Identification of hypoglycaemic compounds from berries of Juniperus oxycedrus subsp. oxycedrus through bioactivity guided isolation technique

Ethnopharmacological relevance

Decoction of Juniperus oxycedrus subsp. oxycedrus L. (Cupressaceae) berries is used internally as tea and pounded fruits are consumed to lower blood glucose levels in Turkey.

Aim of the study

To evaluate hypoglycaemic and antidiabetic activity of J. oxycedrus subsp. oxycedrus berries and to identify active compounds through bioactivity guided isolation technique.

Material and methods

Hypoglycaemic effect of J. oxycedrus subsp. oxycedrus (Joso) berry extracts on oral administration was studied using in vivo models in normal, glucose-hyperglycaemic rats. Streptozotocin induced diabetic rats were used to examine antidiabetic activity of Joso extracts, subextracts, fractions, subfractions and shikimic acid (SA).

Results

Through in vivo bioactivity-guided fractionation processes, shikimic acid, 4-O-β-d-glucopyranosyl ferulic acid and oleuropeic acid-8-O-β-d-glucopyranoside were isolated from the n-butanol subextract by silica gel and reverse phase column chromatography as the main active ingredient of the active subfraction. After 8 days administration of the major compound shikimic acid, blood glucose levels (24%), malondialdehyde levels in kidney tissues (63-64%) and liver enzymes (AST, ALT, ALP) of diabetic rats were decreased.

Conclusion

Results indicated that Joso berry extract and its active constituents might be beneficial for diabetes and its complications.     

Effects of Juniperus oxycedrus ssp. oxycedrus on tissue lipid peroxidation, trace elements (Cu, Zn, Fe) and blood glucose levels in experimental diabetes

Ethnopharmacological relevance

Juniperus oxycedrus L. (Cupressaceae) fruits and leaves are used internally and pounded fruits are eaten for diabetes in Turkey.

Aim of the study

To evaluate the interrelationships between the levels of chosen trace elements (copper, iron, and zinc) and hepatic, renal lipid peroxidation (TBARS) in streptozotocin-induced diabetic rats treated with Juniperus oxycedrus ssp. oxycedrus (J.o.s.o.) leaf and fruit extracts for 10 days.

Materials and methods

J.o.s.o. fruit and leaf extracts were administered in STZ-induced diabetic rats, at doses of 500 and 1000 mg/kg. The blood glucose levels were measured in the 1st, 4th, 7th and 10th day of experiment. Fe, Cu, and Zn contents and lipid peroxidation levels of liver and kidney tissues were determined by atomic absorption spectrophotometry and ultraviolet spectrophotometry, respectively.

Results

Treatment of diabetic rats with the J.o.s.o. fruit and leaf extracts decreased the blood glucose levels and both the levels of lipid peroxidation in liver and kidney tissues. J.o.s.o. extracts have augmented Zn concentrations in liver of STZ-induced diabetic rats.

Conclusions

Results indicated that J.o.s.o. fruit and leaf extracts might be beneficial for diabetes and its complications.     

In vivo antidiabetic and antioxidant potential of Helichrysum plicatum ssp. plicatum capitulums in streptozotocin-induced-diabetic rats

Helichrysum species (Asteraceae) are widely found in Anatolia. Decoction prepared from the capitulums of Helichrysum plicatum ssp. plicatum is used to alleviate the symptoms of diabetes mellitus in folk medicine. In the present study, the hypoglycaemic and antioxidant potential of Helichrysum plicatum ssp. plicatum was evaluated by using in vivo methods in normal and streptozotocin-induced-diabetic rats. After the oral administration of water and ethanolic extracts at doses of 500mg/kg body weight prepared from the capitulums of plant, blood glucose levels were monitored at specific intervals. Tolbutamide was used as a reference drug at a dose of 100mg/kg. The experimental data indicated that water and ethanol extracts of capitulums demonstrate significant antihyperglycaemic and antioxidant activity in streptozotocin-induced rats which confirmed the folkloric utilization. In order to assess the role of polyphenolic components in the relevant activity, phenolic and flavonoid contents of each extract were also determined in terms of total phenols: 113.5+/-8.6mg (gallic acid equivalent/1g extract) and total flavanoids 50.5+/-1.9mg (quercetin equivalent/1g extract) for ethanol extract, total phenols: 75.9+/-3.7, flavonoids: 31.5+/-2.3 for water extract using Folin-Ciocalteu reagent.     

