Screening of the topical anti-inflammatory activity of the bark of Acacia cornigera Willdenow, Byrsonima crassifolia Kunth, Sweetia panamensis Yakovlev and the leaves of Sphagneticola trilobata Hitchcock

Ethnopharmacological relevance

An investigation of topical anti-inflammatory activity was undertaken on plants used in Central America traditional medicine.

Aim of study

Four herbal drugs used in the folk medicine of Central America to treat inflammatory skin affections (Acacia cornigera bark, Byrsonima crassifolia bark, Sphagneticola trilobata leaves and Sweetia panamensis bark) were evaluated for their topical anti-inflammatory activity.

Materials and methods

Petroleum ether, chloroform and methanol extracts were obtained for herbal medicines and then extracts were tested on Croton oil-induced ear dermatitis model in mice.

Results

Almost all the extracts reduced the Croton oil-induced ear dermatitis in mice and the chloroform ones showed the highest activity, with ID₅₀ (dose giving 50% oedema inhibition) values ranging from 112 μg/cm² (Byrsonima crassifolia) to 183 μg/cm² (Sphagneticola trilobata). As reference, ID₅₀ of the non-steroidal anti-inflammatory drug indomethacin was 93 μg/cm².

Conclusions

Lipophilic extracts from these species can be regarded as potential sources of anti-inflammatory principles.     

In vitro activity of Tridax procumbens against promastigotes of Leishmania mexicana

Ethnopharmacological relevance

Tridax procumbens is an active herb against leishmaniasis.

Aim of the study

Leishmaniasis is a group of diseases caused by Leishmania protozoa. We investigated the antileishmanial activity of Tridax procumbens extracts and a pure compound against promastigotes of Leishmania mexicana, the causative agent of cutaneous leishmaniasis in the New World.

Materials and methods

Extracts and (3S)-16,17-didehydrofalcarinol (1) were obtained by chromatographic methods from Tridax procumbens, and the latter identified by spectroscopic analysis. The effect of these extracts and 1 on the growth inhibition of promastigotes of Leishmania mexicana was evaluated. In order to test the safety of extracts and 1, mammalian cells were treated with them, and cell viability was assessed using trypan blue and MTT.

Results

We demonstrated that extracts of Tridax procumbens and 1 showed a pronounced activity against Leishmania mexicana. The methanol extract inhibited promastigotes growth of Leishmania mexicana with a 50% inhibitory concentration (IC₅₀) of 3 μg/ml, while oxylipin 1 exhibited the highest inhibition at IC₅₀ = 0.478 μg/ml.

Conclusions

In this study we report the biological activity of extracts and (3S)-16,17-didehydrofalcarinol (1), obtained from Tridax procumbens, on the promastigote form of Leishmania mexicana, with no effect upon mammalian cells.     

Antihistaminic and antiallergic actions of extracts of Solanum nigrum berries: Possible role in the treatment of asthma

Ethnopharmacological relevance

Berries of the plant Solanum nigrum Linn (Solanaceae) are used for the treatment of asthma in folk medicine and ancient books.

Aim of study

To evaluate potential of the plant berries in the treatment of asthma.

Materials and methods

Petroleum ether, ethanol and aqueous extracts of S. nigrum berries (50, 100 and 200 mg/kg, i.p.) were screened for the treatment of asthma by the various methods viz. effect on clonidine and haloperidol induced catalepsy, milk-induced leucocytosis and eosinophilia, mast cell stabilizing activity in mice and studies on smooth muscle preparation of guinea pig ileum (in vitro). Active petroleum ether extract was standardized by HPTLC.

Results

The petroleum ether extract of S. nigrum berries inhibited clonidine-induced catalepsy significantly but not haloperidol-induced catalepsy. Petroleum ether extract significantly inhibited increased leukocyte and eosinophil count due to milk allergen and showed maximum protection against mast cell degranulation by clonidine. Petroleum ether extract resisted contraction induced by histamine better than other extracts. All the results are dose dependant. Active petroleum ether extract showed presence of antiasthmatic compound, β-sitosterol.

