COVID-19 is a severe acute respiratory syndrome-related corona-virus SARS-CoV-2, that constitutes a pandemic threat to global public health. Unfortunately, there are no specific available therapies. This research work presents the findings of an investigation on traditional Cameroonian remedies of respiratory tract infections, malaria and viral infections, and also recipes that could serve as a baseline for the prevention, alleviate symptoms, treatment and perhaps may help for the anti-COVID-19 drugs discovery. Data on the medicinal plants were collected from traditional healers, Cameroonian medicinal plants books, the internet, and in addition to our personal experience as researchers and herbalists. Details of 85 plant species used to manage these three mentioned diseases in Cameroon and their pharmacological properties are recorded. Due to their ethnomedicinal uses and pharmacological activities, twenty-eight (28) plant species and 13 recipes are suggested for COVID-19 prevention, alleviate symptoms, treatment and baseline for anti-COVID-19 drug discovery. Amongst the proposed plants we have the following, Curcuma longa, Azadirachta indica, Zingiber officinale, Allium sativum and Ocimum gratissimum which were reported to possess certain inhibition properties against COVID-19 protease.

Background Vector-borne diseases are mostly transmitted by mosquitoes. Therefore, these mosquitoes constitute a socio-economic scourge. Due to the resistance of mosquitoes to synthetic chemical insecticides and the pollution they generate, this study was conducted to assess the larvicidal activity of plant crude extracts on larvae of Culex quinquefasciatus. Results Bioassays performed on larvae shown that the extract of Calotropis procera at 0.6 mg/mL recorded the highest mortality rate of 100% for L1, L2 and L3. However, the extract of Albizia lebbeck at 0.7 mg/mL recorded the highest mortality rate of 100% for all the four stages of larvae. Negative and positive controls recorded 16% and 100% mortalities, respectively, after 24 h of exposure. The extract of Calotropis procera recorded LC50 values as follows: 0.194, 0.251, 0.258 and 0.284 mg/mL for L1, L2, L3 and L4, respectively. The LC90 of Calotropis procera were: 0.340, 0.433, 0.444 and 0.502 mg/mL for L1, L2, L3 and L4, respectively. In contrast, the extract of Albizia lebbeck recorded the following LC50: 0.238, 0.264, 0.290 and 0.316 mg/mL for L1, L2, L3 and L4, respectively. Also, its LC90 were: 0.456, 0.498, 0.531 and 0.580 mg/mL, respectively, to L1, L2, L3 and L4. Conclusion The larvicidal bioassays performed revealed that these plant extracts have significant larvicidal properties. In the framework of fighting against vector-borne diseases, these two plants constitute alternative products to control mosquitoes.