference in body weight between the control and all treatment groups with the exception of the body weight of the female group treated with 200 mg/kg/day of the extract which was statistically significantly less than that of its control counterpart on day 90 but the percent weight changes of both groups were almost similar. Some statistically significant differences in hematological and biochemical parameters as well as in some internal organ weights of both male and female rats treated with the extract at the highest dose were observed. However, no abnormality of internal organs was observed in both gross and histopathological examinations.

Conclusions

These results suggest that the oral lethal dose of Nelumbo nucifera stamens extract for male and female rats is in excess of 5000 mg/kg and the no-observed-adverse-effect level (NOAEL) of the extract for both male and female rats is considered to be 200 mg/kg/day.     

Immunomodulatory activity of Asparagus racemosus on systemic Th1/Th2 immunity: Implications for immunoadjuvant potential

Ethnopharmacological relevance

Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations.

Aim of the study

To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals.

Materials and methods

We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside^®) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls.

Results

Treatment with ARE (100 mg/(kg b.w. p.o.)) resulted in significant increase of CD3⁺ and CD4/CD8⁺ percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes.

Conclusion

The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.     

Characterization of the antinociceptive and anti-inflammatory activities from Cocos nucifera L. (Palmae)

Aim of the study

Cocos nucifera cultivated in Brazil is known as “coco-da-Bahia” or “coqueiro-da-Índia”. The tea from the husk fiber is widely used to several inflammatory disorders. Crude extract and fractions obtained from Cocos nucifera “common variety” were evaluated to test the anti-inflammatory and antinociceptive activities.

Materials and methods

Crude extract (CE, 50, 100, and 150 mg/kg), fraction 1 (F1, molecular weight lesser than 1 kDa, 1, 10, and 50 mg/kg), fraction 2 (F2, molecular weight higher than 1 kDa, 1, 10, and 50 mg/kg), and the references drugs morphine (5 mg/kg), acetilsalicilic acid (200 mg/kg), prometazine (30 mg/kg), and metisergide (5 mg/kg) were evaluated on models of analgesia and inflammation.

Results

CE, F1, and F2 significantly develop peripheral and central antinociceptive activity but with less effect on supra-spinal regions of the brain. Administration of the opioid antagonist, naloxone (5 mg/kg) inhibited the antinociceptive effect indicating that Cocos nucifera crude extract and fractions may be acting in opioid receptors. CE and F1 also inhibited rat paw edema induced by histamine, and serotonin.

Conclusions

results demonstrated that Cocos nucifera and its fractions have antinociceptive and anti-inflammatory activities which confirm the popular use of this plant in several inflammatory disorders.     

Immunomodulatory potential of Enicostema axillare (Lam.) A. Raynal, a traditional medicinal plant

Ethnopharmacological relevance

Enicostema axillare (Lam.) A. Raynal., (Gentianaceae) has been used in traditional Indian system of medicine as depurative and for the treatment of psoriasis, intermittent fever and cancer. Ethnobotanical survey conducted in Theni District indicated a high consensus for this plant as blood purifier and to treat dermatopathy and venereal infections. The present study evaluated the immunomodulatory activity of the methanol extract of Enicostema axillare.

Materials and methods

In vivo immunomodulatory activity of Enicostema axillare methanol extract (100 and 200 mg/kg b.w) was evaluated by assessing its effect on the total and differential leukocyte count, organ weight, hemaggultinating antibody titer, plaque forming cells, quantitative hemolysis of SRBC and delayed type hypersensitivity. Sheep red blood cells (SRBC, 5 × 10⁸ cells/0.1 mL) were used to immunize the animals. In vitro immunomodulatory potential of the extract was studied using peritoneal macrophages by evaluating its effects on NBT reduction, NO production and cytokine release.

Results

The animals treated with Enicostema axillare methanol extract showed a significant (P ≤ 0.05) increase in weight of the thymus and spleen. The total leukocyte and lymphocyte count was increased significantly (P < 0.005) by the treatment. There was no significant alteration in neutrophil count. A dose dependent increase in antibody titer value was observed. A decreased response to DTH reaction induced by SRBC was recorded. A potential phagocytic response was seen on treatment with the extracts at 10 and 25 μg/mL. The extract inhibited the release of pro-inflammatory cytokines and production of NO significantly in a dose dependent manner.

