Transport phenomena of Cu-S-Te chalcogenide nanocomposites: frequency response and AC conductivity.

In this work, the development and electrical characterization of several chalcogenide nanocomposites have been reported. X-ray diffraction (XRD) has been used to reveal their microstructures. Mott's variable range hopping model has been used to interpret the DC conductivity data of the nanocomposites at lower temperatures. The DC conductivity data at higher temperatures has been explained well using Greave's model. To explain the AC conductivity data, the Meyer-Neldel (MN) conduction rule has been employed. The AC conductivity spectra at different temperatures have been analyzed using Almond-West formalism. Different conduction models, namely, correlated barrier hopping (CBH) and modified non-overlapping small polaron tunneling (NSPT), have been used to interpret the conduction mechanism of the nanocomposites. Scaling of the AC conductivity spectra reveals that the electrical relaxation process is independent of temperature, but depends on the nanocomposite composition. The conductivity mechanism is explained using a schematic structural model.

Medicinal plants and natural products in amelioration of arsenic toxicity: a short review.

CONTEXT: Chronic arsenic toxicity (arsenicosis) is considered a serious public health menace worldwide, as there is no specific, safe, and efficacious therapeutic management of arsenicosis. OBJECTIVES: To collate the studies on medicinal plants and natural products with arsenic toxicity ameliorative effect, active pre-clinically and/or clinically. METHODS: Literature survey was carried out by using Google, Scholar Google and Pub-Med. Only the scientific journal articles found on the internet for last two decades were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded. RESULTS: Literature study revealed that 34 medicinal plants and 14 natural products exhibited significant protection from arsenic toxicity, mostly in preclinical trials and a few in clinical studies. CONCLUSION: This research could lead to development of a potentially useful agent in clinical management of arsenicosis in humans.

A Review on Protease Inhibitors of Herbal Origin to Combat Malignancy.

Protease is the enzyme accountable for the breakdown of proteins i.e., proteolysis. Proteases are reportedly involved in the events of growth, development, progression and metastasis of cancers. If any agent could inhibit/retard the protease enzyme, i.e., protease inhibitor, it would arrest the cancer; thus indicating the significance of exploring protease inhibitors for latest anti-malignant drug discovery. Higher plants are the rich sources of different protease inhibitors that are effective against several types of malignancies both at preclinical and clinical stages. Natural protease inhibitors of herbal origin have both cancer chemopreventive and chemotherapeutic properties together with inhibitory activity against different types of pertinent proteases. Clinically, these herbal agents are found to be safe unlike the synthetic antineoplastic agents. Further studies in this direction are necessary in pursuit of newer generation drugs without adverse reactions for the prevention and treatment of malignancies.

Antitumor activity and antioxidant role of Streblus asper bark against Ehrlich ascites carcinoma in Swiss albino mice.

The present study assessed the methanol extract of Streblus asper stem bark (MESA) for antitumor effect and antioxidant influence against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. Twenty four hours after intraperitonial inoculation of tumor (EAC) cells in mice, MESA was administered at 200 and 400 mg/kg body weight daily for 9 consecutive days. On the 10 th day, half of the mice were sacrificed for estimation of tumor parameters, haematological, liver and kidney antioxidant parameters; and the rest were kept alive for assessment of survival. MESA exhibited dose dependent and significant (p < 0.01) decrease in tumor proliferation and extended the life span of EAC bearing mice. Hematological profiles were significantly (p < 0.01) restored near to normal in MESA treated mice as compared to EAC control. MESA treatment significantly (p < 0.01) modulated the hepatic and renal antioxidant parameters as compared to EAC control. The present study demonstrated that S. asper bark possessed promising antitumor efficacy in mice, plausibly mediated by amelioration of oxidative stress by multiple mechanisms.

The triterpenoid fraction from Trichosanthes dioica root suppresses experimentally induced inflammatory ascites in rats.

CONTEXT: Trichosanthes dioica Roxb. (Cucurbitaceae), called pointed gourd in English, is a dioecious climber found wild throughout the plains of the Indian subcontinent and traditionally used in India for several medicinal purposes. OBJECTIVE: The present study evaluated the protective effect of the triterpenoid enriched fraction from T. dioica root (CETD) against experimentally induced acute inflammatory ascites in Wistar albino rats. MATERIALS AND METHODS: The CETD was administered orally at the different doses (25, 50 and 100 mg/kg body weight) to overnight fasted rats, and then ascites was induced by intraperitoneal administration of formalin solution. After 7 h, the rats were sacrificed and the volume of ascitic fluid was measured. RESULTS: The CETD demonstrated significant (p < 0.01) reduction of ascitic fluid formation in a dose-dependent manner as compared with control. CONCLUSION: The CETD produced significant and dose-dependent inhibition of experimentally induced inflammatory ascites in Wistar albino rats.

