Ethnopharmacology and integrative medicine - Let the history tell the future

Traditional systems of medicines need more evidence-based studies on both crude drugs and purified phytomolecules. Utilization of natural products as pharmacological tools could lead to a number of new major therapeutically active metabolites. Lead molecules are further screened for their potential in terms of quality control, safety assessments, and studies about molecular pharmacology and their related properties. Identification, and quality and safety evaluation of natural products, is a fundamental requirement of industry and other organizations dealing with natural health products (NHPs). Marker analysis, based on chemo-profiling and development of characteristic fingerprints for individual plants, could help to develop uniform standardization tools. Beside such evaluations of clinical parameters, safety profiles as well as drug-herb and herb-herb interactions are the most important parameters for assessment and promotion. With the steady growth of the NHPs, advanced analytical- and mechanism-based screening should be considered for their promotion and value addition in every way for the betterment of healthcare. Thus, there is an urgent need for the development of international co-ordination to promote and develop NHPs, including their assessment, perspectives, pharmacovigilance, and potential harmonization of regulation, quality control and clinical uses.

Lead finding for acetyl cholinesterase inhibitors from natural origin: structure activity relationship and scope

Acetylcholinesterase (AChE) inhibitors are considered as promising therapeutic agents for the treatment of several neurological disorders such as Alzheimer's disease (AD), senile dementia, ataxia and myasthenia gravis. There are only few synthetic medicines with adverse effects, available for treatment of cognitive dysfunction and memory loss associated with these diseases. A variety of plants has been reported to possess AChE inhibitory activity and so may be relevant to the treatment of neurodegenerative disorders such as AD. Hence, developing potential AChE inhibitors from botanicals is the need of the day. This review will cover some of the promising acetylcholinesterase inhibitors isolated from plants with proven in vitro and in vivo activities with concern to their structure activity relationship.

Potential of Baliospermum montanum against compound 48/80-induced systemic anaphylaxis

CONTEXT

Decoctions of Baliospermum montanum Müll. Arg. (Euphorbiaceae) leaves are reported to be useful in the treatment of asthma and other respiratory complications in the Ayurvedic system.

OBJECTIVE

To evaluate the mast cell stabilization and antihistaminic activities of the chloroform (BMLC) and ethanol (BMLE) extracts of the leaves of Baliospermum montanum.

MATERIALS AND METHODS

The stabilization potential was studied on mouse peritoneal mast cells and the antihistaminic activity was carried out by determining the mortality rate of mice treated with toxicant (compound 48/80) and the effect on elevation of histamine release upon degranulation.

RESULTS

The increased number of intact mast cells (43.640 ± 1.7% and 61.57 ± 1.79% at 200 and 400 mg/ kg, respectively) suggested that the BMLC stabilized the mast cell degranulation and showed decreased elevation of histamine.

CONCLUSION

BMLC extract was found to be most effective against degranulation and release of histamine from mast cells. Identifying the lead from this plant will be a definite target for treating allergic diseases.

Radioprotective effects of Aegle marmelos (L.) Correa (Bael): a concise review

The effective use of radiotherapy in cancer cure and palliation is compromised by the side-effects resulting from radiosensitivity of bordering normal tissues, which are invariably exposed to the cytotoxic effects of ionizing radiation during treatment. In this situation, use of radioprotective compounds that can protect normal tissues against radiation injury are of immense use. In addition to protecting normal tissue these compounds will also permit use of higher radiation doses to obtain better cancer control and possible cure. However, to date, no ideal radioprotectors are available as most synthetic compounds are toxic at their optimal concentrations and have produced little success in clinics. Radiation ill-effects are principally the result of generation of free radicals, and the antioxidant compounds that counter them are supposed to be of immense use in preventing them. In Ayurveda, the traditional Indian system of medicine, several plants have been observed to avert/ameliorate free radical-mediated ailments--an effect that has been documented--and such plants have recently been the focus of attention. Aegle marmelos (L.) Correa (Bael), commonly known as bael, has been used since antiquity for treating various ailments, some of which are now known to be the result of oxidative stress. In studies spanning nearly a decade, it has been observed that bael prevented radiation-induced ill-effects, and the results of these studies indicate that it has the potential to be an effective, nontoxic radioprotective agent. In this current review, for the first time, an attempt is made to summarize these observations and to discuss the plausible reasons responsible for bael's radioprotective effects.