Conclusion

The petroleum ether extract of S. nigrum berries can inhibits parameters linked to the asthma disease.     

Evaluation of hepatoprotective activity of Kyllinga nemoralis (Hutch & Dalz) rhizomes

Aim of study

In view of the use of rhizomes of Kyllinga nemoralis L., against hepatopathy in ethnomedicine the present study was aimed at evaluating the hepatoprotective activity of the rhizomes of Kyllinga nemoralis against carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats.

Materials and methods

Hepatotoxicity was induced in male Wistar rats by carbon tetrachloride and olive oil (50%, v/v). i.p. ethanolic and petroleum ether extracts of Kyllinga nemoralis rhizomes were administered to the experimental rats (100 and 200 mg/kg, p.o. for seven days). The hepatoprotective effect of these extracts was evaluated by the assay of liver function biochemical parameters and histopathological studies of the liver compared with silymarin.

Results

Both extracts showed significant hepatoprotection when compared to control, similar to standard silymarin. Histology of liver sections also revealed that the extracts protected liver from injury.

Conclusions

The study identified a plant with potential hepatoprotective constituents which will be isolated and characterized in future.     

In vitro pharmacological evaluation of three Barleria species

Ethnopharmacological relevance

Various parts of Barleria prionitis L. (Acanthaceae) are used in traditional medicine to treat infection-related ailments. A comparison of their activities and knowledge of their mechanisms of action are important for drug development and conservation.

Aims of the study

This study investigated the antibacterial effects and underlying mechanisms of action of the anti-inflammatory activities of different parts of three Barleria species of South African origin.

Materials and methods

Crude extracts of different parts of three Barleria species were investigated in vitro for their biological activity. Antibacterial activity was evaluated using the micro-dilution assay against two Gram-positive and two Gram-negative bacteria. Anti-inflammatory activity was evaluated using the cyclooxygenase COX-1 and COX-2 assays.

Results

All the extracts showed broad-spectrum antibacterial activity with minimum inhibitory concentrations ranging from 0.059 to 6.25 mg/ml. Twelve out of 21 crude extracts evaluated showed good activity (>70%) in the COX-1 assay while 10 extracts showed good activity in the COX-2 assay. All the petroleum ether extracts (except B. prionitis stem) exhibited good inhibition of prostaglandin synthesis in COX-1.

Conclusion

The results demonstrated the therapeutic potential of these plants as antibacterial and anti-inflammatory agents. Their anti-inflammatory properties are mediated by the inhibition of the cyclooxygenase enzymes.     

Analgesic and anti-inflammatory effects of Cassia siamea Lam. stem bark extracts

Aim of the study

The present study was carried out to investigate analgesic and anti-inflammatory activities of Cassia siamea Lam stem bark extracts. We have also determined the cytotoxicity of each extract.

Materials and methods

C. siamea, a widespread medicinal plant traditionally used in sub-Saharan Africa, was collected in Congo Brazzaville. Stem bark was extracted with petroleum ether (CSE1), chloroform (CSE2), ethanol (CSE3) and water (CSE4). Analgesic, anti-inflammatory and antipyretic activities of these extracts were assessed in rats with hot plate test, paw pressure and carrageenan induced paw oedema. Cytotoxicity was assessed against KB and Vero cells.

Results

At the doses used (100, 200, and 400 mg/kg) ethanol and water extracts showed significant and dose-dependent analgesic and anti-inflammatory effects. None of the extracts had cytotoxic activity on KB and Vero cell lines and the most active extracts (CSE3 and CSE4) had no acute toxicity.

Conclusions

The study highlighted the analgesic and anti-inflammatory of C. siamea stem bark. Four major families of compounds present in the plant may explain these activities: triterpenes (lupeol, oleanolic acid, ursolic acid, friedelin, betulin), flavonoids (apigenin, kaempferol, luteolin), anthraquinones (emodin), phytosterols (stigmasterol, beta-sitosterol).     

