Immunomodulatory effects of aqueous extract of Tridax procumbens in experimental animals

The immunomodulatory properties of ethanol insoluble fraction of aqueous extract of Tridax procumbens Linn. (TPEIF) have been investigated. After intraperitoneal administration of TPEIF in doses of 0.25 and 0.5 g/kg body weight (BW) a significant increase in phagocytic index, leukocyte count and spleenic antibody secreting cells was noticed. Stimulation of humoral immune response was further observed with elevation in heamagglutination antibody titer. Heightened delayed type hypersensitivity reaction suggested convincing evidence for activation of cellular immune system. Protective action of herbal medicine in case of anaphylactic shock was also studied. In addition, elicitation of specific antibody titer against tetanus toxoid (TT) challenge was measured in order to explore the possible use as adjuvant along with clinical vaccination program to reduce number of non-responders. The results suggest that TPEIF influences both humoral as well as cell mediated immune system vis-a-vis assists in genesis of improved antibody response against specific clinical antigen.     

Immunomodulatory activity of an aqueous extract of Azadirachta indica stem bark

The interference of an aqueous extract of the stem bark of Azadirachta indica with different parts of the human immune system was investigated. The extract showed strong anticomplementary effects which were dose-and time-dependent and most pronounced in the classical complement pathway assay. Moreover, a dose-dependent decrease in the chemiluminescence of polymorphonuclear leukocytes was observed and a dose-dependent increase in the production of migration inhibition factor by lymphocytes.     

Immunomodulatory effect of Achyrocline satureioides (LAM.) D.C. aqueous extracts

The immunomodulatory activity of aqueous extract from Achyrocline satureioides, prepared using heating, was investigated with a mitogen-induced cell proliferation assay and IL-2 secretion in BALB/c mice. The results showed a slightly immunosuppressive activity.     

Antidiarrhoeal activity of Geranium incanum Burm. f. (Geraniaceae) leaf aqueous extract in mice

Ethnopharmacological relevance

Geranium incanum Burm. f. (Geraniaceae) is used in South Africa especially in rural communities by traditional medicine practitioners to treat diarrhoea. However, scientific evidence does not exist in any literature to corroborate the claim of therapeutic success of the plant species in diarrhoea.

Aim of study

The study intended to investigate the antidiarrhoeal activity of the leaf aqueous extract of Geranium incanum in mice.

Materials and Methods

Castor oil induced diarrhoeal test was used to assess the antidiarrhoeal activity of Geranium incanum. Gastrointestinal tract transit of charcoal meal test was used to assess the antipropulsive activity of the plant extract while the acute toxicity study and phytochemical analysis were carried out using well established protocols and methods.

Results

The antidiarrhoeal activity of Geranium incanum was investigated by studying the effect of leaf aqueous extract of the plant species on castor oil-induced diarrhoea in mice. The leaf aqueous extract of Geranium incanum significantly reduced faecal output in castor oil -induced diarrhoea and also significantly reduced the number of diarrhoeal episodes. Geranium incanum significantly delayed the onset of diarrhoea induced by castor oil and significantly reduced the number of animals exhibiting diarrhoea. Loperamide, a standard antidiarrhoeal drug, produced similar effects to the leaf aqueous extract of Geranium incanum on castor oil-induced diarrhoea. Both Geranium incanum and loperamide significantly reduced the intestinal propulsion of charcoal meal in mice. The phytochemical analysis of the leaves revealed the presence of tannins, saponins particularly steroidal saponin, and flavonoids. The LD₅₀ of the plant species obtained was greater than 4000 mg/kg (p.o.).

Conclusion

The data obtained indicate that the leaf aqueous extract of Geranium incanum has both antidiarrhoeal and antipropulsive activities The data also show that the plant material given orally may be safe and/or non toxic in mice. However, further investigation on the acute toxicity and on the mechanism of the antidiarrhoeal effect of the plant species needs to be carried out.     

Toxicological studies of the aqueous extract from Achyrocline satureioides (Lam.) DC (Marcela)

Achyrocline satureioides (Lam.) DC (Marcela) is known to possess a broad spectrum of pharmacological, medicinal and therapeutic properties. Previous studies have demonstrated various protective abilities of the marcela extracts against various pathological conditions. However, no extensive safety studies have been conducted on these extracts to date. In this paper, we evaluated the acute toxicity (dose levels of 30-300 mg/kg) of an aqueous extract of marcela, administered intraperitoneally and orally in mice and rats. The acute oral maximun tolerable dose in repeated administration during 4 h (1, 3 until 5 g/kg) was also studied in rats. The extract had low acute toxicity when administered intraperitoneally and no toxicity upon oral administration. The LD(50) of aqueous extracts of marcela was found to be greater than 5 g/kg when administered once via gastric intubation to rats. Weight gain, toxicity signs, enzymatic studies (transaminases and phosphatases) and histological evaluation of several organs indicated that the extract was devoid of acute toxicity. These acute studies demonstrated that an aqueous extract of marcela obtained after a 2% infusion is safe and did not cause any detrimental effects in vivo under the conditions investigated in this study.     

