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.     

Evaluation of anti-migraine potential of Areca catechu to prevent nitroglycerin-induced delayed inflammation in rat meninges: possible involvement of NOS inhibition

Ethnopharmacological relevance

Areca catechu nut extract is a popular folk remedy for the treatment of migraine in Kerala and Tamil Nadu states of India.

Aim of the study

In order to prove the claimed utilization of plant, the effect of hydroalcoholic extract of Areca catechu nut (ANE) was investigated in nitroglycerine induced inflammation in rat meninges. In these models infusion of nitric oxide donor glyceryl trinitrate (GTN) produces augmented plasma protein extravasation (PPE) in dura mater, provides an important substrate for the development of migraine in rats.

Materials and methods

The effect on plasma protein extravasation was assessed in both the models of intravenous and topical GTN application following oral administration of ANE (250 mg/kg and 500 mg/kg) in both curative and preventive treatment and compared with that of control positive. The l-NAME (15 mg/kg, i.v.) was used as reference standard. Plasma protein extravasation was measured using fluorescein as marker and was measured using a Perkin-Elmer LS-30 luminescence spectrometer.

Results

Expression of iNOS in the spleen after intravenous injection produced PPE into the dura mater in control positive group was significantly (P < 0.01) reduced to 1.553 ± 0.02499 and 1.398 ± 0.01887 by preventive treatment with ANE at the dose of 250 and 500 mg/kg, orally, respectively. The extravasation produced by topical GTN due to expression of iNOS in dural macrophages was also reduced to 1.555 ± 0.03384 and 1.425 ± 0.01204 by preventive treatment with ANE at the dose of 250 and 500 mg/kg, orally, respectively. While ANE do not showed any significant results in curative treatment in both the models of i.v. and topical GTN application.

Conclusion

These findings collectively indicate that the extract exhibited significant inhibition of iNOS, which may be the probable mechanism for its anti-migraine activity, providing evidence, at least in part, for its folkloric use.     

Antidiabetic potential of unripe Carissa carandas Linn. fruit extract

Ethnopharmacological relevance

Carissa carandas commonly known as Karanda have a long history of use in traditional system of medicine. It is used by tribal healers of Western Ghat region of Karnataka as hepatoprotective and antihyperglycemic. However, no scientific data is available to validate the folklore claim. The present study has been designed to evaluate its unripe fruit for the antidiabetic activity.

Aim

In the present study, methanol extract of unripe fruits and its fractions were studied for its antidiabetic potential.

Materials and methods

The methanol extract and its fractions were screened for antidiabetic activity in alloxan induced diabetic rats. The polyphenolic, flavonoid and flavanone contents of methanolic extract and its fractions were also determined and correlated with its antidiabetic activity.

Results

The experimental data indicated that the methanol extract and its ethyl acetate soluble fraction has significantly lowered the elevated blood glucose levels by 48% (p < 0.001) and 64.5% (p < 0.001) respectively at dose level of 400 mg/kg per oral after 24 h as compared to diabetic control. In order to assess the role of polyphenolic components in the relevant activity, polyphenolic and flavonoid contents were determined. The polyphenolic and flavonoid content of methanol extract and its ethyl acetate soluble fraction were found to be 15.8 ± 1.2 mg and 18.55 ± 0.34 mg (gallic acid equivalent/g extract) and flavonoid content 2.92 ± 0.03 mg and 1.534 ± 0.30 mg (rutin equivalent/g extract) respectively.

Conclusion

The increased antidiabetic potential of ethyl acetate fraction over methanol extract is due to its partial purification achieved by fractionation which resulted in increase in degree of polymerization and segregation of secondary metabolites.     

Anti-inflammatory, analgesic and antipyretic properties of Thespesia populnea Soland ex. Correa seed extracts and its fractions in animal models

Ethnopharmacological relevance

Thespesia populnea Sol. ex Correa (Malvaceae) is commonly known as “Indian tulip tree”. The plant has been used as an astringent, antibacterial, anti-inflammatory, antinociceptive and hepatoprotective in Indian system of traditional medicine.

Materials and methods

Thespesia populnea seeds were successively extracted by soxhlet extraction using petroleum ether (40-60 °C) (TPO) and ethanol (TPE). Unsaponifiable matter (TPOUM) and fatty acids were separated from seed oil. A GC-MS analysis of fatty acid methyl esters was carried out. Ethanolic extract was fractionated using CHCl₃, EtOAc, n-BuOH and H₂O. Acute arthritis was induced by sub-plantar injection of carrageenan into the left hind paw of rats. The paw volume was measured using plethysmometer. Analgesic activity was assessed by heat induced pains (tail immersion model) and antipyretic activity assessed using brewers yeast-induced pyrexia model.

