Evaluation of medicinal plants from Mali for their in vitro and in vivo trypanocidal activity

Water, methanol and dichloromethane extracts prepared from various parts of 40 medicinal plant species from Mali were investigated for their trypanocidal activity against Trypanosoma brucei brucei. Of a total of 165 extracts tested in vitro in the Low Inoculation Long Incubation Test (LILIT), 24 extracts showed a high trypanocidal activity. Using the Long-Term Viability Assay (LtVA) for corroboration of the results of the 24 extracts, it was found that 15 samples had minimum inhibitory concentration (MIC) values > 10 microg/ml, eight MIC values of 100 microg/ml and one MIC values of 50-100 microg/ml. So far, four extracts with MIC values < or = 100 microg/ml were tested for antitrypanosomal activity in mice, experimentally infected with Trypanosoma brucei brucei. Only, the aqueous extracts of the leaves of Terminalia avicennioides Guill. and Perr. (Combretaceae) and the stem bark of Ceiba pentandra (L.) Gaertn. (Bombacaceae) were able to reduce the parasitaemia in animals treated at the dose of 100 mg/kg b.w. (intraperitoneally, two times daily for 3 days) and of 150 mg/kg b.w. (per os, two times daily for 3 days), respectively. The reduction of parasitaemia was, however, statistically significant (p=0.002) only in case of treatment with Terminalia avicennioides.     

Toxicological study on Glinus lotoides: A traditionally used taenicidal herb in Ethiopia

Seeds of Glinus lotoides L. (Molluginaceae) are used traditionally in the treatment of tapeworm infestation in Ethiopia. Previous studies on its anthelmintic activities confirmed its traditional claims, but data on safety profile were lacking. To this effect, single and repeated dose oral toxicities of the methanolic extracts of seeds of Glinus lotoides were conducted in rats. Doses of 0, 1000 and 5000 mg/kg of crude extract of Glinus lotoides were employed in single dose toxicity studies, while doses of 0, 250, 500, and 1000 mg/kg were used in repeated toxicity studies. In the single dose toxicity test, oral administration of 5000 mg/kg of Glinus lotoides produced mortality in two females and one male on day 4. No significant differences in body and organ weights were observed between controls and treated surviving animals. Moreover, both gross and microscopic examinations of organs did not show detectable differences between controls and treated animals of both sexes. In repeated dose toxicity studies, no mortality was observed when varying doses of the extracts were administered per day for a period of 28 days. There were no significant differences in body weight, absolute and relative organ weights between controls and treated animals of both sexes. Hematological analysis showed no differences in most parameters examined. In the biochemistry parameter analysis, no significant change occurred. Pathologically, neither gross abnormalities nor histopathological changes were observed. These finding suggest that none of the organs appeared to be target and the data could provide satisfactory preclinical evidence of safety to launch clinical trial on standardized formulation of plant extracts.     

Reproductive toxicity potentials of Salvia fruticosa (Labiatae) in rats

The antiimplantation, antifertility and reproductive toxicity potentials after ingestion of aqueous and ethanolic extracts of Salvia fruticosa leaves have been investigated in male and female rats. The ingestion of 200, 400 and 800 mg/kg of aqueous or 400 mg/kg of ethanolic extracts of S. fruticosa from day one to day six of pregnancy by female rats did not cause pregnancy failure. However, the ingestion of an ethanolic extract reduced the number of viable fetuses and increased the number of resorptions in the pregnant rats. The ingestion of aqueous extract (800 mg/kg) or ethanolic extract (400 mg/kg) of S. fruticosa for 30 consecutive days by adult female rats had no effect on the occurrence of pregnancy. However, the ingestion of these extracts reduced both the number of implantations and viable fetuses and increased the number of resorptions in the pregnant females. The ingestion of aqueous extract (800 mg/kg) or ethanolic extract (400 mg/kg) of S. fruticosa for 30 consecutive days by adult male rats had no effect on the number of females impregnated by these males. However, the number of implantations and viable fetuses were reduced in females impregnated by males which ingested either aqueous or ethanolic extracts of S. fruticosa, whereas the number of resorptions was increased in females impregnated by males administered either aqueous or ethanolic extracts of S. fruticosa. On the other hand, the prenatal exposure of male and female rat offspring to 400 mg/kg ethanolic extract of S. fruticosa had no effects on the timing of testicular descent and vaginal opening, respectively. It would appear from these experiments that the ingestion of S. fruticosa may produce adverse effects on the fertility of male and female rats.     

