Status and Sources of Medicinal Plant
Medicinal plants have attracted the attention of several stakeholders around the world [49]. They have chemical diversity and can play a significant role in new drug development [50]. In this study, the majority of respondents in Nepal reported that the use of medicinal plants has increased during COVID-19, they also believed that information about the medicinal plants has increased, and most of them recommend medicinal plants to prevent COVID-19. Researchers such as Rastogi et al. (2020) and Vellingiri et al. (2020) have claimed that the medicinal plant based treatment should be beneficial to treat and prevent COVID-19 [20, 51]. Yang et al. (2020) reported that plant species traditionally used as food can help to enhance the immune system of the body and help to prevent the manifestation of COVID-19 [52]. In the past, the medicinal plants were combined with western medicine to treat a similar disease, severe acute respiratory syndrome (SARS) [53].
There is no effective medicine available so far for the treatment of COVID-19, medicinal plants are being used globally that might have increased the demand for medicinal plants [54]. Some plants are useful to treat viral disease, but COVID-19 is a new disease, and the effectiveness of the medicinal plants to cure it has not been tested yet. Therefore, the excessive use of medicinal plants, however, could be problematic and is a matter of concern. Easy access to social media which often publish unreliable advertisements might have a role to play in the increasing use of medicinal plants. Moreover, local availability of, medicinal plants, and an incorrect belief that medicinal plants have no side effects among the people might also be responsible for the same. All the stakeholders including the ethnobotanist, community leaders and other stakeholders to come together to educate people about the proper use of medicinal plants.
Medicinal plants recorded and Frequency of Citation
Most of the species reported in this study are locally available, home garden species and used for daily food at home. The leaves were the most used parts of the plants corroborating the findings of other related studies in Asia [55, 56]. The use of leaves is mainly due to the presence of active secondary metabolites [57]. Underground parts roots and rhizomes, that are rich in bioactive constituents [58, 59]. However, indiscriminate use of underground parts might lead to conservation threats particularly to the wild species [60]. Similarly, the use of bark in an excessive amount and the whole plant use, particularly implied for her [61], might create problems in conservation.
The citation of species might have been influenced from the social media along with the cultural, religious and community leaders within Nepal and neighbouring India. For instance, the famous Hindu Swami Ramdev of India has suggested that Tinospora cordifolia boiled in water Curcuma caesia,Zanthoxylum piperitum powder and Ocimum tenuiflorum leaves can prevent COVID-19 (written in India TV News of 14 March 2020).The most cited species in this study are also the most commonly used species in Nepal, such as Z.ingiber officinale, C. caesia, and Allium sativum.These species are planted in almost every household of rural Nepal and these species are also listed by Nepal Ministry of Health & Population Department of Ayurveda & Alternative Medicine, Teku, Kathmandu, as an alternative medicine to boost immunity power of people [62]. The plants like Curcuma caesia, Cuminum cyminum, A.llium sativum, Terminalia bellirica, Z. officinale, O. tenuiflorum, Cinnamomum verum, Piper nigrum, Vitis vinifera and Citrus spp. were also recommended by the Indian Government to boost immunity power but doesn not claim that can cure or treat COVID-19 [63].
The medicinal plants reported in the study have different chemical compounds and constituents that have been proved in treating different diseases and ailments. T bellirica,Cinnamomum verum, Piper nigrum, dry Z. officinale and raisin contain phytonutrients chlorophyll, vitamins, minerals eugenol and a bioactive compound, Z. officinale contains sesquiterpenes [64].
Chemical constituents 8-Gingerol, 10-Gingerol from Z. officinale were active against COVID-19 [65]. COVID-19 patients might have cytokine storm [66, 67] and Curcumacaesia has capacity to block cytokine release [68]. Allium sativum contain sulphoxide, proteins and polyphenols like bioactive sulphur containing compound which are antiviral with immunostimulatory potential [69, 70]. Tinospora cordifolia has alkaloids, glycosides, lactones and steroids with immunomodulatory roles and can treat fever, chronic diarrhea asthuma [71, 72]. Citrus species contain polysaccharides and polyphenolic compounds which improve immunity of body [73]. Ocimum tenuiflorum extraxt contains Tulsinol (A, B, C, D, E, F, G) and dihydrodieuginol that possess immunomodulatory and Angiotensin-converting enzyme 2 (ACE II) blocking properties to inhibit replication of Corona Virus [74]. Phyllanthus emblica has antioxidative and anti-inflammatory and its extract Phyllaemblicin G7 has potential to treat COVID-19 [75]. Azardirachta indica extracts Nimbolin A, Nimocin and Cycloartanols (24-Methylenecycloartanol and 24-Methylenecycloartan-3-one) have shown potential to inhibit COVID-19 [76]. Mentha arvensis posses eugenol, terpenes, and flavonoids which are good antioxidants and modulators of xenobiotic enzymeshelp to inhibit COVID-19 [77]. Cinnamom unverum contains compounds like eugenol, cinnamic acid, caryophyllene which are antioxidant and antiviral which might help to inbhit COVID-19 [78].
