Drug/substance reversal effects of a novel tri-substituted benzoflavone moiety (BZF) isolated from Passiflora incarnata Linn.--a brief perspective

Natural products as the therapeutic strategies for addiction

World Drug Report 2023 concluded that 296 million people abused drugs, 39.5 million became addiction and 494,000 died as a direct or indirect result of addiction. Addiction has become a growing problem that affects individuals, their families, societies, countries and even the world. However, treatment for addiction is only limited to some developed countries because of the high cost, difficult implementation, and time consuming. Therefore, there is an urgent need to develop a low-cost, effective drug for the development of addiction treatment in more countries, which is essential for the stability and sustainable development of the world. In this review, it provided an overview of the abuse of common addictive drugs, related disorders, and current therapeutic regimen worldwide, and summarized the mechanisms of drug addiction as reward circuits, neuroadaptation and plasticity, cognitive decision-making, genetics, and environment. According to their chemical structure, 43 natural products and 5 herbal combinations with potential to treat addiction were classified, and their sources, pharmacological effects and clinical trials were introduced. It was also found that mitragine, ibogine, L-tetrahydropalmatine and crocin had greater potential for anti-addiction.

Natural Product-Inspired Targeted Protein Degraders: Advances and Perspectives

Targeted protein degradation (TPD), a promising therapeutic strategy in drug discovery, has great potential to regulate the endogenous degradation of undruggable targets with small molecules. As vital resources that provide diverse structural templates for drug discovery, natural products (NPs) are a rising and robust arsenal for the development of therapeutic TPD. The first proof-of-concept study of proteolysis-targeting chimeras (PROTACs) was a natural polyketide ovalicin-derived degrader; since then, NPs have shown great potential to promote TPD technology. The use of NP-inspired targeted protein degraders has been confirmed to be a promising strategy to treat many human conditions, including cancer, inflammation, and nonalcoholic fatty liver disease. Nevertheless, the development of NP-inspired degraders is challenging, and the field is currently in its infancy. In this review, we summarize the bioactivities and mechanisms of NP-inspired degraders and discuss the associated challenges and future opportunities in this field.

Evaluation of phytochemical constituents and sedative-hypnotic activity of the methanol leaf extract of Ficus exasperata in mice

Background and Aim

Sedative drugs mostly cause dose-dependent depression of the central nervous system which results in hypnosis and anesthesia possibly; however, these agents are associated with some side effects ranging respiratory, digestive, immune system dysfunctions, tolerance, cognitive function deterioration, and physical dependence; hence, investigations of newer and safer agents are, therefore, imperative. The current study was aimed at investigating the sedative-hypnotic (S-H) effects of the methanol leaf extract of Ficus exasperata in mice.

Materials and Methods

Phytochemical screening of the leaf extract was conducted, and S-H activity of the plant extract was evaluated. Twenty Swiss Albino mice were randomly divided into four groups of five mice each. The mice in Groups A and B were injected with the extract intraperitoneally (IP) at the dose rate of 100 and 200 mg/kg, respectively, those in Group C were injected with xylazine at the dose rate of 10 mg/kg, while Group D mice received distilled water at the dose rate of 2 ml/kg. All the four experimental groups were injected with ketamine (IP) at the dose rate of 100 mg/kg after 30 min.

Results

Phytochemical analysis of the extract revealed the presence of carbohydrates, cardiac glycosides, reducing sugars, steroids and triterpenes, saponins, tannins, condensed tannins, and flavonoids, while anthraquinones, anthracene derivatives, and alkaloids were absent. Results from the S-H evaluation show no significant difference (p≥0.05) on the onset of sleep time between the four experimental groups; however, statistically significant difference (p≤0.05) was recorded in the sleep duration time between the groups treated with only ketamine and the other experimental groups pre-treated with either the extract or xylazine before ketamine administration. The group pre-treated with a high dose of the plant extract (200 mg/kg) and the treated with ketamine after 30 min exhibited longer sleeping duration time. The plant extract, xylazine and ketamine, sedated the mice for some period of time after arousal from sleep.

