# Antioxidant and Antibacterial Properties of Extracts and Bioactive Compounds in Bryophytes
## 5 Conclusions and Future Perspective  
Bryophytes synthetize unique compounds that have shown a wide range of biological activities such as antimicrobial, antiviral, antifungal, anticarcinogenic, insecticidal, neurotrophic, muscle relaxing, cardiotonic, and anti-obesity activities [2]. To our knowledge, bryophytes extracts/pure compounds have only been in vivo tested for their anti-inflammatory and antinociceptive [93], wound healing [94], anticarcinogenic [95,96], nanoparticle pharmacokinetics [97], and antilipidemic activities [29]. Although extensive research has been conducted on in vitro antioxidant activity, no investigations have examined the antioxidant activity of bryophytic extracts and pure compounds in in vivo models. Antioxidant activity should not be concluded based on single or multiple in vitro tests [25]. Physiological processes such as absorption, distribution, metabolism, and excretion can affect the effectiveness of certain compounds [98]. Bryophytes' antibacterial compounds have shown promising activities against some human alarming pathogens. However, very little has been attempted in testing bryophytes against the most concerning pathogenic strains, apart from a few studies against MRSA. Furthermore, as for antioxidants, most of the data concerning the antibacterial activity were gathered from in vitro studies. In vitro antibacterial testing is based on two main techniques, namely the disk diffusion test and broth dilution test [99]. Both techniques involve the direct contact of the tested molecules with the bacterial cells, and therefore do not consider the pharmacokinetics and pharmacodynamics of the tested molecules [55]. Moreover, at the present stage only two studies have looked at the toxicity of pure bryophytic compounds and extracts [100,101]. Toxicity screening is an essential step in the drug development process [102] and should  
out first with respect to in vitro and in vivo experimentations. Future research should be focused on the in vivo testing of antioxidant and antibacterial byophytic compounds. This would help to circumscrib the huge number of molecules that have been discovered. Moreover, further experimentations should focus on the efficacy of byophytic antibacterial against antibiotic-resistant strains. In conclusion, bryophytes can be exploited as a source of antioxidants and antibacterial compounds in perspective pharmaceutical and nutraceutical applications. Bibenzyls, terpenoids, phenols, and polyphenols from bryophytes are promising chemicals for the future development of novel antioxidant and antibiotic drugs. However, at the current stage, knowledge sustaining concrete applications of antioxidants and antibacterial from bryophytes is still fragmentary, and more in-depth multidisciplinary research is needed to select the safest and most effective compounds.  
Conceptualization, A.B. and P.C.; methodology, P.C.; literature search, P.C., V.M. and S.S.; writing-original draft preparation, A.B., P.C., V.M. and S.S.; writing-review and editing, A.B. and P.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Data available upon request.  
The authors declare no conflict of interest.