Anti-Neuropathic Pain Activity of Ageratum conyzoides L due to The Essential Oil Components

Author(s):  
Yedy Purwandi Sukmawan ◽  
Kusnandar Anggadiredja ◽  
I Ketut Adnyana

Background: Neuropathic pain is one of the contributors to the global burdens of illness. At present many patients do not achieve satisfactory pain relief even with synthetic pain-killers. Taking this into consideration, it is necessary to search for natural product-derived alternative treatment with confirmed safety and efficacy. Ageratum conyzoides L is a plant often used as analgesic in Indonesia, however, anti-neuropathic pain activity of this plant is still unknown. Objective: To determine the anti-neuropathic pain activity of the essential oil and non-essential oil component (distillation residue) of A. conyzoides L. Methods: We conducted separation of the essential oil component from other secondary metabolites through steam distillation. Both components were tested for anti-neuropathic pain activity using chronic constriction injury animal models with thermal hyperalgesia and allodynia tests. The animals were divided into 7 test groups namely normal, sham, negative, positive (pregabalin at 0.195 mg/20 g BW of mice), essential oil component (100 mg/kg BW), and non-essential oil component (100 mg/kg BW). Naloxone was tested against the most potent anti-neuropathic pain component (essential oil or nonessential oil) to investigate the involvement of opioid receptor. Results: The GC-MS of the essential oil component indicated the presence of 60 compounds. Meanwhile, non-essential oil components contained alkaloid, flavonoid, polyphenol, quinone, steroid, and triterpenoid. This non-essential oil component contained a total flavonoid equivalent to 248.89 ppm quercetin. The anti-neuropathic pain activity test showed significantly higher activity of the essential oil component compared to the non-essential oil component and negative groups (p<0.05). Furthermore, the essential oil component showed equal activity to pregabalin (p>0.05). However, this activity was abolished by naloxone, indicating the involvement of opioid receptor in the action of the essential oil component. Conclusion: The essential oil component of A. conyzoides L is a potential novel substance for use as anti-neuropathic pain.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Prasad Neerati ◽  
Harika Prathapagiri

Abstract Background Chronic neuropathic pain syndrome is associated with impaired quality of life and is poorly manageable. Alpha lipoic acid (ALA) is a powerful antioxidant and showed its effectiveness on diabetic neuropathy and other acute peripheral nerve injuries but it was not evaluated in the chronic neuropathic pain, chronic constriction injury (CCI) in rat model by using duloxetine (DLX) as standard. Methodology The main objective of the study was to expedite ALA effect on chronic peripheral neuropathy induced by CCI of sciatic nerve in rats. In this study, male Wister rats were randomly divided into six groups (n = 8) including, normal saline, sham operated, surgery control, DLX 30mg/kg treated, ALA treated 25mg/kg, and ALA+DLX. The CCI of sciatic nerve was conducted on all animals except normal saline group and studied for 21 days (i.e. 14 days treatment period & 7 days treatment free period) by using different behavioral, biochemical and, histopathology studies. Results ALA showed minor but significant decrease of thermal hyperalgesia, cold allodynia, malondialdehyde (MDA), total protein, lipid peroxidation, and nitric oxide levels and significant increase of motor coordination, glutathione level and decreased axonal degeneration significantly. These effects sustained even during treatment free period. ALA enhanced the effect of DLX when given in combination by showing sustained effect. In conclusion, ALA acted as potent antioxidant may be this activity is responsible for the potent neuroprotective effect. Conclusion Hence, ALA attenuated the nueroinflammation mediated by chronic peripheral neuropathy. Further studies are warranted with ALA to develop as a clinically relevant therapeutic agent for the treatment of neuropathic pain.


Author(s):  
Saurabh Kohli ◽  
Taruna Sharma ◽  
Juhi Kalra ◽  
Dilip C. Dhasmana

Background: Neuropathic pain is associated with prolonged disability and is usually not responsive to conventional analgesics like NSAIDs and opioids. Even the recommended first-line drugs are effective in less than 50% patients. Thus, drugs with different mechanisms of action are needed. Baclofen, a GABA-B agonist has shown benefit in different types of neuropathic pains and is compared against pregabalin.Methods: The sciatic nerve was ligated in 2 groups of 6 rats each as per the chronic constriction injury model of neuropathic pain on day 0. After 14 days the effect of single doses of pregabalin (30mg/kg) and baclofen (5mg/kg) intraperitoneally were assessed over a 2 hours period. Thermal and mechanical hyperalgesia were assessed as measures of neuropathic pain by the hotplate and pin-prick method respectively.Results: Significant thermal and mechanical hyperalgesia was produced 14 days after sciatic nerve ligation in both the groups (p <0.05). Both pregabalin (p <0.001) and baclofen (p <0.01) were effective in decreasing thermal hyperalgesia throughout the two hours study period, but pregabalin was more effective as compared to baclofen (p <0.05) at 30, 60 and 120minutes. Both the drugs produced a significant decrease in mechanical hyperalgesia (p <0.01) throughout the study period. Again, pregabalin was the more effective drug (p <0.05) at all time points.Conclusions: Significant thermal and mechanical hyperalgesia was seen 14 days after sciatic nerve ligation. Both pregabalin and baclofen were effective in reversing the hyperalgesia, but pregabalin was the more effective of the two drugs at all time points.