Further antibacterial diterpenes from the bark and leaves of Juniperus procera hochst. ex Endl

The bark of Juniperus procera yielded three antibacterial diterpenoids, (+)-E-communic acid (1), (+)-Z-communic acid (2) and (+)-totarol (3). Compound 2 exhibited significant activity against Gram-positive bacteria, while 1 was found to be less active. Compound 3, on the other hand, demonstrated potent activity against Mycobacterium organisms, while its corresponding 3β-hydroxy-derivative 4 was found to be inactive. The chromatographic separation of (+)-Z-communic acid (2) from (+)-E-communic acid (1) and those previously unreported spectral data of 1 and 2 are described. In addition, the leaves yielded (+)-8α-acetoxyelemol, β-peltatin A methyl ether and deoxypodophyllotoxin.     

Preliminary study of antidiabetic activity of the methanolic leaf extract of Axonopus compressus (P. Beauv) in alloxan-induced diabetic rats

Ethnopharmacological relevance

Axonopus Compressus is commonly used by the people of Southern Nigeria to treat different ailment such as common cold and diabetes. This study therefore, evaluated the anti-diabetic effect of the methanolic leaf extract of the plant.

Materials and methods

Diabetes was induced in the rats by intraperitoneal (i.p.) injection of alloxan monohydrate at the dose of 180 mg/kg. Three test doses of the extract (250, 500 and 1000 mg/kg) administered per os through gastric gavage to the rats were used in the study. The activity was compared to a standard reference drug (glibenclamide, 2 mg/kg) and a negative control. Blood from the tail snip was used to measure the effects of the extract and drug at 0, 1, 3 and 6 h using autoanalyzer (AccuCheck Active^®) glucose kit.

Results

Methanolic leaf extract of Axonopus compressus at all the doses (250, 500 and 1000 mg/kg) used caused a respective time dependent and significant (p < 0.0001) reduction (by 31.5%, 19.8% and 24.5%) of the blood glucose levels in the diabetic rats when compared to the negative control group at the 6th hour. However, the reference drug (glibenclamide, 2 mg/kg) decreased the blood glucose levels by 69.9% and the tween 20 solution (negative control) increased the blood glucose level by 15.2% at the 6th hour. Moreso, the extract at the different test doses caused various degrees of reduction of the blood glucose levels of the test rats at 1st, 3rd and 6th hours when compared to the negative control rats.

Conclusion

The findings suggest that Axonopus compressus may possess antidiabetic property.     

Antimycobacterial terpenoids from Juniperus communis L. (Cuppressaceae)

Ethnopharmacological relevance

Juniperus communis is a plant which has been reported as a traditional cure for tuberculosis (TB) and other respiratory diseases.

Aim of the study

The aim of this study was to isolate and identify the constituents responsible for the activity of the n-hexane extract of Juniperus communis roots against Mycobacterium tuberculosis H₃₇Rv and Juniperus communis aerial parts against Mycobacterium aurum. Subsequently, it was to evaluate the activity of the pure isolated compounds against (i) drug-resistant Mycobacterium tuberculosis variants, (ii) non-replicating Mycobacterium tuberculosis and (iii) a range of non-tuberculous mycobacteria (NTM).

Materials and methods

The antimycobacterial activity of Juniperus communis extracts, fractions and constituents was determined against Mycobacterium tuberculosis H₃₇Rv, and against rifampicin-, isoniazid-, streptomycin- and moxifloxacin-resistant variants, using the microplate broth Alamar Blue assay (MABA) method. Isolated constituents were tested against non-replicating Mycobacterium tuberculosis H₃₇Rv, using the low oxygen recovery assay (LORA), and against NTM (Mycobacterium aurum, Mycobacterium phlei, Mycobacterium fortuitum and Mycobacterium smegmatis), using a broth microdilution method. Cytotoxicty studies were performed using mammalian Vero cells.

