Cardiopulmonary function and dysregulated cardiopulmonary reflexes following acute oleoresin capsicum exposure in rats.

Cardiopulmonary functions such as respiratory depression, severe irritation, inflamed respiratory tract, hyperventilation and, tachycardia are the most affected ones when it comes to the riot control agent oleoresin capsicum (OC) exposure. However, no studies have been done to elucidate the mechanism underlying deterioration of the combined cardiopulmonary functions. Parameters such as acute respiratory, cardiac, parameters and ultrasonography (USG) measurements were investigated in an in vivo setup using Wistar rats at 1 h and 24 h post inhalation exposure to 2%, 6% and 10% OC, whereas, cell migration in rat peritoneal mast cells (RPMCs), metabolomics and eosinophil peroxidase (EPO) activity in bronchoalveolar lavage fluid (BALF) were investigated in an in vitro setup. Results obtained from electrophysiological recording indicated that OC exposure produces apnea and decrease in mean arterial pressure (MAP) was obtained from hemodynamic parameters whereas cardiac parameters assessment revealed increase in the level of cardiac output (CO) and decrease in stroke volume (SV) with recovery towards the post-exposure period. A decrease in the percentage area of certain fatty acid pathway metabolites in BALF appropriately linked the lung injury following OC exposure which was further cemented by increasing concentration of EPO. Histopathology and SEM also proved to be favorable techniques for the detection of OC induced physiological cardiac and pulmonary modifications respectively. Furthermore, Boyden chamber experiment established the chemoattractant property of OC. It may be concluded from the above studies that these newly reported facets may be utilized pharmacologically to mitigate cardiopulmonary adverse effects owing to OC exposure.

Innate inflammatory response to acute inhalation exposure of riot control agent oleoresin capsicum in female rats: An interplay between neutrophil mobilization and inflammatory markers.

Aim: The use of oleoresin capsicum (OC) sprays, due to their irreversible health effects has now grown into a matter of heated debate. In the present study, the early phase pulmonary events involving chemotactic and inflammatory mediators after short-exposure duration to OC have been presented.Materials and methods: Female Wistar rats used in the evaluation of respiratory parameters at 1 h, 3 h, and 24 h post-exposure, were sacrificed for the evaluation of blood cell counts, BALF cytokine estimation, lung capillary leakage, study of oxidative stress and histopathology of the lungs.Results: Results confirmed a dose-dependent effect of OC exposure on serum clinical chemistry and hematological parameters. Subsequent upregulation of IL-l and TNF-α indicated lung's responses to acute oxidant-induced injury and inflammation after OC exposure. Significant alterations in the pulmonary levels of reactive oxygen intermediates were seen following the inhalation of OC. Infiltration of polymorphonuclear leukocytes, mostly neutrophils, into the site of infection was evident in the cytocentrifuged samples of BALF. Histological samples of rat lung sections revealed the recruitment of inflammatory cells in the airways and around blood vessels in the subepithelium of conducting airways.Conclusion: Results of the present study demonstrated that, exposure to OC spray may mitigate inflammatory response and development of acute lung injury in rats. However, it can be concluded that although OC spray causes pulmonary hazards in the aforementioned concentrations, it can be used as a non-lethal riot control agent in minimal concentration. Understanding the in-depth mechanism of action in the molecular and receptor level will help in developing effective antagonist against OC.

Comparative safety evaluation of riot control agents of synthetic and natural origin.

Riot control agents (RCA) are lachrymatory, irritating compounds which temporarily incapacitate the uncontainable crowd. Ortho-Chlorobenzylidene-malononitrile (CS), 2-chloroacetophenone (CN), dibenz[b,f]1:4-oxazepine (CR), and nonivamide (PAVA) are synthetic RCAs, while oleoresin extract of chili known as oleoresin capsicum (OC) a natural irritant has been in use by various law enforcement agencies. Though efficacy of these agents is beyond doubt, they suffer from certain drawbacks including toxicity, production cost, and ecological compatibility. Presently, we have evaluated the safety of CR, OC, and PAVA on inhalation variables along with oral lethality. Additionally, the liver function test (LFT) in serum and lungs function was evaluated in broncho-alveolar-lavage fluid (BALF), both collected on the 14th day after RCA exposure. Animals then sacrificed and histopathology of liver and lungs was carried out. Results showed OC and PAVA to be more toxic than CR with an oral LD50 of 150 and 200 mg/kg body weight, respectively, while CR was safe at >3 g/kg body weight. All three agents caused severe impairment of respiratory variables bringing down normal respiration by >80% with rise in sensory irritation. Recovery from the irritating effect of CR was more rapid than OC and PAVA. LFT and BALF variables were not significantly different from that of control. There were no remarkable histopathological changes in liver and lungs. Hence, as per results, CR is safest among all synthetic and natural origin RCAs and can be safely used for effective dispersion of disobedient mob.

Clinicopathological effects of pepper (oleoresin capsicum) spray.

OBJECTIVES: Pepper (oleoresin capsicum) spray is one of the most common riot-control measures used today. Although not lethal, exposure of pepper spray can cause injury to different organ systems. This review aimed to summarise the major clinicopathological effects of pepper spray in humans. DATA SOURCES: MEDLINE, EMBASE database, and Cochrane Database of Systematic Reviews were used to search for terms associated with the clinicopathological effects of pepper spray in humans and those describing the pathophysiology of capsaicin. A phone interview with two individuals recently exposed to pepper spray was also conducted to establish clinical symptoms. STUDY SELECTION: Major key words used for the MEDLINE search were "pepper spray", "OC spray", "oleoresin capsicum"; and other key words as "riot control agents", "capsaicin", and "capsaicinoid". We then combined the key words "capsaicin" and "capsaicinoid" with the major key words to narrow down the number of articles. A search with other databases including EMBASE and Cochrane Database of Systematic Reviews was also conducted with the above phrases to identify any additional related articles. DATA EXTRACTION: All article searches were confined to human study. The bibliography of articles was screened for additional relevant studies including non-indexed reports, and information from these was also recorded. Non-English articles were included in the search. DATA SYNTHESIS: Fifteen articles were considered relevant. Oleoresin capsicum causes almost instantaneous irritative symptoms to the skin, eyes, and respiratory system. Dermatological effects include a burning sensation, erythema, and hyperalgesia. Ophthalmic effects involve blepharospasm, conjunctivitis, peri-orbital oedema, and corneal pathology. Following inhalation, a stinging or burning sensation can be felt in the nose with sore throat, chest tightness, or dyspnoea. The major pathophysiology is neurogenic inflammation caused by capsaicinoid in the pepper spray. There is no antidote for oleoresin capsicum. Treatment consists of thorough decontamination, symptom-directed supportive measures, and early detection and treatment of systemic toxicity. Decontamination should be carefully carried out to avoid contamination of the surrounding skin and clothing. CONCLUSION: Pepper (oleoresin capsicum) spray is an effective riot-control agent and does not cause life-threatening clinical effects in the majority of exposed individuals. Early decontamination minimises the irritant effects.