Toxicity,antimicrobial and anthelmintic activities of Vernonia guineensis Benth. (Asteraceae) crude extracts

Ethnopharmacological relevance

This study examined the antibacterial, antifungal, and anthelmintic properties of extracts obtained from the plant Vernonia guineensis, a plant commonly used in traditional Cameroonian medicine.

Materials and methods

For in vitro studies, 10 g of leaf and tuber powder from V. guineensis was extracted separately using dichloromethane, methanol and distilled water. The extracts were dried in vacuo and used for antimicrobial and anthelmintic activity studies. In the antimicrobial assay, extracts were tested against bacterial and fungal organisms including; Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, Aspergillus fumigatus, Candida albicans and Trichophyton mentagrophytes. In the anthelmintic assay, larval and adult stages of the hookworm Ancylostoma ceylanicum and the mouse nematode Trichuris muris were used. For the acute toxicity test, male and female rats of 150–200 g body weight were used in the experiment. The aqueous extract of V. guineensis tubers was administered in 4 doses of 500, 1000, 2000 and 4000 mg/kg per group (n=6), respectively, and the control group received distilled water.

Results

The crude extracts exhibited weak antibacterial and antifungal activity except for the dichloromethane extract, which showed moderate activity against A. fumigatus (MIC=200 μg/ml). In the anthelmintic assay, the organic extracts of the tubers had 100% killing efficacy against T. muris at 2 mg/ml in 48 h, while the aqueous extract showed no activity. The organic leaf extracts demonstrated potent activity killing 100% of the adult worms 1 mg/ml in 24 h. The aqueous leaf extract was active at 2 mg/ml in 72 h, killing 100% of the adult worms. In the acute toxicity test, V. guineensis did not produce any toxic signs or death at the maximum concentration of 4000 mg/kg.

Conclusion

Crude extracts from V. guineensis possess anthelmintic activity against T. muris with only weak antibiotic activity. Acute administration of aqueous extract from V. guineensis tubers did not produce toxic effects in rats. The absence of acute toxicity at the highest concentration tested indicates that the tea decoction from V. guineensis extract is safe at concentrations ≤4000 mg/kg.     

Evaluation of antidiabetic and antihyperlipidemic activity of Artemisia indica linn (aeriel parts) in Streptozotocin induced diabetic rats

Ethnopharmacological relevance

Diabetes mellitus is a major metabolic disorder affecting a huge population all over the world. Artemisia species have been extensively used for the management of diabetes in folkloric medicine. The present study is designed to investigate the antidiabetic and antihyperlipidemic effects of aeriel parts of Artemisia indica.

Materials and methods

Hydromethanolic crude extracts, chloroform, ethyl acetate and n-butanol fractions of aerial parts of Artemisia indica were tested for their antidiabetic potential in Streptozotocin (STZ) (50 mg/kg, i.p.) induced diabetic Sprague-Dawley rats. Blood glucose level, body weight, serum lipid profile and activities of liver enzymes were determined. The extracts were further subjected to preliminary phytochemical analysis.

Results

A daily oral dose of hydromethanolic crude extracts (200 and 400 mg/kg b.w.) and chloroform fraction (200 mg/kg b.w.) of Artemisia indica for 15 days showed a significant reduction in blood glucose level which was comparable to that of the standard antidiabetic drug, glibenclamide (500 μg/kg, p.o.). Artemisia indica extracts also showed reduction in total cholesterol, triglycerides and low density lipoproteins as well as serum creatinine level, serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and alkaline phosphatase (ALP) in diabetic rats.

Conclusion

According to the results Artemisia indica possesses hypoglycemic, antihyperlipidemic and valuable effects on liver and renal functions in diabetic rats, which seems to validate its traditional usage.     