Conclusion

Our finding suggests that methanol leaf extract of F. exasperata possesses S-H potential that may require further scientific investigations.

Standardized Passiflora incarnata L. Extract Reverts the Analgesia Induced by Alcohol Withdrawal in Rats

Passiflora incarnata L. (Passifloraceae) has been traditionally used for treatment of anxiety, insomnia, drug addiction, mild infections, and pain. The aim of this study was to investigate the effect of a commercial extract of P. incarnata in the analgesia induced by alcohol withdrawal syndrome in rats. In addition, brain-derived neurotrophic factor and interleukin-10 levels were evaluated in prefrontal cortex, brainstem, and hippocampus. Male adult rats received by oral gavage: (1: water group) water for 19 days, 1 day interval and water (8 days); (2: P. incarnata group) water for 19 days, 1 day interval and P. incarnata 200 mg/kg (8 days); (3: alcohol withdrawal group) alcohol for 19 days, 1 day interval and water (8 days); and (4: P. incarnata in alcohol withdrawal) alcohol for 19 days, 1 day interval and P. incarnata 200 mg/kg (8 days). The tail-flick and hot plate tests were used as nociceptive response measures. Confirming previous study of our group, it was showed that alcohol-treated groups presented an increase in the nociceptive thresholds after alcohol withdrawal, which was reverted by P. incarnata, measured by the hot plate test. Besides, alcohol treatment increased brain-derived neurotrophic factor and interleukin-10 levels in prefrontal cortex, which was not reverted by P. incarnata. Considering these results, the P. incarnata treatment might be a potential therapy in the alcohol withdrawal syndrome. Copyright © 2017 John Wiley & Sons, Ltd.

α- and β-Naphthoflavone synergistically attenuate H2O2-induced neuron SH-SY5Y cell damage

Previous studies have demonstrated an association between neurological diseases and oxidative stress (OS). Naphthoflavone is a synthetic derivative of naturally occurring flavonoids that serves an important role in the treatment and prevention of OS-related diseases. The current study was designed to apply α- and β-Naphthoflavone individually and in combination to counteract the detrimental effects of OS on neurons in vitro. Neuronal SH-SY5Y cells were subjected to 20 µM H₂O₂, followed by exposure to 20 µM α-Naphthoflavone and/or 10 µM β-Naphthoflavone. Results indicated that α- and β-Naphthoflavone effectively antagonized the apoptosis-promoting effect of H₂O₂ on neuronal SH-SY5Y cells, and that β-Naphthoflavone significantly (P<0.05) reversed H₂O₂-inhibited cell viability. Notably, co-treatment of α- and β-Naphthoflavone reversed the H₂O₂-induced apoptosis rate elevation and cell viability reduction. Further analysis demonstrated that H₂O₂ inhibited the activities of antioxidant enzymes including catalase, superoxide dismutase and glutathione peroxidase, but this was reversed by the co-treatment with α- and β-Naphthoflavone and selectively enhanced by the treatment with α- or β-Naphthoflavone. H₂O₂-stimulated p38 mitogen-activated protein kinase activation was repressed following treatment with α- and/or β-Naphthoflavone, along with a decreased expression of the apoptosis-related factors and inhibited caspase-3 activation. In conclusion, co-treatment with α- and β-Naphthoflavone minimized H₂O₂-led neuron damage compared with treatment with α- or β-Naphthoflavone, suggesting a synergetic effect between α- and β-Naphthoflavone. This indicates that utilizing α- and β-Naphthoflavone together in the clinical setting may provide a novel therapeutic for neurological disease.

Passiflora incarnata attenuation of neuropathic allodynia and vulvodynia apropos GABA-ergic and opioidergic antinociceptive and behavioural mechanisms

Background

Passiflora incarnata is widely used as an anxiolytic and sedative due to its putative GABAergic properties. Passiflora incarnata L. methanolic extract (PI-ME) was evaluated in an animal model of streptozotocin-induced diabetic neuropathic allodynia and vulvodynia in rats along with antinociceptive, anxiolytic and sedative activities in mice in order to examine possible underlying mechanisms.