Antinociceptive activity of aqueous extract of Pachyptera hymenaea (DC.) in mice

The standardized aqueous extract of leaves of Pachyptera hymenaea (DC.) belonging to family Bignoniaceae was investigated for possible antinociceptive effect in mice. Three different models were used to study the effects of extract on nociception, namely acetic acid-induced writhing test, formalin test (paw licking test) and tail flick test in mice. The extract was administered 1h prior to pain induction in the dose range of 25, 50 and 75mg/kg orally. The extract at the given dose range reduced the acetic acid induced nociception by 44.03, 52.90 and 62.46% respectively. The extract reduced formalin effect in both the phases of experiment by 32.36, 41.94, 54.29% and 35.39, 50.17, 55.86% respectively. In the tail flick study, animals' reaction time were increased by 22.69, 38.24 and 40.26% at the above selected doses respectively at 120min after drug administration. Naloxone (2mg/kg; s.c.) significantly antagonized the effect of extract in formalin and tail flick method, while partially antagonized the effect in writhing test. However caffeine completely reverted the extract effect in both the phases of formalin test. Results of these studies revealed that the extract have significant antinociceptive activity in the used models with a possible involvement of central mechanism and adenosine system.     

Immunomodulatory and cellular anti-oxidant activities of an aqueous extract of Limoniastrum guyonianum gall

Ethnopharmacological relevance

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses to disease/infection/etc. or to ameliorate immune based pathologies (i.e., inflammation, autoimmune associated diseases, etc.). In this particular study, the immunomodulatory potential of gall aqueous extract from Limoniastrum guyonianum Boiss. (Zita) was assessed in vitro.

Materials and methods

The effect of G extract on splenocytes proliferation and NK activity were assessed by MTT test. The induction of NO production and the phagocytic activity of macrophages were evaluated in vitro. Activation of the cellular anti-oxidant activity in splenocytes was determined by measuring the fluorescence of the DCF product.

Results

The studies first demonstrated that the extract could enhance lysosomal enzyme activity and nitrite oxide production in murine peritoneal macrophages, suggesting a potential role in activation of these cells. In studies to assess potential effects on humoral immunity, the results indicated that the extract could significantly promote LPS-stimulated splenocyte proliferation implying a potential activation of B-cells and enhanced humoral immune responses in hosts given this natural product. In studies to assess any effects of extract on cellular immunity, the results showed that the extract significantly enhanced the killing activity of isolated NK cells but had negligible effects on mitogen-induced proliferation of splenic T-cells. Considerable effects were also observed on the cellular anti-oxidant activity.

Conclusion

We conclude from these studies that aqueous extract from L. guyonianum gall exhibited an immunomodulator effect which could be ascribed, in part, to its cytoprotective effect via its anti-oxidant capacity. Furthermore, these results suggest that L. guyonianum gall extract contains potent components such as flavonoids which should be potentially used to modulate immune cell functions in physiological and pathological conditions.     

Anticonvulsant effect of Rhus chirindensis (Baker F.) (Anacardiaceae) stem-bark aqueous extract in mice

Extracts of Rhus chirindensis stem-bark are used extensively in South African traditional medicines for the treatment, management and/or control of an array of human ailments, including childhood convulsions and epilepsy. In this study, we investigated the anticonvulsant activity of the plant's stem-bark aqueous extract (RCE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Single intraperitoneal injections of PTZ (90 mg/kg), PCT(10 mg/kg) or BCL (30 mg/kg) produced tonic-clonic seizures. Like the standard antiseizure drugs used, Rhus chirindensis stem-bark aqueous extract (RCE, 100-800 mg/kg i.p.) significantly delayed (p<0.05-0.001) the onset of, and antagonized pentylenetetrazole-induced seizures. The plant's stem-bark aqueous extract (RCE, 100-800 mg/kg i.p.) also profoundly antagonized picrotoxin-induced seizures, but only weakly antagonized bicuculline-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that RCE produces its antiseizure effect by enhancing GABAergic neurotransmission and/or action in the brain. The results of this laboratory animal study indicate that RCE possesses anticonvulsant activity in the mammalian experimental model used, and thus suggest that the plant may be used as a natural supplementary remedy in the management, control and/or treatment of childhood convulsions and epilepsy. In conclusion, the findings of this study lend pharmacological credence to the suggested folkloric, ethnomedical uses of Rhus chirindensis in the management of childhood convulsions and epilepsy in some rural communities of South Africa.     

