Chemical form of metals in traditional medicines underlines potential toxicity in cell cultures

Ethnopharmacological relevance

Mercury (Hg) and arsenic (As) are frequently found in traditional medicines as sulfides, such as cinnabar (HgS) and realgar (As₄S₄). There is a general perception that any medicinal use of such metal-containing remedies is unacceptable. An opposing opinion is that different chemical forms of arsenic and mercury have different toxic potentials.

Aim of the study

To clarify this question, cinnabar, realgar, and cinnabar- and realgar-containing traditional medicine An-Gong-Niu-HuangWan (AGNH), were compared to well-known mercurials (HgS, HgCl₂ and MeHg) and arsenicals (As₂S₂, As₂O₃, NaAsO₂, and Na₂HAsO₄) for their cytotoxicity in human and rodent cell lines.

Materials and method

Cultured cells derived from target organs such as brain (HAPI) and liver (Hep3B, HepG2 and TRL1215) were treated with chemicals for 48 h and cytotoxicity was determined by the MTS assay.

Results

MeHg was most toxic with LC₅₀ of 4-20 μM, followed by NaAsO₂ (LC₅₀, 25-250 μM) and HgCl₂ (LC_50, 50-100 μM), Na₂HAsO₄(LC₅₀, 60-400 μM), As₂O₃(LC₅₀, 30-900 μM), and As₂S₂ (LC₅₀, 100-500 μM). In comparison, the LC₅₀ of realgar ranged from 250 to1500 μM; whereas cinnabar or HgS were approximately 20,000 μM and the toxicity of AGNH was in the range of 1500-8000 μM. Approximately 5000-fold differences exist between MeHg and HgS, and over 10-fold differences exist between NaAsO₂ and As₄S₄.

Conclusions

Chemical forms of metals are important factor in determining their toxicity in traditional medicines, both cinnabar and realgar are much less toxic than well-known mercurial and arsenicals.     

In vivo hepatoprotective activity of the aqueous extract of Artemisia absinthium L. against chemically and immunologically induced liver injuries in mice

Aim of the study

This study aimed to evaluate in vivo hepatoprotective activity of the aqueous extract of Artemisia absinthium L. (AEAA), which has been used for the treatment of liver disorders in Traditional Uighur Medicine.

Materials and methods

Qualitative and quantitative phytochemical analysis of the AEAA was performed by means of thin layer chromatography and spectrophometric assays. Aqueous extract (50, 100 or 200 mg/kg body weight/day) was administered orally to experimental mice. Liver injury was induced chemically, by a single CCl₄ administration (0.1% in olive oil, 10 ml/kg, i.v.), or immunologically, by injection of endotoxin (LPS, 10 μg, i.v.) in BCG-primed mice. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) in mouse sera, as well as superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) in mouse liver tissues were measured. The biochemical observations were supplemented by histopathological examination.

Results

Obtained results demonstrated that the pretreatment with AEAA significantly (P < 0.001) and dose-dependently prevented chemically or immunologically induced increase in serum levels of hepatic enzymes. Furthermore, AEAA significantly (P < 0.05) reduced the lipid peroxidation in the liver tissue and restored activities of defense antioxidant enzymes SOD and GPx towards normal levels. In the BCG/LPS model, increase of the levels of important pro-inflammatory mediators TNF-α and IL-1 was significantly (P < 0.01) suppressed by AEAA pretreatment. Histopathology of the liver tissue showed that AEAA attenuated the hepatocellular necrosis and led to reduction of inflammatory cells infiltration. Phytochemical analyses revealed the presence of sesquiterpene lactones, flavonoids, phenolic acids and tannins in the AEAA.

Conclusions

The results of this study strongly indicate the protective efect of AEAA against acute liver injury which may be attributed to its antioxidative and/or immunomodulatory activity, and thereby scientifically support its traditional use.     

Acute, subacute toxicity and mutagenic effects of anacardic acids from cashew (Anacardium occidentale Linn.) in mice

Aim of the study

Anacardium occidentale Linn. (cashew) is a Brazilian plant that is usually consumed in natura and is used in folk medicine. Anacardic acids (AAs) in the cashew nut shell liquid are biologically active as gastroprotectors, inhibitors of the activity of various deleterious enzymes, antitumor agents and antioxidants. Yet, there are no reports of toxicity testing to guarantee their use in vivo models.

