Importantly, the full-spectrum cannabis extract totally relieved thermal hyperalgesia, mechanical allodynia and withdrawal latency in CCI rats. In contrast, treatment with purified CBD or purified THC, given at the same dose existing in the extract, showed only a partial anti-nociceptive effect. Thus, this study suggests that full-spectrum cannabis extract has a better analgesic effectiveness than CBD or THC alone in rats with neuropathic pain. Intriguingly, the authors also found that the anti-nociceptive effect of the full-spectrum cannabis extract was independent of CB1 and CB2 receptors. Indeed, the anti-nociceptive effect of the full-spectrum cannabis extract was mainly due to the activation of the vanilloid receptor, TRPV1. This conclusion was supported by the finding that treatment of animals withCB1 and CB2 receptor blockers could not abolish the protective effect of the full-spectrum cannabis extract. Conversely, TRPV1 receptor antagonist, capsazepine, completely blocked the effect of full-spectrum cannabis extract suggesting a TRPV1-dependent mechanism . Overall, this study clearly demonstrated that the beneficial effects of the full-spectrum cannabis extract was superior to purified THC or CBD in the treatment of neuropathic pain and that this effect was not mediated via the classical CB receptor-mediated signaling. The anti-nociceptive effect of full-spectrum cannabis extract has been confirmed in streptozotocin-induced diabetic neuropathy in rats. Treatment of these animals with full-spectrum cannabis extract significantly ameliorated mechanical allodynia and the physiological thermal pain perception. Of importance, the observed effect was independent of hyperglycemia, suggesting a direct neuronal effect. Indeed, evidence suggests that the anti-nociceptive effect may be due to the activation of the neurotrophic factor, nerve growth factor , by one or more components within the cannabis extract. In addition to the anti-nociceptive effect, full-spectrum cannabis extract protected against oxidative stress-induced neuronal damage in these diabetic rats.
Collectively, this study supports the concept that the combination of cannabinoid and non-cannabinoid compounds, vertical grow rack as present in the aforementioned extract, produces a profound benefit in the treatment of neuropathic pain . In addition to the pre-clinical studies, full spectrum cannabis extract such as Sativex has been investigated in numerous clinical trial on patients with MS-related symptoms . These trials are either double-blind randomized placebo-controlled parallel-group trials, an uncontrolled open-label or non-interventional trials that have studied the effect Sativex as a monotherapy or as an add-on therapy on patient with MS-related symptoms. Notably, Sativex reduces neuropathic pain, muscle stiffffness and spasticity, bladder dysfunction, and improves sleep quality in MS patients. Importantly, the effect of Sativex on MS-related neuropathic pain was more pronounced when administered as an adjuvant therapy. Overall, these trials confirm the notion that full spectrum cannabis extract such as Sativex is effective for the treatment of MS-related neuropathic pain. While small scale clinical studies suggest that full-spectrum cannabis extract like Sativex is safe and effective in the treatment of MSassociated symptoms such as neuropathic pain, this might not necessarily hold true for all other cannabis products. Indeed, purified oral THC lacks beneficial effects for the treatment of neuropathic pain associated with MS . In addition, oral products with purified or high THC content produces cognitive dysfunction, undesirable psychological effects and tachycardia. Thus, care should be taken in the interpretation of the effectiveness and safety of the types of cannabis products used in treating neuropathic pain.While the major undesirable effects of THC containing products are cognitive dysfunction, particularly the loss of short-term memory consolidation, anxiety, tachycardia and hunger, these are obviously not common adverse effects of full spectrum cannabis extract like Sativex. In fact, given that full spectrum cannabis extract consists of a variety of cannabinoids and terpenes, we postulate that these cannabinoids and terpenes can help minimize the undesirable effects of THC. In support of this notion, CBD was shown to reduce unpleasant THC-induced effects such as psychological reactions, anxiety, tachycardia and hunger through the more traditional CB receptor-mediated pathway. Indeed, the reduction of the unpleasant THC effects are mediated by the following mechanisms: CBD appears to compete with THC for CB1 receptor binding site and acts as a CB1 receptor antagonist or reverse agonist and CBD suppresses the activity of CYP2C and CYP3A enzymes involved in the metabolism of THC in the liver, which subsequently inhibits the hydroxylation of THC to its 11-hydroxy metabolite.