Immunomodulatory activity of the aqueous extract from rhizome of Smilax glabra in the later phase of adjuvant-induced arthritis in rats

Our previous paper has reported that the aqueous extract from Rhizoma Smilacis Glabrae (RSG) remarkably inhibited the primary inflammation of adjuvant arthritis (AA) in rats. In the present study, we further examined the activity of RSG and its mechanism on the secondary inflammation of AA. The administration of RSG (400 and 800 mg/kg) during the later phase significantly inhibited the swelling of the adjuvant-non-injected footpad of AA rats. The lipopolysaccharide-induced production of IL-1, TNF and NO by peritoneal macrophages was significantly reduced. In contrast, the extract significantly recovered the decrease in weight gain of the AA rats and Concanavalin A-induced T lymphocyte proliferation and IL-2 production by their splenocytes, while prednisolone (10mg/kg) showed a significant aggravation. Furthermore, RSG significantly recovered the picryl chloride-induced delayed-type hypersensitivity to almost normal levels from the higher or lower levels induced by different treatments of cyclophosphamide with a normalization of CD4/CD8 ratio. These results suggest that RSG exhibit an improvement on AA through down-regulating over-activated macrophages and up-regulating the dysfunctional T lymphocytes during the later phase of arthritis. Such characteristics of RSG on AA may be advantageous to the long-term treatment of clinical rheumatoid arthritis.     

穿心莲的研究进展

总结了近年来穿心莲在生药学、化学、药理、质量控制等方面的研究进展。     

Anti-anaemic potentials of aqueous extract of Sorghum bicolor (L.) moench stem bark in rats

The effects of oral administration of aqueous extract of Sorghum bicolor (L.) Moench stem bark at the doses of 200, 400 and 800 mg/kg body weight on iron sufficient and iron deficient weaning rats were investigated. Weaning rats of 21 days old were maintained on iron sufficient and iron deficient diets for 6 weeks before the administration of the aqueous extract of Sorghum bicolor stem bark at various doses for 7 days. Proximate analysis of the iron sufficient and iron deficient diets showed that they were similar except in the amount of iron. Phytochemical screening of the extract revealed the presence of alkaloids and saponins. Extract administration produced significant increase in haemoglobin, packed cell volume and red blood cells in iron sufficient and iron deficient groups (P < 0.05). There was also significant increase (P < 0.05) in the catalase activity of the rat liver and kidney without any significant change (P > 0.05) in the serum catalase activity. The results revealed that extract administration has restored the anaemic condition in the iron deficient group and thus lend credence to its use in folklore medicine in the management of anaemia.     

Evaluation of the developmental toxicity of the aqueous extract from Trigonella foenum-graecum (L.) in mice

Aim of the study

The use of medicinal plant products to treat various ailments is a common practice in many developing countries. However, a lack of information on the adverse effects of these plants raises questions on their safety and possible adverse side effects. This study was undertaken to evaluate the potential toxic effects of fenugreek seeds on pregnant mice and foetal development.

Materials and methods

Lyophilized aqueous extract from fenugreek seeds (LAE-FS) was administered to mated female mice during the entire period of pregnancy, at doses of 500 and 1000 mg/kg/day. Females were examined for standard parameters of reproductive performance. Foetuses were weighed and examined for externally visible malformations.

Results

In pregnant females, there were no obvious symptoms of toxicity, LAE-FS-related deaths or macroscopic abnormalities. Developmental toxicity in offspring included an increase in the foetal death rate, a decrease in the litter size, and a reduction in the foetal body weight. In addition there was an increase in the incidence of morphological abnormalities.

Conclusions

Based on these results, it was concluded that fenugreek seeds extract may have deleterious toxic effects on reproductive performance and potential teratogenic effects in foetuses.     

Evidence of the mechanism of action of Erythrina velutina Willd (Fabaceae) leaves aqueous extract

Ethnopharmacological relevance

Erythrina velutina is traditionally used for sleepiness, convulsions and nervous system excitation in Brazil. Although central effects have been reported for Erythrina velutina, little is known about its mechanism of action.

Aim of the study

To investigate the pharmacological evidences of mechanism of action of Erythrina velutina leaves aqueous extract (AE).

Materials and methods

Terminal segments of the guinea-pig ileum (n = 5–8) were mounted in an organ bath and isotonic contractions were recorded. Phytochemical screening was carried out on AE.