Results

The antimycobacterial activity of Juniperus communis was attributed to a sesquiterpene identified as longifolene (1) and two diterpenes, characterised as totarol (2) and trans-communic acid (3). All compounds were identified following analysis of their spectroscopic data (1D- and 2D-NMR, MS) and by comparison with the literature and commercial authentic standards when available. Revised assignments for 3 are reported. Totarol showed the best activity against Mycobacterium tuberculosis H₃₇Rv (MIC of 73.7 μM). It was also most active against the isoniazid-, streptomycin-, and moxifloxacin-resistant variants (MIC of 38.4, 83.4 and 60 μM, respectively). Longifolene and totarol were most active against the rifampicin-resistant variant (MICs of 24 and 20.2 μM, respectively). Totarol showed the best activity in the LORA assay (MIC of 81.3 μM) and against all NTM species (MICs in the range of 7–14 μM). Trans-communic acid showed good activity against Mycobacterium aurum (MIC of 13.2 μM). The low selectivity indices (SI) obtained following cytotoxicity studies indicated that the isolated terpenoids were relatively toxic towards mammalian cells. This is the first report of the isolation of (1) and (2) from Juniperus communis roots, and of (3) from the aerial parts. The antimycobacterial activity of (1) and (3), and the activity of (2) against Mycobacterium aurum, Mycobacterium fortuitum and Mycobacterium phlei, is reported for the first time. The effect of totarol on drug-resistant variants and non-replicating Mycobacterium tuberculosis has never been published.

Conclusions

The presence of antimycobacterial terpenoids in Juniperus communis aerial parts and roots justifies, to some extent, the ethnomedicinal use of this species as a traditional anti-TB remedy.     

Anti-inflammatory activity of extracts and 11,13-dihydrozaluzanin C from Gochnatia polymorpha ssp. floccosa trunk bark in mice

Aim of this study

Gochnatia polymorpha ssp. floccosa (Asteraceae), popularly known as “cambará”, is well recognized in Brazilian traditional medicine to treat the respiratory tract inflammatory diseases and rheumatism. However, no scientific data have been published to support this ethnopharmacological use. This work aimed to evaluate the anti-inflammatory action of its ethanol (EEGP) extract, ethyl acetate (EA), dichloromethane (DCM), petroleum ether (PE) butanolic (BT) fractions, and the isolated compounds bauerenyl acetate (GPC1) and 11,13-dihydrozaluzanin C (GPC2).

Materials and methods

The anti-inflammatory activities were evaluated in mice subjected to paw oedema and carrageenan-induced air pouch inflammation models.

Results

The oral administration of EEGP (30, 100 and 300 mg/kg), DCM (50 mg/kg), BT (20 mg/kg) and GPC2 (10 and 30 mg/kg), but not EP and EA fractions (both at 30 mg/kg) and GPC1 (1 and 10 mg/kg), significantly inhibited the paw oedema induced by carrageenan (41 ± 13, 39 ± 5 and 60 ± 10% for EEGP at the three doses, respectively; 44,47 ± 12.8 and 70.19 ± 11.52% for DCM and BT, respectively; and 29.52 ± 4.8 and 31.67 ± 5.4%, for 11,13-dihydrozaluzanin C at 10 and 30 mg/kg, respectively) compared to control group. The oral administration of EEGP (30, 100 and 300 mg/kg) inhibited the carrageenan-induced leukocyte migration in the air pouch model (37.2 ± 12.5, 62.6 ± 5.0 and 54.3 ± 6.8%, respectively), as well as protein extravasation (47.9 ± 12.5, 51.7 ± 15.2 and 60.9 ± 13.7%, respectively) compared to control group. In a similar way, DCM (50 mg/kg) or GPC2 (10 mg/kg), but not BT (20 mg/kg) given by oral route inhibited leukocyte infiltration into the pouch (29.5 ± 10.6 and 54.4 ± 21.8%, respectively). Also DCM and GPC2 significantly reduced the protein levels in the supernatants (52.4 ± 15.0 and 51.83 ± 16.9%, respectively).