Materials and methods

We evaluated AAs biosafety by measuring the acute, subacute and mutagenic effects of AAs administration in BALB/c mice. In acute tests, BALB/c mice received a single oral dose of 2000 mg/kg, whereas animals in subacute tests received 300, 600 and 1000 mg/kg for 30 days. Hematological, biochemical and histological analyses were performed in all animals. Mutagenicity was measured with the acute micronucleus test 24 h after oral administration of 250 mg/kg AAs.

Results

Our results showed that the AAs acute minimum lethal dose in BALB/c mice is higher than 2000 mg/kg since this concentration did not produce any symptoms. In subacute tests, females which received the highest doses (600 or 1000 mg/kg) were more susceptible, which was seen by slightly decreased hematocrit and hemoglobin levels coupled with a moderate increase in urea. Anacardic acids did not produce any mutagenic effects.

Conclusions

The data indicate that doses less than 300 mg/kg did not produce biochemical and hematological alterations in BALB/c mice. Additional studies must be conducted to investigate the pharmacological potential of this natural substance in order to ensure their safe use in vivo.     

The medicinal use of realgar (As₄S₄) and its recent development as an anticancer agent

Ethnopharmacological relevance

Arsenicals have been known as poisons and paradoxically as therapeutic agents. In the early 1970s, Chinese physicians from Harbin revived the medicinal use of arsenicals as anticancer agents. Notable success was observed in the treatment of acute promyelocytic leukemia (APL) with arsenic trioxide (ATO). The FDA approved ATO injection in the year 2000 for the treatment of APL. In contrast, the clinical use of the other arsenical, realgar (As₄S₄), is currently much less established, though it has also long been used in medical history. According to ancient medical records and recent findings in clinical trials, realgar was found as effective as ATO, but with relatively good oral safety profiles even on chronic administration. These give realgar an advantage over ATO in maintenance treatment. Though there is increasing understanding on the mechanisms of action and metabolic profiles of ATO, similar aspects of realgar are unclear to date.

Materials and methods

We outline the use of realgar in traditional medicines, especially in traditional Chinese medicines (TCM) from ancient times to present. The clinical and experimental observations on realgar as a therapeutic agent are described with an emphasis on those findings that may imply the rationale and future directions of realgar as a potential anticancer drug candidate.

Results

There is an increasing understanding in the mechanisms of action of realgar as an antileukemic agent. However, there is still sparse information on its metabolism and toxicity profiles.

Conclusions

Realgar is poorly soluble in water. Recently, several types of realgar nanoparticles (NPs) have been developed. Some of these realgar NPs also possess the unique optical properties of quantum dots. The activities and bioavailability of realgar NPs are much influenced by their sizes, making realgar an interesting biomedical and pharmaceutical research candidate.     

Pentacyclic triterpenoids and ceramide mediate the vasorelaxant activity of Vitex cienkowskii via involvement of NO/cGMP pathway in isolated rat aortic rings

Ethnopharmacological relevance

Vitex cienkowskii Kotschy & Peyritsch is a deciduous tree, prescribed by Cameroonian traditional healers as one of the most popular plant widely used in many disorders including cardiovascular diseases. The preliminary pharmacological studies carried out on Vitex cienkowskii showed its vasorelaxant activities on guinea-pig aortic rings.

Aim of the study

The present work evaluated the vasorelaxant activity of extract and isolated compounds from Vitex cienkowskii.

Materials and methods

Rat aortic rings were used to evaluate the in vitro vascular effect of the extract. The antioxidant activity was determined by measuring the reduction of the free radical 1,1-diphenyl-1-picryl-hydrazyl (DPPH).