Antibacterial activity and phytochemical analysis of Vochysia divergens (Vochysiaceae)

Vochysia divergens Pohl (Vochysiaceae) is a tree commonly found in wet soils of ‘Pantanal’ of Mato Grosso, Brazil, and used in folk medicine against infections and asthma. We have studied different extracts and some isolated compounds from this plant for antibacterial activity. From the extracts of the stem bark β-sitosterol, betulinic acid and sericic acid were isolated. The minimal inhibitory concentration (MIC) for Staphylococcus aureus were: ethanolic extract (MIC = 1.5 mg/ml); ethyl acetate extract (MIC = 2.0 mg/ml); and sericic acid (MIC = 1.0 mg/ml). Escherichia coli was resistant until 5 mg/ml.     

Antibacterial and antifungal activity of Cassia fistula L.: an ethnomedicinal plant

Hexane, chloroform, ethyl acetate, methanol and water extracts from the flower of Cassia fistula (an ethnomedicinal plant) were tested against bacteria and fungi. All the extracts exhibited antibacterial activity against Gram-positive organisms with minimum inhibitory concentrations (MIC) between 0.078 and 2.5 mg/ml. Among the Gram-negative bacteria, only Pseudomonas aeruginosa was susceptible to the extracts. Ethyl acetate crude extract was fractionated using chromatographic techniques. A crystal was isolated, which was confirmed as 4-hydroxy benzoic acid hydrate using X-ray crystallography. It exhibited antifungal activity against Trichophyton mentagrophytes (MIC 0.5 mg/ml) and Epidermophyton floccosum (MIC 0.5 mg/ml).     

Effects of Piper longum fruit, Piper sarmentosum root and Quercus infectoria nut gall on caecal amoebiasis in mice

The anti-amoebic effects of crude methanol extracts of Piper longum fruit, Piper sarmentosum root and Quercus infectoria nut gall against Entamoeba histolytica infecting the caecum of mice were studied. Caecal amoebiasis in mice was induced by injection of Entamoeba histolytica trophozoites directly into the caecum. The mice were then treated orally with the extract, a standard drug (metronidazole), or vehicle p.o. for five consecutive days, beginning 24 h after the infection and were examined on the sixth day. At a dose of 1000 mg/kg per day, the extracts of Piper longum fruit, Piper sarmentosum root and Quercus infectoria nut gall had a curative rate of 100, 40 and 26%, respectively. At a concentration of 500 and 250 mg/kg/day, extract from Piper longum fruit was still effective in 93 and 46% of the cases, respectively, while extract from Piper sarmentosum root at a dose of less than 1000 mg/kg per day did not cure any mice from amoebiasis. Extract of Quercus infectoria nut gall at a concentration of 500 and of 250 mg/kg per day cured 26 and 13% of mice, respectively. Metronidazole at a concentration of 125 and of 62.5 mg/kg per day had a curative rate of 100 and 60%, respectively. The severity of caecal wall ulceration was reduced in mice which received the extract and metronidazole as compared to the control animals.     

Toxicological Study on MUNOPHIL,Water Extract of Panax ginseng and Hericium erinaceum in Rats

ObjectiveAs data on the safety profile of Panax ginseng and Hericium erinaceum is lacking, the safety of these two compounds was examined in a series of toxicological studies.Materials and MethodsMUNOPHIL, the water extract mixture of Panax ginseng and Hericium erinaceum was tested in an oral subchronic 28-day toxicity study in rats at doses of 1250, 2500 and 5000 mg/kg/day.ResultsIn repeated dose toxicity studies, no mortality was observed when varying doses of the extracts were administered once daily for a period of 28 days. There were no significant differences in body weight, absolute and relative organ weights between controls and treated rats of both sexes. Hematological analysis showed no differences in most parameters examined. In the biochemistry parameter analysis, no significant change occurred. Pathologically, neither gross abnormalities nor his-topathological changes were observed. Therefore, MUNOPHIL appears to be safe and non-toxic in these studies and a no-observed adverse effect level in rats was established at 5000 mg/kg/day.ConclusionThe data could provide satisfactory preclinical evidence of safety to launch clinical trials on standardized formulation of plant extracts.     