Conclusion

The results suggest that EEGP, and BT and DCM fractions from G. polymorpha possess anti-inflammatory activity and probably the compound 11,13-dihydrozaluzanin C was responsible, at least in part, for this action.     

Flavonoids with anti-inflammatory and antinociceptive activity from Cistus laurifolius L. leaves through bioassay-guided procedures

Extracts obtained from the leaves and branches of various Cistus species have been used worldwide as folk remedy for the treatment of various inflammatory ailments including rheumatism and renal inflammations. Effects of the extracts and fractions from the leaves with non-woody branches of Cistus laurifolius L. (Cistaceae) were studied using two in vivo models of inflammation in mice. Model one was based on observed potent inhibitory activity against carrageenan-induced hind paw oedema and the second model used was acetic acid-induced, increased vascular permeability model. Through bioassay-guided fractionation and isolation procedures three flavonoids; 3-O-methylquercetin (1), 3,7-O-dimethylquercetin (2) and 3,7-O-dimethylkaempferol (3) were isolated as the main active ingredients from the ethanol extract. Later on, these flavonoids were shown to possess potent antinociceptive activity, which was assessed through inhibition of p-benzoquinone-induced writhing reflex. Results of the present study have clearly supported the utilization of Cistus laurifolius in Turkish traditional medicine. Subsequently, three flavonoids were shown to have strong antinociceptive and anti-inflammatory activities, per os without inducing any apparent acute toxicity as well as gastric damage.     

Antinociceptive activity of Syzygium jambos leaves extract on rats

Syzygium jambos (L.) Alston (Myrtaceae) (syn Eugenia jambos) is a widespread medicinal plant traditionally used in sub-Saharan Africa to treat several diseases. The analgesic potential of leaf hydro-alcoholic extracts was assessed in rats. Hot plate and formalin tests were used to estimate cutaneous nociception whereas measurements of forelimb grip force were done to assess muscular nociception under normal and inflammatory conditions. In the hot plate test, Syzygium jambos extract produced a significant increase in the withdrawal response latencies in a dose-dependant manner (10-300 mg/kg i.p.) and with a maximal effect (analgesic efficacy) similar to that of morphine. The extract (100-300 mg/kg i.p.) significantly reduced pain scores in all the phases of the formalin test with an analgesic efficacy higher than that shown by diclofenac. Although the extract (300 mg/kg) did not alter grip force in intact rats, it reversed the reduction in grip force induced by bilateral injection carrageenan in the forelimb triceps. This analgesic effect of the extract on muscle hyperalgesia was not antagonized, but enhanced, by naloxone. Thus, the Syzygium jambos extract has remarkable analgesic effects on both cutaneous and deep muscle pain that is not mediated by opioid receptors.     

Healing potential of Rosmarinus officinalis L. on full-thickness excision cutaneous wounds in alloxan-induced-diabetic BALB/c mice

Aim of the study

Rosmarinus officinalis (Rosemary) used in Jordanian folk medicine for wound management and treatment. Therefore, the present study was conducted to assess the healing efficacy of both aqueous extract and essential oil of the aerial parts on alloxan-induced diabetic BALB/c mice.

Materials and methods

Two full-thickness round wounds were created in the dorsal area of each mouse. Animals were divided into four groups of twenty mice each: untreated normal, untreated diabetic, aqueous extract- (intraperitoneal injection of 0.2 ml at a dose of 10% for 3 days) and essential oil-treated diabetic mice (topical application of 25 μl/excision wound, twice a day for 3 days). For 15 days, the wounds were visually observed; blood glucose level, body weight, regenerated granulation tissue weight and the percentage of wound contraction were measured. On days 6 and 15 after wounding, the animals were sacrificed and the histology of wound area was examined.