Effects of the hook of Uncaria rhynchophylla on neurotoxicity in the 6-hydroxydopamine model of Parkinson's disease

Ethnopharmacological relevance

While the hook of Uncaria rhynchophylla (URH) is a traditional herb used in northeast Asia for the treatment of Parkinson's disease (PD)-like symptoms such as tremor, it has not been experimentally evaluated in a PD model.

Aim of the study

We investigated the effects of URH on 6-hydroxydapamine (6-OHDA)-induced neurotoxicity in in vitro and in vivo models of PD.

Materials and methods

The cell viability, anti-oxidative activity, and anti-apoptotic activity of a water extract of URH (URE) were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, reactive oxygen species (ROS), total glutathione (GSH), and caspase-3 assays in PC12 cells stressed by 6-OHDA. We also investigated the behavioral recovery and dopaminergic neuron protection of URE using an apomorphine-induced rotation test and tyrosine hydroxylase immunohistochemistry in the hemi-parkinsonian rat model of the unilateral 6-OHDA lesion of the medial forebrain bundle.

Results

In PC12 cells, URE significantly reduced cell death and the generation of ROS, increased GSH levels, and inhibited caspase-3 activity induced by 6-OHDA. In 6-OHDA-lesioned rats, posttreatment with URE (5 mg/kg/day for 14 days) significantly reduced apomorphine-induced rotation, and it lowered dopaminergic neuronal loss in substantia nigra pars compacta.

Conclusions

URE possesses neuroprotective activity against 6-OHDA-induced toxicity through anti-oxidative and anti-apoptotic activities in PD models.     

Antioxidant and anti-inflammatory activities of the phenolic extracts of Sapium sebiferum (L.) Roxb. leaves

Ethnopharmacological relevance

The leaves of Sapium sebiferum have long been used in Traditional Chinese Medicine (TCM) for the treatment of eczema, shingles, edema, swelling, ascites, scabs, and snakebites, among other maladies.

Aim of this study

The present study aimed to investigate the antioxidant and anti-inflammatory effects of the phenolic extracts of Sapium sebiferum leaves using in vitro and in vivo models.

Materials and methods

The in vitro antioxidant activities of the extracts were measured using common chemical methods (total phenolic content; total flavonoid content; scavenging of DPPH·, ABTS+·, superoxide, and nitrite radicals; reducing power; β-carotene bleaching; and FTC assays). The in vivo topical anti-inflammatory activities were tested using the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced dermatitis animal model. The SOD and CAT activities and the GSH content of ear tissue were also determined using test kits.

Results

The extracts of Sapium sebiferum leaves exhibited strong in vitro antioxidant activities. They also showed significant (P<0.001) and dose-dependent anti-inflammatory activities in an acute dermatitis model at the doses of 0.03 mg/ear, 0.1 mg/ear, and 0.3 mg/ear. The application of Sapium sebiferum leaf extracts increased the SOD and CAT activities and the GSH content relative to those of the TPA treatment group. The anti-inflammatory effect of the Sapium sebiferum leaf extract was positively correlated with its antioxidant activity.

Conclusion

These results demonstrate that Sapium sebiferum leaf extract is an effective anti-inflammatory agent in the TPA-induced dermatitis model, and its anti-inflammatory effect is related, at least in part, to its antioxidant activity.     

Anxiolytic-like effect of Sonchus oleraceus L. in mice

Ethnopharmacological relevance

Sonchus oleraceus L. has been used as a general tonic in Brazilian folk medicine. Nevertheless, available scientific information regarding this species is scarce; there are no reports related to its possible effect on the central nervous system.

Aim of the study

This study was conducted to establish the anxiolytic effect of extracts from the aerial parts of Sonchus oleraceus.

Materials and methods

This study evaluated the effect of hydroethanolic and dichloromethane extracts of Sonchus oleraceus in mice submitted to the elevated plus-maze and open-field tests. Clonazepam was used as the standard drug.