Conclusion

These findings suggested that the methanol extract of Enicostema axillare acted on both humoral and cell mediated immune functions and decreased the release of pro-inflammatory cytokines in the peritoneal macrophages.     

Immunosuppressive activity of ethanolic extract of seeds of Moringa oleifera Lam. in experimental immune inflammation

Ethnopharmacological relevance

Traditionally, the plant Moringa oleifera Lam. (Moringaceae) is used for the treatment of ascites and rheumatism, while the dried seeds of the plant are used as an ‘anti-allergic’ agent.

Aim of the study

The aim of the study was to assess the efficacy of ethanolic extract of seeds from Moringa oleifera Lam. in experimental immune inflammation.

Materials and methods

Circulatory and splenic leukocyte counts, delayed-type hypersensitivity reactions and humoral antibody responses were measured in mice using SRBC as the antigen. In addition, macrophage phagocytosis was measured by the carbon clearance test.

Results

The extract dose-dependently (50, 100 and 200 mg/kg) inhibited spleen weight as well as circulatory leukocyte and splenocyte counts. The delayed-type hypersensitivity reaction was significantly inhibited (P < 0.01) by decreasing the mean foot pad thickness at 48 h. The production of the humoral antibody titer was significantly ameliorated at a dose of 100 and 200 mg/kg (P < 0.05 and P < 0.01, respectively). Furthermore, the extract caused a down-regulation of macrophage phagocytosis due to carbon particles.

Conclusion

Taken together, the above findings suggest that the seeds of Moringa oleifera have immunosuppressive activity.     

Acute toxicity studies of the leaf extract of Ficus exasperata on haematological parameters,body weight and body temperature

Introduction

The plant, Ficus exasperata is popularly used in Nigeria and in several parts of Africa for a variety of ailments.

Aim of study

This study was thus mapped out to investigate the toxicity profile of the aqueous leaf extract (AET) on haematological parameters, body weight and body temperature in mice.

Methodology

In the present study, AET was evaluated for acute toxicity over 24 h and 14-day periods. The LD₅₀ was assessed via oral and intraperitoneal administration.

Results

The LD₅₀ was indeterminable via the oral route but was determined to be 0.54 g/kg i.p. In the 24 h and 14 days single dose study, oral administration of 2.5, 5, 10 and 20 g/kg of AET produced neither mortality nor changes in behavior or any other physiological activity in mice. Body weights and body temperatures were not significantly altered. Haematological analysis showed no marked differences in any of the parameters examined (WBC count, platelet and haemoglobin estimation) in either the control or treated groups. However, the 14 days daily dose study showed significant increase in body temperature (p < 0.05) and a significant decrease in the red blood cell count, haemoglobin count and haematocrit values (p < 0.05), while other parameters remained unchanged.

Conclusion

In summary, AET was found to be relatively safe on short-term oral administration. However, chronic toxicity studies are required for the support of the safe use of this plant.     

Effect of plants used in Mexico to treat gastrointestinal disorders on charcoal–gum acacia-induced hyperperistalsis in rats

Ethnopharmacological relevance

A total of 28 plant extracts, belonging to 26 different plant species are commonly used in Traditional Mexican Medicine for the treatment of gastrointestinal disorders such as diarrhea.

Aim of the study

To evaluate the effect of medicinal plant extracts on induced hyperperistalsis in rats.

Materials and methods

Charcoal meal test was used in this study. Extracts were tested at a dose of 300 mg/kg.

Results

From all the plant extracts tested, only Geranium mexicanum (roots) showed 100% of inhibition. The extracts of Artemisia absinthium, Matricaria recutita, Caesalpinia pulcherrima, Lygodium venustum, Chenopodium ambrosoides (green variety), Aloysia triphylla, Artemisia ludoviciana, Chiranthodendron pentadactylon, and Cocos nucifera showed moderate inhibitory activity with values ranging from 30 to 57%. Their activities were greater than that of or equal to loperamide (34% of inhibition at doses of 10 mg/kg) drug used as control. The remaining plants exhibited marginal or null inhibitory effect on hyperpropulsive movement of the small intestine.

Conclusions

The results obtained in this study give some scientific support to the popular use of 23 of the plants tested for the treatment of gastrointestinal disorders such as diarrhea in Mexican traditional medicine. However, roots of Geranium mexicanum should be used in herbal medicine with care to avoid toxicity.     