Effects of Teucrium polium on Insulin Resistance in Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease, the most common chronic liver disorder, is frequently associated with the clinical features of metabolic syndrome such as insulin resistance. We aimed to determine the effect of the crude and the ethyl acetate extracts of Teucrium polium on insulin resistance in rats with nonalcoholic steatohepatitis. Rats were divided into four groups. Group A was fed a normal diet for 11 weeks. Nonalcoholic steatohepatitis was induced in the remaining groups using a methionine/choline deficient (MCD) diet for 8 weeks. After nonalcoholic steatohepatitis development, group B continued with receiving the MCD diet alone; group C rats were given the MCD diet along with crude extract of T. polium (equivalent to 1 g leaves powder/kg body weight/day); group D rats were given the ethyl acetate fraction of T. polium by intragastric administration for 3 weeks. MCD diet led to grade 1 liver steatosis. In group C and D, these factors abated to grade 0 in 80% of the rats. In the groups receiving the extract, lipoprotein profiles were significantly improved relative to those not receiving the extract. Also, a dramatic reduction was observed in sera alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. In addition, in groups C and D, an increase in the activities of liver superoxide dismutase, glutathione peroxidase and glutathione reductase enzymes were also associated with a decrease in the malondialdehyde level relative to group B. Moreover, both extracts significantly decreased plasma glucose and insulin levels along with insulin resistance. In conclusion, both extracts of T. polium could reverse the adverse effects of an MCD diet.     

Screening of Taiwanese crude drugs for antibacterial activity against Streptococcus mutans

Preliminary antibacterial screening of local crude drugs was carried out using the cariogenic bacterium, Streptococcus mutans. Of 79 aqueous extracts tested, 6 crude drugs were shown to have significant antibacterial activity with minimal inhibitory concentration equal to or lower than 7.8 mg/ml (expressed in terms of dry starting material). Of these effective crude drugs, Morus australis, Ludwigia octovalvis and Thuja orientalis were very effective in inhibiting the growth of serotypes c and d of S. mutans (MIC less than or equal to 2.0-7.8 mg/ml). Elephantopus scaber, Artemisia vulgaris, Mosla chinensis and Orthosiphon aristatus also exhibited considerable antibacterial activity (MIC = 7.8-23.4 mg/ml) against both serotypes. In the presence of 5% sucrose, the antibacterial potency of the majority of the extracts did not change for type c, while the potency decreased about one-half for type d.     

In vivo antimalarial activities of Quassia amara and Quassia undulata plant extracts in mice

Extracts obtained from two Nigerian Simaroubaceae plants, Quassia amara L. and Quassia undulata (Giull and Perr) D. Dietr were screened for antimalarial properties using a total of six extracts. The plant extracts showed significant antimalarial activities in the 4 day suppressive in vivo antimalarial assay in mice inoculated with red blood cells parasitized with Plasmodium berghei berghei. Plant extracts were studied at 100 mg and 200 mg per kg body weight mouse per day, respectively. At a concentration of 100 mg/kg of mouse, Q. amara leaf hexane extract had the highest suppressive activity with a parasite density of 0.16 +/- 0.001%. Q. amara leaf methanol extract had an outstanding activity; of 0.05 +/- 0.03% at 200 mg/kg. Chloroquine (10 mg/kg, positive control) had a suppressive activity of 0.34 +/- 0.02 in the same assay on day 4.     

Hepatoprotective effects of lychee (Litchi chinensis Sonn.): a combination of antioxidant and anti-apoptotic activities

Aim of the study

Gimjeng and Chakapat lychee (Litchi chinensis Sonn.) were evaluated for hepatoprotective activity on CCl₄-induced hepatotoxicity in rats.

