Effect of Bacopasides on acquisition and expression of morphine tolerance

Bacopa monnieri attenuates glutamate-induced nociception and brain mitochondrial toxicity in Zebrafish

Bacopa monnieri L. (BM; Family: Scrophulariaceae), commonly known as Brahmi, is traditionally used as a nootropic agent. BM also exhibits significant analgesic activity in experimental models of pain. However, the effect of Bacopa monnieri against glutamate-induced nociception in zebrafish is yet to be explored in experimental condition. Therefore, the present study was designed to evaluate the effect of BM against glutamate-induced nociception and brain mitochondrial toxicity in adult zebrafish (Danio rerio). BM at 0.625, 1.25 and 2.5 mg/ml was administered to adult zebrafish and after half an hour glutamate was injected through i.m. route of administration. Indomethacin was used as standard drug. After behavioral analysis, the fish were euthanized and the brain was isolated and stored for further biochemical analysis. BM (1.25 and 2.5 mg/ml) and indomethacin significantly attenuated the glutamate-induced increase in number of line crossing compared to control group animals. Additionally, BM (1.25 and 2.5 mg/ml) and indomethacin significantly reduced the glutamate induced increase in cytosolic calcium level. Further, there was a substantial improvement in mitochondrial function, integrity and bioenergetics in term of respiratory control rate and ADP/O in zebrafish brain. Moreover, BM (1.25 and 2.5 mg/ml) and indomethacin significantly reduced the glutamate-induced mitochondria-dependent apoptosis in zebrafish brain. Therefore, BM could be a potential alternative drug candidate in the management of pain.

Antinociceptive activity of standardized extract of Bacopa monnieri in different pain models of zebrafish

ETHNOPHARMACOLOGICAL RELEVANCE

Bacopa monnieri L. (Scrophulariaceae) is commonly known as Brahmi and traditionally used as a neuroprotective herbal medicine. Recently, Bacopa monnieri exhibited significant therapeutic activity against animal model of neuropathic pain. However, the therapeutic potential of methanolic extract of Bacopa monnieri in experimental animal model is yet to establish.

AIM OF THE STUDY

The present study was designed to evaluate the anti-nociceptive potential of standardized methanolic extract of Bacopa monnieri in experimental adult zebrafish (Danio rerio) model of pain.

MATERIALS AND METHODS

The methanolic extract of Bacopa monnieri (BME) was standardized to bacoside-A using chromatographic method. Subsequently, BME (0.75, 1.25 and 5.0 mg/ml) was evaluated for anti-nociceptive activity using adult zebrafish model.

RESULTS

Standardized BME showed antioxidant effect through radical quenching activity in in vitro study. BME at 1.25 mg/ml significantly decreased the nociceptive effect induced by different noxious agents like acetic acid where as BME at 2.5 mg/ml exhibited significant antinociceptive activity against glutamate, formalin, capsaicin, cinnamaldehyde when compared to control and sham group animals.

CONCLUSION

BME exerted antinociceptive activity in adult zebrafish. It could be presumed that BME may involve glutamatergic receptor, ASIC and TRP channel activity in its anti-nociceptive effect. BME could be considered as a potential therapeutic option in the management of pain.

Plants with Anti-Addictive Potential

Drug addiction is prevalent among individuals of modern society, being a major cause of disability and premature loss of life. Although the drug addiction have profound social, economical and health impact in the world population, its management remains a challenge as available pharmacological treatments remains ineffective for most people. The limited efficacy and adverse effects have led to a search for alternative therapies to treat drug addiction. In this context, natural products are an important source for new chemical substances with a potential therapeutic applicability. Therefore, this chapter will present data obtained after an extensive literature search regarding the use of medicinal plants as a pharmacological alternative for drug addiction treatment.