1990 ◽  
Vol 30 (5) ◽  
pp. 681 ◽  
Author(s):  
E Diatloff

Three native species of Leptospermum (L. petersonii, L. Flavescens, L. luehmannii) were grown in an amended podsolic soil under 4 nitrogen (N) levels, 0, 20, 40 and 60 kg Nha, supplied as NH4N03. Plants were harvested after 16 weeks growth, leaves were separated from stems, and essential oil was distilled from leaves by steam distillation. Extracted oils were analysed for their components by gas chromatography. Oil density from L. petersonii was also determined. Growth and oil yield of the 3 Leptospermum species showed no response to N fertilisation. However, the oil composition in L. petersonii and L. flavescens leaves was affected. The greatest response was in the geranial and citronella1 contents in L. petersonii, which peaked in the 40 kg N/ha treatment. This is the first known report of the manipulation of essential oil composition of Australian native plants by N fertilisation. The low optimal level of N fertiliser required for maximum production of valuable oil components indicates that Leptospermum spp. are suitable for infertile soils. The low �-pinene yield of L. luehmannii makes it unsuitable for commercial exploitation.


Author(s):  
Mehdi Sadeghi ◽  
◽  
Homa Manaheji ◽  
Jalal Zaringhalam ◽  
Abbas Haghparast ◽  
...  

Introduction: The modality of γ-aminobutyric acid receptors (GABAA) in control of dorsal horn neuronal excitability and inhibition of sensory information is ambiguous. The aim of the present study was to investigate the expression of GABAA receptor and the effects of its agonist muscimol on wide dynamic range (WDR) neuronal activity in the chronic constriction injury (CCI) model of neuropathic pain. Methods: Adult male Wistar rats weighing 200 to 250 g were used for the induction of CCI neuropathy. 14 days after surgery, muscimol (0.5, 1, and 2 mg/kg i.p.) was injected. Then, the behavioral tests were performed. Thereafter, the animals were sacrificed, and the lumbar segments of the spinal cords were collected for Western blot analysis of the GABAA receptor α1 subunit expression. The electrophysiological properties of WDR neurons were studied by single unit recordings in separate groups on the 14th day after CCI. Results: The outcomes indicated the development of thermal hyperalgesia and mechanical allodynia after neuropathy; nonetheless, the expression of GABAA receptor α1 subunit did not change significantly. Moreover, the evoked responses of the WDR neurons to electrical, mechanical, and thermal stimuli were significantly increased. 14 days after CCI, muscimol administration decreased thermal hyperalgesia, mechanical allodynia, and hyper-responsiveness of the WDR neurons in CCI rats. Conclusion: It confirms that the modulation of the spinal GABAA receptors after nerve injury can offer further insights to design new therapeutic agents in order to reduce the neuropathic pain symptoms.


2021 ◽  
Author(s):  
Jia Sun ◽  
Jia-Yan Li ◽  
Long-Qing Zhang ◽  
Dan-Yang Li ◽  
Jia-Yi Wu ◽  
...  

Abstract BackgroundNeuropathic pain is a debilitating disease with few effective treatments. Emerging evidence indicates the involvement of mitochondrial dysfunction and oxidative stress in neuropathic pain. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a potent regulator of antioxidant response system. In this study, we investigated whether RTA-408 (a novel synthetic triterpenoid under clinical investigation) could activate Nrf2 and promote mitochondrial biogenesis (MB) to reverse neuropathic pain and the underlying mechanisms.MethodsNeuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve. Pain behaviors were measured via the von-Frey test and Hargreaves plantar test. The L4-6 spinal cord was collected to examine the activation of Nrf2 and MB.ResultsRTA-408 treatment significantly reversed mechanical allodynia and thermal hyperalgesia in CCI mice in a dose-dependent manner. Furthermore, RTA-408 increased the activity of Nrf2 and significantly restored MB that was impaired in CCI mice in an Nrf2 dependent manner. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α) is the key regulator of MB. We found that PGC-1α activator also exhibited a potent analgesic effect in CCI mice. Moreover, the antinociceptive effect of RTA-408 was reversed by the pre-injection of PGC-1α inhibitor.ConclusionsNrf2 activation attenuates chronic constriction injury-induced neuropathic pain via induction of PGC-1α-mediated mitochondrial biogenesis in the spinal cord. Our results indicate that Nrf2 may be a potential therapeutic strategy to ameliorate neuropathic pain and many other disorders with oxidative stress and mitochondrial dysfunction.