Results

In the elevated plus-maze test, the Sonchus oleraceus extracts increased the percentage of open arm entries (P < 0.05) and time spent in the open-arm portions of the maze (P < 0.05). The extracts induce an anti-thigmotactic effect, evidenced by increased locomotor activity into the central part of the open field set-up (P < 0.05). The extracts administered at 30–300 mg/kg, p.o. had a similar anxiolytic effect to clonazepam (0.5 mg/kg, p.o.).

Conclusion

These data indicate that Sonchus oleraceus extract exerts an anxiolytic-like effect on mice.     

Prophylactic and curative activities of extracts from Warburgia ugandensis Sprague (Canellaceae) and Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae) against Plasmodium knowlesi and Plasmodium berghei

Ethnopharmacological relevance

This work reports the anti-plasmodial activities of Warburgia ugandensis and Zanthoxylum usambarense commonly used as phytomedicines against malaria by some Kenyan communities.

Aim of study

To determine the anti-plasmodial activities of extracts from Warburgia ugandensis and Zanthoxylum usambarense against Plasmodium knowlesi and Plasmodium berghei.

Materials and methods

Eight plant extracts were screened for in vitro anti-plasmodial activity against Plasmodium knowlesi, in a 96-well plate incubated at 37 °C on a RPMI culture medium supplemented with baboon serum. Of the eight, three were investigated for prophylactic and curative activities in BALB/c mice against drug-sensitive Plasmodium berghei in a 4-day test at a dose rate of 200 mg/kg/day.

Results

Inhibitory concentrations (IC₅₀) values of between 3.14 and 75 μg/ml, up to 69% chemosuppression of parasites growth and over 80% survivorship of treated mice were observed.

Conclusion

The two medicinal plants, Warburgia ugandensis and Zanthoxylum usambarense possess bioactive compounds against malaria parasites and could be exploited for further development into malaria therapy.     

Antimicrobial activity of the extracts of Craniotome furcata (Lamiaceae)

Ethnopharmacological relevance

Craniotome furcata (Link.) O. Kuntze (Lamiaceae) is used in the traditional medicine for the treatment of cuts and wounds indicating antimicrobial activity.

Aim of the study

To validate the traditional medicinal claim, in vitro antimicrobial activity of the extracts was screened against eleven human pathogenic bacteria and fungi.

Materials and methods

The ethyl acetate (CE) and n-butanol (CB) extracts of the aerial parts of Craniotome furcata were tested against four Gram-positive bacteria, four Gram-negative bacteria and three fungi species. Antimicrobial activity was determined by the tube-dilution method.

Results

The CE and CB extracts showed antimicrobial activity against all of the tested microorganisms, with minimum inhibitory concentration (MIC) values in the range of 0.41–4.58 mg/ml.

Conclusions

The tested microbes Micrococcus flavus and Escherichia coli were highly susceptible to extract CE and antimicrobial activity of CB is comparable to that of extract CE against Escherichia coli and Staphylococcus faecalis while it is better than that of extract CE, against Klebsiella pneumoniae. Both the extracts were found less susceptible against tested fungi.     

Induction of apoptosis in human hepatocarcinoma SMMC-7721 cells in vitro by flavonoids from Astragalus complanatus

Aim of the study

Flavonoids extracted from the seeds of Astragalus complanatus R.Br. reduce the proliferation of many cancer cells. The present study was carried out to evaluate the effects of these flavonoids from Astragalus complanatus (FAC) on human hepatocarcinoma cell viability and apoptosis and to investigate its mechanisms of action in SMMC-7721 cells.

Materials and methods

Cell viability was measured using the MTT assay. To detect apoptotic cells, SMMC-7721 cells treated with FAC were stained with Hoechst 33258 and subjected to agarose gel electrophoresis. Quantitative detection of apoptotic cells was performed by flow cytometry. The effects of FAC on apoptosis and cell cycle regulatory genes and proteins in SMMC-7721 cells were examined using an S series apoptosis and cell cycle gene array and Western blot analysis.