Immunomodulatory potential of rhizome and seed extracts of Nelumbo nucifera Gaertn

ETHNOPHARMACOLOGICAL RELEVANCE

Nelumbo nucifera Gaertn. (Nymphaeaceae) is a well-known aquatic plant which has been used for the treatment of several disorders including skin disease, cough, inflammation, fever and many other disorders.

AIM OF THE STUDY

To explore the immunomodulatory activity of extract of rhizome (NNRE) and seed (NNSE) of the plant.

MATERIALS AND METHODS

The immunomodulatory activity of NNRE and NNSE was evaluated using various in vivo models including the total and differential leukocyte count (TLC and DLC), nitroblue-tetrazolium reduction (NBT) test, neutrophil adhesion test, phagocytic response and delayed type hypersensitivity (DTH) reaction. Sheep red blood cells (SRBC, 5 x 10(9)cells/ml) were used to immunize the animals. NNRE and NNSE at the doses of 100 and 300 mg/kg were administrated.

RESULT

The TLC and lymphocyte count increased significantly but the neutrophil count was decreased for NNRE and NNSE treated groups compared to the control. A dose-dependent potentiation of DTH reaction induced by SRBC was observed from the extracts. The percentage of neutrophil adhesion to the nylon fiber was increased in NNRE treated groups (63.22 and 62.91%) compared to the NNSE treated group (54.86 and 54.23%). A potential phagocytic response was seen on treatment of the extracts, and significant changes were observed in the formation of formazone crystals.

CONCLUSION

This finding suggests that the extract of rhizome and seed Nelumbo nucifera stimulate defense system by modulating several immunological parameters.

Evaluation of the cytotoxic effect of the monoterpene indole alkaloid echitamine in-vitro and in tumour-bearing mice

The cytotoxic effect of various concentrations of echitamine chloride was studied in HeLa, HepG2, HL60, KB and MCF-7 cell lines in-vitro and in mice bearing Ehrlich ascites carcinoma (EAC). Exposure of various cells to different concentrations of echitamine chloride resulted in a concentration-dependent cell killing, and KB cells were found to be most sensitive amongst all the cells evaluated. EAC mice treated with 1, 2, 4, 6, 8, 12 or 16 mgkg−1 echitamine chloride showed a dose-dependent elevation in the anti-tumour activity, as evident by increased number of survivors in comparison with the non-drug treated controls. The highest dose of echitamine chloride (16 mg kg−1) caused toxicity in the recipient mice, therefore 12 mg kg−1 was considered the best cytotoxic dose for its anti-tumour effect. Administration of 12 mg kg−1 echitamine chloride resulted in an increase in the median survival time (MST) up to 30.5 days, which was 11.5 days higher than the non-drug treated control (19 days). Administration of 16 mg kg−1 echitamine chloride to EAC mice resulted in a time dependent elevation in lipid peroxidation that reached a peak at 6 h post-treatment, whereas glutathione concentration declined in a time dependent manner and a maximum decline was reported at 3 h post-treatment. Our study demonstrated that echitamine chloride possessed anti-tumour activity in-vitro and in-vivo.

Mast cell stabilization and antihistaminic potentials of Curculigo orchioides rhizomes

AIM OF THE STUDY

To investigate the mast cell stabilization and antihistaminic activities of the rhizomes of Curculigo orchioides (COR). Extract of Curculigo orchioides Gaertn. (Fam. Amaryllidaceae) has been reported to possess immunostimulant, and anti-inflammatory potentials. In Indian traditional system of medicine it is also used as anti-asthmatic and anti-inflammatory.