In Vitro Propagation, Phytochemical and Neuropharmacological Profiles of Bacopa monnieri (L.) Wettst.: A Review

Bacopa monnieri has been used as a reputed drug in the Indian traditional ayurvedic system for centuries. This medicinal herb with important phytopharmaceuticals has been popularly known as “Brahmi”. In recent years, B. monnieri has been extensively studied for its bioactive constituents, constituents responsible for memory enhancing effect, and also its diverse other useful effects. It possesses many pharmacological activities such as antioxidant, gastrointestinal, endocrine, antimicrobial, anti-inflammatory etc. The plant has been also used for the treatment of neurological and neuropsychiatric diseases. Due to its multipurpose therapeutic potential, micropropagation using axillary meristems and de novo organogenesis has been extensively studied in the species and is being reviewed. High frequency direct shoot organogenesis can be induced in excised leaf and internode explants in the absence of exogenous phytohormones and the rate of induction is enhanced in the presence of exogenous cytokinins, supplements, growth regulators, etc. Using explants from tissue culture raised plants, direct shoot regeneration leading to production of more than 100 rooted plants/explant within 8–12 weeks period with 85%–100% survival in the field after acclimatization can be expected following optimized protocols. Bioreactor based micropropagation was found to increase the multiplication rate of shoot cultures for the commercial propagation of B. monnieri plants. The maximum content of bacosides has been recorded in shoot biomass using an airlift bioreactor system. Further studies for the biosynthesis of bacosides and other secondary metabolites need to be conducted in the species utilizing untransformed shoot cultures in bioreactors.

A bacosides containing Bacopa monnieri extract alleviates allodynia and hyperalgesia in the chronic constriction injury model of neuropathic pain in rats

BACKGROUND

The current therapy of neuropathic pain is inadequate and is limited by the extent of pain relief and the occurrence of dose dependant side effects. Insufficient control of pain with conventional medications prompts the use of complementary and alternative medicine therapies by patients with neuropathic pain. This study therefore investigated a standardized methanolic extract of Bacopa monnieri, a widely reputed nootropic plant, for prospective antinociceptive effect in the chronic constriction injury (CCI) model of neuropathic pain.

METHODS

Placement of four loose ligatures around the sciatic nerve produced partial denervation of the hindpaw in rats. Bacopa monnieri (40 and 80 mg/kg, p.o) and the positive control, gabapentin (75 mg/kg, i.p), were administered daily after CCI or sham surgery and the behavioral paradigms of static- and dynamic-allodynia (paw withdrawal threshold to von Frey filament stimulation [PWT] and paw withdrawal latency to light-brushing [PWL]), cold-allodynia (paw withdrawal duration [PWD] to acetone), heat- (PWL to heat-stimulus) and punctate-hyperalgesia (PWD to pin-prick) were assessed on days 3, 7, 14 and 21.

RESULTS

CCI consistently generated static- (days 3-21), dynamic- (days 14-21) and cold-allodynia (days 3-21) plus heat- and mechano-hyperalgesia (days 3-21). The tested doses of Bacopa monnieri significantly attenuated the CCI-induced allodynia and hyperalgesia, exemplified by increased PWT (days 7-21), PWL to light brushing (days 14-21) and heat (days 7-21) as well as decreased PWD to pin prick and cold stimuli (days 3-21). The extract also counterbalanced the CCI-induced aberrations in the nociceptive behaviors by increasing the pain threshold to that of pre-surgery baseline. Gabapentin also afforded analogous beneficial behavioral profile but of higher magnitude.

CONCLUSIONS

Our findings suggest that Bacopa monnieri can be used as adjuvant therapy for neuropathic pain conditions afflicted with allodynia and hyperalgesia.

Beneficial effects of Bacopa monnieri extract on opioid induced toxicity

The present study examined the hepatotoxicity and nephrotoxicity of morphine and illicit street heroin and their amelioration by a standardized methanolic extract of Bacopa monnieri (L.) (mBME) in rats. Morphine or street heroin was administered at a dose of 20 mg/kg for 14 and 21 days. mBME (40 mg/kg) or ascorbic acid (50 mg/kg) was administered two hours before morphine or street heroin. High performance liquid chromatography (HPLC) was used for the standardization of bacoside-A major components in mBME. The antioxidant potential of mBME was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Administration of morphine and street heroin resulted in marked elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatinine. Histopathological changes induced by morphine and street heroin after 14 days were of reversible nature while treatment for 21 days was associated with irreversible changes. Pretreatment with mBME or ascorbic acid restored the elevation of serum ALT, AST and creatinine and protected liver and kidneys from the toxicological influence of morphine and street heroin. HPLC analysis showed that mBME contained bacoside-A major components i.e. bacoside-A₃ (37.5 μg/mg), bacopaside-II (4.62 μg/mg) and bacopasaponin-C (1.91 μg/mg). The EC₅₀ for the DPPH free radical scavenging assay revealed that mBME possessed strong antioxidant potential. These results concluded that as compared to morphine, street heroin was associated with severe biochemical and histopathological changes in the liver and kidneys. Bacopa monnieri having strong antioxidant potential may provide a beneficial herbal remedy for the efficient management of opioid related hepatotoxicity and nephrotoxicity.