Materials and methods

Fruit pulp extracts of the lychees were examined for vitamin C, phenolic contents, anti-lipid peroxidation activity and hepatoprotective effect. Male Wistar albino rats were intraperitoneally injected (ip) with CCl₄ (2 ml/kg), then were orally administered (po) with silymarin (100 mg/kg), and Gimjeng or Chakapat extracts (100 and 500 mg/kg). After ten days, the rats were sacrificed and their livers were examined histopathologically and immunohistochemically. Their serum glutamate-pyruvate transaminase, glutamate-oxalate transaminase, and alkaline phosphatase activities were analyzed. Apoptotic activity of the livers was assessed quantitatively.

Results

The Gimjeng and Chakapat extracts showed the contents of vitamin C (1.2 ± 0.6 and 4.3 ± 0.1 mg/100 g) and phenolics like trans-cinnamic acid and pelargonidin-3-O-glucoside (9.80 ± 0.21 and 19.56 ± 0.4 mg GAE/g extract, respectively), and trolox equivalent antioxidant capacity (TEAC) values (11.64 and 9.09 g/mg trolox), respectively. The Gimjeng as compared to the Chakapat demonstrated a better antioxidant activity as revealed by anti-lipid peroxidation activity with the TEAC values. Administration of CCl₄ in rats elevated the serum GPT, GOT, and ALP level whereas silymarin, Gimjeng and Chakapat extracts prevented these increases significantly. Significant decrease of apoptotic cells together with restoration of morphological changes confirmed the hepatoprotective effect in the CCl₄-induced rats pretreated with the extracts.

Conclusion

Antioxidant properties of the Gimjeng and Chakapat lychees as evidenced by the vitamin C and phenolic compounds, anti-lipid peroxidation and anti-apoptosis could explain the hepatoprotective effects in CCl₄-induced hepatotoxicity.     

In vitro and in vivo antitrypanosomal activity of Xanthium strumarium leaves

Antitrypanosomal activity of crude 50% ethanolic extract of Xanthium strumarium leaves was studied in vitro and in vivo. The extract exhibited trypanocidal activity at all the four concentrations tested i.e. 5, 50, 500 and 1000 μg/ml, in vitro. In vivo trial revealed that the extract exerted antitrypanosomal effect at dosage of 100, 300 and 1000 mg/kg, intraperitoneally. At 100 and 300 mg/kg doses the survival period of the Trypanosoma evansi infected mice was significantly prolonged. However, the extract was found to be toxic to the animals at 1000 mg/kg dose.     

Antihepatotoxic activity of a quantified Desmodium adscendens decoction and d-pinitol against chemically-induced liver damage in rats

Ethnopharmacological relevance

The isolation of d-pinitol (or 3-O-methyl-d-chiro-inositol) from an aqueous decoction of Desmodium adscendens (Fabaceae) leaves and twigs is reported. The protective and curative effect of this decoction, in which d-pinitol was quantified, and of pure d-pinitol, against chemically-induced liver damage in rats has been evaluated.

Materials and methods

Enzyme levels of aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP), which are among the usual biomarkers for liver damage, were determined in serum samples of experimental animals. The protective effects against d-galactosamine-induced and ethanol-induced liver damage of a decoction of D. adscendens, quantified on its main constituent d-pinitol, was investigated in rats. In addition, the curative effects of pure d-pinitol and D. adscendens against chronic d-galactosamine-induced and acute acetaminophen-induced hepatotoxicity in rats was studied. Silymarin was used as positive control.

Results

In a first experiment evaluating the protective effect against acute d-galactosamine-induced liver damage in rats, a significant decrease of AST and ALT was observed for the D. adscendens decoction at a dose equivalent to 5 mg/kg/day and 20 mg/kg/day d-pinitol, as well as 20 mg/kg/day pure d-pinitol. With respect to chronic ethanol-induced liver damage in rats, the protective effects of D. adscendens at doses equivalent to 2 mg/kg/day and 10 mg/kg/day d-pinitol, were not observed for serum AST and ALT levels. However, with respect to reduced mortality of animals, statistical analysis showed a trend towards significance for the Desmodium group receiving a dose equivalent to 10 mg/kg/day d-pinitol, versus the untreated hepatotoxic animals. Additional experiments in rat models of acute acetaminophen-induced and chronic d-galactosamine-induced liver damage indicated that D. adscendens decoction and pure d-pinitol had no curative effect when given in a dose equivalent to 10 mg/kg/day d-pinitol, or up to 20 mg/kg/day as a pure compound daily, respectively.