Results

Vitex cienkowskii induced significant relaxation in a concentration- and endothelium-dependent manner (EC₅₀ = 12.12 μg/ml, CH₂Cl₂-MeOH, 1:1) and did not produce a vasorelaxant effect on contraction evoked by KCl (60 mM). In order to determine its mode of action, Vitex cienkowskii-induced relaxant effect was evaluated in the presence of indomethacin (10 μM), L-NAME (100 μM), ODQ (1 μM) and SQ22356 (100 μM). Relaxation was significantly blocked by L-NAME and ODQ. These results indicate that Vitex cienkowskii-mediated relaxation is endothelium dependent, probably due to NO release, and the consequent activation of vascular smooth muscle soluble guanylate cyclase (sGC), a signal transduction enzyme that forms the second messenger cGMP. Bio-guided study of Vitex cienkowskii allowed the isolation of the known pentacyclic triterpenoids and a ceramide. It is the first report of salvin A, maslinic acid and a ceramide from Vitex cienkowskii. The activity induced by these compounds indicated that they may be partly responsible for the vasorelaxant effect of the plant extract.A dose of 40 mg/kg of CH₂Cl₂-MeOH (1:1) extract administered intravenously induced a decrease of mean arterial pressure but did not affect the heart rate. Moreover the plant extracts were found to be highly active in the DPPH radical scavenging assay.

Conclusion

Vitex cienkowskii extract possesses antioxidant property, vasorelaxing, and hypotensive effect linked to the endothelium related factors, where nitric oxide is involved.     

Antibacterial, antioxidant and fibroblast growth stimulation activity of crude extracts of Bridelia ferruginea leaf, a wound-healing plant of Nigeria

Aim of the study

Determination of pharmacological activity relevant to wound healing of Bridelia ferruginea leaf, a traditional medicine used to treat wounds in rural Nigeria.

Materials and methods

Aqueous and ethanolic leaf extracts were tested against bacterial species of relevance to wound infections: Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ethanolic extracts were assessed for their ability to stimulate the growth of human dermal fibroblasts (FS5) and protect against damage induced by hydrogen peroxide. Antioxidant activity was also assessed using the DPPH assay.

Results

Both aqueous and ethanolic extracts had weak antibacterial activity (MIC > 470 μg/ml). A significant effect (p < 0.001) on the growth of FS5 fibroblasts was observed only at a concentration of 5 μg/ml (28% increase), above which the extracts appeared toxic to the cells. The ethanolic extract offered the highest protection against H₂O₂ damage to FS5 cells, comparable with catalase (82% at 250 μg/ml). The DPPH assay revealed antioxidant activity of the ethanolic leaf extract with IC₅₀ 12.5 ± 0.3 μg/ml comparable to l-ascorbic acid (7.3 ± 0.1 μg/ml).

Conclusion

The antibacterial, modest fibroblast stimulation activity and relatively strong antioxidant activity lend some support to the topical use of Bridelia ferruginea leaf for wound-healing in the traditional medicine of South-western Nigeria.     

Anti-inflammatory, antioxidant, anti-tyrosinase and phenolic contents of four Podocarpus species used in traditional medicine in South Africa

Ethnopharmacological relevance

Species of Podocarpus are used traditionally in their native areas for the treatment of fevers, asthma, coughs, cholera, chest complaints, arthritis, rheumatism, venereal diseases and distemper in dogs.

Aims of the study

To investigate the antioxidant, anti-inflammatory and anti-tyrosinase activities of four Podocarpus species, Podocarpus elongatus, Podocarpus falcatus, Podocarpus henkelii and Podocarpus latifolius, used in traditional medicine in South Africa. Phytochemical analysis to determine the phenolic contents was also carried out.

Materials and methods

DPPH, FRAP and β-carotene-linoleic acid assays were used to determine the antioxidant/radical scavenging activities of these species. Anti-inflammatory activity of these species was assayed against two cyclooxygenase enzymes (COX-1 and COX-2). Tyrosinase inhibition activity was analysed using the modified dopachrome method with l-DOPA as the substrate. Phenolics were quantitatively determined using spectrophotometric methods.