Results

Oral administration of TPO and TPE at 200 and 400 mg/kg b.w. and tested fractions at 200 mg/kg significantly reduced carrageenan induced paw edema and brewers yeast-induced pyrexia. In tail immersion method also extracts and fractions showed significant analgesic activity. Amongst all fractions EtOAc showed most significant results. TPOUM showed significant anti-inflammatory and analgesic activity. GC-MS analyses showed the presence of fourteen fatty acids, predominant fatty acids were palmitic and stearic acid.

Conclusion

These results highlighted anti-inflammatory, analgesic and antipyretic effects of Thespesia populnea seeds.     

Treatment of high fat diet induced type 2 diabetes in C57BL/6J mice by two medicinal plants used in traditional treatment of diabetes in the east of Algeria

Aim of the study

Hydro-alcoholic extracts of Centaurium erythraea Rafn (CE), Gentianaceae and Artemisia herba-alba Asso (AHA), Asteraceae, medicinal plants used in traditional treatment of diabetes in north-eastern Algeria, were tested in established type 2 diabetes induced with a standardized high fat diet (HFD) in mice.

Materials and methods

After confirmation of diabetes (17th week), plant extracts were administered orally by gavage at a dose of 2 g/kg daily for 18 weeks to male C57BL/6J mice fed HFD. Animals were weighed, food intake and plasma glucose measured weekly, insulin and lipid profile at study end.

Results

At 35 weeks, groups treated with AHA or CE vs. HFD control had a significant reduction in mean (±SD) fasting blood glucose concentrations (143.8 ± 23.9 and 139.5 ± 14.2 vs. 229.0 ± 20.8 mg/dL, p < 0.05, respectively), triglyceride (18.9 ± 11.1 and 16.0 ± 6.5 vs. 62.8 ± 18.3 mg/dL, p < 0.05), total cholesterol (1.2 ± 0.1 and 1.2 ± 0.3 vs. 1.8 ± 1.1 g/L, p < 0.05) and serum insulin concentrations (1.7 ± 0.7 and 0.9 ± 0.7 vs. 3.3 ± 14.3 ng/mL, p < 0.05). Plant extracts also markedly reduced insulin resistance as compared to HFD controls (AHA: 15.6 ± 9.1, CE: 9.0 ± 7.7 vs. HFD control 38.5 ± 30.3, p < 0.05). The plant extracts decreased calorie intake and had little effect on body weight or HDL-cholesterol.

Conclusion

AHA has already been shown to have a antihyperglycaemic and antihyperlipidemic effect but this is the first demonstration of an effect of AHA and CE on established HFD-induced diabetes.     

Pharmacokinetic study of the prokinetic compounds meranzin hydrate and ferulic acid following oral administration of Chaihu-Shugan-San to patients with functional dyspepsia

Aim of the study

The prokinetic activity of ferulic acid derived from Ligusticum chuanxiong hort in the Chaihu-Shugan-San formula has been shown to be similar to Chaihu-Shugan-San, a popular traditional Chinese medicine for treating functional dyspepsia. The effects of meranzin hydrate, a compound isolated from Fructus aurantii in the Chaihu-Shugan-San formula, are unclear, as the pharmacokinetics have never been studied in patients with functional dyspepsia. This study aimed to describe the pharmacokinetics of ferulic acid and merazin hydrate by evaluating the prokinetics induced by Chaihu-Shugan-San and meranzin hydrate.

Materials and methods

Gastric emptying and intestinal transit were measured after oral administration of a single dose of Chaihu-Shugan-San or meranzin hydrate in rats. The tone of rat ileum was selected as direct evidence of the prokinetic activity of meranzin hydrate. Patients with functional dyspepsia were recruited, and meranzin hydrate and ferulic acid were identified by ultra performance liquid chromatography with tandem mass spectrometry in the plasma of patients following a single oral administration of Chaihu-Shugan-San. The resulting pharmacokinetic properties were determined by ultra performance liquid chromatography coupled to photo diode array.