Results

Significant positive differences (p < 0.01) between treated and control groups were observed at different aspects of diabetic wound healing process. Reduced inflammation and enhanced wound contraction, re-epithelialization, regeneration of granulation tissue, angiogenesis and collagen deposition were detected in the treated wounds.

Conclusions

Results indicated that the essential oil of Rosmarinus officinalis was the most active in healing diabetic wounds and provide a scientific evidence for the traditional use of this herb in wound treatment. However, further scientific verification is required to confirm and assess the range of wound healing potential of essential oils of Rosemary chemotypes.     

Comparative study on hemostatic, cytotoxic and hemolytic activities of different species of Paris L

Ethnopharmacological relevance

The rhizoma of Paris polyphylla var. yannanensis or P. polyphylla var. chinensis called Rhizoma Paridis as a traditional Chinese medicine has an effect of heat-clearing and detoxicating, detumescence and acesodyne in folk for a long time. The increasing application of Rhizoma Paridis resulted in the shortage of wildlife resources. Here, we compared the major activities of other species of genus Paris to find the replacement plants.

Materials and methods

Six species (P. polyphylla var. yunnanensis, P. delavayi var. delavayi, P. fargesii var. Fargesii, P. bashanensis Wang et Tang, P. polyphyllar var. minora, and P. polyphylla var. pseudothibetical) were collected from three Provinces in China, and compared the hemostatic, cytotoxic and hemolytic activities by different assays.

Results

For the hemostatic activity, all the plants except Paris fargesii var. Fargesii could significantly shorten the tail bleeding time and blood clotting time (P<0.05). For further mechanism study, they reduced the prothrombin time (PT) and activated partial thromboplastin time (APTT), but they had no significant effect on thrombin time (TT). P. fargesii var. Fargesii showed the similar cytotoxicity to P. polyphylla var. yunnanensis (IC₅₀: 18.21 and 15.73 μg/mL, respectively). HD₅₀ was used as the index of hemolytic activity. P. delavayi var. delavayi and P. bashanensis Wang et Tang were the last to have this activity as the values were 3.027 and 1.222 mg/mL.

Conclusions

The different species of genus Paris have different activities. Paris delavayi var. delavayi and Paris bashanensis Wang et Tang could be used as the resources of hemostatic drugs and P. fargesii var. Fargesii as the antitumor medicine.     

A review of the antibacterial activity of Hypericum perforatum L.

Hypericum perforatum L. (Hypericaceae) is a perennial herb that is commonly known as St. John's Wort. The plant has been valued for its important biological and chemical perspectives and its use in the treatment of infectious diseases has been documented in ethnobotanical reports. Most recent interest in H. perforatum has focused on its antidepressant effects, and only recently has its antimicrobial activity been evaluated against a number of bacterial and fungal strains. The present review gives a comprehensive summary of the ethnobotanical uses, chemical constituents and biological effects (antibacterial and antifungal) of this species. A comprehensive account of the chemical constituents including anthraquinone derivatives (naphthodianthrones), flavonoids, prenylated phloroglucinols, tannins and volatile oils is also included. Various types of preparations, ointments, creams and extracts prepared with and compounds isolated from this species have been found to possess a broad spectrum of biological and pharmacological effects such as antidepressant effects, wound-healing, antiviral and antimicrobial activity. The antibacterial activity of crude extracts can be related to the use of the herb as a wound healer in ancient times. The sole antibacterial principle isolated to date is a tetraketone, hyperforin, also thought to be responsible for the antidepressant activity of the herb. The available literature indicates that it has a higher antibacterial activity against Gram-positive than Gram-negative bacteria, and alcoholic extracts (methanolic/ethanolic) were shown to possess more pronounced activity than aqueous extracts. Based on the chemical and pharmacological characteristics of H. perforatum, we concluded that this species has beneficial therapeutic properties and has the potential for use as an effective adaptogenic herbal remedy.     