Honey Can Obviate Heavy Metal Toxicity: A Review.

Toxicity caused by heavy metals inflicts a grave global menace to the habitat and inhabitants. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) are the non-essential yet harmful heavy metals commonly associated with pollution and resultant health complications. Typical chelating/complexing agents are not worthy of combating heavy metal-induced sub-chronic and chronic toxicities. It transpires from scientific data mining that, honey obviates investigational heavy metal toxicity. This review aims to collate such investigations conducted against As, Cd, and Pb toxicity. There is a total of 19 pre-clinical works demonstrating the ameliorative effect of honey against empirical As, Cd, and Pb toxicity. Pre-clinical reports against Hg and clinical study against these heavy metals could not found. From the outcome of the current literature investigation, it seems that honey has a marked heavy metal toxicity meliorative effect which is chiefly ascribed to its innate antioxidant effect due to its diverse polyphenol content.

A Review on Experimentally Proven Medicinal Plants and Their Constituents against Fluoride Toxicity.

Fluoride toxicity, principally by polluted groundwater, is regarded as a momentous global public health risk, as there is no particular and proven treatment for chronic fluoride toxicity i.e., fluorosis which leads to several serious health complications. Scientific literature reveals several medicinal plants and natural products alleviate experimentally induced fluoride toxicity. The present review attempts to collate those experimental studies on medicinal plants and plant derived natural products with fluoride toxicity ameliorative effects. Literature scrutiny was performed by using online bibliographic databases and the studies for the last 15 years were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded. Literature study revealed that 25 medicinal plants and 17 natural products exhibited significant protection from fluoride toxicity in experimental animal models i.e., preclinical studies. Two clinical studies on medicinal plants were also found in literature showing beneficial yet poorly correlated outcome. Relevant research in this field could lead to development of a potentially useful agent in therapeutic management of fluoride toxicity in humans.

An Insight into the Salutary Prospect of the Probiotic Microorganisms for the Remediation of Mercury Toxicity.

Heavy metal toxicity imposes a potential worldwide threat to environment and humans. Mercury toxicity is regarded as a serious global community health risk, as there is no particular and proven treatment for chronic mercury toxicity. Probiotics include the live apathogenic microorganisms, which are administered orally to revamp the gut microbial equilibrium thus bestowing benefit to the host. Scientific literature demonstrates different probiotic microorganisms can obviate mercurey toxicity. The present article puts together the experiments on probiotics with mercury toxicity alleviation effects in pursuit of the mechanistic hypotheses. Literature scrutiny was performed by using online bibliographic databases. Literature survey revealed that, eight types of probiotic microorganisms demonstrated significant protection from mercury toxicity in experimental pre-clinical studies. Clinical investigation with noteworthy outcome was not reported yet. Results of these studies indicate that probiotic microorganisms may hold the promise in amelioration and therapeutics of mercury toxicity. Probiotic supplementation may serve as a dietary therapeutic approach against mercurials along with extant therapies.

The triterpenoid fraction from Trichosanthes dioica root exhibits antiproliferative activity against Ehrlich ascites carcinoma in albino mice: involvement of possible antioxidant role.

The present study assessed the triterpenoid fraction from T dioica root (CETD) for antiproliferative effect and antioxidant influence against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. Twenty-four hours after intraperitoneal inoculation of tumor (EAC) cells in mice, CETD was administered at 2 and 4 mg/ kg body weight daily for 9 consecutive days. On the 10th day, half of the mice were sacrificed for estimation of tumor proliferation, haematological, and hepatic antioxidative parameters viz. lipid peroxidation, reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase(SOD)and catalase (CAT); the rest were kept alive for assessment of survival parameters. The antiproliferative effect of CETD was assessed by evaluating tumor weight, tumor volume, packed cell volume, viable and non-viable tumor cell counts, mean survival time and percentage increase in life span of EAC-bearing mice. CETD exhibited dose dependent and significant (p < 0.001) decreases in tumor weight, tumor volume, packed cell volume and viable cell count and extended the life span of EAC-bearing mice. Hematological profiles were significantly (p < 0.001) normalized in CETD treated mice as compared to EAC control. CETD treatment significantly (p < 0.001) modulated the aforementioned hepatic antioxidative parameters as compared to EAC control. The present study demonstrated that CETD possessed promising antiproliferative efficacy against EAC in mice, plausibly mediated by alleviation of oxidative stress by multiple mechanisms.