Inhibitory effect of bacopasides on spontaneous morphine withdrawal induced depression in mice

Bacopa monnieri is a perennial herb with a world known image as a nootropic. We investigated the effect of Bacopa monnieri methanolic extract (Mt Ext BM) 10, 20, and 30 mg/kg body weight (b.w) on acquisition and expression of morphine withdrawal induced depression in mice. Locally available Bacopa monnieri (BM) was screened for contents of Bacoside A3, Bacopasaponin C, and Bacopaside II using HPLC with UV. Morphine dependence was induced in mice using twice daily escalating chronic morphine treatments (20-65 mg/kg b.w) for eight consecutive days. Morphine withdrawal induced depression was assayed in animals using forced swimming test (FST), three days after last morphine injection. The HPLC analysis revealed that Mt-ext BM contained Bacoside A3 as major component, i.e. 4 µg in each mg of extract. The chronic treatment with Met Ext BM 10, 20, and 30 mg/kg b.w. dosing significantly inhibited opioid withdrawal induced depression in mice. These findings imply a newer potential role of Bacopa monnieri in the clinical management of opioid withdrawal induced depression which can be attributed to Bacoside A3.

Endogenous opiates and behavior: 2011

This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).

Effect of c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (p38 MAPK) in morphine-induced tau protein hyperphosphorylation

Opioids have been widely used in clinical practice as potent pain relievers for centuries. However, opioids have many deleterious effects. It has been reported that opioid increases tau protein phosphorylation. Hyperphosphorylation of tau is also a pathological feature of Alzheimer's disease and other chronic neurodegenerative disorders. However, the underlying mechanism by which opioids enhance tau phosphorylation is not yet known. In this study, we treated rat embryo cortical neurons with morphine and observed its effect on tau phosphorylation. We found that morphine induced tau hyperphosphorylation and increased levels of phospho-JNK and phospho-p38; these effects were blocked by pretreatment with naloxone. Inhibition of JNK by SP600125 significantly reduced tau hyperphosphorylation in neurons treated with morphine. Similarly, SB203580, an antagonist of p38 MAPK, abolished tau hyperphosphorylation in neurons treated with morphine. Our data suggest that JNK/p38 MAPK, activated by morphine in an opioid receptor-dependent manner, may lead to tau hyperphosphorylation.

A Bacoside containing Bacopa monnieri extract reduces both morphine hyperactivity plus the elevated striatal dopamine and serotonin turnover

Bacopa monnieri (BM) has been used in Ayurvedic medicine as a nootropic, anxiolytic, antiepileptic and antidepressant. An n-butanol extract of the plant (nBt-ext BM) was analysed and found to contain Bacoside A (Bacoside A3, Bacopaside II and Bacopasaponin C). The effects of the BM extract were then studied on morphine-induced hyperactivity as well as dopamine and serotonin turnover in the striatum since these parameters have a role in opioid sensitivity and dependence. Mice were pretreated with saline or nBt-ext BM (5, 10 and 15 mg/kg, orally), 60 min before morphine administration and locomotor activity was subsequently recorded. Immediately after testing, striatal tissues were analysed for dopamine (DA), serotonin (5HT) and their metabolites using HPLC coupled with electrochemical detection. The results indicated that nBt-ext BM significantly (p < 0.001) decreased locomotor activity in both the saline and morphine treated groups. Additionally, nBt-ext BM significantly lowered morphine-induced dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-H1AA) upsurges in the striatum but failed to affect DA, 5-HT and their metabolites in the saline treated group. These findings suggest that nBt-ext BM has an antidopaminergic/serotonergic effect and may have potential beneficial effects in the treatment of morphine dependence.