Nuciferine stimulates insulin secretion from beta cells-an in vitro comparison with glibenclamide

Ethnopharmacological relevance

Several Asian plants are known for their anti-diabetic properties and produce alkaloids and flavonoids that may stimulate insulin secretion.

Materials and methods

Using Vietnamese plants (Nelumbo nucifera, Gynostemma pentaphyllum, Smilax glabra, and Stemona tuberosa), we extracted two alkaloids (neotuberostemonine, nuciferine) and four flavonoids (astilbin, engeletin, smitilbin, and 3,5,3′-trihydroxy-7,4′-dimethoxyflavone), and studied their insulin stimulatory effects.

Results

Nuciferine, extracted from Nelumbo nucifera, stimulated both phases of insulin secretion in isolated islets, whereas the other compounds had no effect. The effect of nuciferine was totally abolished by diazoxide and nimodipine, and diminished by protein kinase A and protein kinase C inhibition. Nuciferine and potassium had additive effects on insulin secretion. Nuciferine also stimulated insulin secretion in INS-1E cells at both 3.3 and 16.7 mM glucose concentrations. Compared with glibenclamide, nuciferine had a stronger effect on insulin secretion and less beta-cell toxicity. However, nuciferine did not compete with glibenclamide for binding to the sulfonylurea receptor.

Conclusions

Among several compounds extracted from anti-diabetic plants, nuciferine was found to stimulate insulin secretion by closing potassium-adenosine triphosphate channels, explaining anti-diabetic effects of Nelumbo nucifera.     

Erythropoietic activity of Asteracantha longifolia (Nees.) in rats

Ethnopharmacological relevance

Asteracantha longifolia Nees. (Family-Acanthaceae) is a wild herb commonly used in traditional ayurvedic medicine as Kokilaaksha and the Unani drug as Talimakhana in India and Srilanka for various medicinal uses as aphrodisiac, tonic, sedative and blood diseases etc.

Aim of the study

The aim of the current study was to validate and explore the folk use of Asteracantha longifolia Nees. (AL) (Leaf part) on pharmacological grounds using haloperidol induced iron deficiency anemia for the assessment of erythropoietic activity.

Materials and methods

Determination of iron in plant extracts was carried out using spectrophotometric method. Plant extract was obtained from crude drugs using extraction with ethanol. In vivo study, haloperidol induced iron deficiency anemia model was used in experimental studies.

Results

An administration of ethanolic extract of AL at the doses of 100 mg/kg and 200 mg/kg body weight, i.p., demonstrated a significant (P < 0.05) increase in erythrocyte count, haemoglobin count, serum iron and serum protein etc. This effect may be due to the presence of iron (622 μg/50 mg) in extract estimated by spectrophotometric method.

Conclusion

An ethanolic extract of AL effectively restored the hematological parameters, serum iron and serum protein and normalized the microcytic (smaller in size), anisocytosis (disturbed shape) and hypochromic RBCs. These observations could justify the inclusion of this plant in the management of iron deficiency anemia due the presence of iron and other constituents as flavonoids, terpenoids, steroids, lupeol and betulin.     

Augmentation of expression of immunocytes’ functions by seed extract of Ziziphus mauritiana (Lamk.)

Aim of the study

The present study was carried out to evaluate the immunomodulatory potential of Ziziphus mauritiana (Lamk.) seed extract to ascertain the folkloric claim as immunomodulator.

Materials and methods

The aqueous-ethanolic seed extract (100–400 mg kg⁻¹) of Z. mauritiana was investigated for immunomodulatory potential in mice. The extract was standardized with HPLC using betulinic acid as a marker. Functions of various immunocytes in the form of humoral (development of anti-SRBC (sheep red blood cells) antibody titers) and cell-mediated immune response (delayed type hypersensitivity, nitroblue tetrazolium reduction, inducible nitric oxide synthase activity and bactericidal activity) was studied in SRBC immunized mice. The cytokine, IFN-γ (interferon-gamma) and IL-4 (interleukin-4) secretion was also measured quantitatively by ELISA as the expression of functions of Th-1 and Th-2 respectively. Levamisole (2.5 mg kg⁻¹) was used as standard drug.

Results

The seed extract demonstrated significant (P < 0.05–0.001) up-regulation of cell-mediated, humoral immune response and Th-1 mediated cytokine IFN-γ and decline in Th-2 mediated cytokine IL-4. At higher dose of extract the results were comparable to that of the levamisole.