Essential Trace Metals as Countermeasure for Lead Toxicity.

Lead (Pb) is the most common toxic heavy metal that is physiologically non-essential and imposes health complications in animals and humans. Chelation therapy is considered as the definite therapy for acute lead toxicity; clinical uses of chelating agents are not recommended in long-term lead toxicity and in children. Research reveals that essential trace metals can counteract empirical Pb toxicity. This article collates the prototypical evidence of the preventive action of essential trace metals towards Pb toxicity in animals. Zinc, selenium, and their combinations are effective here. The key mechanisms of homeostasis of essential metals and cytoprotection are: modulation of signal transduction pathways of apoptosis, inflammation and immune functions (for selenium), attenuation of oxidative stress by augmenting non-enzymatic and enzymatic antioxidative systems and interference in lead accumulation in the body. By means of these mechanisms, these essential trace metals may counteract long-term lead toxicity for susceptible subjects. These mineral nutritional supplementation can easily be employed with no or less adverse effects compared to the typical chelation treatment.

Protective Role of the Essential Trace Elements in the Obviation of Cadmium Toxicity: Glimpses of Mechanisms.

Cadmium (Cd) is toxic non-essential heavy metal that precipitates adverse health effects in humans and animals. Chelation therapy, the typical treatment for cadmium toxicity, has certain safety and efficacy issues to treat long term cadmium toxicity, in particular. Recent studies have shown that essential trace elements can play important roles in obviating experimental Cd toxicity. This study organizes and reviews the prototypical evidences of the protective effects of essential trace elements against Cd toxicity in animals and attempts to point out the underlying mechanisms. Zinc, selenium, iron, and combinations thereof are reported to be active. The major mechanisms elucidated inter alia are-induction of metallothionein (MT) synthesis and Cd-MT binding (for zinc), modulation of oxidative stress and apoptosis, interference in cadmium absorption and accumulation from body-thereby maintenance of essential metal homeostasis and cytoprotection. Based on the findings, essential trace elements can be recommended for the susceptible population. The application of these trace elements appears beneficial for both the prevention and remediation of long-term Cd toxicity operative via multiple mechanisms with no or minimal adverse effects as compared to the conventional chelation therapy.

Antidiabetic and antihyperlipidemic effects of Premna spinosa bark in experimental animal models.

The purpose of the study is to evaluate the antidiabetic and hyperlipidemic potential of stem bark extract of Premna spinosa (Lamiaceae), by using streptozotocin (STZ)-nicotinamide (NA)-induced diabetic and triton-induced hyperlipidemic models in albino rats. The blood glucose, total cholesterol, and triglyceride levels were determined in STZ-NA-induced diabetic and triton-induced hyperlipidemic rats, as per the respective protocols. It was found that there is the dose dependent and significant reduction in foregoing parameters on the administration of extract from Premna spinosa stem bark at the doses of 200, 400, and 800 mg/kg body weight to diabetic and hyperlipidemic rats. From these observed results it may be inferred that the stem bark of Premna spinosa possesses remarkable antidiabetic and antihyperlipidemic properties.

The biological buffer bicarbonate/CO2 potentiates H2O2-mediated inactivation of protein tyrosine phosphatases.

Hydrogen peroxide is a cell signaling agent that inactivates protein tyrosine phosphatases (PTPs) via oxidation of their catalytic cysteine residue. PTPs are inactivated rapidly during H(2)O(2)-mediated cellular signal transduction processes, but, paradoxically, hydrogen peroxide is a rather sluggish PTP inactivator in vitro. Here we present evidence that the biological buffer bicarbonate/CO(2) potentiates the ability of H(2)O(2) to inactivate PTPs. The results of biochemical experiments and high-resolution crystallographic analysis are consistent with a mechanism involving oxidation of the catalytic cysteine residue by peroxymonocarbonate generated via the reaction of H(2)O(2) with HCO(3)(-)/CO(2).

Antitumor efficacy and amelioration of oxidative stress by Trichosanthes dioica root against Ehrlich ascites carcinoma in mice.