The effect of Cree traditional medicinal teas on the activity of human cytochrome P450-mediated metabolism

Ethnopharmacological relevance

Rhododendron groenlandicum (Bog Labrador tea), Rhododendron tomentosum (Marsh Labrador tea) and Juniperus communis (Juniper) are used in medicinal teas by Canadian aboriginal cultures alone and in combination with conventional drug products. The safety of this combination had not been previously examined and this study was initiated to examine the potential of medicinal teas to inhibit the major human drug metabolizing enzyme, cytochrome P450 3A4 (CYP3A4).

Materials and methods

The decoctions of Rhododendron groenlandicum and Rhododendron tomentosum leaves and Juniperus communis berries were examined in a microtiter fluorometric assay to examine their potential to inhibit CYP-mediated metabolism.

Results

The decoctions showed progressive inhibition towards CYP3A4 the longer the leaves or berries were brewed. R. Rhododendron groenlandicum and Juniperus communis may have the potential to inhibit CYP3A4-mediated metabolism.

Conclusions

The findings of this study with these traditional medicines are significant in that they provide mechanistic support that these products have the potential to affect the safety and efficacy of other health and medicinal products. As this study only examined CYP3A4, it is possible that these medicinals contain substances that could also affect other metabolic enzymes.     

Mechanisms involved in the gastroprotective activity of Celtis iguanaea (Jacq.) Sargent on gastric lesions in mice

Ethnopharmacological relevance

Celtis iguanaea (Canabaceae) is popularly known as esporão-de-galo, stands out among the medicinal plants used for treatment of gastric ulcers. In Brazil, the leaves they are used traditionally in infusion forms as an analgesic, antiasthmatic, digestive and diuretic.

Aim of the study

The present study was aimed to investigate the antiulcer mechanisms of hexane extract Celtis iguanaea leaves (HE) in several induced-gastric ulcer and characterize its chemical composition.

Materials and methods

The HE was obtained by exhaustive extraction in Soxhlet apparatus. The chemical characterization of HE was performed by Electrospray Fourier transform ion cyclotron mass spectrometry (ESI FT-ICR MS) analysis. Mice were used for the evaluation of the gastroprotective activity. HE was analyzed in the HCl/ethanol, hypothermic restraint stress ulcer and acetic acid. In the investigation of the gastroprotective mechanisms of HE, were performed the amount of adhered gastric mucus, participation of the α₂-adrenoceptor, nitric oxide (NO) and prostaglandins (PGs) using the HCl/ethanol-induced gastric mucosa lesion model.

Results

ESI FT-ICR MS analysis of HE suggest the presence of compounds as lipids, sterol lipids, steroids glycosides and polyphenol glycosides. The oral administration of HE at doses of 100 mg/kg or 200 mg/kg was able to protect the gastric mucosa against HCl/ethanol (10 mL/kg p.o.), and HE at dose of 100 mg/kg protected against hypothermic-restraint stress and acetic -induced gastric lesions. The pretreatment with Yoimbine (2 mg/kg, s.c.), an antagonist α₂-adrenergic, L-NAME (20 mg/kg, s.c.), an inhibitor of nitric oxide synthesis or indomethacin (10 mg/kg, s.c.), an inhibitor of prostaglandin production, reversed the gastroprotective activity of HE (100 mg/kg, p.o.).

Conclusions

Our results suggest that the Celtis iguanaea HE exhibits gastroprotective activity in different gastric ulcer models. The mechanism of gastroprotective effect of Celtis iguanaea HE suggests the participation of mucus as well as the involvement of α₂-adrenergic receptors, NO and prostaglandins. The hydroxyl-linolenic acid, linoleic acids and conjugated oxo-linoleic acids are among the phytoconstituents that were identified in the Celtis iguanaea HE.     

Anti-nociceptive activity of Pereskia bleo Kunth. (Cactaceae) leaves extracts

Ethnopharmacological relevance

Local communities in Malaysia consume Pereskia bleo Kunth. (Cactaceae) leaves as raw vegetables or as a concoction and drink as a tea to treat diabetes, hypertension, rheumatism, cancer-related diseases, inflammation, gastric pain, ulcers, and for revitalizing the body.