Results

AE (0.025–2.50 mg/ml) produced contractile response in the guinea-pig ileum, yielding typical concentration–response curves (EC₅₀ = 0.63 mg/ml). Electrically evoked contractions were significantly increased in the presence of AE. AE-elicited contractions were significantly reduced by bicuculline, tetrodotoxin, atropine, verapamil or incubation in low calcium–high potassium solution. Atropine along with verapamil abolished AE contractile response. Alkaloids, catechins, steroids, flavonols, flavononols, flavonoids, phenols, saponins, tannins, triterpenoids, and xanthones were detected in AE.

Conclusions

AE contains important constituents for pharmacological activities. AE-induced contractions seem to involve GABA_A receptor activation, acetylcholine release, muscarinic receptor activation, augmentation of Ca²⁺ entry through L-type calcium channels, and calcium release from the intracellular stores. These findings provide further support for Erythrina velutina traditional uses.     

Anti-diabetes and hypoglycaemic properties of Hemionitis arifolia (Burm.) Moore in rats

Hemionitis arifolia, a folklore anti-diabetes fern, was evaluated for its hypoglycaemic and anti-diabetic properties using rats. Glucose lowering effect and anti-diabetes activity were studied using glucose tolerance test in normal rats and alloxan diabetic rats, respectively. When different extracts were tested, the ethanol and, to some extent, the water extracts were found to lower the levels of blood glucose in glucose fed rats. The ethanol extract showed optimum activity at 200 mg/kg. The extract exhibited only marginal hypoglycaemic activity in overnight fasted normal rats and it was devoid of conspicuous toxic symptoms in sub-acute toxicity evaluation in mice. When the alcohol extract was fractionated by sequential solvent extraction, the activity was found in ethyl acetate fraction (50 mg/kg). This fraction containing steroids and coumarins showed anti-diabetes activity in alloxan diabetic rats as judged from serum glucose levels, liver glycogen content and body weight. This fraction is an attractive material for further research vis-à-vis drug development.     

Prokinetic activity of an aqueous extract from dried immature fruit of Poncirus trifoliata (L.) Raf

Aqueous extracts from dried immature fruit of Poncirus trifoliata Raf. (Rutaceae) (PF-W) are used as a traditional Korean folk medicine for the treatment of digestive dysfunction. In the present study, PF-W exhibited no significant toxicity even at a dose of 5 g/kg when orally administered to mice. The effect of PF-W on gastrointestinal (GI) motor function was investigated by examining its effect on the serum concentration of orally administered ranitidine, a putative indicator of GI motility, in human subjects. The area under the serum concentration-time curve and the peak serum concentration of ranitidine following an oral administration (300 mg/individual) were decreased by one half as the result of a predose (10 g/individual) of PF-W, except for the time to reach peak serum concentration and the serum half-life at the terminal phase of ranitidine. In rat studies, PF-W had no effect on the apparent permeability of ranitidine across the jejunum or the gastric emptying rate (GER) of phenol red. However, the transit time for charcoal in the intestine was significantly increased by the PF-W pretreatment. The above results are consistent with the hypothesis that PF-W has a unique prokinetic activity, which accelerates the transit of intestinal contents, but has no effect on the GER.     

Bronchodilator activity of Phymatodes scolopendria (Burm.) Ching and its bioactive constituent

Phymatodes scolopendria (Burm.) Ching (Polypodiaceae) is widely used in the Eastern coast of Madagascar to treat respiratory disorders. Bioassay-guided fractionation using guinea pig trachea pre-contracted with histamine to monitor the activity led to the isolation of 1,2-benzopyrone (coumarin) as the main active constituent. Effectively, it induced a concentration-dependent relaxation of the histamine with a median effective concentration (EC(50)) of 35.03 microg/ml, or carbachol (EC(50) = 33.41 microg/ml) pre-contracted guinea pig trachea, and also provoked 100% relaxation at 72.10 microg/ml. It was less active either on KCl pre-contracted trachea (EC(50) = 130.78 microg/ml) or endothelium denuded trachea (153.4 +/- 22 microg/ml). It inhibited, in a non-competitive manner, the histamine and the external calcium spasm effect on the isolated trachea but it did not significantly modify the broncho-constrictive activity of KCl. When combined with theophylline, coumarin produced a significant additive relaxing effect on pre-contracted trachea. Furthermore, its bronchodilator effect was not blocked by propranolol. In vivo, pre-treated guinea pig with coumarin showed significant resistance to histamine inhalation, with an adequate dose protecting 50% of the tested animals (AD(50)) of 75 mg/kg. These results indicate that the bronchodilator effect of coumarin is partly due to the endothelium-dependent tracheal relaxation, and may be mediated through a non-specific tracheal relaxation.     