Results

In rats, single doses of Chaihu-Shugan-San (20 g/kg) and meranzin hydrate (28 mg/kg) significantly accelerated gastric emptying and intestinal transit (Chaihu-Shugan-San: 68.9 ± 5.6% and 72.3 ± 4.7%, meranzin hydrate: 72.9 ± 3.8% and 75.2 ± 3.1%) compared with the control (55.45 ± 3.7% and 63.51 ± 5.1%, P < 0.05), showing similar results as cisapride (69.6 ± 4.8% and 71.6 ± 6.3%). Meranzin hydrate (30, 100 μmol/L) directly increased the amplitude of rat ileum compared with the control (P < 0.01). The pharmacokinetics profiles of meranzin hydrate and ferulic acid in patient plasma was fitted with a two-compartment model detected by a simple, rapid and accurate UPLC method. Time to reach peak concentration of meranzin hydrate (0.371 mg/L) and ferulic acid (0.199 mg/L) was 23.57 min and 27.50 min, respectively. The elimination half-life and area under the concentration-time curve from t = 0 to the last time of meranzin hydrate and ferulic acid were 139.53 min and 31.445 μg min/mL and 131.27 min and 14.835 μg min/mL, respectively. The absorption constant and volume of distribution of meranzin hydrate and ferulic acid were 0.185 ± 0.065 min⁻¹ and 3782.89 ± 2686.72 L/kg and 0.524 ± 0.157 min⁻¹ and 11713 ± 7618.68 L/kg, respectively. The experimental results of the pharmacokinetic parameters of meranzin hydrate and ferulic acid indicate that they were absorbed and distributed rapidly.

Conclusions

The pharmacodynamics and pharmacokinetics of prokinetic Chaihu-Shugan-San and its compounds are useful for monitoring Chaihu-Shugan-San formulas in clinical practice and for understanding therapeutic mechanisms.     

Analgesic effects and anti-inflammatory properties of the crude methanolic extract of Schwenckia americana Linn (Solanaceae)

Aim of the study

To evaluate analgesic effect and anti-inflammatory properties of Schwenckia americana (Solanaceae), a medicinal plant used for treating rheumatic pains and swelling in North-western Nigeria.

Materials and methods

Three doses (25 mg/kg, 50 mg/kg and 100 mg/kg) of the crude methanolic extract of Schwenkia americana were evaluated for analgesic and anti-inflammatory activities using acetic acid induced writhing test, formalin induced nociception, and formalin induced hind paw oedema in rats.

Results

All doses (25, 50, 100 mg/kg) of the extract tested were effective. The extract at the tested doses produced a percentage inhibition of the acetic acid induced abdominal constriction of (53.3, 58.0 and 86.7%), respectively. A percentage inhibition of the formalin induced nociception of 44.00, 56.04, and 56.04% (early phase) and 33.00, 36.63 and 59.71% (late phase) was also produced. The inhibition of oedema formation increased with increasing dosage from 25 to 100 mg/kg. The crude extract produced a statistically significant analgesic and anti-inflammatory activity comparable to the effect of standard drug (10 mg/kg Piroxicam).

Conclusion

This study demonstrated the potential analgesic and anti-inflammatory properties of crude methanolic extract of Schwenkia americana thus justifying its traditional usage.     

Typhonium flagelliforme induces apoptosis in CEMss cells via activation of caspase-9, PARP cleavage and cytochrome c release: Its activation coupled with G0/G1 phase cell cycle arrest

Ethnopharmacological relevance

The plant Typhonium flagelliforme (TF), commonly known as ‘rodent tuber’ in Malaysia, is often used as traditional remedy for cancer, including leukemia.

Aim of the study

We had previously identified morphologically that the linoleic acid rich fraction (DCM/F7) from the tubers of this plant induces selective anti-proliferative effects and apoptosis in CEMss cells. In this present study, we subjected the same DCM/F7 fraction to cell based activity analyses in order to determine the possible mechanism of cell death in leukemic CEMss cells in vitro.

Materials and methods

Extraction of Typhonium flagelliforme tuber has done and fractionation has been done by vacuum liquid column chromatography. The anti-proliferative activity was assayed using MTT and the apoptosis detection was done by Annexin V and DNA laddering assay. Colorimetric caspase assay and immunoblot analysis were employed to detect the expression of protein associated with cell death. Cell cycle analysis was done using flow cytometry.

Results

We found that the cancer inhibitory effect of the DCM/F7 fraction in CEMss cells was 3 ± 0.08 μg/ml (IC₅₀). An early apoptotic induction in CEMss cells was observed by Annexin V assay, which showed a clear dose-dependent DNA fragmentation being observed in gel electrophoresis at 10 and 20 μg/ml. The DCM/F7 fraction at 3 μg/ml significantly arrested CEMss cells at G0/G1 phase (p < 0.05). A constant but increasing pattern-related Sub-G0/G1 index was observed between 12 and 72 h treatment. In relation to this, we further investigated the biochemical events leading to cell death and found that the DCM/F7 fraction increased the cellular levels of caspase-3 and -9 on treated cells. Our results indicated that cytochrome c from mitochondria into the cytosol increased gradually as the DCM/F7 concentration increases, which later lead to the subsequent cleavage of PARP in to 85 kDa fragments. On the contrary, Bcl-2 protein was found to decrease concomitantly during treatment.