Results

The growth of SMMC-7721 and HepG2 cells was inhibited by treatment with FAC. Cell death induced by FAC was characterized by nuclear condensation and DNA fragmentation. Moreover, the cell cycle was arrested in the G0/G1 and S phases in FAC-treated SMMC-7721 cells. A sub-G1 peak with reduced DNA content was also formed. The activity of caspase-3 was significantly increased following FAC treatment. Microarray data indicated that the expression levels of 76 genes were changed in SMMC-7721 cells treated with FAC: 35 genes were up-regulated and 41 were down-regulated. Western blot analysis showed that caspase-3, caspase-8, Bax, P21, and P27 protein levels in SMMC-7721 cells were increased after 48 h of FAC treatment, while cyclinB1, cyclinD1, CDK1, and CDK4 protein levels were decreased.

Conclusions

These results suggest that FAC may play an important role in tumor growth suppression by inducing apoptosis in human hepatocarcinoma cells via mitochondria-dependent and death receptor-dependent apoptotic pathways.     

Hypoglycaemic activity of four plant extracts traditionally used in South Africa for diabetes

Aim

To validate plant species for hypoglycaemic activity.

Materials and methods

Four plants were investigated for hypoglycaemic activity by evaluating inhibiting effects on carbohydrate-hydrolising enzymes: α-glucosidase and α-amylase. Acetone plant extracts were screened against C2C12 myocytes, 3T3-L1 preadipocytes and Chang liver cells by measuring glucose uptake. Cytotoxicity was done in preadipocytes and hepatocytes.

Results

Extract of Euclea undulata rootbark exhibited highest activity, displaying a glucose uptake of 162.2% by Chang liver cells at 50 μg/ml. An inhibition concentration of 50% for Euclea undulata was found to be 49.95 μg/ml for α-glucosidase and 2.8 μg/ml for α-amylase. No cytotoxicity was recorded for Euclea undulata, while Schkuhria pinnata and Elaeodendron transvaalense exhibited cytotoxicity at 12.5 μg/ml. α-Glucosidase and α-amylase assays showed inhibitory activity on enzymes for three plant extracts.

Conclusion

Euclea undulata, Schkuhria pinnata and Elaeodendron transvaalense showed in vitro hypoglycaemic activity. Schkuhria pinnata and Elaeodendron transvaalense indicated cytotoxicity on 3T3-L1 preadipocytes and Chang liver cells. Euclea undulata, Pteronia divaricata and Elaeodendron transvaalense inhibited α-glucosidase and α-amylase enzymes.

Ethnopharmacological relevance

Screening of plant extracts scientifically validated traditional use of Euclea undulata for treatment of diabetes. Cytotoxicity results revealed that acetone extracts of Schkuhria pinnata and Elaeodendron transvaalense are toxic and raise concern for chronic use.     

Anti-spasmodic effects of Zizyphus lotus (L.) Desf. extracts on isolated rat duodenum

Aim of the study

The present study deals with the anti-spasmodic activity of the aqueous and the methanolic extracts of the leaves and the root barks of Zizyphus lotus (L.) Desf. on male rats.

Materials and methods

This activity was assessed on contractions of isolated rat duodenum, induced by acetylcholine, KCl, and BaCl₂ and compared with the effect of atropine and papaverine.

Results

Both extracts of leaves and root barks caused significant relaxation of spontaneous contractions and produced a concentration-dependent inhibition (P < 0.01–0.001) of contraction induced by spasmogenic agents.

Conclusion

These results indicate that Zizyphus lotus extracts contain anti-spasmodic constituents mediating their effect through cholinergic receptors and blockade Ca²⁺ influx. This could explain the traditional use of Zizyphus lotus in the treatment of the intestinal diseases.     

In vitro antiplasmodial activity of plants used in Benin in traditional medicine to treat malaria

Aim of the study

The aim of the study was to evaluate the in vitro antiplasmodial activity of crude extracts of 12 plant species traditionally used in Benin for the treatment of malaria in order to validate their use.