Results

Stems of Podocarpus latifolius exhibited the lowest EC₅₀ (0.84 μg/ml) inhibition against DPPH. The percentage antioxidant activity based on the bleaching rate of β-carotene ranged from 96% to 99%. High ferric reducing power was observed in all the extracts. For COX-1, the lowest EC₅₀ value was exhibited by stem extracts of Podocarpus elongatus (5.02 μg/ml) and leaf extract of Podocarpus latifolius showed the lowest EC₅₀ against COX-2 (5.13 μg/ml). All extracts inhibited tyrosinase activity in a dose-dependent manner with stem extract of Podocarpus elongatus being the most potent with an EC₅₀ value of 0.14 mg/ml. The total phenolic content ranged from 2.38 to 6.94 mg of GAE/g dry sample.

Conclusion

The significant pharmacological activities observed support the use of these species in traditional medicine and may also be candidates in the search for modern pharmaceuticals in medicine, food and cosmetic industries.     

In vitro studies of Gynura divaricata (L.) DC extracts as inhibitors of key enzymes relevant for type 2 diabetes and hypertension

Aim of the study

To evaluate traditionally used herb, Gynura divaricata (L.) DC (Bai Bei San Qi) as in vitro inhibitors of key enzymes involved in the pathogenesis of hyperglycemia and hypertension. We also determined the distribution of enzyme inhibitory activities in different aqueous and non-aqueous extracts.

Materials and methods

The water extract (extract 1) from the aerial parts of Gynura divaricata (L.) was prepared first and then partitioned sequentially with n-butanol, ethyl acetate, and macroporous adsorptive resin (HPD-40) to yield extracts 2-4; the remaining water phase was named extract 5. Angiotensin-1 converting enzyme (ACE), α-amylase α-glycosidase inhibitory activities of the extracts were determined in vitro and chemical composition including total sugar, protein, flavonoid and total alkaloids in the extract were also evaluated.

Results

The water extract of this herb significantly inhibited (p < 0.05) ACE activity (IC₅₀ = 0.37 mg/ml) and showed a moderate potential hypoglycemic effect via in vitro α-amylase (IC₅₀ = 1.36 mg/ml) and α-glycosidase (IC₅₀ = 2.17 mg/ml) inhibition in dose-dependent manner. Further partitioning of the water extract (extracts 2-4) resulted in higher α-amylase inhibitory activities in extract 2 and 3. For α-glycosidase inhibition, extract 3 gave the highest inhibition. ACE inhibitory activities of the extracts were not improved by partitioning. Sugar, protein, flavonoid and alkaloid were found in water extract but only a small portion was partitioned in the n-butanol extract. However, a large portion of the flavonoids and alkaloids were found in ethyl acetate extract.

Conclusion

The results confirmed potential empirical use of Gynura divaricata (L.) DC for the management of hyperglycemia as well as hypertension. The active compounds for inhibition of α-amylase and α-glycosidase inhibition were flavonoids and alkaloids while ACE inhibition probably resulted from synergic effects of all the herb compounds.     

Evaluation of antiasthmatic activity of Clitoria ternatea L. roots

Aim of study

Clitoria ternatea L. (Family: Fabaceae) is being used in traditional medicine for the treatment of severe bronchitis and asthma. So the aim of study was to evaluate antiasthmatic activity of ethanol extract of Clitoria ternatea roots.

Materials and methods

In the present study ethanol extract of Clitoria ternatea root (ECTR) was evaluated for preliminary phytochemical screening, acute toxicity studies and antiasthmatic activity using milk induced leucocytosis and eosinophilia in mice, egg albumin induced mast cell degranulations in rats and passive cutaneous anaphylaxis in rats at doses (100-150 mg/kg ip).

Results

The results of present investigation showed that the LD₅₀ of ECTR is more than 1300 mg/kg. ECTR significantly decreases milk induced leucocytosis and eosinophilia, protects egg albumin induced degranulations of mast cells in mice and inhibits area of blue dye leakage in passive cutaneous anaphylaxis in rats at (100-150 mg/kg, i.p.). Phytochemical studies observed the presence of steroids, saponin, flavonoids, and glycosides.

Conclusion

The present investigation concludes that the antiasthmatic activity of ECTR may be due to the presence of flavonoids or saponins.     