Aim of the study

To evaluate anti-nociceptive activity of the extracts and vitexin, isolated for the first time in this species, in two analgesic models; formalin-induced licking and acetic acid-induced abdominal writhing.

Materials and methods

Three and a half kilos of P. bleo leaves were extracted using Soxhlet apparatus with ethanol for 72 h. The crude ethanol extract was treated with activated charcoal overnight and subjected to a liquid–liquid partition yielding hexane, dichloromethane, ethyl acetate and butanol extracts. All extracts, including the crude ethanol and vitexin isolated from the ethyl acetate partition were tested for peripheral anti-nociceptive activity using formalin test and acetic acid-induced abdominal writhing, besides having their acute toxicity assays performed.

Results

The phytochemical analyses resulted in the isolation of vitexin (1), β-sitosterol glucoside (2) and β-sitosterol (3) isolated from the ethyl acetate, dichloromethane and hexane extracts, respectively. This is the first time vitexin and β-sitosterol glucoside are isolated from this species. The anti-nociceptive activities for all extracts were only moderate. Vitexin, which was isolated from the ethyl acetate extract did not show any activity in all models tested when used alone at the same concentration as it appears in the extract.

Conclusion

This study showed that all the extracts possess moderate anti-nociceptive activity. Vitexin is not the compound responsible for the anti-nociceptive effect in the ethyl acetate extract. Further investigations are needed to identify the compound(s) that might be responsible for the anti-nociceptive activity in this plant.     

Gastroprotective activity of Cenostigma macrophyllum Tul. var. acuminata Teles Freire leaves on experimental ulcer models

Ethnopharmacological relevance

Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Leguminosae-Caesalpinioideae), popularly known in Brazil as “caneleiro”, is widely used in folk medicine against gastrointestinal diseases. In previous studies, the ethanol extract of leaves from Cenostigma macrophyllum Tul. var. acuminata Teles Freire had shown antinociceptive, anti-inflammatory, antibacterial, antioxidant and antiulcerogenic activities.

Aim of the study

The aim of this study was to assess the gastroprotective effect of the hydroalcoholic fraction of leaves of Cenostigma macrophyllum Tul. var. acuminata Teles Freire (Cm-FHA), as well as to elucidate the possible underlying mechanisms of action.

Materials and methods

Mice were used for the evaluation of the acute toxicity, and mice and rats to study the gastroprotective activity. The potential gastroprotective of Cm-FHA was assessed on different gastric ulcer models in rodents, such as absolute ethanol, HCl/ethanol, ischemia-reperfusion, cold restraint stress and indomethacin. The participation of prostaglandins, NO-synthase pathway and ATP-sensitive potassium channels (K_ATP) in gastroprotective activity of Cm-FHA were evaluated after treatment with a cyclooxygenase inhibitor (indomethacin), a NO-synthase inhibitor (L-NAME) and a K_ATP channel blocker (glibenclamide 5 mg/kg), respectively. Likewise, the catalase activity was determinated in order to assess the possible participation of antioxidant mechanisms.

Results

No signs of acute toxicity was observed after oral acute administration of Cm-FHA, considering the analyzed parameters. Likewise, Cm-FHA promoted a protective effect against gastric ulcers induced by absolute ethanol (lesion inhibition by 40% at both 100 and 200 mg/kg), HCl/ethanol (lesion inhibition by 50 or 48% at 100 or 200 mg/kg, respectively), ischemia-reperfusion (lesion inhibition by 49 or 90% at 100 or 200 mg/kg, respectively) and cold restraint stress (lesion inhibition by 63 or 76% at 100 or 200 mg/kg, respectively), as well as a increase of catalase activity was observed. Otherwise, Cm-FHA was not able to protect gastric mucosa against indomethacin-induced lesions. Nitric oxide release, the of K_ATP channels opening and antioxidant activity are the possibly involved in the Cm-FHA-induced gastroprotective activity.