Methods

PI-ME was tested preliminary for qualitative phytochemical analysis and then quantitatively by proximate and GC-MS analysis. The antinociceptive property was evaluated using the abdominal constriction assay and hot plate test. The anxiolytic activity was performed in a stair case model and sedative activity in an open field test. The antagonistic activities were evaluated using naloxone and/or pentylenetetrazole (PTZ). PI-ME was evaluated for prospective anti-allodynic and anti-vulvodynic properties in a rat model of streptozotocin induced neuropathic pain using the static and dynamic testing paradigms of mechanical allodynia and vulvodynia.

Results

GC-MS analysis revealed that PI-ME contained predominant quantities of oleamide (9-octadecenamide), palmitic acid (hexadecanoic acid) and 3-hydroxy-dodecanoic acid, among other active constituents. In the abdominal constriction assay and hot plate test, PI-ME produced dose dependant, naloxone and pentylenetetrazole reversible antinociception suggesting an involvement of opioidergic and GABAergic mechanisms. In the stair case test, PI-ME at 200 mg/kg increased the number of steps climbed while at 600 mg/kg a significant decrease was observed. The rearing incidence was diminished by PI-ME at all tested doses and in the open field test, PI-ME decreased locomotor activity to an extent that was analagous to diazepam. The effects of PI-ME were antagonized by PTZ in both the staircase and open field tests implicating GABAergic mechanisms in its anxiolytic and sedative activities. In the streptozotocin-induced neuropathic nociceptive model, PI-ME (200 and 300 mg/kg) exhibited static and dynamic anti-allodynic effects exemplified by an increase in paw withdrawal threshold and paw withdrawal latency. PI-ME relieved only the dynamic component of vulvodynia by increasing flinching response latency.

Conclusions

These findings suggest that Passiflora incarnata might be useful for treating neuropathic pain. The antinociceptive and behavioural findings inferring that its activity may stem from underlying opioidergic and GABAergic mechanisms though a potential oleamide-sourced cannabimimetic involvement is also discussed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1048-6) contains supplementary material, which is available to authorized users.

Effects of Withania somnifera on oral ethanol self-administration in rats

Recent evidence has shown that Withania somnifera Dunal (Ashwagandha or Indian ginseng), a herbal remedy used in traditional medicine, impairs morphine-elicited place conditioning. Here, we investigated the effect of W. somnifera roots extract (WSE) on motivation for drinking ethanol using operant self-administration paradigms. Wistar rats were trained to self-administer ethanol (10%) by nose-poking. The effects of WSE (25-75 mg/kg) were evaluated on acquisition and maintenance, on ethanol breakpoint under a progressive-ratio schedule of reinforcement and on the deprivation effect and reinstatement of seeking behaviours. Moreover, on the basis of the recent suggestion of an involvement of GABAB receptors in WSE central effects, we studied the interaction between WSE and GABAB ligands. The effect of WSE on saccharin (0.05%) oral self-administration was also tested. The results show that WSE reduced the acquisition, maintenance and breakpoint of ethanol self-administration. WSE also reduced the deprivation effect, reinstatement of ethanol-seeking behaviours and saccharin reinforcement. Furthermore, the GABAB receptor antagonist, phaclofen, counteracted the ability of WSE to impair the maintenance of ethanol self-administration. These findings show that WSE, by an action that may involve GABAB receptors, impairs motivation for drinking ethanol and suggest that further investigations should be performed to determine whether W. somnifera may represent a new approach for the management of alcohol abuse.