Conclusion

The immunostimulatory potential of this seed extract is likely to be mediated through its effect on macrophage function and Th-1 mediated immunity confirming the folkloric use of this plant.     

Inhibitory effects of Geijigajakyak-Tang on trinitrobenzene sulfonic acid-induced colitis

Aim of the study

Water extract of Geijigajakyak-Tang (GJT) consisting of five crude drugs [dried root of P. lactiflora Peony (Paeoniaceae), dried trunk bark of C. cassia Blume (Lauraceae), seed of Z. jujube var. inermis Mill (Rhamnaceae), fresh root of Z. officinale Rocoe (Zingiberaceae) and dried trunk bark of G. uralensis Fish (Leguminosae)] is a folk medicine used for the treatment of chronic colitis. This study was designed to further elucidate the effect of GJT on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.

Materials and methods

GJT orally given to mice before and after TNBS intoxication, and their clinical and morphological changes, myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels in colon tissues, were evaluated on Day 8 post-TNBS. Furthermore, the effect of six major constituents of individual herbs on ileum smooth muscle contraction and neutrophil chemotaxis was studied.

Results

GJT had a significant anti-inflammatory effect based on clinical and morphologic changes, MPO activity and MDA levels in colon tissues as compared with sham control. GJT and 5 major active constituents of individual herbs, paeoniflorin, cinnamaldehyde, jujuboside A, jujubogenin, and diammonium glycyrhhizinate significantly inhibited neutrophil chemotaxis. GJT significantly inhibited muscle contraction (IC₅₀; 2.10 ± 0.11 mg/ml), and 1,8-cineol has the most spasmolytic activity (IC₅₀; 0.10 ± 0.03 mg/ml).

Conclusion

GJT has significant anti-inflammatory effects on TNBS-induced colitis via inhibitions of smooth muscle contraction and neutrophil chemotaxis.     

Anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) against Trichostrongylid nematodes of sheep

Ethnopharmacological relevance

Ziziphus nummularia (Rhamnaceae) and Acacia nilotica (Fabaceae) are being used as anthelmintics in ethnoveterinary medicinal system of Pakistan.

Aim of the study

Present study was conducted to determine the anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) in order to justify their traditional use in veterinary medicine.

Materials and methods

In vitro anthelmintic activity of crude methanolic extract (CME) of both the plants was determined against Haemonchus contortus by the adult motility assay, the egg hatch test and the larval development assay. In vivo anthelmintic activity was evaluated in sheep naturally infected with gastrointestinal nematodes by administering increasing doses of crude powder (CP) and CME (1.0–3.0 g/kg).

Results

Both the plants exhibited dose- and time-dependent anthelmintic effects by causing mortality of worms, and inhibiting egg hatching and larval development. Acacia nilotica (LC₅₀ = 512.86 and 194.98 μg/ml) was found to be more potent than Ziziphus nummularia (LC₅₀ = 676.08 and 398.11 μg/ml) in egg hatch test and larval development assay, respectively. In vivo, maximum fecal egg count reduction (84.7%) was recorded on day 13 post-treatment in sheep treated with Ziziphus nummularia CME (3.0 g/kg) followed by 78.5% on same day with Acacia nilotica CME (3.0 g/kg).

Conclusions

These data show that both Ziziphus nummularia and Acacia nilotica possess anthelmintic activity in vitro and in vivo, justifying their use in traditional veterinary medicine in Pakistan.     

Evaluation of anticancer activity of Cleome gynandra on Ehrlich's Ascites Carcinoma treated mice

Ethnopharmacological relevance

The plant Cleome gynandra L. (Capparidaceae), is commonly known as ‘Hurhur’and ‘Karaila’ in India and ‘Cat's whiskers’ in English. Traditionally the whole plant is used in the treatment of tumor, anti-inflammatory and lysosomal stability actions.

Aim of study

The objective of present study is to explore the anticancer activity of the methanol extract of the Cleome gynandra in Swiss albino mice against Ehrlich Ascites Carcinoma (EAC) cell line.

Materials and methods

Anticancer activity of methanol extract of Cleome gynandra (MECG) was evaluated in Swiss albino mice against Ehrlich Ascites Carcinoma (EAC) cell line at the doses of 200 and 400 mg/kg body weight intraperitoneally. MECG was administered for nine consecutive days. Twenty-four hours of last dose and 18 h of fasting, the mice were sacrificed and antitumor effect of MECG assessed by evaluating tumor volume, viable and nonviable tumor cell count, tumor weight and hematological parameters of EAC bearing host.