Safety evaluation of tea (Camellia sinensis (L.) O. Kuntze) flower extract: assessment of mutagenicity, and acute and subchronic toxicity in rats

Ethnopharmacological relevance

Tea (Camellia sinensis (L.) O. Kuntze, Theaceae) flowers possess many physiological functions and have been used in traditional medicines for deodorization, skin care, cough suppressant and expectorant in China. However, there is a little information about its possible toxicity.

Aim of the study

The present investigation was carried out to evaluate the safety of tea flower extract by mutagenicity and acute and subchronic toxicity studies.

Materials and methods

Mutagenicity of tea flower extract was evaluated by the Ames test in Salmonella typhimurium strains TA97, TA98, TA100 and TA102 at concentrations of 0.008, 0.04, 0.2, 1.0, 5.0 mg/plate. In the acute toxicity study, Sprague-Dawley rats were administered a single dose of 12.0 g/kg of body weight by gavage, and were monitored for 14 days. In the subchronic toxicity study, tea flower extract was administered by gavage at doses of 1.0, 2.0 and 4.0 g/kg body weight daily for 13 weeks to Sprague-Dawley rats.

Results

In the Ames test, there was no mutagenic effect of tea flower extract (up to 5.0 mg/plate) towards four tested strains (TA97, TA98, TA100, TA102), with or without metabolic activation (S9). In the acute toxicity study, all animals gained weight and appeared active and normal, so the LD₅₀ value must be >12.0 g/kg body weight. In the subchronic toxicity study, no dose-related effects on survival, growth, hematology, blood chemistry, organ weights, or pathologic lesions were observed.

Conclusion

These results indicate that tea flower extract does not possess mutagenic potential, and that both acute and subchronic toxicity towards animals is very low. A no-observed adverse-effect level (NOAEL) for tea flower extract is 4.0 g/kg bw/day for rats under the conditions of this study.     

Normal and delayed wound healing is improved by sesamol, an active constituent of Sesamum indicum (L.) in albino rats

Ethno-pharmacological relevance

The seeds of Sesamum indicum Linn. (Pedaliaceae) has been used traditionally for the treatment of wounds in Buldhana district of Maharashtra state. Sesamol is the main anti-oxidative constituent contained mainly in the processed sesame seed oil which has not been explored scientifically for its wound healing activity.

Aim of the study

To investigate the influence of sesamol (SM) on wound repair, both in normal and dexamethasone (DM) delayed healing processes in albino rats.

Materials and methods

Incision, excision and dead space wounds were inflicted on albino rats (180-220 g) of either sex, under ketamine anaesthesia. Group I served as control, group II received SM 50 mg/kg i.p., group III was treated with dexamethasone (DM) i.m. (0.17 mg/kg) and SM + DM was given to group IV. The tensile strength, wound contraction, hydroxyproline, lysyl oxidase and total RNA and DNA levels (in granulation tissue) were measured.

Results

The tensile strength significantly (p < 0.05) increased with SM at 471.40 ± 14.66 g when compared to control at 300.60 ± 9.16 g in normal and DM suppressed healing. No significant change was observed in duration of wound contraction and lysyl oxidase when compared to control at 2.98 ± 0.10 mg. SM treated rats showed a significant (p < 0.05) rise in hydroxyproline levels at 6.45 ± 0.45 mg when compared to control at 1.75 ± 0.20 mg.

Conclusion

These results indicate that sesamol could be a promising drug in normal as well as delayed wound healing processes.     

Phaleria macrocarpa (Scheff.) Boerl fruit aqueous extract enhances LDL receptor and PCSK9 expression in vivo and in vitro

Ethnopharmacological relevance

Phaleria macrocarpa (Scheff.) Boerl (Pm) has been shown to reduce cholesterol level in vitro and in vivo experiment.

Aim of the study

This study investigated the effects of Pm fruit on weight control and mechanistic basis of its anti-hypercholesterolemic effect in both in vivo and in vitro.

