Nigerian researchers have identified and validated local plants for the treatment of viral infections.
The local plants include: Bambusa vulgaris (bamboo) and Aframomum melegueta (alligator pepper), Azadirachta indica (neem), Allium cepa (onion), Allium sativum (garlic), rhizomes of Curcuma longa (turmeric), and Aloe vera, Vernonia amygdalina (bitter leaf), Garcinia kola (bitter kola), Citrus medica (lemon), Cymbopogon citratus (lemon grass), Moringa, Phyllanthus amarus, avocado (Persea americana), and Gardonema mushroom.
Researchers had also identified asthma herb (Euphorbia hirta), pawpaw (Carica papaya), bitter melon (Momordica charantia) and guava (Psidium guajava) extracts as potential cures for viral infections.
Researchers from Ekiti State University, Ado Ekiti, and Kings University, Osun State had validated antiviral properties of two Nigerian plants – alligator pepper (grains of paradise) and bamboo. The study was published in African Journal of Plant Science.
However, a recent study published in the journal Medicinal & Aromatic Plants concluded that the juice of Carica papaya (pawpaw) leaves is an effective herbal therapy for curing the dengue fever. The study is titled “Leaf Juice of Carica papaya L.: A Remedy of Dengue Fever.” The results of the study led by Chandra Prakash Kala from the Ecosystem & Environment Management, Indian Institute of Forest Management, Madhya Pradesh, India, showed Papaya leaf juice was effective in curing the dengue fever.
According to the researchers, out of twenty-two local plants reported against dengue, only four have been studied scientifically. Azadirachta indica, Carica papaya, Hippophae rhamnoides and Cissampelos pareira extracts were found effective and demonstrated improvement in clinical symptoms and direct inhibitory effect on dengue virus.
Interestingly, a researcher, Amaka Ubani, in her presentation on medicinal plants for treating Lassa fever said documented natural therapies for hepatitis C virus have been demonstrated to be effective in treating Lassa fever.
Also, the same conventional drug, ribavirin, is used for the treatment of Lassa fever and hepatitis C virus. Intravenous ribavirin drastically reduces deaths from Lassa fever. Ribavirin is a powerful antiviral drug used to treat chronic hepatitis C infection.
However, avocado and soursop have shown promise as possible treatments for hepatitis C virus (HCV). Nigerian researchers in collaboration with their American and German counterparts investigated extracts and fractions from five different traditional Nigerian medicinal plants (Jatropha podagrica, Persea americana – avocado), Annona muricata (soursop), Jatropha multifida, and Picralima nitida), which are used in Nigerian folk medicine for the treatment of parasitic infections, cancer and hepatitis.
The study published in African Journal of Pharmaceutical Research & Development found: “In this preliminary study, it is obvious that A. muricata is a good candidate for anti HCV agents. “Annona muricata, J. podagrica and P. americana class has never been evaluated for there anti HCV activity, interesting activity profile of these extracts and fractions, opens up a new class of anti HCV metabolites.
Further purification of these herbal extracts and isolation of the active metabolites may identify new lead molecules, which could be developed into anti HCV drugs.
The study is titled: “Anti-hepatitis C Virus Activity of five Selected Endemic Medicinal Plants of Nigeria.”
The researchers from the Department of Pharmaceutical Chemistry, University of Benin, Nigeria; Institute of Chemistry, University of Rostock, Albert Einstein, Rostock, Germany; Department of Pharmacognosy, School of Pharmacy, University of Mississippi, Oxford, Mississippi, United States (U.S.); Department of Crop Science, University of Benin, Nigeria; and Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Delta State University, Abraka, Delta State, Nigeria, concluded:
“In conclusion, we have demonstrated that the extracts of A. murcata stem and P. americana root possess a significant inhibitory effect on HCV replication. These results, showing in particular an interesting anti HCV activity, confirm the relevance of the investigation on the therapeutic potential of plants used by rural communities.”
According to the researchers, it is worthy to note that traditional medical practitioners have achieved success with the use of these local plants as remedies against hepatitis. Jatropha podagrica is known locally in southwestern Nigeria as lapalapa funfun. It is widely distributed in different parts of Nigeria, and is used in folk medicine to treat various diseases including parasitic skin infections and hepatitis. Different parts of the plant have been investigated chemically and many compounds including flavonoids, steroids, alkaloids and diterpenoids have been isolated from this plant and related species.
Picralima nitida has widely varied applications in Nigerian folk medicine as antipyretic, antimalarial, anti-trypanocidal, anti-lesishmanial and anti-parasitic. Jatropha multifida otherwise known as coral bush is a fast growing evergreen shrub or small tree. The roots, stems, leaves, seeds and oil of the plant have been widely used in African folk medicine for the treatment of oral candidiasis, viral diseases, gonorrhea, fever, as purgative and for wounds and skin infections.