CONTEXT: Trichosanthes dioica Roxb. (Cucurbitaceae) is a dioecious climber, traditionally used in India for several medicinal purposes. OBJECTIVE: The present study assessed the hydroalcoholic extract of T. dioica root (TDA) for antitumor effect and antioxidant influence against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. METHODS: Twenty four hours after intraperitoneal inoculation of tumor (EAC) cells in mice, TDA was administered at 5 and 10 mg/kg body weight daily for 9 consecutive days. On the 10th day, half of the mice were sacrificed for estimation of tumor proliferation, hematological, and liver antioxidant parameters viz. lipid peroxidation, reduced glutathione (GSH), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT); and the rest were kept alive for assessment of increase in life span. The antitumor effect of TDA was assessed by evaluating tumor weight, tumor volume, packed cell volume, viable and non-viable tumor cell counts, median survival time and percentage increase in life span of EAC bearing mice. RESULTS AND DISCUSSION: TDA exhibited dose dependent and significant (p < 0.001) decrease in tumor weight, tumor volume, packed cell volume and viable cell count and extended the life span of EAC bearing hosts. Hematological profiles were significantly (p < 0.001) restored near to normal in TDA treated mice as compared to EAC control. TDA treatment significantly (p < 0.001) modulated the aforesaid liver antioxidant parameters as compared to EAC control. CONCLUSION: The present study demonstrated that TDA possessed promising antitumor efficacy in mice, plausibly mediated by amelioration of oxidative stress by multiple mechanisms.

Hypoglycemic activity of Erythrina variegata leaf in streptozotocin-induced diabetic rats.

CONTEXT: Erythrina variegata Linn. (Fabaceae), commonly known as Tiger's Claw, is a thorny deciduous tree grown in tropical and subtropical regions of Eastern Africa, Southern Asia, and Northern Australia. In India, its leaves are traditionally used for diabetes mellitus. OBJECTIVE: To evaluate the hypoglycemic activity of methanol extract of E. variegata leaf (MEEV) in streptozotocin (STZ)-induced diabetic Wistar rats. MATERIALS AND METHODS: Hyperglycemia was induced in rats by single intraperitoneal injection of STZ (55 mg/kg body weight). Three days after STZ induction, the hyperglycemic rats were treated with MEEV orally at the doses of 300, 600, and 900 mg/kg body weight daily for 21 days. Glibenclamide (1 mg/kg, orally) was used as reference drug. The fasting blood glucose levels were measured on every 7th day during the 21 days of treatment. Serum biochemical parameters including lipid content were estimated. RESULTS AND DISCUSSION: MEEV at the doses of 300, 600, and 900 mg/kg orally significantly (P < 0.01) and dose-dependently reduced and normalized blood glucose levels as compared to that of STZ control group; the dose 900 mg/kg being the most potent showing complete normalization of blood glucose levels. Serum biochemical parameters including lipid profile were significantly (P < 0.01) restored toward normal levels in META-treated rats as compared to STZ control animals. CONCLUSION: This study concludes that E. variegata leaf demonstrated promising hypoglycemic action in STZ-induced diabetic rats substantiating its ethnomedicinal use.

Antihyperglycemic activity and antioxidant role of Terminalia arjuna leaf in streptozotocin-induced diabetic rats.

CONTEXT: Terminalia arjuna Roxb. (Combretaceae), commonly known as Arjuna, is a large tree grown throughout the Indian peninsula and used traditionally for several medicinal purposes. OBJECTIVE: To evaluate antihyperglycemic and antioxidant role of methanol extract of T. arjuna leaf (META) in Wistar rats. MATERIALS AND METHODS: Hyperglycemia was induced in rats by single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight). Three days after STZ induction, the hyperglycemic rats were treated with META orally at the dose of 100 and 200 mg/kg body weight daily for 15 days. Glibenclamide (0.5 mg/kg, orally) was used as reference drug. The fasting blood glucose levels were measured on every fifth day during the 15-day treatment. Serum biochemical parameters such as serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), cholesterol, and total protein were estimated. Antioxidant properties were assessed by estimating hepatic lipid peroxidation, reduced glutathione (GSH), and catalase (CAT). RESULTS AND DISCUSSION: META at the dose of 100 and 200 mg/kg orally significantly (P < 0.001) and dose-dependently reduced and normalized blood glucose levels as compared with that of STZ control group. Serum biochemical parameters were significantly (P < 0.001) restored toward normal levels in META-treated rats as compared with STZ control. META treatment also significantly (P < 0.001) decreased lipid peroxidation and recovered GSH level and CAT activity toward normal as compared with STZ control. CONCLUSION: The present study infers that T. arjuna leaf demonstrated remarkable antihyperglycemic activity in STZ-induced diabetic rats. The potential antihyperglycemic action is plausibly due to its underlying antioxidant role.

Paralytic and lethal effects of Trichosanthes dioica root extracts in experimental worms.