Materials and methods

For each species, dichloromethane, methanol and total aqueous extracts were tested. The antiplasmodial activity of extracts was evaluated using the measurement of the plasmodial lactate dehydrogenase activity on chloroquine-sensitive (3D7) and resistant (W2) strains of Plasmodium falciparum. The selectivity of the different extracts was evaluated using the MTT test on J774 macrophage-like murine cells and WI38 human normal fibroblasts.

Results

The best growth inhibition of both strains of Plasmodium falciparum was observed with the dichloromethane extracts of Acanthospermum hispidum DC. (Asteraceae) (IC₅₀ = 7.5 μg/ml on 3D7 and 4.8 μg/ml on W2), Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (Rubiaceae) leaves and twigs (IC₅₀ = 13.8 and 11.3 μg/ml on 3D7 and IC₅₀ = 26.5 and 15.8 μg/ml on W2, respectively), Carpolobia lutea G.Don. (Polygalaceae) (IC₅₀ = 19.4 μg/ml on 3D7 and 8.1 μg/ml on W2) and Strychnos spinosa Lam. (Loganiaceae) leaves (IC₅₀ = 15.6 μg/ml on 3D7 and 8.9 μg/ml on W2). All these extracts had a low cytotoxicity.

Conclusion

Our study gives some justifications for the traditional uses of some investigated plants.     

Chrysanthemum morifolium Ramat (CM) extract protects human neuroblastoma SH-SY5Y cells against MPP-induced cytotoxicity

Ethnopharmacological relevance

Chrysanthemum morifolium Ramat (Asteraceae) has (CM) long been used in Korean and Chinese traditional herbal medicines with numerous therapeutic applications.

Aim of the study

To evaluate the neuroprotective activities of Chrysanthemum morifolium (CM) extract against 1-methyl-4-phenylpridinium ions (MPP⁺), Parkinsonian toxin through oxidative stress and impaired energy metabolism, in human SH-SY5Y neuroblastoma cells and the underlying mechanisms.

Materials and methods

The effects of CM against MPP⁺-induced cytotoxicity and neuronal cell viability, oxidative damage, the expression of Bcl-2 and Bax, caspase-3 and poly(ADP-ribose) polymerase (PARP) proteolysis were evaluated by using SH-SY5Y neuroblastoma cells.

Results

CM effectively inhibited the cytotoxicity and improved cell viability. CM also attenuated the elevation of reactive oxygen species (ROS) level, increase in Bax/Bcl-2 ratio, cleavage of caspase-3 and PARP proteolysis.

Conclusion

These results demonstrate that CM possesses potent neuroprotective activity and therefore, might be a potential candidate in neurodegenerative diseases such as Parkinson's disease.     

Evaluation of the antinociceptive activity of extracts of Sonchus oleraceus L. in mice

Ethnopharmacological relevance

Sonchus oleraceus L. has been used to relieve pain in Brazilian folk medicine.

Aim of the study

Sonchus oleraceus L. has been used to relieve pain in Brazilian folk medicine. This study was conducted to establish the antinociceptive properties of hydroethanolic and dichloromethane extracts from aerial parts of Sonchus oleraceus in mice using chemical and thermal models of nociception.

Materials and methods

The formalin, hot plate, and tail immersion tests as well as acetic acid-induced writhing were used to investigate the antinociceptive activity in mice.

Results

Given orally, the extracts at test doses of 30–300 mg/kg, produced significant inhibitions on chemical nociception induced by intraperitoneal acetic acid and subplantar formalin since decreased the number of writhing episodes and the time licking. Treatment with the extracts in the same doses produced a significant increase of the reaction time in tail immersion and in the hot plate test. The extracts administered at 300 mg/kg, p.o. had a stronger antinociceptive effect than indomethacin (5 mg/kg, p.o.) and morphine (10 mg/kg, p.o.).

