# Phytocannabinoids Biosynthesis in Angiosperms, Fungi, and Liverworts and Their Versatile Role
## 6 Phytocannabinoids and Their Derivative Role and Bioactivity in Humans and Animals
### Cannabinoid Receptors in Humans and Their Role  
CB1R (cannabinoid receptor type 1, first cloned in 1990) mRNA is highly expressed in the brain. It is also found in the heart, lung, ovary, adrenal gland, thymus, testes, prostate, tonsils, bone marrow, and uterus. CB1R is also widely distributed inside non-neuronal \begin{table}
\begin{tabular}{c c c} \hline \hline
**Phytocannabinoids** & **Bioactivity in Animals and Human** & **References** \\ \hline \(\Delta^{9}\)-THC & pleiotropic effects such as analgesic, muscle relaxation, and pain tolerance & [1] \\  & increases weight and appetite; improves sleep and depression; alters mood, & [72; 73] \\  & behavior, feeling, and thoughts & \\  & cures neuropathic pain, spasticity, dysphagia, and anxiety disorders & [74; 75] \\  & antiemetic activity, i.e., prevents vomiting in cancer patient & [76] \\  & during chemotherapy & [76] \\  & displays antiglaucoma activity and reduces intraocular pressure & [76] \\ \hline \(\Delta^{9}\)-THCA & neuroprotective and antitumor activity & [77] \\ \hline \(\Delta^{9}\)-THCV & non-psychoactive effect; cures obesity & [75] \\  & effective against metabolic disorders, pancreatic disease, and & \\  & hepatosteatosis syndrome & [1] \\ \hline CBC & non-psychotropic and anti-inflammatory activity & [77; 78] \\ \hline CBD & cures memory loss, obesity, convulsive disorder, and rheumatoid arthritis & [79] \\  & cures epilepsy; exhibits antipsychotic, antinausea, and antianxiety activity & [80] \\ \hline CBDA & anti-inflammatory and antihyperalgesia effect & [81; 82] \\ \hline CBG & non-psychotic activity & [75] \\ \hline CBC, CBL, and DCA & cures HIV and cancer; possess immune boosting activity & [83] \\ \hline CBG and amofrutin & anti-inflammatory activity & [84] \\ \hline CBL & anti-inflammatory, anti-microbial, antipsychotic, and antiallergic activity & [5] \\ \hline GFA and DCA & anti-microbial activity & [85] \\ \hline PET & increases analgesia, catalepsy, hypolocomotion and hypothermia & [28] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Bioactivity and effect of different phytocannabinoid in animals and humans. tissues and inside various cells, tissues and also co-exist with other CBRs [86; 87]. CB\({}_{1}\)R is found inside the brain and displays high protein density and expression inside brain parts such as the cerebellar molecular layer, substantia nigra pars reticulate, globus pallidus external and internal, olfactory bulb, olfactory nucleus (anterior), hippocampus and layers II-III, Va and VI of the cerebral cortex. Additionally, in humans, the highest CB\({}_{1}\)R level is found inside the cingulated gyrus, motor cortices and frontal secondary somatosensory. CB\({}_{1}\)R is found in moderate levels inside the hypothalamus and ventral striatum and low levels in the brainstem; other respiratory control centers lack CB\({}_{1}\)R. Moreover, this is the main reason CB\({}_{1}\)R has a low effect on respiratory and cardiovascular activities [88]. Another important receptor, CB\({}_{2}\)R, has high density inside immune cells and tissues, whereas a low amount is expressed inside the brain. Inside the brain, most of the presynaptic CBRs are observed as CB\({}_{1}\)R, whereas it was displayed that presynaptic inhibitory CB\({}_{2}\)R in GABAergic terminals of the hippocampus [86; 87]. Phytocannabinoid applies its strong physio-psychotropic and psychotogenic actions along with the modulation of fast synaptic transmission in the brain showing its action on receptor CB\({}_{1}\)R, present in the synaptic region. Additionally, fast synaptic activity encloses signaling via GABA and glutamate (activate ionotropic receptors). However, CB\({}_{1}\)R contributes to psychoactivity and neuro-physiology along with phytocannabinoid [89]. CB\({}_{2}\)R is found inside pyramidal cells (II/III) of the medial prefrontal cortex; when it activates, it causes IP3-dependent opening of calcium-activated chloride channels and ultimately resulted in the inactivation of neuronal firing [90; 91].