Of note, 11- OH-THC is 4 times more psychoactive compared to THC , and thus reducing the formation of 11-hydroxy metabolite by CBD should minimize the unpleasant psychological reactions of THC. In addition to CBD, α-pinene, a bicyclic monoterpene, was shown to aid the memory and minimize cognitive dysfunction via blunting the activity of acetylcholinesterase in the brain. Together, the absence of the major undesirable effects of THC is an important advantage of full spectrum cannabis extract like Sativex. Nevertheless, side effects such as somnolence, dizziness, confusion, fatigue, dry mouth, white and red buccal mucosal patches and nausea have been reported in patients on Sativex. In contrast to Sativex, the presence of CBD in some cannabis grow racks extracts, particularly the oral extracts, can sometimes exacerbate some of the psychological effects of THC which might be due to the profound effect of CBD on the hepatic first pass metabolism of THC whereby CBD elevates the blood level of THC . Thus, oral broad spectrum CBD extract might be safer than oral THC or THC/CBD cannabis extract products. Nevertheless, while highly purified CBD extract lack any psychoactive adverse effects, a risk of hepatotoxicity, in addition to suicidal ideation have been reported with a chronic high dose of extracted CBD. Other adverse effects such as fatigue, somnolence and gastrointestinal disturbances have been also reported.Cannabis sativa L. is one of the oldest cultivated plants in history with multifarious applications, ranging from the textile, construction and paper industries to the nutritional, pharmaceutical and cosmetic sectors. While the stems provide cellulosic and woody fibres of very high quality, and the seeds are a rich source of fatty acids and proteins for the feed and food industries, the leaves and inflorescences are a gold-mine for phytochemicals. The rich spectrum of bioactive compounds can be exploited for several pharmaceutical applications . The plant is known for its therapeutic usage as antiemetic, analgesic, and appetite stimulant or to treat epilepsy, glaucoma, and Tourette’s syndrome . In total, a broad spectrum of more than 500 phytochemicals has been identified from the leaves, flowers, bark, seeds, and roots. This includes numerous cannabinoids, flavonoids, and terpenoids, as well as sterols , which are of industrial interest. The phytochemical spectrum, however, varies significantly with chemovar and plant part , and also with agronomic and environmental factors . Traditionally, stems, inflorescence and seeds were the most used plant parts. In medicine, the major focus has always been on cannabidiol and Δ9 -tetrahdydrocannabinol as bioactive compounds, which are mainly present in the flowers, as well as the leaves. Thus, the roots have been investigated less with respect to the reported pharmaceutical potential. Nonetheless, the roots have historically been used for the treatment of fever, inflammation, infections, as well as arthritis . Recently, the presence of phytocannabinoids has been reported in hairy roots for the first time, although in almost negligible amounts compared with the rest of the plant .