Results

MECG showed significant decrease in (p < 0.01) tumor volume, viable cell count, tumor weight and elevated the life span of EAC tumor bearing mice. Hematological profile such as RBC, hemoglobin, WBC and lymphocyte count reverted to normal level in MECG treated mice.

Conclusion

From the result it was showed that the extract has potent dose dependent anticancer activity and that is comparable to that of 5-fluorouracil.     

Antinociceptive and anti-inflammatory activities of Bowdichia virgilioides (sucupira)

Ethnopharmacological relevance

Bowdichia virgilioides Kunth (Leguminosae Papilonoideae) is a plant with anti-inflammatory activity used in folk medicine. The importance of this plant promoted its inclusion in Brazilian Pharmacopoeia.

Aim of the study

In order to evaluate the actions of this plant, studies were performed on antinociceptive and anti-inflammatory activities.

Materials and methods

The aqueous extracts (AE) of Bowdichia virgilioides inner bark and leaves were used at 100, 200, and 400 mg/kg. Antinociceptive activity of plant extract was evaluated by writhing, hot-plate and formalin tests. Anti-inflammatory activity was evaluated using paw oedema and peritonitis methods.

Results

Oral treatment with the AE of inner bark or leaves elicited inhibitory activity (P < 0.01) on acetic acid effect at 200 and 400 mg/kg, and reduced the formalin effect at the second-phase (200 and 400 mg/kg, P < 0.01), however it did not elicit any inhibitory effect on hot-plate test. The indomethacin inhibited the acetic acid-induced writhing and the formalin effect at the second-phase (P < 0.001), and the morphine reduced the both phases of formalin test (P < 0.001). Carrageenan-induced oedema formation and neutrophil migration into the peritoneal cavity were reduced with the AE of inner bark or leaves at 100, 200, and 400 mg/kg (P < 0.05), and by the reference compounds aspirin (P < 0.001) and dexamethasone (P < 0.001), respectively.

Conclusions

The AE of Bowdichia virgilioides shows antinociceptive and anti-inflammatory activities, supporting the folkloric usage of the plant to treat various inflammatory diseases.     

Citrus limetta leaves extract antagonizes the hypertensive effect of angiotensin II

Ethnopharmacological relevance

Citrus limetta Risso (Rutaceae) is widely used in Mexico for healing purposes, among them as antihypertensive treatment.

Aim of the study

To assess the antihypertensive effect of C. limetta leaves as one of its ethnomedical uses.

Materials and methods

The acute response of blood pressure to angiotensin II administration was measured in mice. Additionally, the acute oral toxicity profiles were determined.

Results

The findings of the current investigation showed that different concentrations of the aqueous extract prevented the raise of systolic blood pressure (p ≤ 0.001 vs. vehicle), diastolic blood pressure (p ≤ 0.0002 vs. vehicle) and mean blood pressure (p ≤ 0.0000 vs. vehicle); with a dose dependent effect for diastolic pressures at 125–500 mg/kg dosages. The 500 and 1000 mg/kg doses inhibited the action of Ang II in similar extent to telmisartan. Toxic signs or deaths were not observed in mice treated at 2000 mg/kg of C. limetta extract.

Conclusions

All doses of C. limetta aqueous extract, used in this assay, were safe and effective.     

Sub-acute toxicity of the chloroformic extract of Rapanea melanophloeos (L.) Mez in rats

Ethnopharmacological relevance

Cape beech (Rapanea melanophloeos) is an important medicinal plant that is widely used in most of Africa. Currently, little toxicological information is available on its safety following prolonged use.

Aim of the study

In this study, we sought to evaluate the oral sub-acute toxicity of Rapanea melanophloeos stem bark chloroformic extract using Sprague Dawley rats.

Materials and methods

Six-week old rats were orally administered with the extract at dosage levels of 100 mg/kg, 300 mg/kg and 1000 mg/kg for 28 days. Clinical signs, hematological and clinical chemistry parameters were monitored, while organ weights and organ pathology were evaluated at the end of the study.

Results

The extract caused a significant reduction in bodyweight at 1000 mg/kg. The hematological profiles of animals at this dose showed an increase in the erythrocyte count and the hematocrit that were accompanied by decrease in the mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Biochemical parameters were not altered in a dose-related manner when compared to the controls. There were time associated alterations on both hematological and biochemical parameters, but pathological examination did not reveal any treatment related changes in any of the organs.