Conclusions

The aqueous decoction of D. adscendens showed a protective effect in rats against liver damage induced by d-galactosamine and ethanol, and this effect is at least in part due to the presence of d-pinitol. However, no curative effect of D. adscendens decoction or d-pinitol on liver damage induced by the tested chemicals could be demonstrated.     

Evaluation of hepatoprotective potential of jigrine post-treatment against thioacetamide induced hepatic damage.

Jigrine a polypharmaceutical herbal formulation containing aqueous extracts of 14 medicinal plants developed on the principles of unani system of medicine is used for liver ailments. The hepatoprotective potential of jigrine post-treatment at the dose of 0.5 ml/kg per day p.o. for 21 days was evaluated against thiocetamide induced liver damage in rats. Biochemical parameters like AST, ALT in serum and TBARS and glutathione in tissues were estimated to assess liver function. Data on the biochemical parameters revealed hepatoprotective potential of jigrine post-treatment against thioacetamide induced hepatotoxicity in rats. Silymarin used as reference standard also exhibited significant hepatoprotective activity on post-treatment against thioacetamide-induced hepatotoxity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections.     

Pharmacological characterization of different fractions of Calotropis procera (Asclepiadaceae) in streptozotocin induced experimental model of diabetic neuropathy

Ethnopharmacological relevance

Calotropis procera (Ait.) R.Br. is one of an ancient traditional shrub, which has been used for the treatment of diabetes, pain and inflammation for thousands of years in India. The root extract of Calotropis procera has been widely used by the tribal?s of district Udaipur, Rajasthan (India) for treatment of diabetes mellitus and its associated complications like diabetic neuropathy. The present study was performed to explore the protective effect of root, stem and leaf extracts of Calotropis procera in diabetes and diabetic neuropathy against tactile allodynia, mechanical hyperalgesia and thermal hyperalgesia in streptozotocin induced diabetic rats.

Materials and methods

Diabetes and peripheral neuropathy were induced in Wistar rats by injection of streptozotocin (45 mg/kg/intraperitoneally). The roots, stem and leaves of Calotropis procera were sequentially extracted with petroleum ether, chloroform, ethyl acetate and methanol. All the extracts were assessed by oral administration at 100 and 250 mg/kg in streptozotocin diabetic rats. The following compounds were used as positive controls: insulin NPH (1 IU/kg/day), metformin (500 mg/kg/day), glibenclamide (2.5 mg/kg/day) and a combination of acarbose (20 mg/kg/day) with methylcobalamine (500 µg/kg/day). In contrast, the streptozotocin induced untreated diabetic rats termed as negative control. Thermal hyperalgesia, mechanical hyperalgesia and tactile allodynia were evaluated in all groups of streptozotocin diabetic rats to assess the extent of neuropathy by Eddy?s hot plate, tail immersion, Randall–Selitto and Von Frey hair tests. The basal nociceptive thresholds were assessed in week 4 of post streptozotocin injection. All groups received their treatment on a regular basis from 28 to 42 days following a confirmation of diabetic neuropathy. The nociceptive thresholds were assessed in all groups in week 5 and 6. The histopathology of pancreas and biochemical estimations of plasma insulin and glycosylated haemoglobin (HbA₁C%) levels were also performed in week 6 of post streptozotocin injection.

Results

The negative control rats developed diabetes and diabetic neuropathy after 6 week of streptozotocin administration distinguished by significant (p<0.01) hyperalgesia and tactile allodynia with enhanced HbA₁C% level compared to normoglycemic rats. Chronic administration of root methanol, stem methanol and leaf ethyl-acetate extracts of Calotropis procera for 2 weeks at 100 and 250 mg/kg doses significantly (p<0.01) attenuated the diabetes induced mechanical hyperalgesia, thermal hyperalgesia, tactile allodynia and HbA₁C% level in streptozotocin diabetic rats as compared to negative control rats. Further, the root methanol extract of Calotropis procera in 100 mg/kg dose showed the regeneration capability of β cells in the histology of pancreas with significant (p<0.01) improvement in plasma insulin level in streptozotocin diabetic rats compared to negative control rats.