The species with a lower frequency of citation are also useful in some way; Camellia sinensis has immunomodulatory properties due to the presence of epigallocatechin gallate, quercetin and gallic acid in its leaves [79]. Euphorbia thymifolia has antioxidant and antiviral activities [80]. Functional food such as Allium cepa, Nigella sativa, Carica papayas and other species are functional food they possess immunomodulatory properties in several way and help in effective health management if taken in an adequate manner [52]. However, there is no proper reearch and scientific evidence supporting that medicinal plants can prevent or cure COVID-19. The use of medicinal plants is traditional and has a long history with its own theory, like traditional Chinese medicines whose composition is typical and complicated. A creative evaluation system should be developed before its used to prevent or treat COVID-19 [81]. Some researchers have suggested natural products obtained from plants might be an alternative option to treat COVID-19 [82, 83].
But at present, the use of different, unproven medicine, as well as herbal medicine has been the only way to protect vulnerable patients and such medicines should not be overlooked, or taken without the prescription from health personnel [52]. The effectiveness of above-mentioned medicinal plants should be tested scientifically then added to the discovery of drugs used to treat COVID-19.
Source and Growing Conditions of Medicinal Plants
Most of the respondents obtained medicinal plants from home gardens or farms. It is interesting to find that people are cultivating more medicinal plants during COVID-19, which is a positive sign for the development of gardening or farming practices in the country. This type of activity will support the sustainable conservation of medicinal plants. However, collecting medicinal plants from the jungle will cause several issues in the conservation of plants [84]. Different types of actions can be taken to conserve and sustainable use of such species, including assessing the conditions of plant use and presence as well as policy formation [85]. Some people have also just started to plant medicinal plants which is a good sign for the sustainable livelihood in Nepal.
Number of Plants Reported and Covariates
The use of medicinal plants depends on several covariates, such as occupation, education level, age, class, living condition, and treatment methods that people usually follow. The sociocultural acceptance of people vary within different places and communities [86]. People living in villages most live with their families in Nepal, and studies have found that the use of medicinal plants usually comes from families [87]. During COVID-19, well-educated people used more medicinal plants in Nepal, contrary to the results of other studies, which found that well-educated people often rely on modern medicine for treatment [88]. Females reported more medicinal plants than males, similar to other studies [89], probably because women are more involved in household work, invest more time in the kitchen and caring for their family in food and health, as well as in farm work such as cutting grasses and collecting fodder. People adopting agriculture reported a higher number of medicinal plants, which may be because they have easier access to medicinal plants. In Nepal, people with agricultural occupations and living in rural areas used more traditional methods to stay healthy [90]. The job holders also reported comparatively more number of plants.
Interestingly the youths (age groups below 30) have reported using more medicinal plants, probably because they lived with their families and learned more about the medicinal plants from the elders. This group is also the most active group on social media. Most respondents also claimed that they were more aware of the medicinal plants during COVID-19, which is a good sign as the research by Tiwari et al. (2020) has mentioned that young people are forgetting the use of medicinal plants. However, the misunderstanding of medicinal plants is also dangerous, and the stakeholders need to think about and provide accurate information to the young people [91]. Young people should follow a reliable source to obtain information about medicinal plants. People who primarily use Ayurvedic and homeopathy remedies reported more number of medicinal plants. The use of plants and the acquisition of knowledge usually depends on the culture and primary health care system [92].
Information Sources and Respondent Characteristics
The source of information is the key to using medicinal plants, and it is not good to follow the social website and rely on it, as the usefulness and accuracy of messages regarded COVID-19 provided from social media such as youtube have not been tested [93]. However, in this study, a large number of respondents were found to be engaged in social media to obtain information regarding COVID-19. Most of the people were not relying on WHO and National Health authorities, similar to the study of Bhagavathula et al. (2020) [94]. The most well-educated people, female, job holders, people living with families, people who are following allopathy as a primary treatment, and people who live in the village are all following social media to obtain knowledge of prevention methods, and using medicinal plant-based on the source which might be incorrect and thus harmful. This is because the frequent use of social media and the practices of using several sources of social media has caused an overload and increased people’s concerns [95].
This study recommends the use of official websites of WHO and national health authorities to gain information regarding COVID-19. Most people also rely on the communities for the use of medicinal plants which might cause traditional malfunction. Therefore, it is unwise to adopt unscientific sources of information and use medicinal plants privately. The correct use of medicinal plants passes from generation to generation, which is usually applicable to old diseases. No valid medicine has been developed to prevent or cure COVID-19 so far. The COVID-19 pandemic has created a large crisis, and it needs large scale behavior changes [96]. For instance, we need to change our behavior and follow the valid information to use the different preventive measures to be free from COVID-19. The collaboration between diverse stakeholders such as government, volunteers, people, and other sectors is deemed necessary to transmit information and respond to crisis through improving information flow [97]. Different studies on herbal remedies are deemed necessary which would be helpful to prepare an antiviral drug against COVID-19 as well as to help prevent going against traditional methodology related to the use of medicinal plants [98]. There is an urgent need to dissiminate high level of public awareness to prevent misinformation regarding treatment and prevention mesures of COVID-19 [99].