Materials and method

In the in vivo study, thirty six male Sprague Dawley were randomized to six groups. Five groups were induced into hypercholesterolemia by giving 3% cholesterol enriched-diet for 52 days while one group acted as control. The rats were then treated with Pm extract (0, 20, 30 and 40 mg/ml) or simvastatin for 84 days. The following parameters were determined: (1) body weight, (2) blood lipid profile (total cholesterol, triglyceride, HDL and LDL) and (3) hepatic LDL receptor (160 kDa and 120 kDa) and PCSK9 proteins. In the in vitro study, HepG2 cells were cultured in serum-free RPMI supplemented with 0.2% BSA with or without LDL and in the presence of Pm extract (0, 0.1, 2, 40 and 1000 μg/ml) or simvastatin (4.60 μg/ml) for 24 h. The abundance of both LDL receptor and PCSK9 proteins and mRNA were investigated.

Results

Pm extract significantly (P < 0.05) reduced body weight gain, total cholesterol, triglycerides, HDL LDL levels and upregulated hepatic LDL receptor as well as PCSK9 proteins of hypercholesterolemic rats. These results were supported by studies in HepG2 cells whereby Pm extract also significantly upregulated both LDL receptor and PCSK9 at protein and mRNA levels.

Conclusion

This study enhances the potential usage of Pm fruit for controlling the body weight of obese people and for treating hypercholesterolemia.     

Prospective randomized controlled study of a Chinese herbal medicine compound Tangzu Yuyang Ointment for chronic diabetic foot ulcers: a preliminary report

Aim of the study

The purpose of this study was to evaluate the efficacy and safety of a topical Chinese herbal medicine (CHM) compound Tangzu Yuyang Ointment (TYO) for treatment of chronic diabetic foot ulcers.

Materials and methods

This multi-center, prospective, randomized, controlled and add-on clinical trial was conducted at seven centers in the China mainland. Fifty-seven patients with chronic diabetic foot ulcers of Wagner's ulcer grade 1-3 were enrolled in this study. Patients who were randomly assigned to the control group (n = 28) received standard wound therapy (SWT), whereas those randomized to the treatment group (n = 28) received SWT plus topical TYO. Only 48 patients who finished 24 weeks of observations were entered for data analysis.

Results

The TYO and SWT groups were comparable for baseline characteristics. Ulcer improvement was 79.2% in the TYO group and 41.7% in the SWT group (P = 0.017) at 12 weeks, and 91.7% vs. 62.5% (P = 0.036) at 24 weeks. The number of ulcers that were completely healed at 4, 12 and 24 weeks was similar in both groups, as were the numbers of adverse events. Healing time was 96 ± 56 days (n = 19) in the TYO group and 75 ± 53 days (n = 14) in the SWT group (P = 0.271).

Conclusion

TYO plus SWT is more effective than SWT in the management of chronic diabetic foot ulcers and has few side-effects.     

Pharmacological actions of the South African medicinal and functional food plant Sceletium tortuosum and its principal alkaloids

Ethnopharmacological relevance

The South African plant Sceletium tortuosum has been known for centuries for a variety of traditional uses, and, more recently, as a possible source of anti-anxiety or anti-depressant effects. A standardised extract Zembrin^® was used to test for pharmacological activities that might be relevant to the ethnopharmacological uses, and three of the main alkaloids were also tested.

Materials and methods

A standardised ethanolic extract was prepared from dried plant material, along with the purified alkaloids mesembrine, mesembrenone and mesembrenol. These were tested on a panel of receptors, enzymes and other drug targets, and for cytotoxic effects on mammalian cells.

Results

The extract was a potent blocker in 5-HT transporter binding assays (IC₅₀ 4.3 μg/ml) and had powerful inhibitory effects on phosphodiesterase 4 (PDE4) (IC₅₀ 8.5 μg/ml), but not other phosphodiesterases. There were no cytotoxic effects. Mesembrine was the most active alkaloid against the 5-HT transporter (K_i 1.4 nM), while mesembrenone was active against the 5-HT transporter and PDE4 (IC₅₀'s < 1 μM).

Conclusions

The activity of the Sceletium tortuosum extract on the 5-HT transporter and PDE4 may explain the clinical effects of preparations made from this plant. The activities relate to the presence of alkaloids, particularly mesembrine and mesembrenone.     