Naturally occurring triterpenoids are described as being of therapeutic value because of their anti-cancer, anti-inflammatory, antiulcerogenic or antiviral activities . The first characterized triterpenoids from ethanolic root extracts were friedelin and epifriedelinol, reported in 1971 . Recently β-amyrin was discovered to be accumulated in hemp roots as well . Of the identifiedtriterpenoids, friedelin seems to be the most abundant , which was reported to exhibit anti-inflammatory, antipyretic and analgesic effects in mice and rats . Triterpenoids have been extracted from cannabis roots by conventional extraction with ethanol , ethyl acetate , n-hexane, and petroleum ether . Supercritical fluid extraction has not yet been described for triterpenoids from cannabis roots. However, the extraction with supercritical carbon dioxide in combination with EtOH has been reported for triterpenes from other plants . Furthermore, SFE can be considered an environmentally friendly and highly efficient alternative, compared with volatile solvent extraction . Antioxidant activity of naturally occurring triterpenoids has been determined in several studies. Cai et al. observed DPPH , ABTS, and superoxide anion free radical scavenging activity in extracts from medicinal fungus S. sanghuang. In particular, friedelin, isolated from Azima tetracantha Lam. leaves showed very promising scavenging effects on DPPH, hydroxyl, superoxide, nitric oxide, and suppressive effects on lipid peroxidation . Additionally, phytosterols are known to be antioxidants and β-sitosterol, campesterol, as well as stigmasterol, have been reported to act as modest radical scavengers in solution . Currently there are no studies available on the antioxidative capacity of hemp root extracts, where triterpenoids and phytosterols have been identified. This study presents the extraction of phytochemicals from hemp roots and the identification of heretofore undescribed secondary metabolites to ascertain the exploitation potential of this plant part, which is usually treated as waste. The predominant triterpenoids friedelin and epifriedelinol were directly quantified from the root extracts of three different hemp chemovars by GC–MS/FID analysis. Moreover, the extraction efficiency of the target triterpenoids by conventional extractions with EtOH and n-hexane as well as a supercritical CO2 extraction is discussed herein for the first time. Furthermore, the influence of different harvest times and drying conditions on the triterpenoid concentration for one chemovar was monitored. In addition, in vitro and cellular antioxidant activity assays of the ethanolic cannabis root extracts were measured for the first time, due to the reported antioxidant activities of the accumulated secondary metabolites in hemp roots. The roots of three type III Cannabis sativa L. chemovars , Futura 75 , Felina 32 , and Uso 31 , were cultivated in the fields of BioBloom in 2019.
The crop was planted in rows with an average plant density of 35 plants per m2 . All three chemovars were grown organically in close proximity on a 60 ha plot. For Futura 75, three individual samples, which varied in harvest times and drying conditions were analysed. The hemp roots of Futura 75 , were collected in July 2019, air dried and stored at room temperature. For comparison of chemovars, Futura 75 , Felina 32 , and Uso 31 , were harvested in August 2019 and received the same postharvest treatment as sample A. The third sample of Futura 75 was harvested on an agricultural scale in October 2019 after the vegetative period and after the harvest of the aerial parts. Sample C was heavily washed with the help of a steam cleaner and dried for 30 h at 45◦C in an agricultural drying facility and stored at room temperature until analysis. For analysis, the complete hemp roots were washed with water and chopped to smaller sized parts. The pieces were shock frozen with liquid N2 and milled by a Retsch ZM 100 with sieve at 14,000 rpm . The pulverized material was lyophilised until constant weight and stored in a dark place for further experiments. Qualitative and quantitative analysis of the chemical constituents was carried out with an Agilent 7890A GC-System coupled to a mass detector and a flame ionization detector . An Agilent HP-5MS GCcolumn was used for the separation. The initial flow was set to 1.3 mL/min and helium was used as a carrier gas. The samples were injected without split. The temperature program for the analysis was as follows: 1 min at 100◦C as initial conditions, 10◦C/min ramp up to 325◦C, and 15 min hold at 325◦C. The FID was operated at 350◦C. Electronic ionization was used for the detection mass spectrometry. Source and single quad temperature were 230◦C and 150◦C. The total ion current was measured between 35 to 750 m/z after a solvent delay of 6.5 min. The method was developed and modified according to recent literature for the separation of triterpenoids . For the quantification with GC-FID, an analytical grade standard of friedelin was purchased from Sigma-Aldrich . A stock solution in chloroform was prepared and diluted for calibration. The triterpene epifriedelinol was expressed as mg friedelin equivalent per g dried hemp root. The identification of the compounds was performed by comparing fragmentation patterns with an intern mass spectrometric library, National Institute of Standards and Technology database , and corresponding literature data or the purchased pure standard substance.