Introduction

Members of the Plants kingdom play a crucial role of life on Earth. Life without plants would be impossible because they produce special substances in their vegetative and reproductive parts — roots, leaves, flowers, or seeds — which help them and members of the Animalia kingdom to survive. Since earliest times, our ancestors have gathered these substances to create herbal medicines and treat certain diseases. Tropical plants in particular possess valuable knowledge regarding medicinal plants. With proper research, scientists believe they are capable of finding cures for some of the world’s deadliest diseases among rainforest plants; some of these plants have not even been discovered yet. At present day, many of the powerful drugs used in modern medicines originate in plants and thanks to the advancement of technology, today’s plant-based drugs treat a range of diseases, from headaches to cancer.

Greater burdock (Arctium lappa) and Mosquito (Culex tritaeniorhynchus)

Japanese encephalitis, the leading cause of acute encephalopathy, is caused by the Japanese encephalitis virus (Flavivirus), which is transmitted by the Culex tritaeniorhynchus (mosquito).

It is prevalent in the tropics (Southeast Asia) and occurs during rainy seasons when there is stagnant water — a breeding ground for mosquitoes. Researchers have found that antiviral agents such as arctigenin (C21H24O6), a polyphenolic lignan naturally obtained in the Asteraceae plant family such as the Arctium lappa or greater burdock, can be used to lessen the severity of the effects of Japanese encephalitis. The arctigenin found in Arctium lappa has been found to impede with the activation of kinases, thus, reducing viral load and replication, oxidative stress, inflammation, and neuronal cell death.

Basil (Ocimum tenuiflorum) and Scorpion (Scorpiones)

Ocimum tenuiflorum or Holy Basil, is a perennial plant endowed with amazing health benefits as it possesses chemopreventive and radioprotective properties.

This miraculous herb possesses several medicinal qualities such as: anti-inflammatory, analgesic, antipyretic, antidiabetic, hepatoprotective, hypolipidemic, antistress, and immunomodulatory activities. This plant is capable of mediating the aforementioned by increasing the antioxidant activity, altering the gene expressions, inducing apoptosis, and inhibiting angiogenesis and metastasis.

Scorpions are very fascinating creatures as these predatory arachnids possess a venomous stinger on its posterior end. Most scorpions possess neurotoxic poisons and its sting has been considered to be one of the main health problems in developing tropical and subtropical countries which cause immense clinical consequences and in worst case scenarios, death. The optimum environmental condition that enhances the status of scorpion sting varies in different regions and countries based on one’s lifestyle, economic social status, way of providing health services, and species present in every geographical area.

Rauvolfia (Rauvolfia serpentina) and Snake (Serpentes)

Rauvolfia serpentina, commonly known as Sarpgandha, is the most popular species of Rauvolfia genus. Based on the accumulated data and statistics, alkaloids were observed to be present in the leaf as well as on the fruit samples of R. serpentina, inhibiting histamine in in vitro models. The roots of Rauvolfia serpentina are being used as a remedy for high blood pressure, insomnia, anxiety, excitement, schizophrenia, and insanity. Presence of alkaloid was expected due to associated reports from related species which have proven medicinal records — alkaloids with antihypertensive, antipsychotic, etc. properties. As a result, root decoction is currently being used as an antidote to snake venom. According to research and based on the gathered data, most cases of snake bites occur in rural areas or tribal rich districts.

Iranian Garden Thyme (Thymus vulgaris) and Entamoeba hystolytica

Amoebiasis or amoebic dysentery is an infection causing abdominal pain and severe diarrhea with blood or pus in the stool. Amebiasis can be caused by eating food or having direct contact with fecal matter that are infected with the Entamoeba hystolityca.

Amoeba grows especially on tropical locations with poor sanitary conditions. The Iranian garden thyme extract and essential oil can inhibit the growth of amoeba and can possibly kill it and its thropozoites. The essential oil of the plant exhibit antiamebic properties most likely because of the abundance of thymol, carvacrol, borneol, and linalool. Thus, the Iranian garden thyme is considered a good substitute to the commercial medicine metronidazole.

Neem tree (Azardirachta indica) and Setaria cervi

Filiarisis is a disease which causes permanent disability to its hosts and can be mostly observed in tropical and subtropical areas. It is caused by the filarial worm Setaria cervi transmitted by a vector mosquito which are abundant in stagnant waters during rainy seasons.

Azadirachta indica, or neem tree, has been found to exhibit antifilarial and anthelmintic activities due to the malate dehydrogenase and malic enzyme found in its leaves and flowers, causing alterations in the morphology of adult filarial worms. The oil extract of neem trees can also be used as an insect repellant, considering that it contains a compound called Azadirachtin which has detrimental effects to insects.