MATERIALS AND METHODS

Estimation of histamine release is key parameter for evaluating any target for its anti-allergic potential. The stabilization potential of the alcoholic extract of COR (100-400mg/kg) against mast cell degranulation was studied on isolated mice peritoneal mast cells. The antihistaminic activity was performed by determining the mortality rate of mice upon exposure to compound 48/80 and effect on inhibition of histamine release upon degranulation.

RESULTS

The raised number of intact mast cells intimates that the COR stabilized the mast cell degranulation (60.96+/-1.96%) and percentage antihistaminic potential of the extract (63.58+/-1.8 inhibition at dose of 400mg/kg) and it virtues further work towards the isolation of phytoconstituents from this plant.

CONCLUSION

This finding provides evidence that COR inhibits mast cell-derived immediate-type allergic reactions and mast cell degranulation.

Altered intravenous pharmacokinetics of topotecan in rats with acute renal failure (ARF) induced by uranyl nitrate: Do adenosine A1antagonists (selective/non-selective) normalize the altered topotecan kinetics in ARF?

A series of exploratory investigations with multiple agents was carried out in normal rats and in rats with uranyl nitrate-induced acute renal failure to understand the disposition characteristics of intravenous topotecan (TPT) used as a model substrate. The disposition of TPT was unaltered in normal rats when treated with methotrexate, whereas treatment with probenecid increased the systemic exposure of TPT. In case of uranyl nitrate-induced acute renal failure (UN-ARF) rats, the systemic exposure of TPT was increased when compared with normal rats, whereas in UN-ARF rats treated with probenecid a further reduction in renal clearance of TPT was noted as compared with that of UN-ARF induced rats. Thus, TPT may be involved in the tubular secretory pathway when a passive glomerular filtration pathway for elimination was not possible. The disposition of TPT did not normalize in UN-ARF rats when treated with caffeine, a non-selective adenosine A1 receptor antagonist, whereas the selective adenosine A1 receptor antagonist (1,3-dipropyl-8-phenylxanthine, DPPX) normalized TPT pharmacokinetic disposition by improving renal function. Renal excretion studies demonstrated that CLR improved by almost fivefold following DPPX treatment in ARF rats. In addition, the qualitative stability/metabolism pattern of TPT in liver microsomes prepared from various groups of rats (normal rats, UN-ARF rats, rats treated with DPPX, and UN-ARF rats treated with DPPX) was found to be similar. In summary, using a pharmacokinetic tool as a surrogate, it has been shown that the pharmacokinetic disposition of TPT improved considerably upon treatment with DPPX, a selective adenosine A1 antagonist.

Evaluation of the radioprotective effect of bael leaf (Aegle marmelos) extract in mice

PURPOSE

To investigate the radioprotective activity of a leaf extract of bael leaf (Aegle marmelos) (AME) in mice exposed to different doses of gamma-radiation.

MATERIALS AND METHODS

The acute toxicity of AME was evaluated in Swiss albino male mice administered various intraperitoneal single doses of AME. For radioprotection studies, mice were administered different doses, 0, 5, 10, 15, 20 or 40 mg kg(-1), of AME or sterile physiological saline intraperitoneally once daily consecutively for 5 days before exposure to 10 Gy 60Co gamma-radiation or five doses of 15 mg kg(-1) AME before exposure to 6, 7, 8, 9, 10 or 11 Gy. The animals were monitored for symptoms of radiation sickness and mortality up to 30 days post-irradiation. Glutathione and lipid peroxidation were estimated in the surviving animals of both groups on day 31 post-irradiation.