Conclusions

Collectively, results presented in this study demonstrated that the DCM/F7 fraction inhibited the proliferation of leukemia cells, leading to the programmed cell death, which was confirmed to be through the mitochondrial pathway.     

Wound healing activity of Glycosmis arborea leaf extract in rats

Ethnopharmacological relevance

Glycosmis arborea Roxb, syn. Glycosmis pentaphylla Retz, (Rutacea) is a shrub found all over India, have been used for the healing of wounds of livestock in Indian folk medicine.

Aim of the study

The present study provides a scientific evaluation for the wound healing potential of ethanolic extract of Glycosmis arborea leaves.

Methods and materials

Excision and incision wounds were inflicted upon four groups containing six rats each. Group-1 was assigned as control (ointment base), Group-2 and Group-3 were treated with 5 and 10% EtOH extract ointment. Group-4 was treated with standard Nitrofurazone (0.2%) ointment. The parameters observed were percentage of wound contraction, epithelization period, tensile strength, hydroxyproline content. Ethanolic extract of Glycosmis arborea leaves was given orally at a dose of 200, 400 mg/kg/day in dead space wound model.

Results

Topical application of Glycosmis arborea ointment (10%) in excision wound model significantly (P < 0.05) increased the percentage of wound contraction (96.91%) compared with control (60.27%) and decreased the epithelization time. The tensile strength significantly (P < 0.05) increased in Group-3 at 560.33 ± 6.48 g when compared to control at 319.17 ± 6.16 g. Rats treated with Glycosmis arborea extract (400 mg/kg) showed significant (P < 0.05) increase in hydroxyproline content at 54.94 ± 0.96 mg/g when compared with control at 30.77 ± 1.13 mg/g.

Conclusion

The ethanolic extract of Glycosmis arborea facilitated wound healing significantly, corroborating the folk medicinal use of this plant.     

Antipyretic and anti-inflammatory properties of the ethanolic extract,dichloromethane fraction and costunolide from Magnolia ovata (Magnoliaceae)

Aim of the study

Magnolia ovata (A.St.-Hil.) Spreng (formerly Talauma ovata), known as “pinha-do-brejo” or “baguaçu”, is a large tree widely distributed in Brazil. Its trunk bark has been used in folk medicine against fever. However, no data have been published to support the antipyretic ethnopharmacological use. This study investigated the antipyretic and anti-inflammatory effects of the ethanolic extract (EEMO), dichloromethane fraction (DCM), and the isolated compound costunolide.

Materials and methods

The antipyretic and anti-inflammatory activities were evaluated in experimental models of fever and inflammation in mice.

Results

The oral administration of EEMO, DCM and costunolide inhibited carrageenan (Cg)-induced paw oedema (ID₅₀ 72.35 (38.64–135.46) mg/kg, 5.8 (2.41–14.04) mg/kg and 0.18 (0.12–0.27) mg/kg, respectively) and was effective in abolishing lipopolysaccharide (LPS)-induced fever (30 mg/kg, 4.5 mg/kg and 0.15 mg/kg, respectively). EEMO was also effective in reducing cell migration in the pleurisy model. Intraplantar injection of costunolide also reduced the paw oedema, myeloperoxidase and N-acetyl-glucosaminidase activity induced by Cg in mice.

Conclusions

Collectively, these results show, for the first time, that extracts obtained from Magnolia ovata possess antipyretic and anti-inflammatory properties, and costunolide appears to be the compound responsible for these effects.     

Antiulcer effects of Achyrocline satureoides (Lam.) DC (Asteraceae) (Marcela), a folk medicine plant,in different experimental models

Ethnopharmacological relevance

Achyrocline satureoides is a medium-sized South American indigenous herb, commonly known as “Marcela” or “Macela”. The infusion obtained from inflorescences of this plant is widely used in Brazilian folk medicine as an antispasmodic, anti-inflammatory, hypoglycemic, and hypocholesterolemic, mainly to treat gastrointestinal disorders such as gastric ulcers and dyspepsia. However, the antiulcer properties of this species have not yet been fully studied.

Aim of the study

This study was conducted to evaluate and contribute to validating the antiulcer activity of hydroalcoholic extract of inflorescences of Achyrocline satureoides.

Materials and methods

The antiulcer assays were performed using the ethanol-induced ulcer, and nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer protocols. Gastric secretion parameters were also evaluated (volume, pH and total acidity) by the pylorus ligated model, and the mucus in the gastric content was determined.