CONTEXT: Trichosanthes dioica Roxb. (Cucurbitaceae), called pointed gourd in English, is a dioecious climber and its roots are traditionally used in India as a hydrogouge cathartic, tonic, and febrifuge, and in the treatment of jaundice, anasarca, and ascites. OBJECTIVE: To evaluate the in vitro effects of different solvent extracts of T. dioica root in experimental worms, viz. annelids and nematodes. MATERIALS AND METHODS: The in vitro paralytic and lethal effects of defatted dichloromethane (DCTD), methanol (METD), and aqueous (AQTD) extracts of T. dioica root were evaluated against Pheretima posthuma (Annelida) and Ascaridia galli (Nematoda) by keeping the worms in different concentrations of each test extract under specific experimental conditions followed by determination of mean paralysis and lethal times. Albendazole was used as the reference drug. RESULTS AND DISCUSSION: All the extracts demonstrated concentration-dependent paralytic and lethal effects on P. posthuma and lethal effects on A. galli. The DCTD was found to be the most potent followed by the METD and AQTD. A. galli was found to be more sensitive than P. posthuma against all extracts, indicating T. dioica root as an effective nematocide. CONCLUSION: The present study establishes the in vitro wormicidal property of T. dioica root extracts against the experimental worms, showing promising nematocidal (and hence anthelmintic) potential.

Antitumor activity of Sansevieria roxburghiana rhizome against Ehrlich ascites carcinoma in mice.

CONTEXT: Sansevieria roxburghiana Schult. & Schult. f. (Agavaceae) is a herbaceous perennial plant traditionally used for coughs, rheumatism; as an expectorant, febrifuge, purgative, and tonic. OBJECTIVE: To evaluate the hydroalcoholic extract of S. roxburghiana rhizome (HASR) for antitumor activity against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. METHODS: Twenty-Four hours after intraperitoneal inoculation of tumor (EAC) cells in mice, HASR was administered at 50 and 100 mg/kg body weight for nine consecutive days. On day 10 half of the mice were sacrificed and rest were kept alive for assessment of increase in life-span. The antitumor effect of HASR was assessed by evaluating tumor volume, packed cell count, viable and non-viable tumor cell count, median survival time and increase in life-span of EAC bearing hosts. Hematological profiles and serum biochemical parameters were estimated. Further, antioxidant properties were assessed by estimating lipid peroxidation, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). RESULTS AND DISCUSSION: HASR showed a significant (p < 0.001) decrease in tumor volume, packed cell volume and viable cell count and increased the life span of EAC bearing mice. Hematological and serum biochemical profiles were restored to normal levels in HASR treated mice as compared to EAC control. HASR treatment significantly (p <0.001) decreased lipid peroxidation and recovered GSH, SOD and CAT towards normal as compared to EAC control. CONCLUSION: The present study demonstrates that S. roxburghiana rhizome exhibited remarkable antitumor activity in Swiss mice that is plausibly attributable to its augmenting endogenous antioxidant mechanisms.

The Role of Probiotics in the Amelioration of Cadmium Toxicity.

Cadmium is extremely toxic heavy metal, and there is no specific, safe, and efficacious therapeutic management of cadmium toxicity. Scientific literature reveals several probiotic microorganisms which alleviate experimentally induced cadmium toxicity in animals. The present review attempts to collate the experimental studies on probiotics and probiotic-derived natural products with cadmium toxicity ameliorative effects. Literature survey revealed that seven (7) types of probiotic microorganisms exhibited significant protection from cadmium toxicity in experimental pre-clinical studies. Clinical study with significant outcome was not found in literature. From the outcomes of the pre-clinical studies, it appears that probiotics have the prospect for alleviation and treatment of cadmium toxicity.

The Role of Spirulina (Arthrospira) in the Mitigation of Heavy-Metal Toxicity: An Appraisal.

Heavy-metal toxicity imposes a potential worldwide threat to the environment and humans. Cadmium, mercury, lead, and arsenic are nonessential toxic heavy metals that are most frequently involved in environmental and health hazards. Conventional chelating agents are unsuitable for subchronic and chronic heavy-metal toxicities. Scientific literature reveals that Spirulina (Arthrospira), a photosynthetic filamentous cyanobacterium that is generally known as blue-green algae, alleviates experimentally induced heavy-metal toxicity. The present review attempts to summarize such studies regarding cadmium, mercury, lead, and arsenic toxicity. A total of 58 preclinical studies demonstrate the alleviative effect of Spirulina against experimental arsenic, cadmium, lead, and mercury toxicities. Five clinical studies reported protective effects of Spirulina against arsenic toxicity in humans. Clinical studies against three heavy metals were not found in the literature. The present literature study appears to show that Spirulina possesses promising heavy-metal toxicity-ameliorative effects that are mainly attributed to its intrinsic antioxidant activity.