Avocado, soursop show promise against hepatitis C

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 plants as remedies against hepatitis. Jatropha podagrica is known locally in south western 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.

Botanically called Persea americana, avocado belongs to the plant family Lauraceae. Persea americana is a terrestrial, evergreen tree of 15 to 20 metre in height. The leaves, root, seeds and other morphological parts of P. americana possess medicinal properties as antiparasitic, antiallergic, antihypertensive, analgesic and anti-inflammatory remedies. Traditional herbal healers use the root bark and seeds for the treatment of hepatitis and other infections.

Until now, avocado fruits and seeds have been shown to be effective in treating hypertension, diabetes, bad cholesterol, rheumatism, asthma, infectious processes as well as diarrhoea and dysentery. Recent studies have also found that extracts of avocado seed also have protective effect on the pancreas, kidneys and liver; and could be used to relieve pain and treat multi drug-resistant tuberculosis (TB). Scientists have found that extracts of the leaves, fruits, seeds and bark of avocado can protect the body from the damages of air pollution.

Commonly called Soursop, Annona muricata is a plant, which belongs to the family Anonaceae. Annona muricata is a fruit tree cultivated throughout the tropical regions of the world. The fruit is eaten raw. Researchers have shown that a meal of soursop could be the cure for diabetes, heart disease, cancer, hepatitis, and diarrhoea.

Soursop is a medicinal plant that has been used as a natural remedy for a variety of illnesses. Several studies by different researchers demonstrated that the bark as well as the leaves has anti-hypertensive, vasodilator, anti-spasmodic (smooth muscle relaxant) and cardio depressant (slowing of heart rate) activities in animals.

The researchers wrote: “Some medicinal plants (Persea americana seed, PAS; Persea americana root, PAR; Persea americana leaf, PAL; Annona muricata stem bark, AMS; Annona muricata leaf, AML; Jatropha podagrica root, JPR and Picralima nitida stem bark, PNS were carefully selected using the ethno-pharmacological approach.

“The methanol extracts were partitioned to give fractions. Evaluation for In vitro anti-hepatitis C activity against HCV RNA virus was investigated using standard and established protocols.“Significant and notable cell growth inhibition against HCV RNA was observed for extracts PAR, PAS, and JPR and AMS against HCV rRNA virus. Among these extracts, AMS showed the most potent antiviral activities against HCV with EC
50, EC90 and CC50 values of 5.8, 33.1 and 22.6 μg/ml, respectively. In addition, the methanol extract of PNS showed a weak activity (10.75 per cent HCV, rRNA 4.97).

“Taken together, these results indicate that A. muricata and P. americanna might offer a promising source of antiviral drugs against HCV. Purification of the active compound(s) would be required in the future.”

Indeed, the cure for HCV is attracting serious attention from scientists worldwide with a view to discovering new lead drugs for combating this disease. HCV belongs to the family Flaviviridae, positive-stranded RNA virus.It has been estimated that approximately 175 million people worldwide are chronically infected with HCV, which is one of the leading causes of chronic hepatitis, cancer of the liver and cirrhosis.

About 20 per cent of individuals infected with HCV spontaneously clear the virus in the acute phase, up to 90 per cent develop chronic infection progressing to liver carcinoma and related diseases.

To date, no vaccine against HCV has been developed owing to the presence of large numbers of HCV genotypes and quasi-species, and lack of easily available animal models for vaccination tests.