Effect of aqueous leaf extract of Cassia alata (Linn.) on some haematological indices in albino rats

The effect of an aqueous leaf extract of Cassia alata (Linn.) on haematological indices in albino rats was studied. Increasing doses (10, 50, 100 and 150 mg/kg body weight) of the extract were administered orally to different groups of rats daily for a period of 14 days. Significant dose-dependent decreases in the levels of haemoglobin (Hb) and erythrocyte count (p < 0.05) were observed. In addition, increased packed cell volume (PCV) mean corpuscular volume (MCV), and mean corpuscular haemoglobin concentration (MCHC) were also observed. However, mean corpuscular haemoglobin (MCH) did not show any change. Clinical symptoms of loss of appetite, emaciation and loss of weight in the treated rats indicated toxicity. The observed symptoms of toxicity have been discussed in relation to the saponin content of the plant extract. © 1998 John Wiley & Sons, Ltd.     

肿节风对白血病CEM细胞的抑制作用

目的:研究肿节风水提物对白血病CEM细胞的抑制作用及其机制。方法:以白血病CEM细胞作为研究对象,采用MTT比色试验检测肿节风水提物对CEM细胞的抑制率;光镜、电镜技术观察肿节风水提物作用CEM细胞后其形态的改变;DNA琼脂糖凝胶电泳检测肿节风水提取物对白血病CEM细胞的凋亡作用。结果:肿节风水提物能明显抑制CEM细胞的生长,生药浓度在1.79mg/ml作用24h后,即具有显著的抑制作用,抑制率随剂量的加大和时间的延长而增强,作用48h的半数抑制生药浓度(IC50)约为24.2mg/ml;与对照组相比,实验组光镜、电镜下可见细胞体积缩小,胞浆浓缩、细胞膜皱缩,核解聚、染色质明显浓缩、聚集,边聚于核膜下,甚至形成凋亡小体;琼脂糖凝胶电泳结果显示实验组出现明显的DNA梯形凋亡带,而对照组没有出现梯形条带。结论:肿节风水提物对白血病CEM细胞的生长具有明显的抑制作用,诱导细胞凋亡可能是其抑制白血病CEM细胞生长的机制之一。     

Immunomodulatory activities of the ethanolic extract of Caesalpinia bonducella seeds

Caesalpinia bonducella FLEMING (Caesalpiniaceae) is a plant well known for its medicinal value in Indian Ayurveda. However, to prove its efficiency for the clinical utilization, more experimental data will be beneficial.

Aims of the study

The present study involved the investigation of immunomodulatory activities of ethanolic extract of Caesalpinia bonducella seeds.

Materials and methods

Neutrophil adhesion test, haemagglutinating antibody (HA) titre, delayed-type hypersensitivity (DTH) response, phagocytic activity and cyclophosphamide-induced myelosuppression were determined by in vivo experiments.

Results

The evaluation of immunomodulatory potential by oral administration of ethanolic seed extract of Caesalpinia bonducella (200–500 mg/kg) evoked a significant increase in percent neutrophil adhesion to nylon fibers as well as a dose-dependent increase in antibody titre values, and potentiated the delayed-type hypersensitivity reaction induced by sheep red blood cells. Also it prevented myelosuppression in cyclophosphamide drug treated rats and good response towards phagocytosis in carbon clearance assay.

Conclusions

The results obtained in this study indicate that Caesalpinia bonducella possesses potential immunomodulatory activity and has therapeutic potential for the prevention of autoimmune diseases.     

赶黄草水提浓缩液抗衰老作用及其机制研究

目的研究赶黄草Penthorum chinense水提浓缩液抗衰老作用及其机制。方法以D-半乳糖制备亚急性衰老小鼠模型,采用小鼠避暗实验考察小鼠的学习记忆功能,测定脾脏指数、肝组织中单胺氧化酶(MAO)、血清中超氧化物歧化酶(SOD)及丙二醛(MDA)的水平,Western blotting检测脑组织中p53、p21蛋白的表达。结果赶黄草水提浓缩液能增强衰老模型小鼠的学习及记忆能力,增加脾脏指数,提高血清中SOD的活性,降低血清中MDA和肝脏中MAO的量,同时明显抑制脑组织中p53、p21蛋白表达,呈现一定的剂量依赖性。结论赶黄草水提浓缩液具有明显的抗衰老作用,其机制可能与其下调衰老信号通路p53/p21的蛋白表达、增强机体免疫功能、清除自由基有关。