1) Cinchona Plant : In 1820, French scientists Pelletier and Caventou discovered Quinine as the first antimalarial drug, which was originally extracted from the barks of Cinchona plants. Cinchona plants are used as folk medicines in South America by Peruvian Indians, and they were introduced to Europe in the 17th Century.

Quinine is commercially obtained by solvent extraction from cultivated Cinchona plants in indonesia or wild-growing species in South America.

Chloroquine a synthetic form of Quinine , was developed in 1934 by Dr. Johann Andersag (better known as Hans Andersag) at the Bayer Laboratories.

Chloroquine’s antiviral properties were explored in the mid-1990s against HIV and in the following decade against severe acute respiratory syndrome, or SARS, which is closely related to the novel coronavirus. Chloroquine, an old antimalarial is being repurposed for the clinical trial treatment of COVID-19. The drug was first tested in vitro (in the lab) using standard assays to measure the effects on the cytotoxicity, virus yield and infection rates of COVID-19.

The drug was reported to function as antiviral at both the entry and post-entry stages of COVID-19 infection. Chloroquine has also recently been reported as potential broad-spectrum antiviral drug.

President Donald Trump of the United States had through the United States Centre for Disease Control (CDC) deployed hydroxyl chloroquine and other drugs for the emergency treatment of patients with the deadly virus in the United States and reports showed that the drug is performing tremendously well in clinical trials. State Council of China, indicated that chloroquine phosphate had demonstrated marked efficacy and acceptable safety in treating COVID-19 associated pneumonia in a multi-center clinical trials conducted in China. The study involved 10 hospitals in Wuhan, Jingzhou, Guangzhou, Beijing, Shanghai, Chongqing and Ningbo, and 100 patients. The investigators reported that chloroquine phosphate is superior to the control in inhibiting the pneumonia associated with COVID-19, and shortening the course of the disease.

In Russia, the Federal Biomedical Agency has developed a drug for the treatment of COVID-19. The agency said its drug was based on mefloquine, which is used to prevent or treat malaria. The drug will allegedly provide effective treatment for COVID-19 patients with varying severity. According to the agency's statement, the drug prevents virus replication in cells and as a result, stops the inflammatory process caused by the virus. Veronika Skvortsova, the agency’s head, said Mefloquine has to be combined with antibiotics for the maximum effect, allowing an increase in the concentration of antiviral agents in blood plasma and lungs.

In Nigeria, Director General of National Agency for Food and Drug Administration and Control, NAFDAC, Prof. Mojisola Adeyeye has ordered the manufacturing of Chloroquine for possible clinical trial treatment of coronavirus in the country.

2) Neem Plant : Azadirachta indica (Neem) is a medicinal plant , in Nigeria it is called dogonyaro in Hausa. It's active compounds have been identified as anti- malaria, anti-inflammatory, anti-ulcer, anti-hyperglycaemic, immune-modulator, anti-mutagenic, anti-carcinogenic, anti-oxidant, and anti-viral drugs.

In a study titled “Designing and screening of universal drug from neem (Azadirachta indica) and standard drug chemicals against influenza virus nucleoprotein.” The compound Hyperoside from Neem leaf extract along with drugs LGH, Naproxen, BMS-885838 and BMS-883559 showed best interactions with conserved residues of the nucleoprotein. So these compounds have been identified for holding great potential for utilization as a universal drug against influenza virus strains. These observations require further considerations for in-vivo and in-vitro validations.

Nearly all parts of the neem tree are useful, and many of its medicinal and cosmetic uses are based on its antibacterial and antifungal properties. Neem is commonly used in shampoos for treating dandruff and in soaps or creams for skin conditions such as acne, psoriasis, and athlete’s foot. It is also a component in some toothpastes and mouthwashes, especially in the Indian subcontinent, and young twigs are used directly as crude toothbrushes in rural areas. Neem leaves have long been used as a traditional treatment for diabetes, and there is some clinical evidence suggesting that it may help control blood sugar levels.

Oil extracted from the seeds can be used directly as an insect and mite repellent, insecticide, and fungicide and is the source of many commercial pesticide products, including dusts, granules, and concentrates. The primary active insecticidal ingredient, azadirachtin, works to disrupt the hormones involved with insect molting, preventing larvae from developing properly into adults, and is a feeding inhibitor. Neem oil can kill soft-bodied insects on contact and decreases mating and reproductive behaviours, reducing pest fecundity. As a fungicide, neem oil is used to control rust, black spot, mildew, scab, anthracnose, and blight. Given that neem oil breaks down quickly with exposure to ultraviolet light, repeated applications are often necessary. Neem-based pesticides generally have low toxicity for mammals and are common in organic farming applications.

Caution: Neem oil and neem bark and leaves are unsafe for consumption by pregnant women and can cause miscarriage.

The leaves of hospital -too -far have been proven to improve respiratory problems.

It could probably help with respiratory congestion.