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

Abstract

BackgroundThe 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.MethodsPlacement 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.ResultsCCI 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.ConclusionsOur findings suggest that Bacopa monnieri can be used as adjuvant therapy for neuropathic pain conditions afflicted with allodynia and hyperalgesia.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-017-1807-z) contains supplementary material, which is available to authorized users.

The flavonoid 6-methoxyflavone allays cisplatin-induced neuropathic allodynia and hypoalgesia

“…6-MF was administered once daily in doses of 25, 50 and 75 mg/kg via the intraperitoneal route [23]. Gabapentin was used as a positive control and was administered intraperitoneally once daily at a dose of 75 mg/kg (i.p) [24][25]. The animals were randomly divided into the following groups (n = 6 animals per group) and the study was continued for 28 days (4 weeks): which point further application ceased.…”

RETRACTED ARTICLE: Ultra-diluted Toxicodendron pubescens attenuates pro-inflammatory cytokines and ROS- mediated neuropathic pain in rats

“…Global occurrences of neuropathic pain are escalating due to an increase in the ageing population, enhanced survival from cancer chemotherapy and progressively increasing incidence of diabetes mellitus 1 . Despite the emergence of novel drug discovery technologies and advancements in the field of neuroscience, the issue of neuropathic pain management with safe and effective remedies is still unresolved 4 , 5 . Many randomized controlled trials have presented the clinical efficacy of opioids, gabapentinoids, tricyclic antidepressants, serotonin reuptake inhibitors and calcium channel ligands in the treatment of neurogenic pain.…”

“…However, these agents do not suffice the targets of managing of neuropathic pain. The efficacy of available anti-neuropathic drugs is limited due to occurrence of several side effects and inadequate or delayed pain relief 4 , 6 . The need to discover novel treatment modalities for neuropathic conditions still prevails.…”

“…Natural products or complementary and alternative medicines are frequently used to manage the chronic neurological disorders like neuropathic pain 4 . Few preclinical studies on homeopathic remedies have also demonstrated the efficacy of homeopathic remedies in the management of neuropathic pain 9 , 10 .…”

Analgesic and Anti-allodynic Effects of Two Flavonoids in Partial Sciatic Nerve Ligation in Rat Model

“…2 Peripheral neuropathic pain is generally detected in patients with long-established diseases and disorders like AIDS, diabetes, leprosy, aminotomy, cervical disc protrusion, cancer and after surgery. [7][8][9][10] Additionally, post-mastectomy, post-thoracotomy, post-sternotomy and post-herniorrhaphy are other situations which are correlated with peripheral neuropathy. 2,11 Neuropathic pain is characterized by hyperalgesia (increased pain response to a normally painful stimulus), paraesthesia (abnormal sensation to a stimulus that is normally not unpleasant), dysesthesia (unpleasant abnormal sensation) and allodynia (pain due to a stimulus that normally does not provoke pain).…”