RESULTS

AME was non-toxic up to a single dose of 1750 mg kg(-1). The optimum radioprotective dose was five consecutive doses of 15 mg kg(-1) AME, where the highest survival to 10 Gy radiation was observed. The irradiation caused a dose-dependent decline in survival, while treatment of mice with AME enhanced survival. The dose reduction factor was 1.15. Irradiation caused a dose-dependent decline in the level of glutathione accompanied by an elevation in lipid peroxidation. AME pretreatment arrested glutathione decline and lipid peroxidation significantly.

CONCLUSION

AME treatment reduced the symptoms of radiation-induced sickness and increased survival. The radioprotective action might be due to free-radical scavenging and arrest of lipid peroxidation accompanied by an elevation in glutathione.

Bioavailability Enhancement of Poorly Water Soluble and Weakly Acidic New Chemical Entity with 2-Hydroxy Propyl-β-Cyclodextrin: Selection of Meglumine, a Polyhydroxy Base, as a Novel Ternary Component

The purpose of the present study was to investigate the influence of a polyhydroxy base, N-acetyl glucamine (also know as Meglumine), as a ternary component on the complexation of DRF-4367, a poorly water-soluble and weakly acidic anti-inflammatory molecule, with 2-hydroxypropyl-beta-cyclodextrin (HPbetaCD). The molecular inclusion of DRF-4367 with HPbetaCD alone and in combination with ternary component was aimed at improvement in solubility and, subsequently, dissolution rate-limited oral bioavailability. The solid complexes of DRF-4367 and HPbetaCD with or without meglumine (binary and ternary systems, respectively) were prepared as coevaporated product in different stoichiometric ratios and compared against physical mixture. The formation of inclusion complexes was confirmed by using classical instrumental techniques. Phase solubility studies suggested that meglumine was responsible for solubility improvement via multiple factors rather than just providing a favorable pH. Mechanisms and factors governing solubility enhancement were investigated by using phase solubility and thermodynamic parameters. The complexation of DRF-4367 with HPbetaCD is thermodynamically favored because the Gibbs free energies of transfer of the drug to the cyclodextrin cavity are negative. The solubilization efficiency and stability were further improved while retaining the favorable Gibbs free energies of transfer with the addition of meglumine. Inclusion ternary complex of DRF-4367 with HPbetaCD and meglumine showed significant improvement in dissolution compared with uncomplexed drug and binary system. Moreover, the phenomena of reprecipitation observed with binary system during dissolution could be avoided with meglumine as an enabling ternary component. This improved physicochemical behavior of ternary complex with the novel inclusion of a polyhydroxy base translated into an enhanced oral bioavailability of DRF-4367 compared with either uncomplexed drug or nanosuspension.

Modulation of doxorubicin-induced genotoxicity by Aegle marmelos in mouse bone marrow: a micronucleus study

The effect of various concentrations of Aegle marmelos (AME) on the doxorubicin (DOX)-induced genotoxic effects in mice bone marrow was studied. Treatment of mice with different concentrations of DOX resulted in a dose-dependent elevation in the frequency of micronucleated polychromatic (MPCE) as well as normochromatic (MNCE) erythrocytes in mouse bone marrow. The frequencies of MPCE and MNCE increased with scoring time, and the greatest elevation for MPCE was observed at 48 hours post-DOX treatment, whereas a maximum increase in MNCE was observed at 72 hours post-DOX treatment. This increase in MPCE and MNCE was accompanied by a decline in the polychromatic erythrocytes-normochromatic erythrocytes (PCE/NCE) ratio, which showed a DOX-dose-dependent decline. Treatment of mice with 200, 250, 300, 350, and 400 mg/kg body weight of AME, orally once daily for 5 consecutive days before DOX treatment, significantly reduced the frequency of DOX-induced micronuclei accompanied by a significant elevation in the PCE/NCE ratio at all scoring times. The greatest protection against DOX-induced genotoxicity was observed at 350 mg/kg AME. The protection against DOX-induced genotoxicity by AME may be due to inhibition of free radicals and increased antioxidant status.