Passiflora incarnata L.: ethnopharmacology, clinical application, safety and evaluation of clinical trials

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Passiflora incarnata Linnaeus comprises approximately 520 species belonging to the Passifloraceae family. The majority of these species are vines found in Central or South America, with rare occurrence in North America, Southeast Asia and Australia. The genus Passiflora incarnata has long been used in traditional herbal medicine for the treatment of insomnia and anxiety in Europe, and it has been used as a sedative tea in North America. Furthermore, this plant has been used for analgesic, anti-spasmodic, anti-asthmatic, wormicidal and sedative purposes in Brazil; as a sedative and narcotic in Iraq; and for the treatment of disorders such as dysmenorrhoea, epilepsy, insomnia, neurosis and neuralgia in Turkey. In Poland, this plant has been used to treat hysteria and neurasthenia; in America, it has been used to treat diarrhoea, dysmenorrhoea, neuralgia, burns, haemorrhoids and insomnia. Passiflora incarnata L. has also been used to cure subjects affected by opiate dependence in India. This review aims to provide up-to-date information about the pharmacology, clinical efficacy and clinical safety of Passiflora incarnata L. based on the scientific literature. In particular, the methodological accuracy of clinical trials is analysed in accordance with current consolidated guidelines on reporting the clinical efficacy of herbal medicine, offering new insight into opportunities for future research and development.

METHODS

A bibliographic investigation was performed by examining the available data on Passiflora incarnata L. from globally accepted scientific databases and search engines (Pubmed, Scopus and Web of Science, SciFinder and Google Scholar). We selected studies, case reports, and reviews addressing the pharmacology and safety of Passiflora incarnata.

RESULTS

Although numerous Passiflora incarnata L. derivative products have been commercialised as alternative anxiolytic and sedative remedies based on their long tradition of use, their supposed efficacy does not appear to be adequately corroborated by the literature, with clinical studies often featuring inadequate methodologies and descriptions of the products under investigation. This medicinal plant has shown a wide spectrum of pharmacological activities in preclinical experiments, including anxiolytic, sedative, antitussive, antiasthmatic, and antidiabetic activities. The plant has a good safety profile. The clinical trials that we included in this review were designed to evaluate and in some cases confirm promising observations of preclinical pharmacological activity, and the methodological limits of these studies are characterised here.

CONCLUSION

In conclusion, clinical studies on the effects of products containing herbal preparations based on Passiflora incarnata reveal crucial weaknesses such as poor details regarding the drug extract ratio, limited patient samples, no description of blinding and randomisation procedures, incorrect definition of placebo, and lack of intention to treat analysis. In conclusion, the results of this review suggest that new clinical trials should be conducted using a more rigorous methodology to assess the traditional putative efficacy of Passiflora incarnata L.

Passion flower extract antagonizes the expression of nicotine locomotor sensitization in rats

CONTEXT

Nicotine, a bioactive component of tobacco, is highly addictive. Numerous therapies have been developed or are currently under investigation for smoking cessation, and all have met with limited success and/or side effects, indicating the need for additional therapies.

OBJECTIVE

This study examines the ability of a commerically-available aqueous extract of Passiflora incarnata Linn. (Passifloraceae) to ameliorate the signs of nicotine sensitization using a rat model.

MATERIALS AND METHODS

Rats were administered 0.4 mg/kg nicotine or vehicle once a day for four consecutive days. Nicotine adminstration produces sensitization of locomotor activity, a phenomenon implicated in the development of nicotine dependence. On the fifth day, locomotor activity of the subjects was monitored as rats from each treatment group were administered 800 mg/kg of Passiflora incarnata extract (or its vehicle) followed by a challenge dose of 0.4 mg/kg nicotine.

RESULTS

When given to rats sensitized to nicotine for 4 days, the challenge dose of nicotine increased locomotor activity by more than 2-fold over activity following nicotine challenge in rats treated with vehicle during the sensitization phase. The difference was significant from 15-40 min after nicotine administration. Rats sensitized to nicotine then treated with Passiflora incarnata extract prior to the nicotine challenge exhibited a level of locomotor activity the same as the vehicle-treated controls.

DISCUSSION

Passiflora incarnata extract did antagonize the expression of nicotine locomotor sensitization.