Conclusion

Root methanol extract of Calotropis procera (100 mg/kg) has shown ameliorative effect in diabetic neuropathy which may be attributed by its multiple actions including potent hypoglycemic and antioxidant.     

An antimicrobial investigation of plants used traditionally in southern Africa to treat sexually transmitted infections

Aim of the study

Eighteen plants were assessed for antimicrobial activity against pathogens associated with prevalent urogenital/sexually transmitted infections. Plant selection was based on information obtained from the ethnobotanical literature.

Materials and methods

Dried plant material was submerged in a 1:1 mixture of methanol and dichloromethane for 24 h. Aqueous extracts were prepared by submerging dried plant material in sterile distilled water for 24 h followed by lyophilization. Essential oils were distilled from the two aromatic plant species (Tarchonanthus camphoratus and Croton gratissimus). Antimicrobial activity was assessed using the micro-well minimum inhibitory concentration (MIC) assay with specific modifications to facilitate fastidious growth of pathogens.

Results

Tarchonanthus camphoratus (solvent extract) showed the most significant broad spectrum activity with MIC values ranging between 0.50 and 0.70 mg/ml against five of the six pathogens tested. Other noteworthy activity was found for Hypericum aethiopicum (root) at 0.3 mg/ml (Neisseria gonorrhoeae).Polygala fruticosa and the solvent root extract of Hypericum aethiopicum showed highest sensitivities towards Gardnerella vaginalis at 0.2 mg/ml. Efficacy of the solvent extracts against the pathogen Oligella ureolytica demonstrated antimicrobial activity (MIC values ≤1.0 mg/ml) for seven plant species. The highest activity noted against Ureaplasma urealyticum was for Psidium guajava (solvent extract) at 0.8 mg/ml. In general the aqueous extracts displayed mostly poor anti-STI activity. The most noteworthy susceptibility for the aqueous extracts was noted with the plant extract Syzygium cordatum (MIC value 0.1 mg/ml against Candida albicans). The most noteworthy activity for the essential oils was observed for Tarchonanthus camphoratus (0.8 mg/ml) against Oligella ureolytica.

Conclusions

Antimicrobial activity was observed for a number of the plant samples against at least one or more pathogen, thus validating the ethnobotanical use as an anti-infective to treat sexually transmitted diseases.     

银杏叶提取物调节高脂血症大鼠模型血脂的有效剂量研究

目的 探索银杏叶提取物(ginkgo leaf extracts,GBE)调节高脂血症大鼠模型血脂的有效剂量.方法 SD大鼠随机分为对照组、模型组、DBE(1.2、3.8、12.0、37.9、119.8、378.7 mg/kg)组、非诺贝特(20 mg/kg)组.除对照组,其余大鼠以高脂饲料饲养1周建立高脂血症大鼠模型...     

The evaluation of the therapeutic effect of tao-shang-tsao on alpha-naphthylisothiocyanate and carbon tetrachloride-induced acute liver damage in rats

The hepatoprotective effects of Tao-shang-tsao, Ixeris laevigata Sch.-Bip. var. oldhami Kitam., were studied on cholestatic hepatitis induced by alpha-naphthylisothiocyanate (ANIT, 100 mg/10 ml/kg, in olive oil, i.p.) and acute hepatitis induced by carbon tetrachloride (20% CCl4/olive oil, 1.5 ml/kg, i.p.) in rats by post-treatment with the crude methanolic extracts of I. laevigata (0.3, 1.0, and 2.0 g/kg) orally in the therapeutic model. Hepatoprotective activity was monitored by estimating the serum transaminases concentrations and histopathological changes in the livers of experimental rats. It was found that the I. laevigata extract significantly decreased the acute elevation of serum transaminases by biochemical examination. According to pathohistological studies in the liver of experimental rats, the crude I. laevigata extract ameliorates the central necrosis, fatty change or proliferation of bile duct epithelium focal necrosis caused by ANIT or CCl4-induced hepatitis rats.