Results

In the ethanol-induced ulcer model, it was observed that the treatment with Achyrocline satureoides extract significantly reduced the lesion index by 75.1 ± 8.6, 85.0 ± 9.2, 86.6 ± 7.4 and 75.5 ± 5.3 for the groups treated with 100, 250 and 500 mg/kg of extract of inflorescences of Achyrocline satureoides and the positive control (omeprazole 30 mg/kg), respectively. Significant inhibition was also observed in the lesion index in the indomethacin-induced ulcer model, with decreases of 62.5 ± 7.1, 62.5 ± 6.1, 63.6 ± 5.5 and 96.2 ± 3.6 for the groups treated with 100, 250 and 500 mg/kg of extract and the positive control (cimetidine 100 mg/kg), respectively. The parameters of gastric secretion (pH, volume, [H⁺]) showed no alteration in the different doses of the treatment. On the other hand the treatment with the hydroalcoholic extract of Achyrocline satureoides (100, 250 and 500 mg/kg), significantly increased mucus production (p < 0.01), when compared with the groups treated with indomethacin (100 mg/kg), cimetidine (100 mg/kg) and negative control (vehicle). No signs of toxicity was observed in the acute toxicity study.

Conclusions

The results of the present study show that hydroalcoholic extract of Achyrocline satureoides displays antiulcer activity, as demonstrated by the significant inhibition of the formation of ulcers induced using different models. However, this activity appears not be related to the antisecretor mechanisms. Moreover, this work suggests that preparations obtained from Achyrocline satureoides could be used for the development of new phytotherapic drugs for the treatment of gastric ulcer.     

Antinociceptive effect of the essential oil of Zingiber zerumbet in mice: possible mechanisms

Ethnopharmacological relevance

Zingiber zerumbet (L.) Smith, a wild edible ginger species or locally known as “lempoyang”, commonly used in the Malays traditional medicine as an appetizer or to treat stomachache, toothache, muscle sprain and as a cure for swelling sores and cuts.

Aim

The present study was conducted to investigate the possible mechanism of actions underlying the systemic antinociception activity of the essential oil of Zingiber zerumbet (EOZZ) in chemical-induced nociception tests in mice.

Materials and methods

Acetic acid-induced abdominal constriction, capsaicin-, glutamate- and phorbol 12-myristate 13-acetate-induced paw licking tests in mice were employed in the study. In all experiments, EOZZ was administered systemically at the doses of 50, 100, 200 and 300 mg/kg.

Results

It was shown that EOZZ given to mice via intraperitoneal and oral routes at 50, 100, 200 and 300 mg/kg produced significant dose dependent antinociception when assessed using acetic acid-induced abdominal writing test with calculated mean ID₅₀ values of 88.84 mg/kg (80.88-97.57 mg/kg) and 118.8 mg/kg (102.5-137.8 mg/kg), respectively. Likewise, intraperitoneal administration of EOZZ at similar doses produced significant dose dependent inhibition of neurogenic pain induced by intraplantar injection of capsaicin (1.6 μg/paw), glutamate (10 μmol/paw) and phorbol 12-myristate 13-acetate (1.6 μg/paw) with calculated mean ID₅₀ of 128.8 mg/kg (118.6-139.9 mg/kg), 124.8 mg/kg (111.4-139.7 mg/kg) and 40.29 (35.39-45.86) mg/kg, respectively. It was also demonstrated that pretreatment with l-arginine (100 mg/kg, i.p.), a nitric oxide precursor significantly reversed antinociception produced by EOZZ suggesting the involvement of l-arginine/nitric oxide pathway. In addition, methylene blue (20 mg/kg, i.p.) significantly enhanced antinociception produced by EOZZ. Administration of glibenclamide (10 mg/kg, i.p.), an ATP-sensitive K⁺ channel antagonist significantly reversed antinociceptive activity induced by EOZZ.

Conclusion

Together, the present results suggested that EOZZ-induced antinociceptive activity was possibly related to its ability to inhibit glutamatergic system, TRPV1 receptors as well as through activation of l-arginine/nitric oxide/cGMP/protein kinase C/ATP-sensitive K⁺ channel pathway.     

Cytochrome P450 inhibitory potential of Triphala--a Rasayana from Ayurveda

Ethnopharmacological relevance

‘Triphala’ is one of the age-old, most commonly used polyherbal preparation from Ayurveda as Rasayana drug.

Aim of the study

This study was aimed at evaluating the effect of ‘Triphala’ on drug modulating enzymes to assess its safety through its potential to interact with co-administered drugs.

Materials and methods

The cytochrome P450 inhibitory effect of ‘triphala’ formulation was investigated on rat liver microsomes using CYP450-CO complex assay and on individual isoform such as CYP3A4 and 2D6 using fluorescence screening. RP-HPLC method was developed to standardize ‘triphala’ and its individual components using gallic acid as analytical marker compound.