2012 ◽  
Vol 84 (4) ◽  
pp. 1091-1104 ◽  
Author(s):  
Venkata R.K. Thiagarajan ◽  
Palanichamy Shanmugam ◽  
Uma M. Krishnan ◽  
Arunachalam Muthuraman ◽  
Nirmal Singh

The present study was designed to investigate the ameliorative role of ethanolic extract from leaves of Butea monosperma in chronic constriction injury (CCI) of sciatic nerve induced neuropathic pain in rats. Hot plate, acetone drop, paw pressure, Von Frey hair and tail immersion tests were performed to assess the degree of thermal hyperalgesia, cold chemical allodynia, mechanical hyperalgesia & allodynia in the left hind paw and tail thermal hyperalgesia. Further on, thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and total calcium levels were estimated to assess the biochemical changes in the sciatic nerve tissue. Histopathological changes were also observed in the sciatic nerve tissue. Ethanolic extract of Butea monosperma leaves and pregabalin (serving as positive control) were administered for 14 consecutive days starting from the day of surgery. CCI resulted in significant changes in behavioural and biochemical parameters. Pretreatment of Butea monosperma attenuated CCI induced development of behavioural, biochemical and histopathological alterations in a dose dependent manner, which is comparable to that of pregabalin pretreated group. These findings may be attributed to its potential anti-oxidative, neuroprotective and calcium channel modulatory actions of Butea monosperma.


1999 ◽  
Vol 90 (5) ◽  
pp. 1382-1391 ◽  
Author(s):  
Tatsuo Yamamoto ◽  
Yoshihiko Sakashita

Background Cholecystokinin-B receptor activation has been reported to reduce morphine analgesia. Neuropathic pain is thought to be relatively refractory to opioids. One possible mechanisms for a reduced effect of morphine on neuropathic pain is the induction of cholecystokinin in the spinal cord by nerve injury. The authors evaluated the role of the spinal cholecystokinin-B receptor on morphine analgesia in two rat neuropathic pain models: chronic constriction injury and partial sciatic nerve injury. Methods A chronic constriction injury is created by placing four loosely tied ligatures around the right sciatic nerve. A partial sciatic nerve injury was created by tight ligation of one third to one half of the right sciatic nerve. All drugs were injected intrathecally 7 and 11 days after the nerve injury. The effect of the drugs was reflected in the degree of paw withdrawal latency to thermal nociceptive stimulation. The paw withdrawal latencies of injured and uninjured paws were measured 5, 15, 30, and 60 min after the drugs were injected. Results In the chronic constriction injury model, intrathecal morphine increased the paw withdrawal latencies of injured and uninjured paws. PD135158, a cholecystokinin-B receptor antagonist, potentiated the analgesic effect of morphine on injured and uninjured paws. In the partial sciatic nerve injury model, the effect of morphine on the injured paw was less potent than that on the uninjured paw, and PD135158 potentiated the morphine analgesia in the uninjured paw and had only a minor effect on the morphine analgesia in the injured paw. Conclusions The effectiveness of morphine for thermal hyperalgesia after nerve injury depends on the type of nerve injury. The role of the cholecystokinin-B receptor in morphine analgesia in thermal hyperalgesia after nerve injury also depends on the type of nerve injury.


2014 ◽  
Vol 121 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Franziska Barthel ◽  
Andrea Urban ◽  
Lukas Schlösser ◽  
Volker Eulenburg ◽  
Robert Werdehausen ◽  
...  

Abstract Background: Dysfunction of spinal glycinergic neurotransmission is a major pathogenetic factor in neuropathic pain. The synaptic glycine concentration is controlled by the two glycine transporters (GlyT) 1 and 2. GlyT inhibitors act antinociceptive in various animal pain models when applied as bolus. Yet, in some studies, severe neuromotor side effects were reported. The aim of the current study was to elucidate whether continuous inhibition of GlyT ameliorates neuropathic pain without side effects and whether protein expression of GlyT1, GlyT2, or N-methyl-d-aspartate receptor subunit NR-1 in the spinal cord is affected. Methods: In the chronic constriction injury model of neuropathic pain, male Wistar rats received specific GlyT1 and GlyT2 inhibitors (ALX5407 and ALX1393; Sigma-Aldrich®, St. Louis, MO) or vehicle for 14 days via subcutaneous osmotic infusion pumps (n = 6). Mechanical allodynia and thermal hyperalgesia were assessed before, after chronic constriction injury, and every 2 days during substance application. At the end of behavioral assessment, the expression of GlyT1, GlyT2, and NR-1 in the spinal cord was determined by Western blot analysis. Results: Both ALX5407 and ALX1393 ameliorated thermal hyperalgesia and mechanical allodynia in a time- and dose-dependent manner. Respiratory or neuromotor side effects were not observed. NR-1 expression in the ipsilateral spinal cord was significantly reduced by ALX5407, but not by ALX1393. The expression of GlyT1 and GlyT2 remained unchanged. Conclusions: Continuous systemic inhibition of GlyT significantly ameliorates neuropathic pain in rats. Thus, GlyT represent promising targets in pain research. Modulation of N-methyl-d-aspartate receptor expression might represent a novel mechanism for the antinociceptive action of GyT1 inhibitors.


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