Conclusion

This study corroborates the folk medicine use of Cenostigma macrophyllum for treatment of gastric ulcers, as well as reinforces this species as a valuable source of promising natural drugs with gastroprotective activity.     

Evaluation of the wound healing potential of Wedelia trilobata (L.) leaves

Ethnopharmacological relevance

Wedelia trilobata (L.) Hitchc (Asteraceae) leaves are used in the treatment of wounds by traditional healers. Despite the use of this plant in wound healing, there is a scarcity of scientific data to support its therapeutic application.

Aim of the study

To investigate the wound healing potential of Wedelia trilobata (L.) leaves commonly employed by traditional healers and to clarify its traditional use in a scientific investigation.

Materials and methods

An ethanolic extract of Wedelia trilobata leaves was subjected to column chromatography. Hexane, ethyl acetate (WEA) and chloroform:methanol (50:50) (WCM) fractions were obtained. The fractions were tested using relevant in vitro wound healing assays. Antioxidant activity was measured by the DPPH assay. The fibroblast proliferation, oxidative stress using hydrogen peroxide, an in vitro scratch assay, and increasing collagen content was determined using fibroblast L929. Minimum inhibitory concentrations (MICs) were determined against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa.

Results

WEA (3 μg/mL) promoted fibroblast L929 survivability up to more than 90% before and more than 85% after hydrogen peroxide induced oxidative stress. WEA (3 μg/mL) induced a 70% migration rate in the in vitro scratch assay and the collagen content was increased to 261 μg/mL compared to the control (57.5 μg/mL). WCM exhibited a scavenging activity for DPPH with an IC₅₀ value of 179.5 μg/mL comparable to BHT (139.3 μg/mL). WEA was active against Gram positive bacteria Staphylococcus aureus, Staphylococcus epidermidis with MIC values of 62.5 and 31.25 μg/mL, respectively.

Conclusion

These scientific findings of wound healing activity supports the traditional claims for Wedelia trilobata (L.) leaves. The WEA displayed antibacterial and fibroblast stimulatory activities while WCM exhibited antioxidant to indicate its potential wound healing properties. However further studies to isolate the antibacterial, antioxidant and fibroblast stimulatory compounds that contribute to the wound healing properties of this plant are needed.     

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).     

Evaluation of the acute dermal exposure of the ethanolic and hexanic extracts from leaves of Schinus molle var. areira L. in rats

Ethnopharmacological relevance

Schinus molle var. areira L. (Anacardiaceae) is employed in herbal medicine for many conditions, including respiratory, urinary and menstrual disorders, and as a digestive stimulant, diuretic, astringent and antidepressant. It is also known for its topical use as wound healer, antiseptic, for skin disorders and as repellent and insecticide. In the present work, the acute dermal exposure to ethanolic and hexanic extracts from leaves of Schinus molle var. areira was studied in rats.

Materials and methods

A single dose of 2000 mg/kg of body weight of ethanolic and hexanic extracts from leaves was applied on the shaved skin of male and female rats. After 24 h of exposure, the patch was removed and any sign of irritation was recorded. Behavioral and functional parameters in a functional observational battery and motor activity in an open field were assessed after the exposure to the extracts. Then, after 14 days of observation, animals were retested. Finally, histopathological studies were conducted on several organs.

Results

Slight signs of erythema and edema were observed in the skin site of exposure, but they disappeared after 48 h. The exposure to the hexanic extract produced an increase in parameters of activity, rearing and arousal assessed in the functional observational battery, which reversed after 14 days. On the other hand, the ethanolic extract caused an increase in locomotor activity, reflected in a higher number of rearings performed in the open field in the evaluation carried out on Day 14. No histopathological alterations were detected in the analyzed organs.

Conclusions

The results show that the acute dermal exposure of the ethanolic and hexanic extracts from leaves of Schinus molle var. areira only causes a slight and reversible skin irritation, and a mild stimulatory effect in rats. All these indicate that the topical use of these extracts would be safe.