Results

RP-HPLC analysis demonstrated the presence of gallic acid (4.30 ± 2.09 mg/g) in the formulation. The formulation showed 23% inhibition of the rat liver microsomes through CYP450-CO complex assay which is comparatively less when compared with the individual components. Further, the effect of standardized formulation dissolved in ethanol showed CYP3A4 and CYP2D6 inhibitory activity at the IC₅₀ values of 119.65 ± 1.91 μg/ml and 105.03 ± 0.98 μg/ml respectively. Gallic acid was also found to inhibit both the isoforms at the IC₅₀ values of 87.24 ± 1.11 μg/ml and 92.03 ± 0.38 μg/ml respectively.

Conclusions

Various concentrations of the formulation and its individual components showed significantly less inhibitory activity (p < 0.001) on individual isoforms when compared with the positive control. Assessment on the in vitro effect of ‘triphala’ on drug modulating enzymes has important implications for predicting the likelihood of herb-drug interactions if these are administered concomitantly.     

Bacopa monnieri and its constituents is hypotensive in anaesthetized rats and vasodilator in various artery types

Ethnopharmacological relevance

Bacopa monnieri (Brahmi) provides traditional cognitive treatments possibly reflecting improved cerebral hemodynamics. Little is known about the cardiovascular actions of Brahmi. We sought to assess its effects on blood pressure and on isolated arteries, thus providing insights to clinical applications.

Materials and methods

Intravenous Brahmi (20-60 mg/kg) was tested on arterial blood pressure and heart rate of anaesthetized rats. In vitro vasorelaxation was assessed in arteries, with and without blockers of nitric oxide synthase (L-NAME), cyclooxygenase (indomethacin), and mechanical de-endothelialisation. The effects of Brahmi on Ca²⁺ influx and release from stores were investigated.

Results

Intravenous Brahmi extract (20-60 mg/kg) decreased systolic and diastolic pressures without affecting heart rate. Brahmi evoked relaxation in isolated arteries in order of potency: basilar (IC50 = 102 ± 16 μg/ml) > mesenteric (171 ± 31) > aortae (213 ± 68) > renal (IC50 = 375 ± 51) > tail artery (494 ± 93) > femoral arteries (>1000 μg/ml). Two saponins, bacoside A3 and bacopaside II, had similar vasodilator actions (IC50 = 8.3 ± 1.7 and 19.5 ± 6.3 μM). In aortae, without endothelium or in L-NAME (10-4 M), Brahmi was less potent (IC50 = 213 ± 68 to 2170 ± 664 and 1192 ± 167 μg/ml, respectively); indomethacin (10-5 M) was ineffective. In tail artery, Brahmi inhibited K⁺-depolarization induced Ca²⁺ influx and Ca²⁺ release from the sarcoplasmic reticulum by phenylephrine (10-5 M) or caffeine (20 mM).

Conclusions

Brahmi reduces blood pressure partly via releasing nitric oxide from the endothelium, with additional actions on vascular smooth muscle Ca²⁺ homeostasis. Some Brahmi ingredients could be efficacious antihypertensives and the vasodilation could account for some medicinal actions.     

Effects of Scutellariae radix and Aloe vera gel extracts on immunoglobulin E and cytokine levels in atopic dermatitis NC/Nga mice

Aim of the study

The present study aimed to investigate the effects of Scutellariae radix (SR) and Aloe vera gel (AV), alone or in combination, on levels of immunoglobulin E (IgE) and inflammatory cytokines in spontaneous atopic dermatitis(AD)-like skin lesions.

Materials and methods

After spontaneous AD-like skin lesion was developed by adaptation to conventional conditions, mice were randomly assigned to control, SR (50 mg/kg, p.o.), AV (0.8 mg/kg, p.o.) and SRAV (50 mg of SR and 0.8 mg of AV/kg, p.o.) groups, and were treated for 6 weeks.

Results

SR and SRAV suppressed IL-5 levels compared with control, but had no effects on IgE levels (P < 0.05). AV increased IgE levels, but decreased both IL-5 and IL-10 compared with control (P < 0.05).

Conclusion

These results suggest that SR and AV modulate immunological responses in AD, mainly through influencing IL-5 or IL-10 levels.     

Hypoglycemic effect of a leaf extract of Pseuderanthemum palatiferum (Nees) Radlk. in normal and streptozotocin-induced diabetic rats

Ethnopharmacological relevance

Pseuderanthemum palatiferum (Nees) Radlk (Acanthaceae) was first found in Northern Vietnam and expanded throughout the country including the Mekong Delta region. The leaves of this plant are recommended in folk medicine of Vietnam and Thailand for promoting and treating various diseases including hypertension, diarrhea, arthritis, hemorrhoids, stomachache, tumors, colitis, bleeding, wounds, constipation, flu, colon cancer, nephritis, and diabetes.