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.     

Role for monoaminergic systems in the antidepressant-like effect of ethanol extracts from Hemerocallis citrina

Ethnopharmacological relevance

Hemerocallis citrina, a traditional herbal medicine, has been used for the improvement of emotions in Eastern-Asia countries.

Aim of the study

Herein, we explored the antidepressant-like effect and its monoaminergic mechanism of the ethanol extracts from Hemerocallis citrina (HCE).

Materials and methods

Effect of HCE (90, 180 and 360 mg/kg, p.o.) on the immobility time was assessed in the mouse forced swim test (FST) and tail suspension test (TST), and locomotor activity was evaluated in the open-field test (OFT). Additionally, the monoamine neurotransmitters serotonin (5-HT), noradrenaline (NA) and dopamine (DA) levels involved in the antidepressant-like effect of HCE were also measured in the mice brain regions of frontal cortex and hippocampus.

Results

HCE (90, 180 and 360 mg/kg, p.o.) administration significantly reduced the immobility time in both the FST and TST without accompanying changes in locomotor activity in the OFT. The pretreatment of mice with WAY 100635 (0.1 mg/kg, s.c., a 5-HT_1A receptor antagonist), cyproheptadine (3 mg/kg, i.p., a 5-HT₂ receptor antagonist), prazosin (62.5 μg/kg, i.p., an α₁-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an α₂-adrenoceptor antagonist), propranolol (5 mg/kg, i.p., a β-adrenoceptor antagonist) or sulpiride (50 mg/kg, i.p., a dopamine D₂ receptor antagonist), but not SCH23390 (0.05 mg/kg, s.c., a dopamine D₁ receptor antagonist) prevented the antidepressant-like effect of HCE (360 mg/kg, p.o.) in the TST. In addition, HCE enhanced 5-HT and NA levels in the frontal cortex and hippocampus as well as elevated DA levels in the frontal cortex.

Conclusion

The results indicate that the antidepressant-like effect of HCE is dependent on the serotonergic (5-HT_1A and 5-HT₂ receptors), noradrenergic (α₁-, α₂- and β-adrenoceptors) and dopaminergic (D₂ receptor) systems as well as the elevation of 5-HT, NA and DA levels in the mouse brain.     

Evaluation of the sub-acute toxicity of the sclerotium of Lignosus rhinocerus (Cooke), the Tiger Milk mushroom

Ethnopharmacological relevance

Lignosus rhinocerus (known locally as ‘Tiger Milk mushroom’) is the most important medicinal mushroom used by the indigenous communities of Malaysia to treat fever, cough, asthma, cancer, food poisoning and as a general tonic. The sclerotium of the mushroom is the part with medicinal value. Lignosus rhinocerus was hitherto unexploited commercially because of limited supply. Recently, the mushroom was successfully cultivated.

Materials and methods

Sprague Dawley rats (5 rats/group/sex) were fed orally with 250, 500 and 1000 mg/kg TM02, 1000 mg/kg TM03 as well as 1000 mg/kg wild type Lignosus rhinocerus sclerotial powder. Sclerotial powder was orally administered once daily and consecutively for 28 days. Body weight of each animal was measured and any gross behavioral change was observed daily. Hematological and clinical biochemical parameters as well as histopathological analysis were carried out on 29th day.

Results

The results showed that oral administration of the sclerotial powder at daily dose of up to 1000 mg/kg had no adverse effect on the growth rate, hematological and clinical biochemical parameters (including renal and liver function parameters). Histological studies showed that the treatments did not induce any pathological changes in the liver, kidney, heart, spleen and lung of the animals.

Conclusion

In conclusion, our results show that there was no treatment-related sub-acute toxicity in rats following 28-days oral administration of 250, 500 and 1000 mg/kg TM02, 1000 mg/kg TM03 as well as 1000 mg/kg wild type Lignosus rhinocerus sclerotial powder. As the highest tested dose of 1000 mg/kg was not associated with any toxicity concern, the NOAEL dose is higher than 1000 mg/kg.     

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.