CONCLUSION

Passiflora incarnata extract should be examined in future studies to evaluate its potential for treating nicotine addiction in humans.

Effects of a Rhodiola rosea L. extract on the acquisition, expression, extinction, and reinstatement of morphine-induced conditioned place preference in mice

RATIONALE

Opioid addiction is a chronic, recurrent brain disease that is characterised by compulsive drug seeking and a high rate of relapse even after long periods of abstinence. Prevention of relapse is the primary goal of addiction treatment and is still the major limitation in drug therapy.

OBJECTIVES

The present study investigated the effects of a Rhodiola rosea L. hydroalcoholic extract (RHO), a well-known traditional oriental medicine, on establishment and reinstatement of morphine-induced conditioned place preference (CPP) in mice.

METHODS

CPP was induced by intraperitoneal injection of morphine (10 mg/kg) as an 8-day conditioning schedule. The effects of RHO on the rewarding properties of morphine were tested in mice receiving oral administration of RHO (10, 15, and 20 mg/kg) 60 min prior to each morphine injection (acquisition) or prior to the CPP test on day 9 (expression). Once established, CPP was extinguished by repeated testing, during which conditioned mice were injected daily with different doses of RHO. Finally, the efficacy of RHO in blocking reinstatement of CPP provoked by priming injections and physical stress was also evaluated.

RESULTS

RHO administration showed dose dependency for prevention of establishment of CPP and was effective in facilitating extinction of morphine-induced CPP. RHO suppressed both priming- and stress-induced reinstatement of CPP in a dose-dependent manner.

CONCLUSIONS

In conclusion, as RHO was effective for reducing craving and vulnerability to relapse, it might be a very effective natural remedy for the treatment of opioid addiction.

Effects of a Rhodiola rosea L. extract on acquisition and expression of morphine tolerance and dependence in mice

This study investigated the effect of Rhodiola rosea L. extract on acquisition and expression of morphine tolerance and dependence in mice. Therefore animals were injected with repeated administration of morphine (10 mg/kg, subcutaneous) twice daily for five or six days, in order to make them tolerant or dependent. Rhodiola rosea L. extract (0, 10, 15 and 20 mg/kg) was administered by the intragastric route 60 min prior to each morphine injection (for acquisition) or prior the last injection of morphine or naloxone on test day (for tolerance or dependence expression, respectively). Morphine tolerance was evaluated by testing its analgesic effect in the tail flick test at the 1st and 5th days. Morphine dependence was evaluated by counting the number of withdrawal signs (jumping, rearing, forepaw tremor, teeth chatter) after naloxone injection (5 mg/kg; intraperitoneal) on the test day (day 6). Results showed that Rhodiola rosea L. extract significantly reduced the expression of morphine tolerance, while it was ineffective in modulating its acquisition. Conversely, Rhodiola rosea L. extract significantly and dose-dependently attenuated both development and expression of morphine dependence after chronic or acute administration. These data suggest that Rhodiola rosea L. may have human therapeutic potential for treatment of opioid addiction.

Medicinal plants used in Northern Peru for reproductive problems and female health

Infections of the reproductive tract, complications after childbirth, and reproductive problems continue to be a major health challenge worldwide. An impressive number of plant species is traditionally used to remedy such afflictions, and some have been investigated for their efficacy with positive results. A total of 105 plant species belonging to 91 genera and 62 families were documented and identified as herbal remedies for reproductive problems in Northern Peru. Most species used were Asteraceae (9.52%), followed by Lamiaceae and Fabaceae (8.57% and 6.67%). The most important families are clearly represented very similarly to their overall importance in the local pharmacopoeia. The majority of herbal preparations for reproductive afflictions were prepared from the leaves of plants (22.72%), the whole plant (21.97%), and stems (21.21%), while other plant parts were used less frequently. More than 60% of the cases fresh plant material was used to prepare remedies. Over 70% of the remedies were applied orally, while the remaining ones were applied topically. Many remedies were prepared as mixtures of multiple ingredients. Little scientific evidence exists to prove the efficacy of the species employed as reproductive disorder remedies in Northern Peru. Only 34% of the plants found or their congeners have been studied at all for their medicinal properties. The information gained on frequently used traditional remedies might give some leads for future targets for further analysis in order to develop new drugs.