Conclusion

The extracts of Sonchus oleraceus markedly demonstrated antinociceptive action in mice, which supports previous claims of its traditional use.     

Investigation of antihyperglycaemic activity of aqueous and petroleum ether extract of stem bark of Pongamia pinnata on serum glucose level in diabetic mice

Aim of the study

The aim of the study was to evaluate the antihyperglycaemic activity of aqueous (PPSB-AQE) and petroleum ether (PPSB-PEE) extract of stem bark Pongamia pinnata in alloxan induced diabetic mice.

Materials and methods

Diabetes was induced in mice by alloxan (80 mg/kg, i.v.). After acute and subacute treatment serum glucose was determined. OGTT was performed in PPSB-PEE pretreated animals.

Results

PPSB-PEE (25, 50, 100, 200 and 400 mg/kg) showed significant reduction in serum glucose level in acute and subacute studies. The antihyperglycaemic effects of PPSBPE (100, 200 and 400 mg/kg) showed onset at 2 h and peak effect at 6 h and the effect was sustained until 24th h with 400 mg/kg. In subacute study, antihyperglycaemic effect was observed on 21st day. In PPSBPE treated mice the body weight was not reduced in contrast to that in vehicle group. In OGTT, increased glucose utilization was observed.

Conclusions

It is concluded that PPSB-PEE but not PPSB-AQE showed antihyperglycaemic activity.     

Anti-Helicobacter pylori activity of plants used in Mexican traditional medicine for gastrointestinal disorders

Aim of the study

Helicobacter pylori is the major etiological agent of chronic active gastritis and peptic ulcer disease and is linked to gastric carcinoma. Treatment to eradicate the bacteria failed in many cases, mainly due to antibiotic resistance, hence the necessity of developing better therapeutic regimens. Mexico has an enormous unexplored potential of medicinal plants. This work evaluates the in vitro anti-H. pylori activity of 53 plants used in Mexican traditional medicine for gastrointestinal disorders.

Materials and methods

To test the in vitro antibacterial activity, agar dilution and broth dilution methods were used for aqueous and methanolic extracts, respectively.

Results

Aqueous extracts of Artemisia ludoviciana subsp. mexicana, Cuphea aequipetala, Ludwigia repens,and Mentha × piperita (MIC 125 to <250 μg/ml) as well as methanolic extracts of Persea americana, Annona cherimola, Guaiacum coulteri, and Moussonia deppeana (MIC <7.5 to 15.6 μg/ml) showed the highest inhibitory effect.

Conclusions

The results contribute to understanding the mode of action of the studied medicinal plants and for detecting plants with high anti-Helicobacter pylori activity.     

Active constituents from Sophora japonica exhibiting cellular tyrosinase inhibition in human epidermal melanocytes

Aim of the Study

There is greater consumer awareness of plant-based skin-care products. Sophora japonica L. (Fabaceae) has been used traditionally as a hemostatic agent and also has skin-care and whitening benefits. The effect of the isolated active compounds of Sophora japonica L. (Fabaceae) that inhibits tyrosinase activity in human epidermal melanocytes (HEMn) was examined.

Materials and methods

We used the mushroom tyrosinase inhibitory assay to isolate active constituents from the extracts. The structures of these constituents were characterized by physical and spectroscopic analyses. Cellular tyrosinase kinetics were analyzed and showed by Lineweaver–Burk plot.

Results

A new compound, N-feruloyl-N′-cis-feruloyl-putrescine (8), together with four flavonoids and three putrescine derivatives were obtained after assay-guided isolation of S. japonica. In HEMn, compound 8 was minimally cytotoxic (cell viability >90% at 100 μM) and the IC₅₀ value for suppression of cellular tyrosinase activity was estimated as 85.0 μM. Zymography analysis demonstrated the compound's concentration-dependent effects and the kinetic analysis indicated the compound's mixed-inhibitory action.

Conclusions

We concluded that the new compound 8 is the most potent component of S. japonica yet discovered. Its pigment inhibition activity may be exploitable cosmetically.