Aim of the study

The hypoglycemic effect of an 80% ethanolic leaf extract from the leaves of Pseuderanthemum palatiferum (PPE) was investigated in normal and streptozotocin (STZ)-induced diabetic rats.

Materials and methods

The PPE was administered daily and orally to the rats at the doses of 250, 500, and 1000 mg/kg body weight (b.w.) for 14 days. The levels of fasting plasma glucose (FPG), serum insulin, and biochemical data such as blood urea nitrogen (BUN), triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and alkaline phosphatase (ALP) were evaluated. The hypoglycemic effect of PPE was compared to that of the known anti-diabetic drug glibenclamide (0.25 mg/kg b.w.).

Results

FPG and serum insulin in normal rats were not significantly different from the control and test groups in all dosages. The treated diabetic rats which had received PPE and glibenclamide showed significantly (p < 0.05) decreased FPG and increased serum insulin levels at the end of the experiment. The hypoglycemic effect of PPE at the dose of 250 mg/kg b.w. was significantly (p < 0.05) more effective than that of glibenclamide. The serum insulin in PPE fed diabetic rats at the dose of 250 mg/kg b.w. was not different from those which had received glibenclamide, and this dose was significantly (p < 0.05) more effective than PPE at the doses of 500 and 1000 mg/kg b.w. while PPE increased HDL and decreased TC, TG, LDL, BUN and ALP in the diabetic rats.

Conclusions

PPE has a beneficial effect in hyperglycemic rats and may prevent the complication of diabetes.     

Sedative and anticonvulsant activities of methanol extract of Dorstenia arifolia in mice

Ethnopharmacological relevance

Dorstenia arifolia is a plant that has been used in the folk medicine to produce hypnotic, sedative and ansiolitic effects but the pharmacological properties have not yet been studied. In addition, the smoke of its rhizome is reputed to induce lethargic sensation.

Aims of the study

The present study investigated possible activities of the methanol extract (ME) of Dorstenia arifolia rhizome on the central nervous system (CNS).

Materials and methods

ME was tested for sedative, hypnotic and anticonsulsant effects using locomotor activity evaluation, pentobarbital-induced sleeping time and pentylenetetrazol (PTZ)-induced convulsion, respectively.

Results

Intraperitoneal administration of ME (10 and 50 mg/kg) significantly decreased locomotor activity from 205.2 ± 25.6 movements/min (DMSO) to 112.1 ± 18.4 (P < 0.05) and 114.9 ± 16.9 (P < 0.05), respectively. Flumazenil (10 mg/kg), an antagonist of GABA_A receptor, prevented the ME-induced sedation. Treatment with ME (50 mg/kg) significantly increased the duration of pentobarbital-induced sleeping time from 41.0 ± 2.3 to 57.9 ± 2.9 min (P < 0.05). The latencies to seizures after intraperitoneal injection of PTZ was recorded and compared between groups. ME promoted a significant protection of PTZ-induced seizures and mortality in a dose-dependent manner.

Conclusions

Our findings indicate that ME of Dorstenia arifolia rizhome has pronounced central effects, and that the sedative and anticonvulsant activities may be related to a facilitation of the GABAergic transmission.     

In vitro antimicrobial, anthelmintic and cyclooxygenase-inhibitory activities and phytochemical analysis of Leucosidea sericea

Ethnopharmacological relevance

Leucosidea sericea is used as a vermifuge and in the treatment of ophthalmia by various tribes in southern African countries.

Aim of the study

The study aimed at screening leaves and stems of Leucosidea sericea for pharmacological activity and validating the plant's traditional use. A general phytochemical screening was also carried out.

Materials and methods

Petroleum ether (PE), dichloromethane (DCM), ethanol (EtOH) and water extracts of the plant parts were investigated for antimicrobial, anthelmintic and cyclooxygenase (COX) inhibitory activities. Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and Candida albicans were used for the antimicrobial evaluation. Caenorhabditis elegans was used for the anthelmintic assay using the microdilution technique. Cyclooxygenase-1 and -2 (COX-1 and -2) were used to evaluate the anti-inflammatory potential of the plant extracts. Phytochemical analysis for phenolic compounds, including gallotannins, condensed tannins and flavonoids was done using 50% methanol extracts of the leaves and stems employing spectrophotometric methods.