Possible involvement of GABA A-benzodiazepine receptor in the anxiolytic-like effect induced by Passiflora actinia extracts in mice

Hydroethanol (HE) and methanol (ME) extracts obtained from the leaves of Passiflora actinia Hooker were evaluated for behavioral effects in mice. Single-dose oral administration of HE (300 and 600 mg/kg) or ME (100 and 300 mg/kg) resulted in anxiolytic-like effects in the elevated plus-maze. The anxiolytic-like effects were also seen after the repeated administration of the HE (100 and 300 mg/kg). Flumazenil (10mg/kg, i.p.), a GABA(A)-benzodiazepine receptor antagonist, blocked the effects of ME (300 mg/kg, p.o.) and HE (600 mg/kg). At higher doses, a sedative effect produced by acute administration of HE (600 mg/kg) or ME (300 mg/kg) was indicated by the potentiation of pentobarbital-induced sleep. With regard to memory-disrupting effects of anxiolytics, mice were evaluated by measuring the retest step-down latency 24h after foot-shock in a passive avoidance task. In contrast to diazepam (0.5mg/kg) or piracetam (200mg/kg), ME (30, 100 and 300 mg/kg) or HE (100, 300 and 600 mg/kg) did not influence the step-through latency in the acquisition or retention memory tasks. The present results show an anxiolytic profile for HE and ME of Passiflora actinia. There are also indications of an involvement of GABA(A) system in this effect.

Natural and complementary therapies for substance use disorders

PURPOSE OF REVIEW

To review recent studies that have examined the efficacy of natural and complementary therapies as treatments for substance use disorders and their complications.

RECENT FINDINGS

Despite increasing interest in natural and complementary therapies for substance use disorders, rigorous clinical studies in this area are few in number. Recent clinical studies, although preliminary, have reported potential therapeutic effects for hypericum in the treatment of smoking cessation, for prickly pear extract in the prevention of alcohol hangover and magnesium supplementation as an adjunct to methadone treatment. Other clinical studies have reported negative findings for ginkgo as an adjunctive treatment for cocaine dependence, for artichoke in prevention of alcohol hangover, and acupuncture for alcohol withdrawal. Relevant findings from animal studies are also discussed. Neither vitamin E nor Liv 52 had a useful effect in alcohol-related liver disease. A study of silymarin in baboons, which was undertaken in an attempt to untangle the conflicting findings of human studies, reported a potential for this compound to prevent liver injury. There is increasing awareness of safety issues associated with complementary therapies. Safety issues pertinent to substance use treatment are discussed in this review.

SUMMARY

Several pharmacological and psychosocial treatments for substance use disorders are solidly evidence-based and improve both individual and public health outcomes. At this stage, there remains insufficient evidence to support the use of natural and complementary therapies as a primary intervention for substance use disorders. Further clinical trials are required to clarify the potential role of particular agents.

Passiflora: a review update

This review describes the morphology, microscopy, traditional and folklore uses, phyto-constituents, pharmacological reports, clinical applications and toxicological reports of the prominent species of the genus Passiflora. Flavonoids, glycosides, alkaloids, phenolic compounds and volatile constituents have been reported as the major phyto-constituents of the Passiflora species. A few species of Passiflora have been used for curing various ailments, the most important being Passiflora incarnata Linneaus which possesses significant CNS depressant properties. The studies performed by the authors with the newly isolated benzoflavone (BZF) moiety from P. incarnata have been discussed. In the concluding part, various virgin areas of research on the species of this genus have been highlighted with a view to explore, isolate and identify the medicinally important phyto-constituents which could be utilized to alleviate various diseases affecting the mankind.