Conclusion

Our results demonstrate that the chloroformic stem bark extract of Rapanea melanophloeos may be of no toxicological concern at dosage levels up to 1000 mg/kg. Rapanea melanophloeos can therefore be used confidently in African traditional medicine at these or lower dosage levels.     

Evaluation of the use of Cocos nucifera as antimalarial remedy in Malaysian folk medicine

Ethnopharmacological relevance

White flesh extract of Cocos nucifera (coconut) was studied to ascertain the ethnopharmacological standing of its antimalarial usage in Malaysian folk medicine.

Materials and methods

The crude methanol extract was investigated for phytochemical constituents and acute oral toxicity. Antimalarial activity of different extract doses of 50, 100, 200 and 400 mg/kg were investigated in vivo against Plasmodium berghei (NK65) infections in mice during early, established and residual infections. Chloroquine (20 mg/kg) and pyrimethamine (1.2 mg/kg) were used as reference drugs.

Results

The results revealed that the extract contained some phytochemical constituents and is toxicologically safe by oral administration. The extract significantly reduced the parasitaemia by the 200 and 400 mg/kg doses in the all three in vivo assessment assays. However, the extract did not significantly increase the survival time of the infected mice.

Conclusions

The observed pharmacological activities suggest that the Malaysian folkloric medicinal application of Cocos nucifera has a pharmacological basis.     

Pharmacokinetics and tissue distribution of resveratrol,emodin and their metabolites after intake of Polygonum cuspidatum in rats

Ethnopharmacological relevance

The rhizome of Polygonum cuspidatum SIEB. et ZUCC. (Polygonaceae, PC), a widely used Chinese medicine, is commonly prescribed for the treatments of amenorrhea, arthralgia, jaundice, abscess, scald and bruises.

Aim of the study

PC contains various polyphenols including stilbenes, anthraquinones and flavonoids. This study investigated the pharmacokinetics and tissue distribution of emodin and resveratrol in PC.

Material and methods

Male Sprague-Dawley rats were orally administered PC (2 and 4 g/kg) and blood samples were withdrawn at the designed time points via cardiopuncture. Moreover, after 7-dose administrations of PC (4 g/kg), brain, liver, lung, kidney and heart were collected. The concentrations of resveratrol and emodin in the plasma and tissues were assayed by HPLC before and after hydrolysis with β-glucuronidase and sulfatase.

Results

The glucuronides/sulfates of emodin and resveratrol were exclusively present in the plasma. In liver, kidney, lung and heart, the glucuronides/sulfates of resveratrol were the major forms. For emodin, its glucuronides/sulfates were the major forms in kidney and lung, whereas considerable concentration of emodin free form was found in liver. Neither free forms nor conjugated metabolites of resveratrol and emodin were detected in brain.

Conclusion

The sulfates/glucuronides of resveratrol and emodin were the major forms in circulation and most assayed organs after oral intake of PC. However, the free form of emodin was predominant in liver.     

Effect of feeding Mucuna pruriens on helminth parasite infestation in lambs

Ethnopharmacological relevance

Mucuna pruriens is a tropical legume anecdotally reputed to have anthelmintic properties. This study was conducted to examine the validity of such claims.

Aim of the study

The aim of this study was to determine if ingestion of Mucuna seeds reduces helminth parasite infestation in lambs.

Materials and methods

Thirty-six Dorper × Katahdin ram lambs were assigned to three treatments, a cottonseed meal based control diet, a diet in which Mucuna replaced cottonseed meal and the control diet with levamisole (7.5 mg/kg body weight) administration. All diets were isonitrogenous and isocaloric. The 12 lambs in each treatment were assigned randomly to 4 pens, each containing 3 lambs. Lambs were trickle infected three times per week by gavage with infectious Haemonchus contortus larvae (2000 larvae/lamb) for 3 weeks.

Results

Levamisole treatment decreased fecal egg counts by 87% and abomasal worm counts by 83%. Mucuna intake did not statistically affect fecal egg counts or abomasal worm counts, though numerical (P > 0.10) reductions of 7.4% and 18.1%, respectively were evident. Anemia indicators, feed intake, and lamb growth were unaffected by treatment.

Conclusions

Levamisole reduced the Haemonchus parasite burden in lambs significantly but feeding Mucuna reduced the burden by levels unlikely to eliminate the clinical effects of parasitism.