Results

The leaf extracts exhibited broad spectrum antibacterial activity ranging from 0.025 to 6.25 mg/ml. The most noteworthy minimum inhibitory concentration (MIC) of 0.025 mg/ml was exhibited by PE and DCM leaf extracts against Bacillus subtilis and Staphylococcus aureus, respectively. In the anthelmintic assay, the best minimum lethal concentration (MLC) value of 0.26 mg/ml was observed for the DCM and EtOH leaf extracts. Both leaf and stem organic solvent extracts exhibited high to moderate inhibition against COX-1 and -2 at a screening concentration of 250 μg/ml. At lower concentrations, the extracts displayed a dose-dependent inhibition, with the lowest IC₅₀ values of 0.06 μg/ml (COX-1) and 12.66 μg/ml (COX-2) exhibited by the PE extract of the leaves. Generally, the leaf extracts exhibited better pharmacological activities and contained higher amounts of phenolic compounds than the stem extracts. Alkaloids and saponins were only detected in the leaf and stem extracts, respectively.

Conclusion

The reported results support the local use of Leucosidea sericea against eye infections and as a vermifuge. The pharmacological activities exhibited by the leaf extracts are probably due to their higher phenolic levels.     

Permeability of rosmarinic acid in Prunella vulgaris and ursolic acid in Salvia officinalis extracts across Caco-2 cell monolayers

Ethnopharmacological relevance

Rosmarinic acid (RA), a caffeic acid-related compound found in high concentrations in Prunella vulgaris (self-heal), and ursolic acid (UA), a pentacyclic triterpene acid concentrated in Salvia officinalis (sage), have been traditionally used to treat inflammation in the mouth, and may also be beneficial for gastrointestinal health in general.

Aim of the study

To investigate the permeabilities of RA and UA as pure compounds and in Prunella vulgaris and Salvia officinalis ethanol extracts across human intestinal epithelial Caco-2 cell monolayers.

Materials and methods

The permeabilities and phase II biotransformation of RA and UA as pure compounds and in herbal extracts were compared using Caco-2 cells with HPLC detection.

Results

The apparent permeability coefficient (P_app) for RA and RA in Prunella vulgaris extracts was 0.2 ± 0.05 × 10⁻⁶ cm/s, significantly increased to 0.9 ± 0.2 × 10⁻⁶ cm/s after β-glucuronidase/sulfatase treatment. P_app for UA and UA in Salvia officinalis extract was 2.7 ± 0.3 × 10⁻⁶ cm/s and 2.3 ± 0.5 × 10⁻⁶ cm/s before and after β-glucuronidase/sulfatase treatment, respectively. Neither compound was affected in permeability by the herbal extract matrix.

Conclusion

RA and UA in herbal extracts had similar uptake as that found using the pure compounds, which may simplify the prediction of compound efficacy, but the apparent lack of intestinal glucuronidation/sulfation of UA is likely to further enhance the bioavailability of that compound compared with RA.     

Evaluation of antinociceptive effect of Aegiceras corniculatum stems extracts and its possible mechanism of action in rodents

Ethnopharmacological relevance

Aegiceras corniculatum (Linn.) Blanco is used in various traditional medicinal system(s) for the treatment of rheumatism, painful arthritis and inflammation. Therefore, the pharmacological studies of its antinociceptive effect was undertaken to validate its traditional use.

Materials and methods

n-Hexane, ethyl acetate and methanol extract(s) derived from Aegiceras corniculatum (stems) were studied using various nociceptive model(s) induced chemically or thermally in mice including acetic acid-induced writhing, formalin-induced paw licking and hot plate test.

Results

In acetic acid-induced writhing test, plant extracts dose dependently decreased the writhing numbers. The methanolic extract (1-10 mg/kg, i.p. in mice) of the plant was more potent than acetaminophen and acetyl salicylic acid, with an IC₅₀ of 4.2 ± 0.99 mg/kg. Moreover, the time of nociceptive behaviors induced by intraplantar formalin injection was also suppressed during 1st and 2nd phases in the presence of ethyl acetate extract whereas, n-hexane and methanolic extracts inhibited the paw licking in mice during the 1st (IC₅₀ 12 ± 0.76 mg/kg) and 2nd phases (IC₅₀ 3.8 ± 0.55 mg/kg). Naloxone, β-funaltrexamine, and naltrindole antagonized the n-hexane extract-induced antinociception in the first phase of formalin test indicating its non-selective analgesic response via opioid receptor(s). However, ethyl acetate extract was devoid of any opioid action. Additionally, these extracts significantly inhibited the pain stimulation in hot plate test. Withdrawal syndrome of morphine dependence was also diminished in the presence of plant extracts via potentiation of GABAergic system.

Conclusion

These results suggested that Aegiceras corniculatum extract(s) possesses analgesic properties and acts on the central nervous system, thereby suppressing the inflammatory pain justifying its folklore use.